Satellite technology represents the only technique for measuring sea surface
temperatures (SSTs) on a global scale. SSTs are important as boundary conditions for
climate and atmospheric boundary layer models which attempt to describe phenomena
of all scales, ranging from local forecasts to predictions of global warming.
Historical use of infrared satellite measurements for SST determination has been
based on a theory which assumes that the atmosphere is 'thin', i.e., that atmospheric
absorption of infrared radiation emitted from the sea surface has very little effect on
the radiant intensity that is measured by satellites. However, a variety of independent
radiative transfer models point to the possibility that the so-called 'thin approximation'
is violated for humid atmospheres such as those found in the tropics, leading to errors
in the retrieved SST that would be unacceptable to those who make use of such
products. Furthermore, such tropical regions represent a significant portion of the
globe, where coupled ocean-atmosphere disturbances can have global effects (e.g., the
tropical Pacific El Nino-Southern Oscillation events).
This study evaluates the thin approximation empirically, by combining radiative
transfer theory and satellite data from the Eastern Atlantic ocean region studied during
the Atlantic Statocumulus Transition Experiment (ASTEX). Six months of satellite data
from May, June, and July of 1983 and 1984 are analyzed. To the degree that the data
may be considered representative of globally valid relationships between measured
variables, it is shown that the thin approximation is not appropriate for the tropics.
This suggests that new methods are necessary for retrieving SSTs from the more
humid regions of the globe. / Graduation date: 1993
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28780 |
| Date | 09 February 1993 |
| Creators | Kowalski, Andrew S. |
| Contributors | Coakley, James A. Jr |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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