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| Titel |
Experiment of Rain Retrieval over Land Using Surface Emissivity Map Derived from TRMM TMI and JRA25 |
| VerfasserIn |
Fumie Furuzawa, Hirohiko Masunaga, Kenji Nakamura |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250034985
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| Zusammenfassung |
| We are developing a data-set of global land surface emissivity
calculated from TRMM TMI brightness temperature (TB) and atmospheric
profile data of Japanese 25-year Reanalysis Project (JRA-25) for the
region identified as no-rain by TRMM PR, assuming zero cloud liquid
water beyond 0-C level. For the evaluation, some characteristics of
global monthly emissivity maps, for example, dependency of emissivity
on each TMI frequency or each local time or seasonal/annual variation
are checked. Moreover, these data are classified based on JRA25 land
type or soilwetness and compared. Histogram of polarization difference
of emissivity is similar to that of TB and mostly reflects the
variability of land type or soil wetness, while histogram of vertical
emissivity show a small difference. Next, by interpolating this
instantaneous dataset with Gaussian function weighting, we derive an
emissivity over neighboring rainy region and assess the interpolated
emissivity by running radiative transfer model using PR rain profile
and comparing with observed TB. Preliminary rain retrieval from the
emissivities for some frequencies and TBs is evaluated based on PR
rain profile and TMI rain rate. Moreover, another method is tested to
estimate surface temperature from two emissivities, based on their
statistical relation for each land type. We will show the results for
vertical and horizontal emissivities of each frequency. |
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