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Titel |
Radar-radiometer retrievals of cloud number concentration and dispersion parameter in nondrizzling marine stratocumulus |
VerfasserIn |
J. Rémillard, P. Kollias, W. Szyrmer |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1867-1381
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Measurement Techniques ; 6, no. 7 ; Nr. 6, no. 7 (2013-07-30), S.1817-1828 |
Datensatznummer |
250017929
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Publikation (Nr.) |
copernicus.org/amt-6-1817-2013.pdf |
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Zusammenfassung |
The retrieval of cloud microphysical properties from remote sensors
is challenging. In the past, ground-based radar-radiometer
measurements have been successfully used to retrieve the liquid
water content profile in nondrizzling clouds but offer little
constraint in retrieving other moments of the cloud particle size
distribution (PSD). Here, a microphysical condensational model under
steady-state supersaturation conditions is utilized to provide
additional constraints to the well-established radar-radiometer
retrieval techniques. The coupling of the model with the
observations allows the retrieval of the three parameters of
a lognormal PSD, with two of them being height dependent. Two
periods of stratocumulus from the Azores are used to evaluate the
novel technique. The results appear reasonable in two nondrizzling periods: continental-like
number concentrations are retrieved, in agreement with the
drizzle-free cloud conditions. The cloud optical depth derived from
the retrieved distributions compares well in magnitude and
variability with the one derived independently from a narrow field
of view zenith radiometer. Uncertainties coming from the
measurements are propagated to the retrieved quantities to estimate
their errors. In general, errors smaller than 20% should be
attainable for most parameters, demonstrating the added value of the
new technique. |
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