Spatiotemporal trends in the southwest monsoon wind-driven upwelling in the southwestern part of the South China Sea

Poh Heng Kok, Mohd Fadzil Mohd Akhir, Fredolin Tangang @ Tajudin Mahmud, Mohd Lokman Husain

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

This study analyzes two wind-induced upwelling mechanisms, namely, Ekman transport and Ekman pumping that occur during the southwest monsoon. The results suggest that the coastline of the east coast of Peninsular Malaysia (ECPM) is affected by upwelling with spatiotemporal variations. Characterization of upwelling by using wind-induced upwelling indexes (UIW) indicate the existence of favorable upwelling conditions from May to September. Upwelling intensity increased in May and peaked in August before declining in September, decreasing intensity from the southern tip towards the northern tip along the coastline of the ECPM. The existence of upwelling along the ECPM has resulted in an important difference between the SSTs of the inshore and the oceanic regions. Nonetheless, the use of the SST gradient between the inshore and the oceanic SSTs to characterize upwelling (UISST) was found to be unsuitable because the SST along the ECPM was affected by water advection from the Java Sea and incessant changes in the SST. In order to indicate the major contributor of wind-induced upwelling along the ECPM in terms of the spatiotemporal scale, a comparison between Ekman transport and Ekman pumping was drawn by integrating Ekman pumping with respect to the distance where the positive wind stress curl existed. The estimation of Ekman transport and Ekman pumping indicated that Ekman pumping played a major role in contributing towards upwelling in any particular month during the southwest monsoon along the entire coastline of the ECPM as compared to Ekman transport, which contributed towards more than half of the total upwelling transport. By dividing the ECPM into three coastal sections, we observed that Ekman pumping was relatively predominant in the middle and northern coasts, whereas both Ekman transport and Ekman pumping were equally prevalent in the southern coast.

Original languageEnglish
Article numbere0171979
JournalPLoS One
Volume12
Issue number2
DOIs
Publication statusPublished - 1 Feb 2017

Fingerprint

South China Sea
Malaysia
Oceans and Seas
Coastal zones
China
coasts
Wind stress
Advection
Water

ASJC Scopus subject areas

  • Medicine(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this

Spatiotemporal trends in the southwest monsoon wind-driven upwelling in the southwestern part of the South China Sea. / Kok, Poh Heng; Akhir, Mohd Fadzil Mohd; Tangang @ Tajudin Mahmud, Fredolin; Husain, Mohd Lokman.

In: PLoS One, Vol. 12, No. 2, e0171979, 01.02.2017.

Research output: Contribution to journalArticle

@article{461c2aaab82c48bc915fa82a70ebbc33,
title = "Spatiotemporal trends in the southwest monsoon wind-driven upwelling in the southwestern part of the South China Sea",
abstract = "This study analyzes two wind-induced upwelling mechanisms, namely, Ekman transport and Ekman pumping that occur during the southwest monsoon. The results suggest that the coastline of the east coast of Peninsular Malaysia (ECPM) is affected by upwelling with spatiotemporal variations. Characterization of upwelling by using wind-induced upwelling indexes (UIW) indicate the existence of favorable upwelling conditions from May to September. Upwelling intensity increased in May and peaked in August before declining in September, decreasing intensity from the southern tip towards the northern tip along the coastline of the ECPM. The existence of upwelling along the ECPM has resulted in an important difference between the SSTs of the inshore and the oceanic regions. Nonetheless, the use of the SST gradient between the inshore and the oceanic SSTs to characterize upwelling (UISST) was found to be unsuitable because the SST along the ECPM was affected by water advection from the Java Sea and incessant changes in the SST. In order to indicate the major contributor of wind-induced upwelling along the ECPM in terms of the spatiotemporal scale, a comparison between Ekman transport and Ekman pumping was drawn by integrating Ekman pumping with respect to the distance where the positive wind stress curl existed. The estimation of Ekman transport and Ekman pumping indicated that Ekman pumping played a major role in contributing towards upwelling in any particular month during the southwest monsoon along the entire coastline of the ECPM as compared to Ekman transport, which contributed towards more than half of the total upwelling transport. By dividing the ECPM into three coastal sections, we observed that Ekman pumping was relatively predominant in the middle and northern coasts, whereas both Ekman transport and Ekman pumping were equally prevalent in the southern coast.",
author = "Kok, {Poh Heng} and Akhir, {Mohd Fadzil Mohd} and {Tangang @ Tajudin Mahmud}, Fredolin and Husain, {Mohd Lokman}",
year = "2017",
month = "2",
day = "1",
doi = "10.1371/journal.pone.0171979",
language = "English",
volume = "12",
journal = "PLoS One",
issn = "1932-6203",
publisher = "Public Library of Science",
number = "2",

}

TY - JOUR

T1 - Spatiotemporal trends in the southwest monsoon wind-driven upwelling in the southwestern part of the South China Sea

AU - Kok, Poh Heng

AU - Akhir, Mohd Fadzil Mohd

AU - Tangang @ Tajudin Mahmud, Fredolin

AU - Husain, Mohd Lokman

PY - 2017/2/1

Y1 - 2017/2/1

N2 - This study analyzes two wind-induced upwelling mechanisms, namely, Ekman transport and Ekman pumping that occur during the southwest monsoon. The results suggest that the coastline of the east coast of Peninsular Malaysia (ECPM) is affected by upwelling with spatiotemporal variations. Characterization of upwelling by using wind-induced upwelling indexes (UIW) indicate the existence of favorable upwelling conditions from May to September. Upwelling intensity increased in May and peaked in August before declining in September, decreasing intensity from the southern tip towards the northern tip along the coastline of the ECPM. The existence of upwelling along the ECPM has resulted in an important difference between the SSTs of the inshore and the oceanic regions. Nonetheless, the use of the SST gradient between the inshore and the oceanic SSTs to characterize upwelling (UISST) was found to be unsuitable because the SST along the ECPM was affected by water advection from the Java Sea and incessant changes in the SST. In order to indicate the major contributor of wind-induced upwelling along the ECPM in terms of the spatiotemporal scale, a comparison between Ekman transport and Ekman pumping was drawn by integrating Ekman pumping with respect to the distance where the positive wind stress curl existed. The estimation of Ekman transport and Ekman pumping indicated that Ekman pumping played a major role in contributing towards upwelling in any particular month during the southwest monsoon along the entire coastline of the ECPM as compared to Ekman transport, which contributed towards more than half of the total upwelling transport. By dividing the ECPM into three coastal sections, we observed that Ekman pumping was relatively predominant in the middle and northern coasts, whereas both Ekman transport and Ekman pumping were equally prevalent in the southern coast.

AB - This study analyzes two wind-induced upwelling mechanisms, namely, Ekman transport and Ekman pumping that occur during the southwest monsoon. The results suggest that the coastline of the east coast of Peninsular Malaysia (ECPM) is affected by upwelling with spatiotemporal variations. Characterization of upwelling by using wind-induced upwelling indexes (UIW) indicate the existence of favorable upwelling conditions from May to September. Upwelling intensity increased in May and peaked in August before declining in September, decreasing intensity from the southern tip towards the northern tip along the coastline of the ECPM. The existence of upwelling along the ECPM has resulted in an important difference between the SSTs of the inshore and the oceanic regions. Nonetheless, the use of the SST gradient between the inshore and the oceanic SSTs to characterize upwelling (UISST) was found to be unsuitable because the SST along the ECPM was affected by water advection from the Java Sea and incessant changes in the SST. In order to indicate the major contributor of wind-induced upwelling along the ECPM in terms of the spatiotemporal scale, a comparison between Ekman transport and Ekman pumping was drawn by integrating Ekman pumping with respect to the distance where the positive wind stress curl existed. The estimation of Ekman transport and Ekman pumping indicated that Ekman pumping played a major role in contributing towards upwelling in any particular month during the southwest monsoon along the entire coastline of the ECPM as compared to Ekman transport, which contributed towards more than half of the total upwelling transport. By dividing the ECPM into three coastal sections, we observed that Ekman pumping was relatively predominant in the middle and northern coasts, whereas both Ekman transport and Ekman pumping were equally prevalent in the southern coast.

UR - http://www.scopus.com/inward/record.url?scp=85012111005&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85012111005&partnerID=8YFLogxK

U2 - 10.1371/journal.pone.0171979

DO - 10.1371/journal.pone.0171979

M3 - Article

VL - 12

JO - PLoS One

JF - PLoS One

SN - 1932-6203

IS - 2

M1 - e0171979

ER -