Simulated global-scale response of the climate system

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Greenland; Pacific; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.462.1117; http://www.mpimet.mpg.de/fileadmin/staff/claussenmartin/publications/claussen_al_mis3_climdyn_03.pdf

diate complexity we have studied the global-scale re-sponse of the glacial climate system during marine isotope stage (MIS) 3 to perturbations at high northern latitudes and the tropics. These perturbations include changes in inland-ice volume over North America, in freshwater flux into the northern North Atlantic and in surface temperatures of the tropical Pacific. The global pattern of temperature series resulting from an experi-ment in which perturbations of inland ice and freshwater budget are imposed at high northern latitudes only, agree with paleoclimatic reconstructions. In particular, a positive correlation of temperature variations near Greenland and variations in all regions of the Northern Hemisphere and some parts of the southern tropics is found. Over the southern oceans a weak negative cor-relation appears which is strongest at a time lag of approximately 500 years. Further experimentation with prescribed temperature anomalies applied to the tropical Pacific suggests that perturbation of tropical sea-surface temperatures and hence, the tropical water cycle, is un-likely to have triggered Dansgaard/Oeschger (D/O) events. However, together with random freshwater anomalies prescribed at high northern latitudes, tropical perturbations would be able to synchronize the occur-rence of D/O events via the mechanism of stochastic resonance. 1