Logo des Repositoriums
Zur Startseite
  • English
  • Deutsch
Anmelden
  1. Startseite
  2. SuUB
  3. Dissertationen
  4. ABRUPT CLIMATE SHIFTS IN THE WESTERN TROPICAL TO SUBTROPICAL ATLANTIC REGION DURING THE LAST GLACIAL
 
Zitierlink URN
https://nbn-resolving.de/urn:nbn:de:gbv:46-diss000103939

ABRUPT CLIMATE SHIFTS IN THE WESTERN TROPICAL TO SUBTROPICAL ATLANTIC REGION DURING THE LAST GLACIAL

Veröffentlichungsdatum
2006-06-27
Autoren
Heil, Gerrit M.N.  
Betreuer
Arz, Helge Wolfgang  
Gutachter
Schulz, Michael  
Zusammenfassung
Millennial-scale climate oscillations of the last glacial, called Dansgaard/Oeschger (D/O) cycles, hold great potential for analysing mechanisms of global climate changes. In the tropics, D/O cycles are primarily expressed as precipitation pattern variations, which are coupled to latitudinal shifts of the Intertropical Convergence Zone (ITCZ). These arise from reorganisations of the atmospheric circulation in the northern hemisphere, which are driven by pronounced temperature changes in the high northern latitudes.This study investigates the coupling mechanisms between high northern latitude temperature changes and ITCZ shifts based on proxy records from sediment cores of the western tropical Atlantic. It evaluates the impact of ITCZ shifts on both the spatial extent and the amplitude of associated precipitation pattern changes. Furthermore, it analyses the relation between changes in North Atlantic Deep Water (NADW) production and shifts in tropical precipitation patterns.The main conclusions of this study may be summarised as follows:1) The tropical South American climate system underwent significant reorganisations during D/O cycles which were driven by ITCZ shifts2) The ITCZ position is dynamically coupled to variations in the North Atlantic meridional temperature gradient3) Precipitation records from equatorial regions are dominated by millennial-scale changes, whereas southern tropical regions primarily show shifts of orbital timescale4) In contrast to the modern climate system, tropical sea surface temperature changes do not alter South American precipitation patterns significantly on millennial timescales5) D/O cycles are associated with variations in western tropical Atlantic deep ocean conditions, which arise from changes in NADW production6) Tropical precipitation pattern changes are coupled to variations in NADW production via changes in high northern latitude temperatures, variations in the North Atlantic meridional temperature gradient and ITCZ shifts
Schlagwörter
paleoclimate

; 

precipitation

; 

temperature

; 

tropics

; 

Dansgaard/Oeschger

; 

Heinrich events

; 

foraminifers
Institution
Universität Bremen  
Fachbereich
Fachbereich 05: Geowissenschaften (FB 05)  
Dokumenttyp
Dissertation
Zweitveröffentlichung
Nein
Sprache
Englisch
Dateien
Lade...
Vorschaubild
Name

00010393.pdf

Size

4.15 MB

Format

Adobe PDF

Checksum

(MD5):086769b9a2e1fa1eea3cd22f51397043

Built with DSpace-CRIS software - Extension maintained and optimized by 4Science

  • Datenschutzbestimmungen
  • Endnutzervereinbarung
  • Feedback schicken