Fertility Variability and Water Conditions With Regard Oceanography at The Lombok Strait

Abstract

This study tried to understand the relationship between the variability of marine productivity and oceanographic condition in the Lombok Strait. We utilized Sea Surface Temperature (SST) and Chlorophyll-a data during July 2002 – December 2009 taken from remote sensing satellite of Aqua MODIS NASA, wind data during January 2002 – December 2009 from IFREMER Cersat, and Nutrient data during January 2002 – December 2005 from NOAA and WOD-NODC. The study areas divided by 4 (four) locations representing Flores sea (station 1), Northern part of Lombok strait (Station 2), Southern part of Lombok Strait (Station 3), and Indian Ocean side (Station 4). The result study showed spatial distribution of SST are about 26 – 31 oC and Chlorophyll-a are about 0.1 – 0.95 mg/m³. The temporal distribution of SST showed that during west monsoon have a warm temperature then during east monsoon the water have a cold temperature and also the temporal distribution of Chlorophyll-a have a high concentration during east monsoon and low concentration during west monsoon.We carried out the Empirical Orthogonal Function (EOF) and wavelet spectrum analysis to account for the main modes of the variability. The total variance of EOF mode 1 and 2 of SST explains 78 % for mode 1 and 8,4 % for mode 2 while Chlorophyll-a explains 32,4 % for mode 1 and 20,4 % for mode 2 of total variance. Spatial distribution at station 1 show sea surface temperature and chlorophyll is strongly influenced phenomenon semiannual influences, station 4 is influenced by the dominant influence of the phenomenon annual, while station 2 and 3 tend to be influenced phenomenon mixture of annual and semiannual. While the temporal distribution of show on the East season chlorophyll concentration tend to be hingh in the waters south of the Lombok Straits and West season chlorophyll relatively small concentrations, but relatively high chlorophyll concentrations appear only near the southeast coast island of Bali and western Lombok island. The index of marine productivity in this study has been established and found that at station 4 have high productivity rather then the others station occurred during months of June – September (dry season).