The annual cycle in equatorial convection and sea surface temperature

Journal Article · Thu Oct 01 00:00:00 EDT 1992 · Journal of Climate; (United States)

DOI:https://doi.org/10.1175/1520-0442(1992)005<1140:TACIEC>2.0.CO;2· OSTI ID:6895755

Mitchell, T P; Wallace, J M ^[1]

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1. Washington Univ., Seattle (United States) NASA, Goddard Space Flight Center, Greenbelt, MD (United States)

The coupled atmosphere-ocean system in the equatorial eastern Pacific and Atlantic exhibits a distinct annual cycle that is reflected in contrasting conditions at the times of the two equinoxes. The contrasts are so strong that they dominate the annual march of zonally averaged outgoing long wave radiation for the equatorial belt. The March equinox corresponds to the warm season when the equatorial cold tongues in the eastern Pacific and Atlantic area absent. With the onset of summer monsoon convection over Colombia, Central America, and West Africa in May-June, northward surface winds strengthen over the eastern Pacific and Atlantic, the equatorial cold tongues reappear, and the marine convection shifts from the equatorial belt to the intertropical convergence zones (ITCZs) along 8 deg N. On the basis of observational evidence concerning the timing and year-to-year regularity of the surface wind changes during the development of the cold tongues, it is argued that (1) the increase in the northward surface winds in response to the onset of the northern summer monsoon may be instrumental in reestablishing the cold tongues, and (2) positive feedbacks involving both the zonal and meridional wind components contribute to the remarkable robustness of the cold tongue-ITCZs complexes in both oceans. 36 refs.

• OSTI ID: 6895755
• Journal Information: Journal of Climate; (United States), Vol. 5:10; ISSN 0894-8755
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AMBIENT TEMPERATURE
ANNUAL VARIATIONS
SURFACE WATERS
AIR-WATER INTERACTIONS
CLOUDS
CONVECTION
EARTH ATMOSPHERE
EQUATOR
LONG WAVE RADIATION
MONSOONS
TEMPERATURE DISTRIBUTION
DISASTERS
ELECTROMAGNETIC RADIATION
ENERGY TRANSFER
HEAT TRANSFER
MASS TRANSFER
RADIATIONS
RADIOWAVE RADIATION
STORMS
VARIATIONS
540120* - Environment
Atmospheric- Chemicals Monitoring &amp; Transport- (1990-)
540110