Global structure of marine wind speed variability derived from TOPEX altimeter data
Abstract:As the largest source of momentum for the ocean surface, wind affects the full range of oceanic motion--from individual surface waves to complete current systems. The marine surface wind is among the critical geophysical parameters which determine the most fundamental aspects of the ocean. Using six years (1993-1998) of TOPEX altimeter data with an unprecedented accuracy and continuity, a detailed investigation of the global structure of marine wind climatology and variability is carried out. It is found that the overall pattern of wind climatology is basically determined by solar radiation and therefore dominated by zonal features, while that of the wind variability is largely 'event' determined and thereby dominated by regional features. Consequently, wind climatology and wind variability show a complex relationship in their magnitude of intensity. Strong winds may be associated with high variabilities, such as in the westerlies of the North Atlantic and North Pacific; they may also be associated with low variabilities, such as in the westerlies of the Southern Ocean. Meanwhile, weak wind zones like the doldrums in the western equatorial Pacific can have a very low level of annual variability, while a very high level of interannual variability. The Asian monsoon system has a lower than average climatological mean speed, but exhibits extremely high annual variability. The phase distributions of wind variations carry combined information of climatology and variability. Effects of the Asian monsoon and marine storms are manifested on top of the basically zonal phase pattern. Statistics suggest that semiannual variability exceeds annual variability for 12.2% of the world's oceans, and interannual variability exceeds annual variability for 26.4% of the world's oceans.
Document Type: Research Article
Affiliations: 1: Ocean Remote Sensing Institute Ocean University of China 5 Yushan Road Qingdao 266003 PR China, Email: email@example.com 2: Laboratory of Remote Sensing Information Sciences, Institute of Remote Sensing Applications Chinese Academy of Sciences PO Box 9718 Beijing 100101 PR China 3: Department of Physics Ocean University of China 5 Yushan Road Qingdao 266003 PR China
Publication date: 2003-12-01