ABSTRACT

The previous studies of upwelling within the Indonesian seas only focused on the Southeast Monsoon (SEM) season. The western coast of Sumatra Island; the southern coast of Java Island, Sunda Islands, and Sulawesi Island; the Banda Sea, the Maluku Sea, and the Arafura Sea are well-known SEM upwelling areas. However, the upwelling events during Northwest monsoon (NWM) have never been investigated. The investigation of NWM upwelling is challenging due to the broad cloud coverage, limiting the observation of infrared and visible sensors of the satellites. This study used the blended products of the satellite-based sea surface temperature (SST), chlorophyll-a (chl-a), sea level anomaly (SLA), surface wind, and rainfall to identify the NWM upwelling occurrences. Remote sensing reflectances 443 nm and 555 nm were also used to examine the influence of suspended sediment and organic matter which may bias the chl-a concentration. Along the northern coast of the Lesser Sunda Islands, the north coast of Papua Island and the Malacca Strait are the areas of NWM upwelling as denoted by the positive anomaly of chl-a, the negative anomaly of SST, and the negative anomaly of SLA. Focusing on the area along the northern coast of the Lesser Sunda Islands, the NWM upwelling is generated by offshore Ekman Mass Transport that reduces SST and increases chl-a. From 2010 onwards, El Niňo Southern Oscillation has a more consistent effect on the NWM upwelling than Indian Ocean Dipole. El Niňo (La Niňa) tends to weaken (strengthen) upwelling. The magnitude of NWM upwelling is weaker than SEM upwelling.

摘要

先前对印尼海域上升流的研究仅集中在东南季风（SEM）季节。苏门答腊岛西海岸；爪哇岛，Sun他群岛和苏拉威西岛的南部海岸；班达海，马鲁古海和阿拉法拉海是著名的SEM上升区。但是，从未研究过西北季风（NWM）期间的上升流事件。由于覆盖范围广，对NWM上升流的研究具有挑战性，限制了对卫星红外和可见光传感器的观测。这项研究使用了基于卫星的海面温度（SST），叶绿素a（chl- a），海平面异常（SLA），地表风和降雨来确定NWM上升事件。遥感反射率443 nm和555nm处也被用来研究悬浮沉积物和有机物质可偏置chl-的影响一个浓度。沿着小Sun他群岛的北海岸，巴布亚岛的北海岸和马六甲海峡是西北西北地区的上升区，由chl- a的正异常，SST的负异常和SLA的负异常表示。着眼于沿小巽他群岛的北部海岸地区，是由海上埃克曼大众运输，减少SST和增加chl-产生的NWM涌一。从2010年开始，厄尔尼诺南方涛动比印度洋偶极子对NWM上升的影响更加一致。厄尔尼诺（LaNiňa）倾向于减弱（加强）上升流。NWM上升的幅度比SEM上升的弱。