Physical control of primary productivity on a seasonal scale in the central and eastern Arabian Sea

Journal of Earth system science

M Madhupratap1¹  P M Muraleedharan1¹  M Gauns1¹  S Prasanna kumar1¹  S N De Souza1¹  V V S S Sarma1¹  M Dileep kumar1¹ 

[1] National Institute of Oceanography, Dona Paula, Goa 403 004, India.$$

关键词: Primary production;    upwelling;    winter cooling;    Ekman-pumping;    nutrient transport;    Arabian Sea;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

Using in situ data collected during 1992-1997, under the Indian programme of Joint Global Ocean Flux Study (JGOFS), we show that the biological productivity of the Arabian Sea is tightly coupled to the physical forcing mediated through nutrient availability. The Arabian Sea becomes productive in summer not only along the coastal regions of Somalia, Arabia and southern parts of the west coast of India due to coastal upwelling but also in the open waters of the central region. The open waters in the north are fertilized by a combination of divergence driven by cyclonic wind stress curl to the north of the Findlater Jet and lateral advection of nutrient-rich upwelled waters from Arabia. Productivity in the southern part of the central Arabian Sea, on the other hand, is driven by advection from the Somalia upwelling. Surface cooling and convection resulting from reduced solar radiation and increased evaporation make the northern region productive in winter. During both spring and fall inter-monsoons, this sea remains warm and stratified with low production as surface waters are oligotrophic. Inter-annual variability in physical forcing during winter resulted in one-and-a-half times higher production in 1997 than in 1995.

【 授权许可】

Unknown