Tren Kenaikan Suhu Permukaan Laut Pada Abad Ke-14 Berdasarkan Data Geokimia Sr/Ca Dari Fosil Koral Mentawai

DOI: 10.17014/ijog.v5i2.96Sr/Ca content ratio in coral is a promising tool for a sea surface temperature reconstruction. In this study, Sr/Ca was analyzed from the top core of fossil coral from Central Mentawai, Indonesia (BLS). The dating of U/Th is used for the age determination of the fossil coral. Based on the U/Th dating, the fossil coral used in this study was deposited in 14th century which approximately has a time range 11 years. The result of this study shows that in the 14th century, the sea surface temperature increased by 3.20 C during 11 years period

Sea Surface Temperature Reconstruction Period 1993 - 2007 Based on Content Analysis of Coral Sr/Ca From the Region Labuan Bajo, Simeulue Island

DOI: 10.17014/ijog.v6i3.121Sea surface temperature (SST) is one of the important parameters for (paleo) climate studies. The long time series of SST data are required to understand more the climate change. Coral geochemical proxy such as Sr/Ca overcomes this problem. Coral can provide long time series of climate data continuously from present till hundreds years ago, even fossil (dead) coral can do it till thousand years ago. In this study, Sr/Ca content of Porites coral within 10 m deep from Labuan Bajo, Simeulue Island was analyzed to reconstruct SST. Coral Sr/Ca shows a strong correlation with local SST in seasonal scale as well as in the annual mean scale. Reconstructed SST data show that the monsoon between 1993 2007 strongly influence the SST variation in the Simeulue region. It supposed that the seasonal variation signal strongly influence local SST than the annual mean signal such as El Nino

Geochemical Tracer in Coral as a Sea Surface Temperature Proxy: Records from Jukung Coral

Sr/Ca  has been analyzed from coral core from the Seribu Islands  reef complex  i.e  Jukung  Island.  SST  from  ERSST  dataset  and  air  temperature measured at Jakarta is used for Sr/Ca calibration. The results show that Jukung Island  coral  Sr/Ca  correlates  better  with  SST  than  with  air  temperature.  A comparison  between  the  Sr/Ca  records  with  the  Nino  3.4  index  shows  that Jukung  coral  sites  indicate  warming  sea  surface  temperatures  during  the beginning  of El Nino  events followed by cooling temperatures at the end of El Nino years

Geochemical Tracer in Coral as a Sea Surface Temperature Proxy: Records From Jukung Coral

Sr/Ca has been analyzed from coral core from the Seribu Islands reef complex i.e Jukung Island. SST from ERSST dataset and air temperature measured at Jakarta is used for Sr/Ca calibration. The results show that Jukung Island coral Sr/Ca correlates better with SST than with air temperature. A comparison between the Sr/Ca records with the Nino 3.4 index shows that Jukung coral sites indicate warming sea surface temperatures during the beginning of El Nino events followed by cooling temperatures at the end of El Nino years

Field Correlation Between Precipitation-el Nino Related Variation and Coral ?18o

Coral ?18O from Maudulung-Indonesia was analyzed using Finnigan MAT 251. Using statistical analysis from KNMI database is obtained that the seasonal mean field correlation between coral ? 18OSOI shows strong correlation during October. Field correlation of precipitation-coral ? 18O shows opposite pattern between eastern Pacific and western Pacific during strong El Nino event. Keywords: coral ?18O, field correlation, El Niño, Maudulung Sumba. Kandungan ?18O dalam koral dari wilayah Maudulung, Sumba, dianalisis dengan menggunakan Finnigan MAT 251. Korelasi spasial antara ?18O dengan SOI dalam skala musiman tinggi selama bulan Oktober. Korelasi spasial ini dilakukan dengan menggunakan fasilitas analisa statistik dalam database KNMI. Korelasi spasial antara presipitasi- coral ?18O menunjukkan pola-pola yang berlawanan antara wilayah timur dan barat Pasifi selama El Niño. Kata kunci: Koral ?18O, korelasi spasial, El Niño, Maudulung Sumba

Assessing the accuracy of δ<sup>18<\sup>O<sub>sw<?sub> estimates from corals: lessons from simple Monte Carlo simulations

EGU2008-A-04391 Paired measurements of δ18O and Sr/Ca in coral aragonite are routinely used for deriving estimates of δ18Osw and, by extension, sea surface salinity variations over the past centuries. However, in practice, the accuracy (or the error) of these estimates is often difficult to assess. Here, we use simulated proxy data and Monte-Carlo simulations to investigate the accuracy of δ18Osw estimates from paired coral δ18O and Sr/Ca measurements. First, we estimate expected values of coral Sr/Ca and δ18O from instrumental or reanalysis data of sea surface temperature (SST) and sea surface salinity (SSS). We then add the typical analytical errors onto the expected Sr/Ca (δ18O) data as random numbers and compute δ18Osw+error from the noisy proxy data for a 1000 sample Monte Carlo. From this simple Monte Carlo simulation, the range of correlation coefficients between δ18Osw+error and expected δ18Osw is estimated. As expected, we find that this range mainly depends on the magnitude of the actual SSS variations at a given site, as well as on the slope of the δ18Osw-SSS relationship. A comparison with real coral-based δ18Osw reconstructions from multiple sites indicates that correlations between reconstructed δ18Osw and instrumental SSS fall within the range of correlation coefficients predicted based on our Monte-Carlo simulation. Thus, our simple simulation exercise may help to assess the feasibility of δ18Osw and salinity reconstructions from corals in different climatic settings, provided that (i) some instrumental data of δ18Osw and/or SSS is available, and (ii) the slope of the δ18Osw-SSS relationship is known