東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

Salinity and temperature variability...

Schmidt, Matthew William.

FindBook

Google Book

Amazon

博客來

Salinity and temperature variability in the Caribbean and the North Atlantic gyre during the last three ice age cycles on millennial and orbital time scales.

紀錄類型:	書目-語言資料,印刷品 : Monograph/item
正題名/作者:	Salinity and temperature variability in the Caribbean and the North Atlantic gyre during the last three ice age cycles on millennial and orbital time scales./
作者:	Schmidt, Matthew William.
面頁冊數:	200 p.
附註:	Source: Dissertation Abstracts International, Volume: 66-10, Section: B, page: 5285.
Contained By:	Dissertation Abstracts International66-10B.
標題:	Geology. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3191178
ISBN:	9780542347269

Salinity and temperature variability in the Caribbean and the North Atlantic gyre during the last three ice age cycles on millennial and orbital time scales.
Schmidt, Matthew William.

Salinity and temperature variability in the Caribbean and the North Atlantic gyre during the last three ice age cycles on millennial and orbital time scales. - 200 p.

Source: Dissertation Abstracts International, Volume: 66-10, Section: B, page: 5285.

Thesis (Ph.D.)--University of California, Davis, 2005.

Changes in the density of polar waters, which are governed strongly by both temperature and salinity, may be the fundamental reason for north Atlantic meridional overturning circulation (MOC) instability. In order to determine the role of density-driven changes in past ocean circulation, it is critical to understand past temperature and salinity variation in north Atlantic surface waters. Mg/Ca-SST estimates are combined with measurements of oxygen isotopes in the planktonic foraminifera Globigerinoides ruber from Colombian Basin cores ODP 999A and VM28-122 to reconstruct surface water delta 18O (delta18OSW, a proxy for surface salinity) during the last three glacial cycles (0-360 ky). Results show that Caribbean sea surface salinity (SSS) oscillated between saltier conditions during the cold marine isotope stages (MIS) 2, 4, 6, 8 and 10 and lower salinities during warm MIS 3, 5, 7 and 9, covarying with the strength of North Atlantic MOC. At the initiation of the Bolling/Allerod warm interval, Caribbean SSS decreased abruptly, suggesting that the advection of salty tropical waters into the North Atlantic amplified MOC and contributed to high-latitude warming. Comparison of Caribbean SSS change with similar estimates of tropical Pacific SSS variability over the past 360 ky reveals shifts in the east-west tropical SSS gradient that are consistent with both a southward migration of the glacial Intertropical Convergence Zone and with a glacial El Nino-like mode of tropical circulation.

ISBN: 9780542347269Subjects--Topical Terms:

516570
Geology.

Salinity and temperature variability in the Caribbean and the North Atlantic gyre during the last three ice age cycles on millennial and orbital time scales.
LDR:03328nam 2200301 4500 001 1396726
005 20110620111219.5
008 130515s2005 ||||||||||||||||| ||eng d
020 $a 9780542347269
035 $a (UMI)AAI3191178
035 $a AAI3191178
040 $a UMI $c UMI
100 1 $a Schmidt, Matthew William. $3 1675519
245 1 0 $a Salinity and temperature variability in the Caribbean and the North Atlantic gyre during the last three ice age cycles on millennial and orbital time scales.
300 $a 200 p.
500 $a Source: Dissertation Abstracts International, Volume: 66-10, Section: B, page: 5285.
500 $a Adviser: Howard J. Spero.
502 $a Thesis (Ph.D.)--University of California, Davis, 2005.
520 $a Changes in the density of polar waters, which are governed strongly by both temperature and salinity, may be the fundamental reason for north Atlantic meridional overturning circulation (MOC) instability. In order to determine the role of density-driven changes in past ocean circulation, it is critical to understand past temperature and salinity variation in north Atlantic surface waters. Mg/Ca-SST estimates are combined with measurements of oxygen isotopes in the planktonic foraminifera Globigerinoides ruber from Colombian Basin cores ODP 999A and VM28-122 to reconstruct surface water delta 18O (delta18OSW, a proxy for surface salinity) during the last three glacial cycles (0-360 ky). Results show that Caribbean sea surface salinity (SSS) oscillated between saltier conditions during the cold marine isotope stages (MIS) 2, 4, 6, 8 and 10 and lower salinities during warm MIS 3, 5, 7 and 9, covarying with the strength of North Atlantic MOC. At the initiation of the Bolling/Allerod warm interval, Caribbean SSS decreased abruptly, suggesting that the advection of salty tropical waters into the North Atlantic amplified MOC and contributed to high-latitude warming. Comparison of Caribbean SSS change with similar estimates of tropical Pacific SSS variability over the past 360 ky reveals shifts in the east-west tropical SSS gradient that are consistent with both a southward migration of the glacial Intertropical Convergence Zone and with a glacial El Nino-like mode of tropical circulation.
520 $a Reconstruction of subtropical North Atlantic delta18O SW in the Blake Outer Ridge core ODP 1060 across Dansgaard-Oeschger (D-O) cycles 12-16 (45.9-59.2 ka) demonstrates that salinity increases abruptly at the initiation of each cold stadial event and then rapidly returns to fresher interstadial conditions. These punctuated centennial-scale salinity shifts are followed by plateaus of stable gyre salinity, contradicting the hypothesis that gradual changes in North Atlantic salinity regulate D-O cycles. We theorize that preconditioned stadial salinities played a critical role on interstadial transitions by maintaining elevated North Atlantic surface-water density during periods of increased freshwater flux, thereby enabling an abrupt return to deep overturning circulation and high-latitude warming.
590 $a School code: 0029.
650 4 $a Geology. $3 516570
650 4 $a Physical Oceanography. $3 1019163
650 4 $a Geochemistry. $3 539092
690 $a 0372
690 $a 0415
690 $a 0996
710 2 $a University of California, Davis. $3 1018682
773 0 $t Dissertation Abstracts International $g 66-10B.
790 1 0 $a Spero, Howard J., $e advisor
790 $a 0029
791 $a Ph.D.
792 $a 2005
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3191178