سال انتشار: ۱۳۸۴
محل انتشار: ششمین همایش علوم و فنون دریایی
تعداد صفحات: ۱
Dr. John T. Fasullo – National Center for Atmospheric Research Boulder, CO, 80305, USA
The Asian monsoon is notable, for both its direct socio-economic impact and its role in the general circulation of the atmosphere and oceans. The monsoon introduces a pronounced annual harmonic to the Tropics and is responsible for the most intense interhemispheric transport of mass, moisture, and energy to occur in any season. Monsoon variability is pronounced across a broad range of timescales. Within the monsoon season, 10-20 day and 20-50 day cycles have been used to describe the monsoon’s interseasonal variations. Current perspectives largely maintain that, due to random error growth, prediction of these “active-break” cycles is inherently constrained to timescales less than a month or so. In contrast to the active-break cycle, interannual variability, which is also quite robust, holds the best potential for long range forecasting efforts. Approaches that consider simultaneously the monsoon’s basic boundary forcing, including the evolving nature of both the Eurasian land surface and the tropical oceans, hold perhaps the greatest promise of current forecasting schemes. In this presentation, hydrologic aspects of the above mentioned monsoon characteristics are presented in the context of interannual variability and the monsoon’s basic forcing. Well-documented aspects of interannual variability, such as the monsoon’s associations with ENSO and Eurasian snow cover, are presented and the intrinsic limitations of linear interpretations of these interactions are explored. The cumulative influence of the interactions in the context of recently observed rapid and substantial changes in southwestern Eurasia and the Arabian Sea are then presented.