A 15-year climatology of synoptical disturbance over tropical northwestern Pacific during summer
MetadataShow full item record
This work investigated the sumertime northwestward propagating waves over the tropical western North Pacific and their relationship with tropical cyclone activities. The 15-season (May-October 1974-1988) Navy tropical global band data were separated into three groups according to the degree of organization in the multiple-set canonical correlation (MCC) modes that were computed from the surface v wind. Groups A (6 seasons) and B (5 seasons) showed orderly large-scale propagating patterns at the surface and 700 hPa with an average period of 8 days and a wavelength of about 2500-3000 km. The structure is robust whether the MCC analysis was performed on each of the seasons individually or on groups of years. A strong in-phase relationship between the low-level disturbance cyclonic cells and tropical cyclone centers was found. Composite analysis of all cases in these two groups whose MCC mode 1 amplitude exceeded 1.5 m/s showed organized northwestward propagating divergence/convergence patterns at 200 hPa. Group C (4 seasons) shows the least organized structure, with a large difference between MCC modes obtained from the entire group and those from each individual season. The possibility that group C contains irregular tropical cyclone tracks was discussed.
Showing items related by title, author, creator and subject.
Hildebrand, Paula E. (Monterey, California. Naval Postgraduate School, 2001-03);We have examined the impacts of El Nino (EN) and La Nina (LN) events on North Atlantic tropical cyclones (TCs), and the physical mechanisms that produce these impacts. We constructed composites of best- track data from the ...
The climatological seasonal response of the ocean mixed layer in the equatorial and tropical Pacific Ocean Ries, Harry J. (Monterey, California. Naval Postgraduate School, 1988);Seasonal changes of mixed layer depth (MLD) can be related to the forcing by the net surface heating and wind speed. This is shown in this study by comparing the monthly mixed layer depth from temperature profiles in the ...
Li, T.; Wang, B.; Chang, C.-P.; Zhang, Y. (2003);A conceptual coupled atmosphere-ocean model was constructed to understand the origin of the Indian Ocean Dipole Mode (IODM). In the model various positive and negative air-sea feedback processes were involved. Among them ...