Menarik untuk dilihat klo ternyata hujan “di wilayah kita” ini secara umum dimulai setelah matahari berada di atas ufuk. Kok di bilang “di wilayah kita”? Soalnya “di wilayah kita” yang dimakasud disini ya di tempat kita tinggal yaitu di daratan. Klo tinggalnya di laut berati ga termasuk wilayah kita ya .

coba dilihat deh baik2, klo pas pagi hari hampir seluruh wilayah daratan di Indonesia bening alias putih alias ga ada hujan, pas dah sore, seluruh wilayah daratan indonesia itu gelap gulita alias memiliki hujan lebat.

OK, kita coba lihat mulai dan akhir siklusnya. kita start pagi hari ya, seperti waktu sekolah gitu hehehe… saat jam 7 pagi (lihat gambar pertama pojok kiri, jngan lihat jam UTCnya, itu jam di inggris sono heheh..) hampir seluruh wilayah Indonesia clear dari hujan. saat ini biasanya angin darat masih kencang (angin dari darat ke laut) sehingga awannya ke dorong ke laut, sekalian lihat pada jam 7 pagi tuh hujan banyak terjadi di laut , yang itam2nya banyak di laut, khususnya di laut jawa (antara pulau jawa dan pulau kalimantan. kenapa disini gelap bngat, ya karena di pengaruhi oleh angin darat yang ga hanya dari jawa tetapi juga dari kalimantan… makanya hujan di laut sini sangat deras klo pas pagi hari. trus kita maju lagi ke jam 10.  disini hujan di laut dah mulai sedikit berkurang, di darat hujannya kadang dah mulai terjadi. angin laut dah mulai terjadi saat2 jam segini.

jam 1 siang wilayah darat dah mulai gelap, khususnya pulau jawa tuh. laut dah mulai tampak, angin laut dah memainkan perannya dalam membawa awan ke wilayah daratan jam segini. nah saat jam 4 sore, pulau-pualu di indonesia dah benar2 gelap semua. akibat angin laut yang sebelumnya terjadi, efeknya baru terlihat jam segini ini. awan2 yang di bawa tai dah benar2 daam kondisi siap melapaskan air hujan, terjadilah hujan deras jam segini ini. kondisi ini berlanjut sampai jam 10 malam. jadi hati2, klo daerahhnya rawan banjir, jam2 segini ini yang secara umum sering menyebabkan banjir.

setelah lewat jam 10 malam, angin darat kembali berperan dalam menghilangkan awan di darat. awan2 di darat mulai hilang akibat mendinginkan kondisi daratan dan juga berbelaknya arah angin yang menuju kelaut. saat jam segini banyak daerah pantai memiliki hujan yang cukup deras. kondisi ini berlanjut sampai jam jam 4. setelah jam 4 hujan kembali terjadi lautan dan di daratan dah mulai clear lagi… kejadian spt ini terjadi terus menuerus setiap hari…. makanya dinamakan siklus hujan harian

tp ini kejadian pola umum. ga bisa dijadikan patokan klo bakal spt itu hujan terjadi. krn faktor pengendali hujan di indonesia itu banyak dan kompleks. data2 diatas itu menggunakan data huja per 3 jam dari data pengginderaan jauh selama lebih kurang 10 tahun. ini merupakan salah satu kelebihan data hujan dari penginderaan jauh. walaupun belum bisa digunakan nilai hujannya, tp pola hujan harian secara keruangan bisa kita dapatin. kondisi spt diatas tidak bisa kita dapat dari data hujan yang ada di darat, walaupn di darat juga dah ada data hujan dari radar, tp jangkauannya masih terbatas. dari data2 tersebutnya akhir bisalah kita mengira2 spt bagaimana terjadinya hujan secara harian. gambar dibawah adalah ilustrasi bagainama curah hujan harian terjadi untuk wilayah Tropis dan khusunya di pulau Sumatra (Biasutti et al., 2011;  Okamoto et al., 2004).

yang mau bermain2 dengan kondisi spt diatas untuk penelitiannya, data TRMM 2A25 dengan resolusi spasial lebih kurang 0.05 derajat atau TRMM 3B42 dengan resolusi spasial 0.25 derajat bisa digunakan.  utk bahan bacaan, silahkan baca2 artikel dibawah.  semoga tilisan kecil ini berguna..

Bahan Bacaan:
Qian, J-H. 2008. Why Precipitation Is Mostly Concentrated over Islands in the Maritime Continent. Journal of the Atmospheric Sciences 65. 1428–1441. http://dx.doi.org/10.1175/2007JAS2422.1
Biasutti, M., S.E. Yuter, Ca.D. Burleyson, and A.H. Sobel. 2011. Very high resolution rainfall patterns measured by TRMM precipitation radar: seasonal and diurnal cycles. Climate Dynamics http://dx.doi.org/10.1007/s00382-011-1146-6
Okamoto, N., F. Murata, N. Sakurai, H. Hashiguchi, and T. Sribimawati. 2004. Diurnal Land–Sea Rainfall Peak Migration over Sumatera Island, Indonesian Maritime Continent, Observed by TRMM Satellite and Intensive Rawinsonde Soundings. Monthly Weather Review 132, 2021–2039. http://dx.doi.org/10.1175/1520-0493(2004)132%3C2021:DLRPMO%3E2.0.CO;2.

AirAsia :: Booking Online

AirAsia Indonesia Bookings: Cara Booking & Bayar : Apakah yang di maksud booking tanpa tiket? Konsep tanpa tiket adalah pengganti metode tiket pesawat yang ada saat ini, yang telah digunakan AirAsia selama beberapa tahun terakhir. Dengan perjalanan Tanpa tiket, yang perlu anda lakukan hanyalah membooking penerbangan anda dan anda akan diberi Nomor/Kode Booking. Anda tidak perlu membawa Rencana Perjalanan/Flight Itinerary anda untuk check-in. Yang perlu anda ingat hanyalah Nomor Booking anda, atau sebutkan nama anda. Anda harus memperlihatkan kartu identitas atau paspor anda untuk keperluan identifikasi dan Check-in Lengkap: http://www.airasia.com.

Batavia Air :: Booking Online

Batavia Air Indonesia Bookings. Batavia Air adalah perusahaan penerbangan nasional pertama yang mengoperasikan pesawat Airbus A-319 sejak Januari 2006. Batavia Air saat ini mengoperasikan lebih dari 150 penerbangan setiap harinya dan melayani 29 kota tujuan di Indonesia serta Guangzhou-Cina dan Kuching-Malaysia. Batavia Air memiliki 36 pesawat yang terdiri dari pesawat Boeing 737-200, 737-300, 737-400, Airbus A-319 dan Airbus A-320.

Citilink :: Booking Online

Citilink is LCC Airlines, Business Airlines, Bisnis LCC, penerbangan murah di indonesia, moto get simplycity and fly : Citilink berusaha dengan sungguh-sungguh untuk memberikan layanan transportasi udara sederhana kepada semua pelanggan, dan kami selalu berusaha mencari cara untuk menyempurnakan hal tersebut. Layanan-layanan kami, yang mencakup aspek-aspek tertentu dari pemesanan kursi dan persyaratan perjalanan, dirancang untuk mencerminkan kesungguhan tersebut, bahkan dalam beberapa hal kami memberikan lebih dari apa yang disyaratkan secara tegas dalam undang-undang.

Garuda Indonesia Airline :: Booking Online

Garuda Indonesia Airline Bookings Garuda Indonesia’s commitment to total quality improvement in the area of service, safety, on-time departures and load factors has brought the company to a period of dynamic and successful change in providing safe, comfortable and reliable air transportation services.

Gatari Air Services :: Booking Online

It is our pleasure to take you on a journey into the enterprising field of private Air Charter. A world totally dedicated to meeting your unique travel needs : the world of Gatari Air Service. Over more than a decade Gatari has built an enviable reputation as Southeast Asia’s premier air charter operator. Gatari listens to it clients and has constantly adapted to match their special and changing requirements, while adhering strictly to global aviation, standards and procedures.

Kartika Airlines :: Booking Online

Kartika Airlines, a local airline with new world class standard of flying pleasure. Starting on June 2005, Kartika Airlines is flying broader to meet middle-up business needs. Explore new experiences of flying to more domestic destinations with us. We are supported by well trained human resources and our proven aircraft for a highest level of flying satisfaction. And of-course, enjoy our new standard in-flight services, and we will fly you the way you always want to fly.

Lion Air / Wings Air :: Booking Online

From modest beginnings as a one-plane airline that first flew in 2000, Lion Air has navigated its way through the turbulence in the wake of the financial crisis that blew through the region in 1997 to emerge as Indonesia’s leading budget airline carrier. Today, we operate 37 planes flying to not only all of Indonesia’s major cities and wondrous tourist destinations, but to Singapore, Penang and Kuala Lumpur as well. And we’re just taking off.

Mandala Airlines :: Booking Online

Mandala Airlines has developed a Total Experience service concept focused on customer satisfaction and excellent, high quality service. Berdiri sejak 1967, Mandala Airlines merupakan salah satu perintis usaha penerbangan komersial di Indonesia. Mandala adalah satu-satunya perusahaan penerbangan non-pemerintah generasi awal yang telah berhasil melewati masa krisis dan mampu berkembang pesat untuk menghadapi persaingan modern dengan mengembangkan organisasi, kemampuan operasional dan juga armada pesawatnya.

Merpati Nusantara Airline :: Booking Online

Merpati Nusantara Airlines was born by the motherland and has grown up among the difference of cultures and language atmospheres which Merpati has been challenged to obtain its maturity. It has improved from year to year. Merpati always sends its best service through nations as the good image building for national aviation. A national leading airlines company is the commitment of achievement. The pole has been planted and the flag has been displayed. Merpati continues to take off through global era to share the value of nation.

Trigana Air :: Booking Online

The main attribute and underlying strength of TRIGANA AIR SERVICE is our aircrews, with their maturity, experience and dedication, their customer oriented hospitality, their combined commitment to performance and service and most of all, their belief in and practice of the highest safety standards, which have been declared by the Company to be our corporate culture. For ease we have named our philosophy as – professional – which has become our standard for operation and maintenance.

Valuair / Jetstar :: Booking Online

Jetstar is Australia’s and Singapore’s new low fares airline (Valuair) for Indonesia, Singapore, Australia and the Asia-Pacific. Our aim is to provide consistent low fares to Australian, New Zealand and Asian leisure travellers. We started flying within Australia on the 25th of May, 2004 and within Asia just over six months later, offering customers a simple and fresh travel experience. Our bold and distinctive brand is indicative of the fresh and vibrant approach toward low cost travel in the region.

Sekalian nambahin info Tips dan trik cara pesan tiket on line yang . (sumber: http://ririegranita.blogspot.com/2008/11/tips-dan-trik-mendapat-tiket-pesawat.html)

1. jangan bepergian di peak season alias dimana musim orang bepergian seperti liburan taunan anak sekolah, idul fitri di H-10 mpe H+10 biasanya, natal & taun baru, atau hari libur nasional yang dempet tanggal merahnya….tetep mau pergi juga……????maka….liat nomor 2 !

2. Pesan tiket jauh-jauh hari dengan buka internet dengan alamat web mereka. jangan buka 1 web saja, incar web maskapai lain 3-4 atau 5web sekaligus. tapi pilih maskapai yang safety nya diakui.murah tapi kepleset di landasan ma pesawat-pesawatnya sih ihhhh amit-amittt…na’uzdubillah

3. setelah buka 5web sekaligus,bandingkan harga. langsung isi jadwal keberangkatan dan tiba anda dan infokan berapa orang yang pergi. eitssss….jagan heboh dulu liat harga dan jam yang cocok misal Rp 100rb.klik dulu pilihan harga tersebut dan go to setujui aturan dan lanjut akan keluar total harga berapa.karena yang diliat baru harga dasar, belum pajak,asuransi, bendin dan kakek nenek biaya lainnya..total adalah 400rb misal. itulah harga yang harus kamu bayar. cek semua maskapai dan copy paste nilai total simpan di file word kamu. masih mahal juga…………..?masih cari yang lebih murah…..?kocek belum pas……….?teuteupppp usaha dunk… lanjut no 4 bang…!

4. masukkan data terbang nyicil alias bila kamu pergi berempat misal, 2adult,1child,1 infant atau adult infant, 1 adult, intinya kamu isi data sebenarnya tapi agk perlu bareng2 requestnya. yang pasti children kudu pergi ma dewasa, infant apalagi.tapi kalo gak ada kursi juga ,coba untuk anak yang 5taunan kamu masukkin kelas adult..bisa jadi harga adult di kelas termurah jauh lebih murah ketika kamu pesan rombongan dia masuk harga child tapi kursiny ayang ada kelas medium. kelas nyicil kamu kena total 3juta,kelas rombongan 3juta 300rb.hahaaa..significant buat jalan2 di tempat tujuan or bakal oleh2… tapi yang jelas pesan di kode pesawat yang sama dan jam yang sama.jangan mpe anak kecil diterbangin sendiri hehe

5.jam penerbangan yang murah adalah malam hari mendekati tengah malam dan dini hari seperti jam 6pagi or lebih pagi.

6.tiap jam dan harinya harga tiket berubah..bisa kadi mahallll atau murah meriah karena sepi peminat.makin banyak peminat harga makin menjulang…

7.Periksalah jika persinggahan atau transit mengurangi harga. Biasanya harga tiket penerbangan langsung lebih mahal. Jika perbedaannya cukup signifikan, tidak ada salahnya mencoba.

8. Jika Anda sering terbang, bergabunglah jadi anggota program diskon yang biasa ditawarkan maskpai penerbangan. Sejumlah maskapi penerbangan menawarkan diskon besar bahkan tiket ekstra serta sejumlah fasilitas lain seperti up grade kelas dari kelas ekonomi ke kelas bisnis jika Anda sudah terbang sekian kali atau telah mencapai miles atau jarak tertentu dengan maskapai yang sama. Semakin sering Anda bepergian, semakin besar peluang Anda untuk mendapat diskon, bahkan bepergian secara gratis.

9. Jika sudah pesan, perhatikan batas waktu issue ticket. Penerbangan internasional biasanya punya jangka waktu lebih pendek dibanding penerbangan domestik.

Seharusnya saya bercerita dulu tentang bagaimana tingkat keakurasian data TRMM ini, saya sudah menulisnya dan akan segera diterbitkan dalam prosiding international, sambil menunggu terbitnya paper itu, saya akan bercerita duluan tentang pengaplikasiannya untuk mengetahui persentase anomali hujannya. Studi kasusnya di Indonesia dan saya mengambil saat kejadian La Nina. Kenapa kejadian La Nina, karena selama berorbitnya satelit ini, belum pernah terjadi ke jadian El Nino yang kuat (rentang waktu 1998-2011), ya mau ga mau untuk kejadian La Nina saja. Tetapi secara umum lokasi anomali iklim yang diakbatkan oleh kejadian La Nina ataupun El Nino di Indonesia adalah sama.

Ada dua penelitian yang akan dishare dalam halaman ini, pertama studi kasus saat La Nina tahun 1998/1999 dan yang kedua saat awal La Nina tahun 2010. dua penelitian yang berbeda. Yang petama tanpa ada validasi data, dan yang kedua hasil analisisnya dikuatkan oleh data anomali curah hujan dari stasiun-stasiun hujan BMKG di seluruh indonesia.

Sebagai gambaran, gambar diatas adalah kondisi anomali hujan saat tahun 1998/1999. semakin merah warnanya menunjukkan bahwa anomali peningkatan hujannya semakin tinggi. Bila semakin biru anomali penurunan curah hujannya samakin tinggi. Sedangkan gambar kedua adalah anomlai hujan saat bulan maret-juni 2010. kenapa cuman segitu aja? Presentasi paper kedua tersebut dilakukan pada tgl 29 Juli 2010, maka hal ini menunjukan bahwa data TRMM bisa digunakan untuk mengupdate data anomali iklim sebulan setelah bulan kejadian.

Gambar dibawah adalah scaterplot anomali iklim yang diperoleh dari data TRMM dan data hujan BMKG. Hasil korelasinya cukup bagus, dibawahnya juga grafik perbedaannya. Untuk lebih bagusnya sebaiknya langsung aja baca papernya. Klo ga mau baca papernya, silahkan lihat abstraknya saja hehehe…

OK semoga berkenan dan bermanfaat…

POLA SPASIAL PENGARUH KEJADIAN LA NINA TERHADAP CURAH HUJAN DI INDONESIA TAHUN 1998/1999; OBSERVASI MENGGUNAKAN DATA TRMM MULTISATELLITE PRECIPITATION ANALYSIS (TMPA) 3B43

Abd. Rahman As-syakur¹⁾²⁾

¹⁾Pusat Penelitian Lingkungan Hidup (PPLH) Universitas Udayana

²⁾Center for Remote Sensing and Ocean Science (CReSOS) Universitas Udayana

Email; ar.assyakur@yahoo.com

ABSTRAK

Tulisan ini menguraikan tentang pola spasial pengaruh kejadian La Nina terhadap curah hujan di Indonesia saat kejadian La Nina tahun 1998/1999 yang diobservasi menggunakan data TRMM Multisatellite Precipitation Analysis (TMPA) 3B43. Data TMPA 3B43 yang digunakan adalah selama 12 tahun dari tahun 1998 sampai 2009 dengan fokus analisis berupa analisis bulanan dan musiman monsoon. Hasil analisis semakin menguatkan hasil-hasil penelitian sebelumnya yang menunjukan bahwa kejadian La Nina tahun 1998/1999 terjadi mulai bulan April sampai November dan atau dampak kuat terjadi selama masa Juni-Juli-Agustus (JJA) dan September-Oktober-November (SON) dengan puncak kejadian bulan Agustus dan Sepetember. Penelitian ini berhasil menemukan fenomena baru terhadap efek kejadian La Nina khususnya terhadap pola spasial sebaran efeknya yaitu bahwa efek La Nina terhadap curah hujan di Indonesia ternyata bergerak dinamis selama masa kejadian dimana efek kejadian dimulai di bagian selatan Indonesia dan berakhir di bagian timur Indonesia. Pemanfaatan data penginderaan jauh seperti TMPA 3B43 ternyata mampu menggambarkan pola spasial efek La Nina terhadap curah hujan di Indonesia.

KATA KUNCI: La Nina; TMPA 3B43; curah hujan; pola spasial; Indonesia

POLA SPASIAL ANOMALI CURAH HUJAN SELAMA MARET SAMPAI JUNI 2010 DI INDONESIA; KOMPARASI DATA TRMM MULTISATELLITE PRECIPITATION ANALYSIS (TMPA) 3B43 DENGAN STASIUN PENGAMAT HUJAN

SPATIAL PATTERNS OF RAINFALL ANOMALIES IN INDONESIA DURING MARCH TO JUNE 2010; COMPARATION BETWEEN MULTISATELLITE TRMM PRECIPITATION ANALYSIS (TMPA) 3B43 WITH RAIN GAUGES DATA

A.R. As-syakur¹⁾²⁾ dan R. Prasetia²⁾³⁾

¹⁾Pusat Penelitian Lingkungan Hidup (PPLH) Universitas Udayana, Bali, 80232

²⁾Center for Remote Sensing and Ocean Science (CReSOS) Universitas Udayana, Bali, 80232

³⁾Badan Meteorologi, Klimatologi, dan Geofisika (BMKG) Negara, Bali, 82213

Email; ¹⁾ar.assyakur@pplh.unud.ac.id, ²⁾rahmatbmg@yahoo.com

Abstrak: Tulisan ini menguraikan tentang pola spasial anomali hujan selama Maret sampai Juni 2010 di Indonesia. Hasil analisis dari data TMPA di komparasikan dengan data yang diperoleh dari 42 stasiun pengamatan hujan di Indonesia. Data TMPA 3B43 yang digunakan adalah selama 13 tahun yaitu dari tahun 1998 sampai tahun 2010 dengan fokus analisis berupa analisis bulanan. Hasil analisis menunjukkan bahwa selama bulan Maret curah hujan di Indonesia masih cukup normal, akan tetapi selama April sampai Juni telah terjadi anomali curah hujan di Indonesia dengan peningkatan lebih dari 100%. Peningkatan ini hanya terjadi di bagian selatan wilayah Indonesia. Hasil komparasi menunjukkan adanya tingkat korelasi yang sedang sampai kuat antara data TMPA dengan data BMKG. Sedangkan kondisi bias eror memperlihatkan kondisi yang sedang. Keadaan ini menggambarkan bahwa data TMPA bisa digunakan sebagai salah satu data alternatif untuk mengetahui sebaran spasial anomali hujan secara terkini. Akan tetapi untuk mengetahui jumlah anomali secara tepat, maka perlu dihilangkan nilai-nilai eror pada deta dengan  melakukan korelasi data secara menyeluruh di Indonesia untuk mendapatkan nilai-nilai faktor koreksi.

Kata kunci: anomali hujan, TMPA 3B43, curah hujan, dan pola spasial

Abstract: This writing describe about spatial patterns of rainfall anomalies in Indonesia during March to June 2010. The results of analysis from TMPA data is compare with 42 data from rain gauge in Indonesia. TMPA data used in this research is 13 years 1998 to 2010 which focuses on monthly analysis. The results show that during March rainfall in Indonesia is still normal, but during April to June the rainfall anomalies in Indonesia has occurred with an increases more than 100%. Increased rainfall is only seen in the southern part of Indonesian. Comparison results indicate the correlations level between TMPA data and BMKG data is moderate to high correlations. Meanwhile, mean bias error value shows are in medium condition. This indicated that the TMPA data can be used as an alternative to determine the spatial pattern of rainfall in recent anomalies. However, to obtain more accurately rainfal anomalies values, it needs to be eliminated on the error values by performing the correlation reverend Indonesia’s overall data to obtain the correction factor values.

Keywords: rainfall anomaly; TMPA 3B43; precipitation; spatial pattern

As-syakur, A.R. 2010. Pola Spasial Pengaruh Kejadian La Nina Terhadap Curah Hujan di Indonesia Tahun 1998/1999; Observasi Menggunakan Data TRMM Multisatellite Precipitation Analysis (TMPA) 3B43. Prosiding Pertemuan Ilmiah Tahunan (PIT) XVII dan Kongres V Masyarakat Penginderaan Jauh Indonesia (MAPIN). 9 Agustus 2010, Institut Pertanian Bogor (IPB). Bogor-Indonesia. pp. 230-234.  Download Full PDF

As-syakur, A.R., dan R. Prasetia. 2010. Pola Spasial Anomali Curah Hujan Selama Maret Sampai Juni 2010 Di Indonesia; Komparasi Data TRMM Multisatellite Precipitation Analysis (TMPA) 3B43 dengan Stasiun Pengamat Hujan. Prosiding Penelitian Masalah Lingkungan di Indonesia 2010; Buku 2. 9 Juli 2010, Universitas Udayana, Denpasar-Indonesia: pp. 505-516. Download Full PDF

Sea-surface temperature and thermal stress in the Coral Triangle over the past two decades – (Penaflor et al.) (2009)  “Increasing ocean temperature has become one of the major concerns in recent times with reports of various related ecological impacts becoming commonplace. One of the more notable is the increased frequency of mass coral bleaching worldwide. This study focuses on the Coral Triangle region and utilizes the National Oceanic and Atmospheric Administration-Coral Reef Watch (NOAACRW) satellite-derived sea surface temperature (SST) and Degree Heating Weeks (DHW) products to investigate changes in the thermal regime of the Coral Triangle waters between 1985 and 2006. Results show an upward trend in SST during this period with an average rate of 0.2C/ decade. However, warming within this region is not uniform, and the waters of the northern and eastern parts of the Coral Triangle are warming fastest. Areas in the eastern part have experienced more thermal stress events, and these stress events appear to be more likely during a La Nina.” Penaflor et al, Coral Reefs (2009) 28:841–850. [full text]

Coral Reefs and Ocean Acidification – Kleypas and Yates (2009) “Coral reefs were one of the first ecosystems to be recognized as vulnerable to ocean acidification. To date, most scientific investigations into the effects of ocean acidification on coral reefs have been related to the reefs’ unique ability to produce voluminous amounts of calcium carbonate. It has been estimated that the main reef-building organisms, corals and calcifying macroalgae, will calcify 10–50% less relative to pre-industrial rates by the middle of this century. This decreased calcification is likely to affect their ability to function within the ecosystem and will almost certainly affect the workings of the ecosystem itself. However, ocean acidification affects not only the organisms, but also the reefs they build. The decline in calcium carbonate production, coupled with an increase in calcium carbonate dissolution, will diminish reef building and the benefits that reefs provide, such as high structural complexity that supports biodiversity on reefs, and breakwater effects that protect shorelines and create quiet habitats for other ecosystems, such as mangroves and seagrass beds. The focus on calcification in reefs is warranted, but the responses of many other organisms, such as fish, noncalcifying algae, and seagrasses, to name a few, deserve a close look as well.” Joan A. Kleypas and Kimberly K. Yates, Oceanography 22(4):108–117, DOI: 10.5670/oceanog.2009.101. [full text]

Monitoring coral reefs from Space – Eakin et al., (2010) “Coral reefs are one of the world’s most biologically diverse and productive ecosystems. However, these valuable resources are highly threatened by human activities. Satellite remotely sensed observations enhance our understanding of coral reefs and some of the threats facing them by providing global spatial and time-series data on reef habitats and the environmental conditions influencing them in near-real time. This review highlights many of the ways in which satellites are currently used to monitor coral reefs and their threats, and provides a look toward future needs and capabilities.” Eakin CM, Nim CJ, Russell EB, Aubrecht C, Elvidge C, Gledhill DK, Muller-Karger F, Mumby PJ, Skirving WJ, Strong AE, Wang M, Weeks SJ, Wentz F, Ziskin D, Oceanography, 23(4):118–133, DOI:10.5670/oceanog.2010.10 [full text]

Rapid poleward range expansion of tropical reef corals in response to rising sea surface temperatures – Yamano et al. (2011) “Rising temperatures caused by climatic warming may cause poleward range shifts and/or expansions in species distribution. Tropical reef corals (hereafter corals) are some of the world’s most important species, being not only primary producers, but also habitat-forming species, and thus fundamental ecosystem modification is expected according to changes in their distribution. Although most studies of climate change effects on corals have focused on temperature-induced coral bleaching in tropical areas, poleward range shifts and/or expansions may also occur in temperate areas. We show the first large-scale evidence of the poleward range expansion of modern corals, based on 80 years of national records from the temperate areas of Japan, where century-long measurements of in situ sea-surface temperatures have shown statistically significant rises. Four major coral species categories, including two key species for reef formation in tropical areas, showed poleward range expansions since the 1930s, whereas no species demonstrated southward range shrinkage or local extinction. The speed of these expansions reached up to 14 km/year, which is far greater than that for other species. Our results, in combination with recent findings suggesting range expansions of tropical coral-reef associated organisms, strongly suggest that rapid, fundamental modifications of temperate coastal ecosystems could be in progress.” Yamano, H., K. Sugihara, and K. Nomura (2011), Geophys. Res. Lett., 38, L04601, doi:10.1029/2010GL046474.

Modeling regional coral reef responses to global warming and changes in ocean chemistry: Caribbean case study – Buddemeier et al. (2011) “Climatic change threatens the future of coral reefs in the Caribbean and the important ecosystem services they provide. We used a simulation model [Combo (“COral Mortality and Bleaching Output”)] to estimate future coral cover in the part of the eastern Caribbean impacted by a massive coral bleaching event in 2005. Combo calculates impacts of future climate change on coral reefs by combining impacts from long-term changes in average sea surface temperature (SST) and ocean acidification with impacts from episodic high temperature mortality (bleaching) events. We used mortality and heat dose data from the 2005 bleaching event to select historic temperature datasets, to use as a baseline for running Combo under different future climate scenarios and sets of assumptions. Results suggest a bleak future for coral reefs in the eastern Caribbean. For three different emissions scenarios from the Intergovernmental Panel on Climate Change (IPCC; B1, A1B, and A1FI), coral cover on most Caribbean reefs is projected to drop below 5% by the year 2035, if future mortality rates are equivalent to some of those observed in the 2005 event (50%). For a scenario where corals gain an additional 1–1.5°C of heat tolerance through a shift in the algae that live in the coral tissue, coral cover above 5% is prolonged until 2065. Additional impacts such as storms or anthropogenic damage could result in declines in coral cover even faster than those projected here. These results suggest the need to identify and preserve the locations that are likely to have a higher resiliency to bleaching to save as many remnant populations of corals as possible in the face of projected wide-spread coral loss.” R. W. Buddemeier, Diana R. Lane and J. A. Martinich, Climatic Change, DOI: 10.1007/s10584-011-0022-z. [full text]

Coral reefs may start dissolving when atmospheric CO₂ doubles – Silverman et al. (2009) “Calcification rates in stony corals are expected to decline significantly in the near future due to ocean acidification. In this study we provide a global estimate of the decline in calcification of coral reefs as a result of increase in sea surface temperature and partial pressure of CO₂. This estimate, unlike previously reported estimates, is based on an empirical rate law developed from field observations for gross community calcification as a function of aragonite degree of saturation (Ω_arag), sea surface temperature and live coral cover. Calcification rates were calculated for more than 9,000 reef locations using model values of Ω_arag and sea surface temperature at different levels of atmospheric CO₂. The maps we produced show that by the time atmospheric partial pressure of CO₂ will reach 560 ppm all coral reefs will cease to grow and start to dissolve.” Silverman, J., B. Lazar, L. Cao, K. Caldeira, and J. Erez (2009), Geophys. Res. Lett., 36, L05606, doi:10.1029/2008GL036282. [full text]

Climate change and coral reef bleaching: An ecological assessment of long-term impacts, recovery trends and future outlook – Baker et al. (2008) “Since the early 1980s, episodes of coral reef bleaching and mortality, due primarily to climate-induced ocean warming, have occurred almost annually in one or more of the world’s tropical or subtropical seas. Bleaching is episodic, with the most severe events typically accompanying coupled ocean–atmosphere phenomena, such as the El Niño-Southern Oscillation (ENSO), which result in sustained regional elevations of ocean temperature. Using this extended dataset (25+ years), we review the short- and long-term ecological impacts of coral bleaching on reef ecosystems, and quantitatively synthesize recovery data worldwide. Bleaching episodes have resulted in catastrophic loss of coral cover in some locations, and have changed coral community structure in many others, with a potentially critical influence on the maintenance of biodiversity in the marine tropics. Bleaching has also set the stage for other declines in reef health, such as increases in coral diseases, the breakdown of reef framework by bioeroders, and the loss of critical habitat for associated reef fishes and other biota. Secondary ecological effects, such as the concentration of predators on remnant surviving coral populations, have also accelerated the pace of decline in some areas. Although bleaching severity and recovery have been variable across all spatial scales, some reefs have experienced relatively rapid recovery from severe bleaching impacts. There has been a significant overall recovery of coral cover in the Indian Ocean, where many reefs were devastated by a single large bleaching event in 1998. In contrast, coral cover on western Atlantic reefs has generally continued to decline in response to multiple smaller bleaching events and a diverse set of chronic secondary stressors. No clear trends are apparent in the eastern Pacific, the central-southern-western Pacific or the Arabian Gulf, where some reefs are recovering and others are not. The majority of survivors and new recruits on regenerating and recovering coral reefs have originated from broadcast spawning taxa with a potential for asexual growth, relatively long distance dispersal, successful settlement, rapid growth and a capacity for framework construction. Whether or not affected reefs can continue to function as before will depend on: (1) how much coral cover is lost, and which species are locally extirpated; (2) the ability of remnant and recovering coral communities to adapt or acclimatize to higher temperatures and other climatic factors such as reductions in aragonite saturation state; (3) the changing balance between reef accumulation and bioerosion; and (4) our ability to maintain ecosystem resilience by restoring healthy levels of herbivory, macroalgal cover, and coral recruitment. Bleaching disturbances are likely to become a chronic stress in many reef areas in the coming decades, and coral communities, if they cannot recover quickly enough, are likely to be reduced to their most hardy or adaptable constituents. Some degraded reefs may already be approaching this ecological asymptote, although to date there have not been any global extinctions of individual coral species as a result of bleaching events. Since human populations inhabiting tropical coastal areas derive great value from coral reefs, the degradation of these ecosystems as a result of coral bleaching and its associated impacts is of considerable societal, as well as biological concern. Coral reef conservation strategies now recognize climate change as a principal threat, and are engaged in efforts to allocate conservation activity according to geographic-, taxonomic-, and habitat-specific priorities to maximize coral reef survival. Efforts to forecast and monitor bleaching, involving both remote sensed observations and coupled ocean–atmosphere climate models, are also underway. In addition to these efforts, attempts to minimize and mitigate bleaching impacts on reefs are immediately required. If significant reductions in greenhouse gas emissions can be achieved within the next two to three decades, maximizing coral survivorship during this time may be critical to ensuring healthy reefs can recover in the long term.” Andrew C. Baker, Peter W. Glynn, and Bernhard Riegl, Estuarine, Coastal and Shelf Science, Volume 80, Issue 4, 10 December 2008, Pages 435-471, doi:10.1016/j.ecss.2008.09.003. [full text]

Coral Reefs Under Rapid Climate Change and Ocean Acidification – Hoegh-Guldberg et al. (2007) “Atmospheric carbon dioxide concentration is expected to exceed 500 parts per million and global temperatures to rise by at least 2°C by 2050 to 2100, values that significantly exceed those of at least the past 420,000 years during which most extant marine organisms evolved. Under conditions expected in the 21st century, global warming and ocean acidification will compromise carbonate accretion, with corals becoming increasingly rare on reef systems. The result will be less diverse reef communities and carbonate reef structures that fail to be maintained. Climate change also exacerbates local stresses from declining water quality and overexploitation of key species, driving reefs increasingly toward the tipping point for functional collapse. This review presents future scenarios for coral reefs that predict increasingly serious consequences for reef-associated fisheries, tourism, coastal protection, and people. As the International Year of the Reef 2008 begins, scaled-up management intervention and decisive action on global emissions are required if the loss of coral-dominated ecosystems is to be avoided.” O. Hoegh-Guldberg, P. J. Mumby, A. J. Hooten, R. S. Steneck, P. Greenfield, E. Gomez, C. D. Harvell, P. F. Sale, A. J. Edwards, K. Caldeira, N. Knowlton, C. M. Eakin, R. Iglesias-Prieto, N. Muthiga, R. H. Bradbury, A. Dubi and M. E. Hatziolos, Science 14 December 2007: Vol. 318 no. 5857 pp. 1737-1742, DOI: 10.1126/science.1152509. [full text]

Effects of climate and seawater temperature variation on coral bleaching and mortality – McClanahan et al. (2007) “Coral bleaching due to thermal and environmental stress threatens coral reefs and possibly people who rely on their resources. Here we explore patterns of coral bleaching and mortality in East Africa in 1998 and 2005 in a region where the equatorial current and the island effect of Madagascar interact to create different thermal and physicochemical environments. A variety of temperature statistics were calculated, and their relationships with the degree-heating months (DHM), a good predictor of coral bleaching, determined. Changes in coral cover were analyzed from 29 sites that span >1000 km of coastline from Kenya to the Comoros Islands. Temperature patterns are influenced by the island effect, and there are three main temperature environments based on the rise in temperature over 52 years, measures of temperature variation, and DHM. Offshore sites north of Madagascar that included the Comoros had low temperature rises, low DHM, high standard deviations (SD), and the lowest relative coral mortality. Coastal sites in Kenya had moderate temperature rises, the lowest temperature SD, high DHM, and the highest relative coral mortality. Coastal sites in the south had the highest temperature rises, moderate SD and DHM, and low relative coral mortality. Consequently, the rate of temperature rise was less important than background variation, as reflected by SD and kurtosis measures of sea surface water temperature (SST), in predicting coral survival across 1998. Coral bleaching responses to a warm-water anomaly in 2005 were also negatively related to temperature variation, but positively correlated with the speed of water flow. Separating these effects is difficult; however, both factors will be associated with current environments on the opposite sides of reefs and islands. Reefs in current shadows may represent refugia where corals acclimate and adapt to environmental variation, which better prepares them for rising temperature and anomalies, even though these sites are likely to experience the fastest rates of temperature rise. We suggest that these sites are a conservation priority and should be targeted for management and further ecological research in order to understand acclimation, adaptation, and resilience to climate change.” McClanahan, Timothy R., Mebrahtu Ateweberhan, Christopher A. Muhando, Joseph Maina, and Mohammed S. Mohammed. 2007, Ecological Monographs 77:503–525, doi:10.1890/06-1182.1. [full text]

The role of zooxanthellae in the thermal tolerance of corals: a ‘nugget of hope’ for coral reefs in an era of climate change – Berkelmans & van Oppen (2006) “The ability of coral reefs to survive the projected increases in temperature due to global warming will depend largely on the ability of corals to adapt or acclimatize to increased temperature extremes over the next few decades. Many coral species are highly sensitive to temperature stress and the number of stress (bleaching) episodes has increased in recent decades. We investigated the acclimatization potential of Acropora millepora, a common and widespread Indo-Pacific hard coral species, through transplantation and experimental manipulation. We show that adult corals, at least in some circumstances, are capable of acquiring increased thermal tolerance and that the increased tolerance is a direct result of a change in the symbiont type dominating their tissues from Symbiodinium type C to D. Our data suggest that the change in symbiont type in our experiment was due to a shuffling of existing types already present in coral tissues, not through exogenous uptake from the environment. The level of increased tolerance gained by the corals changing their dominant symbiont type to D (the most thermally resistant type known) is around 1–1.5 °C. This is the first study to show that thermal acclimatization is causally related to symbiont type and provides new insight into the ecological advantage of corals harbouring mixed algal populations. While this increase is of huge ecological significance for many coral species, in the absence of other mechanisms of thermal acclimatization/adaptation, it may not be sufficient to survive climate change under predicted sea surface temperature scenarios over the next 100 years. However, it may be enough to ‘buy time’ while greenhouse reduction measures are put in place.” Ray Berkelmans and Madeleine J.H van Oppen, Proc. R. Soc. B 22 September 2006 vol. 273 no. 1599 2305-2312, doi: 10.1098/rspb.2006.3567. [full text]

Global assessment of coral bleaching and required rates of adaptation under climate change – Donner et al. (2005) “Elevated ocean temperatures can cause coral bleaching, the loss of colour from reef-building corals because of a breakdown of the symbiosis with the dinoflagellate Symbiodinium. Recent studies have warned that global climate change could increase the frequency of coral bleaching and threaten the long-term viability of coral reefs. These assertions are based on projecting the coarse output from atmosphere–ocean general circulation models (GCMs) to the local conditions around representative coral reefs. Here, we conduct the first comprehensive global assessment of coral bleaching under climate change by adapting the NOAA Coral Reef Watch bleaching prediction method to the output of a low- and high-climate sensitivity GCM. First, we develop and test algorithms for predicting mass coral bleaching with GCM-resolution sea surface temperatures for thousands of coral reefs, using a global coral reef map and 1985–2002 bleaching prediction data. We then use the algorithms to determine the frequency of coral bleaching and required thermal adaptation by corals and their endosymbionts under two different emissions scenarios. The results indicate that bleaching could become an annual or biannual event for the vast majority of the world’s coral reefs in the next 30–50 years without an increase in thermal tolerance of 0.2–1.0°C per decade. The geographic variability in required thermal adaptation found in each model and emissions scenario suggests that coral reefs in some regions, like Micronesia and western Polynesia, may be particularly vulnerable to climate change. Advances in modelling and monitoring will refine the forecast for individual reefs, but this assessment concludes that the global prognosis is unlikely to change without an accelerated effort to stabilize atmospheric greenhouse gas concentrations.” Simon D. Donner, William J. Skirving, Christopher M. Little, Michael Oppenheimer, Ove Hoegh-Guldberg, Global Change Biology, Volume 11, Issue 12, pages 2251–2265, December 2005. [full text]

Coral reefs: Corals’ adaptive response to climate change – Baker et al. (2004) “The long-term response of coral reefs to climate change depends on the ability of reef-building coral symbioses to adapt or acclimatize to warmer temperatures, but there has been no direct evidence that such a response can occur. Here we show that corals containing unusual algal symbionts that are thermally tolerant and commonly associated with high-temperature environments are much more abundant on reefs that have been severely affected by recent climate change. This adaptive shift in symbiont communities indicates that these devastated reefs could be more resistant to future thermal stress, resulting in significantly longer extinction times for surviving corals than had been previously assumed.” Andrew C. Baker, Craig J. Starger, Tim R. McClanahan & Peter W. Glynn, Nature 430, 741 (12 August 2004) | doi:10.1038/430741a. [full text]

Coral reef calcification and climate change: The effect of ocean warming – McNeil et al. (2004) “Coral reefs are constructed of calcium carbonate (CaCO₃). Deposition of CaCO₃ (calcification) by corals and other reef organisms is controlled by the saturation state of CaCO₃ in seawater (Ω) and sea surface temperature (SST). Previous studies have neglected the effects of ocean warming in predicting future coral reef calcification rates. In this study we take into account both these effects by combining empirical relationships between coral calcification rate and Ω and SST with output from a climate model to predict changes in coral reef calcification rates. Our analysis suggests that annual average coral reef calcification rate will increase with future ocean warming and eventually exceed pre-industrial rates by about 35% by 2100. Our results suggest that present coral reef calcification rates are equivalent to levels in the late 19th century and does not support previous suggestions of large and potentially catastrophic decreases in the future.” McNeil, B. I., R. J. Matear, and D. J. Barnes (2004), Geophys. Res. Lett., 31, L22309, doi:10.1029/2004GL021541. [full text, comment by Kleypas et al., reply by McNeil et al.]

Global Trajectories of the Long-Term Decline of Coral Reef Ecosystems – Pandolfi et al. (2003) “Degradation of coral reef ecosystems began centuries ago, but there is no global summary of the magnitude of change. We compiled records, extending back thousands of years, of the status and trends of seven major guilds of carnivores, herbivores, and architectural species from 14 regions. Large animals declined before small animals and architectural species, and Atlantic reefs declined before reefs in the Red Sea and Australia, but the trajectories of decline were markedly similar worldwide. All reefs were substantially degraded long before outbreaks of coral disease and bleaching. Regardless of these new threats, reefs will not survive without immediate protection from human exploitation over large spatial scales.” John M. Pandolfi, Roger H. Bradbury, Enric Sala, Terence P. Hughes, Karen A. Bjorndal, Richard G. Cooke, Deborah McArdle, Loren McClenachan, Marah J. H. Newman, Gustavo Paredes, Robert R. Warner and Jeremy B. C. Jackson, Science 15 August 2003: Vol. 301 no. 5635 pp. 955-958, DOI: 10.1126/science.1085706.

Climate Change, Human Impacts, and the Resilience of Coral Reefs – Hughes et al. (2003) “The diversity, frequency, and scale of human impacts on coral reefs are increasing to the extent that reefs are threatened globally. Projected increases in carbon dioxide and temperature over the next 50 years exceed the conditions under which coral reefs have flourished over the past half-million years. However, reefs will change rather than disappear entirely, with some species already showing far greater tolerance to climate change and coral bleaching than others. International integration of management strategies that support reef resilience need to be vigorously implemented, and complemented by strong policy decisions to reduce the rate of global warming.” T. P. Hughes, A. H. Baird, D. R. Bellwood, M. Card, S. R. Connolly, C. Folke, R. Grosberg, O. Hoegh-Guldberg, J. B. C. Jackson, J. Kleypas, J. M. Lough, P. Marshall, M. Nyström, S. R. Palumbi, J. M. Pandolfi, B. Rosen and J. Roughgarden, Science 15 August 2003: Vol. 301 no. 5635 pp. 929-933, DOI: 10.1126/science.1085046. [full text]

Microbial diseases of corals and global warming – Rosenberg & Haim (2002) “Coral bleaching and other diseases of corals have increased dramatically during the last few decades. As outbreaks of these diseases are highly correlated with increased sea-water temperature, one of the consequences of global warming will probably be mass destruction of coral reefs. The causative agent(s) of a few of these diseases have been reported: bleaching of Oculina patagonica by Vibrio shiloi; black band disease by a microbial consortium; sea-fan disease (aspergillosis) by Aspergillus sydowii; and coral white plague possibly by Sphingomonas sp. In addition, we have recently discovered that Vibrio coralyticus is the aetiological agent for bleaching the coral Pocillopora damicornis in the Red Sea. In the case of coral bleaching by V. shiloi, the major effect of increasing temperature is the expression of virulence genes by the pathogen. At high summer sea-water temperatures, V. shiloi produces an adhesin that allows it to adhere to a β-galactoside-containing receptor in the coral mucus, penetrate into the coral epidermis, multiply intracellularly, differentiate into a viable-but-not-culturable (VBNC) state and produce toxins that inhibit photosynthesis and lyse the symbiotic zooxanthellae. In black band disease, sulphide is produced at the coral–microbial biofilm interface, which is probably responsible for tissue death. Reports of newly emerging coral diseases and the lack of epidemiological and biochemical information on the known diseases indicate that this will become a fertile area of research in the interface between microbial ecology and infectious disease.” Eugene Rosenberg, Yael Ben-Haim, Environmental Microbiology, Volume 4, Issue 6, pages 318–326, June 2002, DOI: 10.1046/j.1462-2920.2002.00302.x. [full text]

The future of coral reefs – Knowlton (2001) “Coral reefs, with their millions of species, have changed profoundly because of the effects of people, and will continue to do so for the foreseeable future. Reefs are subject to many of the same processes that affect other human-dominated ecosystems, but some special features merit emphasis: (i) Many dominant reef builders spawn eggs and sperm into the water column, where fertilization occurs. They are thus particularly vulnerable to Allee effects, including potential extinction associated with chronic reproductive failure. (ii) The corals likely to be most resistant to the effects of habitat degradation are small, short-lived “weedy” corals that have limited dispersal capabilities at the larval stage. Habitat degradation, together with habitat fragmentation, will therefore lead to the establishment of genetically isolated clusters of inbreeding corals. (iii) Increases in average sea temperatures by as little as 1°C, a likely result of global climate change, can cause coral “bleaching” (the breakdown of coral–algal symbiosis), changes in symbiont communities, and coral death. (iv) The activities of people near reefs increase both fishing pressure and nutrient inputs. In general, these processes favor more rapidly growing competitors, often fleshy seaweeds, and may also result in explosions of predator populations. (v) Combinations of stress appear to be associated with threshold responses and ecological surprises, including devastating pathogen outbreaks. (vi) The fossil record suggests that corals as a group are more likely to suffer extinctions than some of the groups that associate with them, whose habitat requirements may be less stringent.” Nancy Knowlton, PNAS May 8, 2001 vol. 98 no. 10 5419-5425, doi: 10.1073/pnas.091092998. [full text]

Coral bleaching: the winners and the losers – Loya et al. (2001) “Sea surface temperatures were warmer throughout 1998 at Sesoko Island, Japan, than in the 10 preceding years. Temperatures peaked at 2.8 °C above average, resulting in extensive coral bleaching and subsequent coral mortality. Using random quadrat surveys, we quantitatively documented the coral community structure one year before and one year after the bleaching event. The 1998 bleaching event reduced coral species richness by 61% and reduced coral cover by 85%. Colony morphology affected bleaching vulnerability and subsequent coral mortality. Finely branched corals were most susceptible, while massive and encrusting colonies survived. Most heavily impacted were the branched Acropora and pocilloporid corals, some of which showed local extinction. We suggest two hypotheses whose synergistic effect may partially explain observed mortality patterns (i.e. preferential survival of thick-tissued species, and shape-dependent differences in colony mass-transfer efficiency). A community-structural shift occurred on Okinawan reefs, resulting in an increase in the relative abundance of massive and encrusting coral species.” Loya, Sakai, Yamazato, Nakano, Sambali, Van Woesik, Ecology Letters, Volume 4, Issue 2, pages 122–131, March 2001, DOI: 10.1046/j.1461-0248.2001.00203.x.

Climate change, coral bleaching and the future of the world’s coral reefs – Hoegh-Guldberg (1999) “Sea temperatures in many tropical regions have increased by almost 1°C over the past 100 years, and are currently increasing at ~1–2°C per century. Coral bleaching occurs when the thermal tolerance of corals and their photosynthetic symbionts (zooxanthellae) is exceeded. Mass coral bleaching has occurred in association with episodes of elevated sea temperatures over the past 20 years and involves the loss of the zooxanthellae following chronic photoinhibition. Mass bleaching has resulted in significant losses of live coral in many parts of the world. This paper considers the biochemical, physiological and ecological perspectives of coral bleaching. It also uses the outputs of four runs from three models of global climate change which simulate changes in sea temperature and hence how the frequency and intensity of bleaching events will change over the next 100 years. The results suggest that the thermal tolerances of reef-building corals are likely to be exceeded every year within the next few decades. Events as severe as the 1998 event, the worst on record, are likely to become commonplace within 20 years. Most information suggests that the capacity for acclimation by corals has already been exceeded, and that adaptation will be too slow to avert a decline in the quality of the world’s reefs. The rapidity of the changes that are predicted indicates a major problem for tropical marine ecosystems and suggests that unrestrained warming cannot occur without the loss and degradation of coral reefs on a global scale.” Ove Hoegh-Guldberg, Marine and Freshwater Research 50(8) 839 – 866, doi:10.1071/MF99078. [full text]

The Significance of Emerging Diseases in the Tropical Coral Reef Ecosystem – Hayes & Goreau (1998) “Novel pathologies of coral reef organisms, especially reef frame building scleractinian corals, have escalated during the decade between 1987 and 1997. These emerging diseases have appeared with progressively greater frequency and over wider distribution, and have revealed more diversified characteristics than ever before. The causes of most of these infections are not yet confirmed, but they evidence a gradual decline in the vital status of the coral reef ecosystem. As specific causes are identified for these afflictions, terminology will shift from non-specific descriptions, such as “white band”, “white plague”, “white pox”, “yellow band” and “black band” diseases, to etiological and pathognomonic characterizations (e.g. aspergillosis and cyanobacteriosis). Stony corals are vulnerable to sedimentation, nutrient overloading, and chemical pollution from agricultural, urban, and domestic sources. They are incapable of relocation to other sites or of self-protection from cumulative effects of exposure to nitrates, phosphates, herbicides, pesticides, and raw sewage. In contrast to stresses attributed to warm water seasonal anomalies (e.g. coral reef bleaching), stresses imparted by pathogenic micro-organisms occur throughout the calendar year, fluctuate with changing temperature, and invariably result in tissue mortality. The coral has several mechanisms for defense. The epidermis, especially in tentacles of the coral polyp, contains nematocysts which are released in response to predators. The epidermal cells also possess cilia and a flagellary apparatus which are responsible for generating microcurrents in boundary water adjacent to the organism. These currents facilitate the entry of food into the coelenteron for digestion. Mesenterial filaments extend through the epidermis, sweep the surface of the colony, initiate digestion of food particles, and eventually return to the coelenteron. Both the epidermis and the gastrodermis contain mucocytes (or “immunocytes”) which release a mucous secretion. That mucous blanket physically insulates the tissue from particulates or soluble toxins, and may also be bacteriostatic because of immunoglobulin (IgA). The recent emergence of diseases in corals may be interpreted as the consequence of (1) changing coastal ocean water quality favoring the proliferation, attachment and colonization of microbes, and (2) reduced efficiency of the coral’s normal defenses. In order to appreciate these changes, research efforts to evaluate the microbial content of reef waters and to analyze the respective roles of mucus, cilia and flagella, and nematocysts of the corals are necessary. In this study, we have begun to detail the structural, physiological, chemical, and immunological attributes of the coral. Our analysis suggests that at least some of the emerging coral diseases may be explained by a decline in the capacity of coral colonies to mount effective protection against the increasing prevalence and varied invasive strategies of marine pathogens.” Raymond L. Hayes and Nora I. Goreau, Revista Biol Trop 46: 173–185. [full text is available in the abstract page]

Coral bleaching: causes and consequences – Brown (1997) “It has been over 10 years since the phenomenon of extensive coral bleaching was first described. In most cases bleaching has been attributed to elevated temperature, but other instances involving high solar irradiance, and sometimes disease, have also been documented. It is timely, in view of our concern about worldwide reef condition, to review knowledge of physical and biological factors involved in bleaching, the mechanisms of zooxanthellae and pigment loss, and the ecological consequences for coral communities. Here we evaluate recently acquired data on temperature and irradiance-induced bleaching, including long-term data sets which suggest that repeated bleaching events may be the consequence of a steadily rising background sea temperature that will in the future expose corals to an increasingly hostile environment. Cellular mechanisms of bleaching involve a variety of processes that include the degeneration of zooxanthellae in situ, release of zooxanthellae from mesenterial filaments and release of algae within host cells which become detached from the endoderm. Photo-protective defences (particularly carotenoid pigments) in zooxanthellae are likely to play an important role in limiting the bleaching response which is probably elicited by a combination of elevated temperature and irradiance in the field. The ability of corals to respond adaptively to recurrent bleaching episodes is not known, but preliminary evidence suggests that phenotypic responses of both corals and zooxanthellae may be significant.” B. E. Brown, Coral Reefs, Volume 16, Supplement 1, S129-S138, DOI: 10.1007/s003380050249. [full text]

Tracking South Pacific Coral Reef Bleaching
by Satellite and Field Observations – Goreau et al. (1997) “South Pacific waters with anomalously high surface temperature were tracked by satellite to identify potential sites for field study of coral reef bleaching. Areas with warm season monthly anomalies exceeding +0.9 degrees C were verified to have coral bleaching by local observers, while other areas were not affected. Comparison of 15 environmental variables, measured at 19 field sites across the area affected in 1994, shows that bleaching correlates significantly only with anomalously high temperature. Live coral cover was inversely correlated with many human population density-dependent stresses, but these were not correlated to bleaching. Observations in the Indian and Atlantic Oceans also show that coral reefs worldwide are acclimated close to their upper temperature limits and probably unable to adapt rapidly to a +1 degree C anomalous warming during the warm season.” T. J. Goreau, R. L. Hayes, and A. E. Strong, Proceedings of the 8th International Coral Reef Symposium 2:1491-1494, 1997. [full text is available in the abstract page]

Coral bleaching relative to elevated seawater temperature in the Andaman Sea (Indian Ocean) over the last 50 years – Brown et al. (1996) Without abstract. B. E. Brown, R. P. Dunne and H. Chansang, Coral Reefs, Volume 15, Number 3, 151-152, DOI: 10.1007/BF01145885.

Periodic mass-bleaching and elevated sea temperatures: bleaching of outer reef slope communities in Moorea, French Polynesia – Hoegh-Guldberg & Salvat (1995) “Mass-bleaching events (in which corals and other symbiotic invertebrates lose their zooxanthellae) have been occurring every 3 to 4 yr since 1979. The last report of widespread mass-bleaching in the Pacific (which included bleaching around French Polynesia) was in February-April 1991. This paper reports on mass-bleaching along the outer reef slope of Moorea, French Polynesia, in April 1994. Mass-bleaching was extensive at all sites visited, with corals being bleached down to 25 m. Colour loss by corals was due to low areal densities of zooxanthellae and the percentage of live coral affected ranged between 39.6 (+/- 7.12, SEM) (NW sites) and 72.4 (+/- 7.11, SEM) (NE sites). Bleaching also varied as a function of depth and included a wide range of species. Acropora spp. showed the most severe bleaching (89.0 to 100% of all colonies completely bleached) and Porites spp. showed the least amount of bleaching (12.9 to 42.5% of all colonies partly bleached). Pocillopora spp. showed intermediate bleaching (73.9 to 92.1% of all colonies either partly or completely bleached). The results of this report indicate that current bleaching is on a scale equal to that of the 1991 bleaching event. Temperatures recorded hourly at 14 m off the outer reef slope from July 1991 to August 1994 (and those from satellite sea surface temperature readings) indicate unusually warm sea temperatures in March 1994, which were approximately 1.0*C higher than the highest temperatures recorded in 1992 and 1993, years in which bleaching on a massive scale did not occur. The appearance of warmer temperatures preceded the onset of bleaching by 2 to 3 wk, which strongly confirms the hypothesis that positive thermal anomalies are responsible for recent bleaching events in the Central and Western Pacific.” Hoegh-Guldberg O, Salvat B, MEPS 121:181-190 (1995), doi:10.3354/meps121181.

Catastrophes, Phase Shifts, and Large-Scale Degradation of a Caribbean Coral Reef – Hughes (1994) “Many coral reefs have been degraded over the past two to three decades through a combination of human and natural disturbances. In Jamaica, the effects of overfishing, hurricane damage, and disease have combined to destroy most corals, whose abundance has declined from more than 50 percent in the late 1970s to less than 5 percent today. A dramatic phase shift has occurred, producing a system dominated by fleshy macroalgae (more than 90 percent cover). Immediate implementation of management procedures is necessary to avoid further catastrophic damage.” Terence P. Hughes, Science 9 September 1994: Vol. 265 no. 5178 pp. 1547-1551, DOI: 10.1126/science.265.5178.1547. [full text]

1994 coral bleaching event, Society Islands, French Polynesia – Fagerstom & Rougerie (1994) “The progression of a temperature-induced bleaching event on the barrier reef at Passe d’Arue, Tahiti, during March–April 1994 was observed at approximately weekly intervals. The event consisted of selective exaggeration of polyp colours (Montipora verneuilli, Pocillopora verrucosa), fluorescence followed by bleaching (Acropora spp.), partial-complete bleaching (Fungia spp., Montastraea curta, anemones) and commencement of polyp death. Porites (massive spp.), P. (Synarea) rus and melobesoid algae were almost untouched by the event.” J.A. Fagerstrom and F. Rougerie, Marine Pollution Bulletin, Volume 29, Issues 1-3, 1994, Pages 34-35, doi:10.1016/0025-326X(94)90423-5. [full text]

Coral reef bleaching: ecological perspectives – Glynn (1993) “Coral reef bleaching, the whitening of diverse invertebrate taxa, results from the loss of symbiotic zooxanthellae and/or a reduction in photosynthetic pigment concentrations in zooxanthellae residing within the gastrodermal tissues of host animals. Of particular concern are the consequences of bleaching of large numbers of reef-building scleractinian corals and hydrocorals. Published records of coral reef bleaching events from 1870 to the present suggest that the frequency (60 major events from 1979 to 1990), scale (co-occurrence in many coral reef regions and often over the bathymetric depth range of corals) and severity (>95% mortality in some areas) of recent bleaching disturbances are unprecedented in the scientific literature. The causes of small scale, isolated bleaching events can often be explained by particular stressors (e.g., temperature, salinity, light, sedimentation, aerial exposure and pollutants), but attempts to explain large scale bleaching events in terms of possible global change (e.g., greenhouse warming, increased UV radiation flux, deteriorating ecosystem health, or some combination of the above) have not been convincing. Attempts to relate the severity and extent of large scale coral reef bleaching events to particular causes have been hampered by a lack of (a) standardized methods to assess bleaching and (b) continuous, long-term data bases of environmental conditions over the periods of interest. An effort must be made to understand the impact of bleaching on the remainder of the reef community and the long-term effects on competition, predation, symbioses, bioerosion and substrate condition, all factors that can influence coral recruitment and reef recovery. If projected rates of sea warming are realized by mid to late AD 2000, i.e. a 2°C increase in high latitude coral seas, the upper thermal tolerance limits of many reef-building corals could be exceeded. Present evidence suggests that many corals would be unable to adapt physiologically or genetically to such marked and rapid temperature increases.” P. W. Glynn, Coral Reefs, Volume 12, Number 1, 1-17, DOI: 10.1007/BF00303779.

Effects of disturbance on coral communities: bleaching in Moorea, French Polynesia – Gleason (1993) “This study examines patterns of susceptibility and short-term recovery of corals from bleaching. A mass coral bleaching event began in March, 1991 on reefs in Moorea, French Polynesia and affected corals on the shallow barrier reef and to >20 m depth on the outer forereef slope. There were significant differences in the effect of the bleaching among common coral genera, with Acropora, Montastrea, Montipora, and Pocillopora more affected than Porites, Pavona, leptastrea or Millepora. Individual colonies of the common species of Acropora and Pocillopora were marked and their fate assessed on a subsequent survey in August, 1991 to determine rates of recovery and mortality. Ninety-six percent of Acropora spp. showed some degree of bleaching compared to 76% of Pocillopora spp. From March to August mortality of bleached colonies of Pocillopora was 17%, 38% recovered completely, and many suffered some partial mortality of the tissue. In contrast, 63% of the Acropora spp. died, and about 10% recovered completely. Generally, those colonies with less than 50% of the colony area affected by the bleaching recovered at a higher rate than did those with more severe bleaching. Changes in community composition four months after the event began included a significant decrease only in crustose algae and an increase in cover of filamentous algae, much of which occupied plate-like and branching corals that had died in the bleaching event. Total coral cover and cover of susceptible coral genera had declined, but not significantly, after the event.” M. G. Gleason, Coral Reefs, Volume 12, Numbers 3-4, 193-201, DOI: 10.1007/BF00334479.

An Assessment of Global Warming Stress on Caribbean Coral Reef Ecosystems – Atwood et al. (1992) “There is evidence that stress on coral reef ecosystems in the Caribbean region is increasing. Recently numerous authors have stated that the major stress results from “abnormally high” seasonal sea surface temperatures (SST) and have implicated global warming as a cause, stating that recent episodes of coral bleaching result therefrom. However, an analysis of available SST data sets shows no discernible warming trend that could cause an increase in coral bleaching. Given the lack of long-term records synoptic with observations of coral ecosystem health, there is insufficient evidence available to label temperatures observed in coincidence with recent regional bleaching events as “abnormally” high.” Atwood, Donald K.; Hendee, James C.; Mendez, Antonio, Bulletin of Marine Science, Volume 51, Number 1, July 1992 , pp. 118-130(13).

Coral reef bleaching in the 1980s and possible connections with global warming – Glynn (1991) “Scleractinian corals and their symbiotic dinoflagellate algae build massive, wave-resistant coral reefs that are pre-eminent in shallow tropical seas. This mutualism is especially sensitive to numerous environmental stresses, and has been disrupted frequently during the past decade. Increased seawater temperatures have been proposed as the most likely cause of coral reef bleaching, and it has been suggested that the recent large-scale disturbances are the first biological indication of global warming. This article describes recent bleaching events and their possible link with sea warming and other environmental stresses, and offers some speculation on the fate of coral reefs if the Earth enters a sustained period of warming.” Peter W. Glynn, Trends in Ecology & Evolution, Volume 6, Issue 6, June 1991, Pages 175-179, doi:10.1016/0169-5347(91)90208-F.

Damage and recovery of coral reefs affected by El Niño related seawater warming in the Thousand Islands, Indonesia – Brown & Suharsono (1990) “Extensive coral bleaching occurred during sea-water warming (as a result of the 1982/3 El Niño Southern Oscillation event) in 1983 on the shallow reefs in the Java Sea. Mean seawater temperatures rose by 2–3° C over a six month period with values greater than 33° C being recorded between 1200–1500 h. As many as 80–90% of corals died on the reef flats at the study sites, with the major casualties being branching species in the genera Acropora and Pocillopora. Five years after the event the community structure of the study sites has recovered significantly, though coral cover is still 50% of its former level. Contrasting patterns of recovery at two selected sites, in close proximity to each other, are discussed.” B. E. Brown and Suharsono, Coral Reefs, Volume 8, Number 4, 163-170, DOI: 10.1007/BF00265007.

Widespread Coral Mortality and the 1982–83 El Niño Warming Event – Glynn (1984) “The massive ‘bleaching’ (loss of zooxanthellae) and death of reef corals that occurred in one area (Gulf of Chiriquí) on the Pacific side of Panamá and in the Galápagos Islands during February—April 1983 continued in these areas until September—October 1983, resulting in a catastrophic disturbance. Similar episodes have been reported subsequently throughout much of the tropical eastern Pacific region (Costa Rica, the entire Pacific coast of Panamá, and Colombia), in the central and western Pacific Ocean, in parts of the western Atlantic Ocean (Caribbean coasts of Costa Rica, Panamá, and Colombia), and in the Florida Keys and Bahama Islands.” Peter W. Glynn, Environmental Conservation (1984), 11: 133-146, DOI: 10.1017/S0376892900013825.

Original text: http://agwobserver.wordpress.com/2011/02/24/papers-on-coral-response-to-global-warming/

Saat ini saya akan memcoba menulis tahun-tahun kejadian El Nino, La Nina, IOD positif, dan IOD negatif. Isu ini saya coba angkat karena masih ada beberapa penulis lepas yang sekedar mengutip informasi tanpa mengecek kembali kebenaran dari informasi tersebut. ENSO merupakan pola berulang dari variabilitas iklim di bagian timur samudera Pasifik yang ditandai dengan anomali temperatur permukaan laut (penghangatan permukaan laut menggambarkan kejadian El Nino sedangkan pendinginan permukaan laut menggambarkan kejadian La Nina) serta anomali Sea level pressure (Southern Oscillation). Perlu diingatkan kembali bahwa kejadian El Nino dicirikan oleh PENGHANGATAN SUHU PERMUKAAN LAUT DI SAMUDERA PASIFIK BAGIAN TENGAH DAN MEMBENTUK SUATU KOLAM HANGAT YANG BEREFEK PADA PENDINGINAN SUHU PERMUKAAN LAUT DI LAUTAN INDONESIA sedangkan kejadian La Nina dicirikan oleh PENDINGINAN SUHU PERMUKAAN LAUT DI SAMUDERA PASIFIK BAGIAN TENGAH DAN KOLAM HANGATNYA BERPINDAH KE BAGIAN BARAT SAMUDERA PASIFIK (DISEKITAR LAUTAN INDONESIA) YANG BEREFEK PADA PENGHANGATAN SUHU PERMUKAAN LAUT DI LAUTAN INDONESIA. IOD dicirikan oleh adanya zona gradien perbedaan suhu permukaan laut yang kuat di wilayah ekuatorial samudera hindia. IOD positif dicirikan oleh MENGHANGATNYA SUHU PERMUKAAN LAUT DI SEKITAR BENUA AFRIKA DAN MENDINGINNYA SUHU PERMUKAAN LAUT DI SEKITAR PULAU SUMATERA. Sedangkan IOD negatif dicirikan oleh MENDINGINNYA SUHU PERMUKAAN LAUT DI SEKITAR BENUA AFRIKA DAN MENGHANGATNYA SUHU PERMUKAAN LAUT DI SEKITAR PULAU SUMATERA. Kondisi ini harus di ingat dan jangan di balik-balik. Beberapa tulisan mengartikan kondisi hangat (warm even) di samudera pasifik juga diartikan kondisi hangat di lautan Indonesia, padahal saat disana itu panas, ya disini dingin…

OK, sekarang kita ngomongin tahun-tahun kejadian El Nino, La Nina, IOD positif, dan IOD negatif tersebut. Tahun-tahun kejadian El Nino, La Nina, IOD positif, dan IOD negatif biasanya sama untuk masing-masing institusi di dunia walaupun cara pengklasifikasian dan tingkat kekuatannya berbeda-beda. Ada banyak cara untuk menentukan waktu kejadian El Nino dan La Nina, tetapi untuk menentukan kejadian IOD hanya menggunakan satu metode yaitu dengan memantau nilai Dipole mode Index (DMI). Klo untuk ENSO bisa menggunakan indeks-indeks SOI, MEI, Nino3.4 Index, Nino3 Index, dan ONI. Berdasarkan indeks-indeks tersebut maka mencoba memperlihatkan tahun-tahun kejdiannya dalam tabel di bawah. Semoga bermanfaat dan berguna bagi yang membutuhkannya

Ini adalah tahun-tahun kejadian El Nino, La Nina, IOD positif dan IOD negatif berdasarkan analisis dari Mayers et al. (2007).

Keterangan: Tahun setelah 1998 secara resmi belum diklasifikasikan karena masih kesulitan dalam menghilangkan efek perubahan iklim

Sedangkan di bawah adalah tahun-tahun kejadian El Nino dan La Nina berdasarkan kondisi ONI. klasifikasinya El Nino atau La Nina lemah bila nilai anomali ONI o,5-0,9. El Nino atau La Nina sedang bila nilai anomali ONI 1,0-1,4. El Nino atau La Nina kuat bila nilai anomali ONI lebih besar dari 1,5 (KOUSKY AND HIGGINS, 2007), (gambar, double klik untuk memperbesar)

sedangkan yang dibawah adalah tahun-tahun kejadian El Nino dan La Nina berdasarkan suhu permukaan laut Japan Meteorological Agency (JMA) yang ditentukan oleh Floroda State University

The Blog-Health-o-Meter™ reads Wow.

Crunchy numbers

The Louvre Museum has 8.5 million visitors per year. This blog was viewed about 300,000 times in 2010. If it were an exhibit at The Louvre Museum, it would take 13 days for that many people to see it.

In 2010, there were 12 new posts, growing the total archive of this blog to 115 posts. There were 54 pictures uploaded, taking up a total of 25mb. That’s about a picture per week.

The busiest day of the year was April 19th with 1,501 views. The most popular post that day was Hubungan Efek Rumah Kaca, Pemanasan Global dan Perubahan Iklim.

Where did they come from?

The top referring sites in 2010 were google.co.id, search.conduit.com, blog-indonesia.com, rahmatkusnadi6.blogspot.com, and facebook.com.

Some visitors came searching, mostly for penyebab banjir, efek rumah kaca, cuaca dan iklim, penginderaan jauh, and el nino dan la nina.

Attractions in 2010

These are the posts and pages that got the most views in 2010.

Hubungan Efek Rumah Kaca, Pemanasan Global dan Perubahan Iklim July 2008
54 comments

Faktor Penyebab Banjir (1) March 2007
45 comments

Faktor Penyebab Banjir (2): Perubahan Lingkungan April 2008
34 comments

Sistem Informasi Geografi (SIG)/Geographic Information System (GIS) April 2007
107 comments

Cuaca dan Iklim April 2007
51 comments

TABLE – IRI Probabilistic ENSO Prediction for NINO3.4 Region
- Made in Dec 2010

Copy paste lagi tulisan penulis lainnya yang menarik buat saya. informasi tentang pemanfaatan Google Maps untuk mencari/memberi arah dari tempat tertentu ke tempat lainnya yang lengkap dengan informasi jalan-jalan mana saja yang akan dilewati. tulisan menarik ini di tulis oleh Alex Pangestu di Blog National Geographic Indonesia dengan judul Asli Cara mudah menunjukkan arah serta dengan alamat website http://teknologi.blog.nationalgeographic.co.id/2010/11/12/cara-mudah-menunjukkan-arah/. semoga tulisan menarik ini bisa membantu kita-kita agar tidak tersesat. soalnya klo tersesat bisa salah masuk kamar katanya Warkop

OK… inilah tulisannya tersebut… *seluruh tulisan berwarna hijau adalah murni copy paste dari tulisannya Alex Pangestu*

Memberi petunjuk jalan jadi lebih gampang dengan pakai peta online. Saya coba berbagi cara bikin petunjuk jalan di Google Maps Indonesia.

Kemarin sore, teman saya menanyakan arah menuju Kantor Imigrasi Tangerang. “Dari arah Serpong deh,” katanya. Daripada saya menjelaskan panjang lebar, saya buka Google Maps Indonesia. Saya cari “Jalan Serpong Raya- Pakulonan”. Begitu ketemu, perbesar peta dulu sampai terlihat jelas Jalan Serpong Raya – Pakulonan itu.

Saya klik kanan di penanda yang muncul di peta, lalu saya klik “Petunjuk arah dari sini” sehingga penanda yang tadinya berwarna merah berubah jadi warna hijau.

Selanjutnya, saya masukkan “Jalan Taman Makam Pahlawan Taruna” di kotak teks “B” yang ada di sebelah kiri. Nama jalan itu adalah alamat Kantor Imigrasi Tangerang yang tertera di situs web Ditjen Imigrasi.

Setelah “Dapatkan Petunjuk Arah” diklik, muncullah garis berwarna biru di peta. Itulah petunjuk arahnya.

Karena kebetulan saya dan teman saya itu sedang ngobrol di Yahoo! Messenger, saya bagi saja link ke peta yang sudah ada arahnya itu. Klik “Link”. Salin (dengan kata lain copy) link yang ada di kotak “Tempelkan link dalam email atau IM”. Lalu, saya tempel (alias paste) link itu di jendela tempat saya ngobrol.

Peta yang sudah ada petunjuknya itu bisa langsung dikirim juga ke e-mail. Nanti dalam e-mail itu ada peta dan kata-kata penuntun. Selain itu, bisa juga dicetak.