TROPICAL INFLUENCE ON THE SOUTH PACIFIC DOUBLE JET VARIABILITY

• Main Authors: キトウ アキオ, Akio KITOH
• Format: Report
• Language: English
• Published: Meteorological Research Institute 1994
• Subjects: West Antarctica; Pacific; Indian; New Zealand; Antarc*; Antarctica; Polar meteorology and glaciology; Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3823; http://id.nii.ac.jp/1291/00003823/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3823&item_no=1&attribute_id=18&file_no=1

An observational and modeling study of the interannual variability of the South Pacific atmospheric circulation is presented. The observed data cover the period 1979-1991. An atmospheric general circulation model (GCM) has been integrated with the observed sea surface temperature (SST) for the period 1970-1989. It is shown that the subtropical jet is positively correlated with the SST anomalies in the central equatorial Pacific. Thus, the jet is directly influenced by the tropical heating. On the other hand, the high latitude jet variability is associated with a wave train through eastern Australia, south-east of New Zealand, West Antarctica and southern South America. It is found from the stationary wave flux analysis that when the SST anomalies in the Indian Ocean are positive, this wave train is formed in a location to weaken the Pacific high latitude jet both in the observed data and in the GCM. The GCM is shown to have a capability to model the interannual variability of the South Pacific double jet forced by the SST variations.