validation and verification of fnmoc cloud and precipitation ...

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3 Νοε 2013 (πριν από 3 χρόνια και 9 μήνες)

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VALIDATION AND VERIFICATION OF FNMOC CLOUD AND PRECIPITATION
PRODUCTS FROM A NEW SINGLE
-
MOMENT COAMPS™ MICROPHYSICAL SCHEME


ABSTRACT


*Roger A. Stocker
1

Jerome M. Schmidt
2

Joseph Turk
2

Jason E. Nachamkin
2


Fleet Numerical Meteorology and Oceanography Cent
er (FNMOC) is
currently involved in a project to partially automate the
generation of Ordinance Employment Field products. These
products provide the warfighter with information concerning
areas that will be favorable or unfavorable for deployment of
vario
us weapons. Among the key METOC considerations is the
horizontal and vertical distribution of clouds between the
release point and the target. The automation effort reported
here involves the use of forecast cloud fields from the Coupled
Ocean/Atmosphere M
esoscale Prediction System (COAMPS™) to
estimate the cloud distribution.


FNMOC is currently testing a new single
-
moment microphysics
scheme, developed by the Marine Meteorology Division of the
Naval Research Laboratory (NRL
-
MRY), from which to derive the

model cloud distribution. The current operational microphysics
scheme was developed in the early 1980s based on predictive
mixing ratio equations for five microphysical variables (vapor,
pristine ice, snow, rain, and cloud water). The new scheme
expands t
his set to include explicit predictive equations for
graupel and drizzle. These changes are expected to improve the
prediction of coastal stratus, orographic clouds, and convective
systems. Other modifications to the current scheme include a
more consisten
t way of handling supersaturation with respect to
ice or water (important to cloud production) and other
enhancements to the prediction of pristine ice.


The purpose of this work is to determine the impact of the new
microphysics scheme on the cloud and ra
infall rates produced by
the model. The impact is determined by statistical comparison
with satellite and
in situ

measurements, and with the current
operational scheme. All comparisons are based on a one
-
month
period of independent, triply nested, 30
-
hour
beta COAMPS
SOUTHWEST_ASIA forecasts using the same initial observations as
the corresponding operational forecasts.



1 FNMOC, 7 Grace Hopper Ave., Stop 1, Monterey CA 93943, Ph. 831
-
656
-
4353, email:
rog
er.stocker@fnmoc.navy.mil

2 NRL, 7 Grace Hopper Ave., Stop 2, Monterey CA 93943, Ph. 831
-
656
-
4721, emails:
scmidt@nrlmry.navy.mil
;
turk@nrlmry.navy.mil
; nachamkin@
nrlmry.navy.mil