Accession Number : ADA294767

Title :   A 15-Year Climatology Of Synoptical Disturbance Over Tropical Northwestern Pacific During Summer.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Cheng, Chu-Chai

PDF Url : ADA294767

Report Date : MAR 1995

Pagination or Media Count : 160

Abstract : 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. (MM)

Descriptors :   *OCEAN WAVES, *TROPICAL REGIONS, *CLIMATOLOGY, *CYCLONES, OCEAN CURRENTS, WIND, THESES, SEASONAL VARIATIONS, WAVE PROPAGATION, AIR WATER INTERACTIONS, AMPLITUDE, TRAVELING WAVES, SUMMER, NORTH PACIFIC OCEAN, TROPICAL CYCLONES.

Subject Categories : Meteorology
      Physical and Dynamic Oceanography

Distribution Statement : APPROVED FOR PUBLIC RELEASE