Observed structure and propagation characteristics of tropical summertime synoptic scale disturbances

Journal Article · Sat Sep 01 04:00:00 EDT 1990 · Monthly Weather Review; (USA)

DOI:https://doi.org/10.1175/1520-0493(1990)118<1888:OSAPCO>2.0.CO;2· OSTI ID:6328614

Lau, K; Lau, N ^[1]

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1. Princeton Univ., NJ (USA) NOAA, Geophysical Fluid Dynamics Laboratory, Princeton, NJ (USA)

Twice daily global analyses for the 1980-1987 period are used here to study the three-dimensional structure and propagation characteristics of tropical synoptic scale transients during the northern summer. Regions of enhanced variability in relative vorticity at 850 mb are found in the western and eastern Pacific, Bay of Bengal, northern India, eastern Atlantic, and western Africa. Lag-correlation and regression analyses show strong teleconnectivity and temporal coherence over all of the active sites with enhanced vorticity variance, as well as over the western Atlantic/Caribbean and the Indochinese Peninsula. A substantial amount of the synoptic scale variability in the tropics is associated with propagating wavelike disturbances that remain coherent over several days and tend to travel west/northwestward. An extended empirical orthogonal function (EOF) technique is used to show that the leading EOF modes in the tropical zone within the 3- to 10-day band are these wavelike disturbances. 43 refs.

• OSTI ID: 6328614
• Journal Information: Monthly Weather Review; (USA), Journal Name: Monthly Weather Review; (USA) Vol. 118; ISSN MWREA; ISSN 0027-0644
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
ATMOSPHERIC CIRCULATION
CURRENTS
DISASTERS
DISTURBANCES
EARTH ATMOSPHERE
EDDY CURRENTS
ELECTRIC CURRENTS
FORECASTING
GLOBAL ASPECTS
MATHEMATICS
REGRESSION ANALYSIS
RESEARCH PROGRAMS
STATISTICS
STORMS
TROPICAL REGIONS
TROPOSPHERE
VARIATIONS
VORTICES
WIND