Prungchan Wongwises

Chlorophyll distribution by oceanic model and satellite data in the Bay of Bengal and Andaman Sea

An oceanic model and satellite data are used to evaluate the seasonal distribution of chlorophyll-a (Chl-a) in the Bay of Bengal (BoB) and Andaman Sea.Satellite data show high Chl-a concentrations because high Chl-a concentrations reduce CO2 and increase O2 at the sea surface, indicating fish abundance in the ocean. Sample collection alone cannot provide an accurate overview of Chl-a concentration over an entire region.The satellite data concerning Chl-a concentration, phytoplankton absorption coefficient, and Sea Surface Temperature (SST) are from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) project and from the Moderate Resolution Imaging Spectroradiometer (MODIS). The oceanic model is created to give the surface circulation as a result. The research finds that the simulation is in agreement with SST, Chl-a concentration, and phytoplankton absorption coefficients obtained from satellites. The conclusion is that the oceanic model can be used to implicitly explain the seasonal distribution of Chl-a in the Bay of Bengal and Andaman sea.

Low-Level Wind Variability over the Indochina Peninsular during Boreal Winter

Low-level wind can be used to represent winter monsoon as an index constructed from 850 hPa wind. The vector empirical orthogonal function (VEOF) method is used to decompose variability of the low-level wind from JRA-25 reanalysis data during the boreal winter (December to February) over the Indochina peninsular. The first VEOF mode exhibits tropical anomalous easterlies over the southern region and anomalous southeasterlies over the central of region. A spatial pattern in positive phase of the first mode exhibits anomalous northeasterlies, and the pattern of negative phase reveals anomalous southwesterlies over the interior of the region. The variability of winter monsoon over the Indochina peninsular shows interannual variation, and long term variability is of interest. The relationship of winter monsoon over the Indochina peninsular to the East Asian winter monsoon (EAWM), which is a major climate feature during boreal winter, is investigated and discussed.