Subtropical Gyre Variability as Seen from Satellites
A satellite multi-sensor approach is used to analyse the biological response of open ocean regions of the subtropical gyres to changes in physical forcing. Thirteen years (1998-2010) of SeaWiFS chlorophyll a (Chl-a), combined with concurrent satellite records of sea-surface temperature (SST) and sea...
Main Authors: | , |
---|---|
Format: | Other/Unknown Material |
Language: | unknown |
Published: |
2011
|
Subjects: | |
Online Access: | http://hdl.handle.net/2060/20110022998 |
id |
ftnasantrs:oai:casi.ntrs.nasa.gov:20110022998 |
---|---|
record_format |
openpolar |
spelling |
ftnasantrs:oai:casi.ntrs.nasa.gov:20110022998 2023-05-15T17:34:39+02:00 Subtropical Gyre Variability as Seen from Satellites Signorini, Sergio R. McClain, Charles R. Unclassified, Unlimited, Publicly available [2011] application/pdf http://hdl.handle.net/2060/20110022998 unknown Document ID: 20110022998 http://hdl.handle.net/2060/20110022998 Copyright, Distribution as joint owner in the copyright CASI Oceanography GSFC.JA.5205.2011 2011 ftnasantrs 2019-07-21T06:25:22Z A satellite multi-sensor approach is used to analyse the biological response of open ocean regions of the subtropical gyres to changes in physical forcing. Thirteen years (1998-2010) of SeaWiFS chlorophyll a (Chl-a), combined with concurrent satellite records of sea-surface temperature (SST) and sea level height, were analysed to investigate the seasonal and interannual variability of Chl-a concentration within these immense so-called ocean deserts. The seasonal variability of Chl-a within the gyres is driven mostly by the warming/cooling of surface waters. Summer warming promotes shallower mixed layers and lower Chl-a due to a reduction of vertical mixing and consequently a decrease in nutrient supply. The opposite happens during the winter cooling period. Therefore, long-term trends in SST have the potential to cause an impact on the interannual variability of Chl-a. Our analyses show that, during the 13 whole years of SeaWiFS data record, the North Pacific, Indian Ocean, and North Atlantic gyres experienced a decrease in Chl-a of 9%, 12%, and 11%, respectively, with corresponding SST increases of 0.27 C, 0.42 C, and 0.32 C. The South Pacific and South Atlantic gyres also showed warming trends but with weak positive trends in Chl-a that are not statistically significant. We hypothesize that the warming of surface waters in these two gyres are counterbalanced by other interacting physical and biological driving mechanisms, as indicated in previous studies. Other/Unknown Material North Atlantic NASA Technical Reports Server (NTRS) Pacific Indian |
institution |
Open Polar |
collection |
NASA Technical Reports Server (NTRS) |
op_collection_id |
ftnasantrs |
language |
unknown |
topic |
Oceanography |
spellingShingle |
Oceanography Signorini, Sergio R. McClain, Charles R. Subtropical Gyre Variability as Seen from Satellites |
topic_facet |
Oceanography |
description |
A satellite multi-sensor approach is used to analyse the biological response of open ocean regions of the subtropical gyres to changes in physical forcing. Thirteen years (1998-2010) of SeaWiFS chlorophyll a (Chl-a), combined with concurrent satellite records of sea-surface temperature (SST) and sea level height, were analysed to investigate the seasonal and interannual variability of Chl-a concentration within these immense so-called ocean deserts. The seasonal variability of Chl-a within the gyres is driven mostly by the warming/cooling of surface waters. Summer warming promotes shallower mixed layers and lower Chl-a due to a reduction of vertical mixing and consequently a decrease in nutrient supply. The opposite happens during the winter cooling period. Therefore, long-term trends in SST have the potential to cause an impact on the interannual variability of Chl-a. Our analyses show that, during the 13 whole years of SeaWiFS data record, the North Pacific, Indian Ocean, and North Atlantic gyres experienced a decrease in Chl-a of 9%, 12%, and 11%, respectively, with corresponding SST increases of 0.27 C, 0.42 C, and 0.32 C. The South Pacific and South Atlantic gyres also showed warming trends but with weak positive trends in Chl-a that are not statistically significant. We hypothesize that the warming of surface waters in these two gyres are counterbalanced by other interacting physical and biological driving mechanisms, as indicated in previous studies. |
format |
Other/Unknown Material |
author |
Signorini, Sergio R. McClain, Charles R. |
author_facet |
Signorini, Sergio R. McClain, Charles R. |
author_sort |
Signorini, Sergio R. |
title |
Subtropical Gyre Variability as Seen from Satellites |
title_short |
Subtropical Gyre Variability as Seen from Satellites |
title_full |
Subtropical Gyre Variability as Seen from Satellites |
title_fullStr |
Subtropical Gyre Variability as Seen from Satellites |
title_full_unstemmed |
Subtropical Gyre Variability as Seen from Satellites |
title_sort |
subtropical gyre variability as seen from satellites |
publishDate |
2011 |
url |
http://hdl.handle.net/2060/20110022998 |
op_coverage |
Unclassified, Unlimited, Publicly available |
geographic |
Pacific Indian |
geographic_facet |
Pacific Indian |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
CASI |
op_relation |
Document ID: 20110022998 http://hdl.handle.net/2060/20110022998 |
op_rights |
Copyright, Distribution as joint owner in the copyright |
_version_ |
1766133541537579008 |