NASA Technical Reports Server (NTRS) 20170000997: Evaluation of Cloud Microphysical Schemes in a Simulated Warm Frontal Snow-Band During the GPM Cold Season Precipitation Experiment (GCPEx)

9.6 MB·English

by  NASA Technical Reports Server (NTRS)

A
THE UNIVERSITY OF
ALABAMA IN HUNTSVILLE
Motivation
• Increasing evidence that bulk microphysical schemes in mesoscale
models underpredict riming within winter storms.
:tor--------..,.----.----------,.------,--------,.----,
~ a)
8 MRR
7
Simulations of nine
winter storms over
Long Island, NY
highlighted
;:10
gl b) underprediction of
s
1 MDR~
7
61
;1.: ~ snow fallspeeds
~ ~ ~
=·~ 4 ~=
during moderate
riming conditions as
~ ~ ~ ~ ~ ~ ~ ~ ~ compared to MRR
Fi,...,.quoncy (%1
measurements
d)' . )
THOM2 SBU-YUN
Molthan et al. (2016)
.5 .o .5 ~-o
M.,. .n Reflectivity-Weighted f'Z>II' Speed (rn s-•)
Frequen.~y (% • . r>eq ueno::y (%)
Some Questions
• What processes led to the rapid intensification and
microphysical changes of the warm frontal precipitation
band (Colle et al. 2016)?
• How well can current, more advanced BMPs (i.e, P3,
Goddard 41CE, SBU, and Morrison) predict the warm
frontal band development and riming intensity for this
event?
• How do cloud microphysical processes modify the
environmental conditions and the subsequent warm
frontal band development?
Warm Frontal Band During GCPEx
18 February 2012: King City Radar Animation 1200 UTC NWS Surface Analysis
··-···-······-··---·········-·······················-.. , ................................... .
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···. .
s.o 10.0
....... \Iii;-
Weather Research and Forecasting Simulations
NASA-Unified-WRF configuration 520N
IC and 6-h RUC Analyses sooN
Boundary starting 1800 UTC 17
Fe~oN
Conditions (30-h run)
46°N
Vertical
44°N
Resolution 50 Levels
PBL Physics Mellor-Yamada-Janjic ooN
4
Cloud P3 scheme for CTL run oN
38
microphysics (Morrison et al. (20 15)
qfloN
~~~~~~~~~~~~~====~
Short- and
Longwave
Radiation RRTMG :
~
.. . ..-·;· ... -- .... .. . . .. ---.. ..... :Kihg'City·Ra.'r ...... ..... ..
Horizonal
:(WKR)
1 km.S"N · ··
Resolution 9km 3km ·~
Detroit, Ml
Cumulus Grell Turned Turned~-~ ';rx). . .... -:· ............ · · .. · · · , ... ·. ---,· ........: . ..... · + --
scheme Freitas off ofLz.s·N . .. ---- . . · - . -- ..
-~- -~- ~~b~;AYI!"
--------------------------------------------------------------
1100 UTC- Mature
OBS
WRF Microphysical Schemes
Scheme I Acronym Moments Notes Selected References
Single ice-phase category evolves freely
Predicted Particle Monison et al. (2015a)
2 in time and space; lookup table for N os, As
Properties I P3 Morrison et al. (2015b)
based on mass and number concentration
Exphcit prediction of' number
Morrison I MORR 2 Morrison et al. (2009)
concentration and mass for each species
Snow tnapping routine for N "'lT,qJ and
Goddard 4ICE I 4ICE 1 Lang et al. (2014)
N og(T,qg)
N os(T) by Houze et al. (1979); M-D and
Lin and Colle (2011)
Stony Brook I SBU 1 V-D functions of diagnosed riming factor
Lin et al. (2011)
Ri, T
Scheme 1-ls Ps (kg m-3)
rr
lookup
P3 predicted -6 Ps 3
table
rr
MORR fCMos, As) 0 100 I 400 2 11.72 I 19.3 0.41 I 0.37
- Ps
6
151.01 I
50 I 300, rr 0.24 I 0.36,
4ICE .f(T, qs) 0 3 330.22,
500 -6 Ps 544.83 0.54
SBU .f(T) 0 .f(D) .f(T, R ;) .f(T, R;) .f(T, Ri) .f(T, Ri)
P::i Cl\IL llr
0 MORR
Reflectivity
Obs vs WRF at
1130 UTC
79~w
20120218 1154
4S'N SSM IS
150 GHz
Satellite
Simulator
44"N
Comparisons
with WRF
Micro at 1130
UTC
Ice Water Content
Intercept Paramete
~.0-·· oJ.V 41CE
+- :\irr:
4.8 - 4ICI
--r: -
!
I -
1.0~
3.5
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:J: :zs
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::c 2.0
LS
1.0~
0.5
()_{)
'10.:0 "10 19~w
Hydrometeor Mu.ss Content (g m··~) ~.-,. tmm, m .i)
20120218 1154
SSMIS
4j'N
150 G Hz
Satellite 44.5'N
...........
Simulator
Comparisons
with WRF
Micro at 1130
.. ···· .........' ...... ... .
UTC
s1·:w
Ice Water Content
Intercept Parameter
~.0-·· !J.O
1- :\in:
4.~ --r.: - - 41Cl
..!, I - - MOl 21S ·>··· ..... ..... : ....... .
1.0: - PJ ... .'
- snu ;no
3.5
f
:E L.S:
·lr; l .
:I: 2.0
1.0:
....·· ·A······· ···
.. Ct. ..
O.!J
().{) s1·:w
1o·- to 10' '] 0~
Hydrometeor Muss Content (g m··'..)