Thursday, 17 January 2002: 11:15 AM
Observations of Atlantic Convergence Zones by QuikSCAT and TRMM
Applying observations from spaceborne microwave scatterometers and radiometers,
seasonal and interannual
variations associated with Atlantic convergence zones are investigated. The
spacebased measurements include surface wind vectors, sea surface temperature
(SST), integrated water vapor, cloud liquid water, and precipitation rate.
With the advantage of high spatial and temporal resolution of data, we reveal
the existence of a second convergence zone
in the southern Atlantic ocean during austral winter, which is the counterpart
of the northern Atlantic ITCZ.
This secondary convergence zone extends from the eastern tip of Amazon at about 7S
to the middle of Atlantic ocean, with coherent structure of SST, surface wind
divergence, rainfall, and sea level change. The preferred timing of this
convergence zone is consistent with the
seasonal march of the equatorial cold tongue. Relationship between the Amazon rainfall
and the Atlantic convergence zones, as well as the remote link to the tropical
Pacific on interannual time scale, will be discussed.
Supplementary URL: