SATELLITE DERIVED EXTRACTION OF SPATIO - TEMPORAL VARIABILITY OF UPWELLING AND ITS INFLUENCE ON MARINE FISHERY RESOURCES

Kanmani Shanmuga Priya Rajkumar ； Ramakrishnan Sunnambukulam Shanmugam

《Journal of Marine Science and Technology》 26卷1期 (2018/02) Pp. 92-101

https://doi.org/10.6119/JMST.2018.02_(1).0003

摘要

Upwelling is an essential mesoscale phenomenon as it contributes to regional as well as global marine biological productivity. The present study deals with utilization of QuikSCAT derived wind speed and wind direction for delineating the potential zones of coastal upwelling with its spatio-temporal variability and its corresponding influence on fishery resources. The Ekman mass transport and Ekman depth were used as the signatures to locate and extract the mesoscale properties of upwelling such as spatial extent and temporal persistence. The upwelling process is known to modulate the physical and biological properties of the ocean surface. In order to confirm the existence of upwelling, the extracted upwelling filaments were related with the satellite derived chlorophyll concentration (CC) and sea surface temperature (SST), the process so called synergistic analysis. It was observed from the synergistic analysis that the upwelling is associated with reduced SST and elevated CC which is an indication of suitable environment for fishes. The two to three fold increase was confirmed within the upwelling zone as compared to outside region. The presence of demersal species in the 30-50 m depth zone gives evidence for the aggregation of fishes in the upwelling zone. The combined analysis of upwelling, CC, SST and fishery catch data sets manifests that the upwelling support the large quantity of fishes as compared to other regions and the satellite based delineation and extraction of upwelling properties is useful for exploration of fishery resources.

關鍵字

upwelling ； sea surface temperature ； chlorophyll concentration ； fishery resources