simulaons+of+pmcs+during+the+aim …lasp.colorado.edu/media/meetings/2012/pmc-trends... · 2012. 5....
TRANSCRIPT
Simula'ons of PMCs during the AIM 'me period using WACCM/CARMA
C. Bardeen, R. Garcia, D. Marsh NCAR
C. Randall University of Colorado
M. Hervig GATS, Inc.
CAWSES-‐II May 4, 2012
Boulder, Colorado
Models • Whole Atmosphere Community Climate Model (WACCM)
– Garcia et al. [2007], Richter et al. [2010],Garcia et al. 2011 – Chemistry Climate Model
• Community Aerosol and Radia'on Model for Atmospheres (CARMA) – Turco et al. [1979], Toon et al. [1988], Jacobson et al. [1994], … – Sec'onal Microphysical Model
• WACCM/CARMA 3.1.9 – 4˚x5˚, 125 Levels – Free Running
• SD-‐WACCM/CARMA 4 – 1.9˚x2.5˚, 88 Levels – Nudged (1%) below 60 km to GEOS-‐5 Analysis
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WACCM/CARMA
PMC Model
Microphysical Model
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Meteor Dust/Smoke
5 Bardeen et al. [2008] Hervig et al. [2009]
PMCs, WACCM 3.1.9 SOFIE Summary, NH 2007
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SOFIE v1.01 WACCM/CARMA
Events 1432 1432
Clouds 1130 78.9% 959 66.9%
Zmax < 79 km 88 6.2% 0 0.00%
Units SOFIE WACCM Difference Height km 83.53 83.26 -0.27 km Base km 80.16 80.78 0.62 km Top km 87.01 87.69 0.68 km Thickness km 6.85 6.92 0.96% Column IWC ug m-2 36.65 30.32 -17.26% B(3.064) km-1 4.36E-05 4.54E-05 4.18% Re nm 35.68 42.43 18.91% Mass ng m-3 13.45 13.68 1.69% Number cm-3 406.68 75.95 -81.33% Water Vapor ppmv 4.35 4.90 12.53%
Summary
Seasonal Mean
Bardeen et al. [2010]
SOFIE: Temperature, Water, Ex'nc'on
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SOFIE: Cloud Proper'es
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CIPS Albedo
9
1x10
-6 s
r-1 T
hres
hold
7x
10-6
sr-1
Thr
esho
ld
Ice Mass
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CIPS, 2007 NH WACCM/CARMA
Adapted from Stevens et al. [2007]
Too Few High Number Events
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Temperature Variability
12 Rapp et al. [2002]
Model Improvements
• CARMA 3.0 – Beeer Numerics for Nuclea'on/Growth – (Op'onal) Integra'on with Radia've Transfer (RRTMG)
– Par'cle Hea'ng (Per LW/SW Band) – Ice in Radia've Transfer
– Ice/Dust Coagula'on • WACCM 4
– 1.9˚x2.5˚ Horizontal Resolu'on – Specified Dynamics – Physically based Gravity Wave Sources
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SOFIE: Temperature, Water, Ex'nc'on
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SOFIE: Cloud Proper'es
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SD-‐WACCM4/CARMA, Ice Mass Par'ally tuned
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CIPS SD-‐WACCM/CARMA
Days Since 01 Jan 2007
SD-‐WACCM4/CARMA 3.1.9 GWs, Needs Further Tuning
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CIPS SD-‐WACCM/CARMA
Days Since 01 Jan 2007
Gravity Wave Formula'on
• WACCM 3.1.9 – Orographic – Background
• Everywhere, All the 'me • Prescribed source strength (Day, La'tude) • Efficiency/Intermieency Factor
• WACCM 4 – Orographic – Convec'on – Frontogensis
• Only when threshold exceeded • Constant source strength
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Temperature, 70N
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Benefits of a Microphysical Model
• Physically Based • Sensi've to poten'al trends in
– Ice Nuclei (Meteor Smoke?) – Water – Temperature – Temperature Variability – Transport
• Constraints – Ice Mass (Horizontal & Ver'cal) -‐> Temperature -‐> Gravity Waves, Teleconnec'ons
– Dust Mass (Ver'cal) -‐> Meteoric Influx, Transport – Size Distribu'on links model to measurements
• Verify against AIM 'me period using SD-‐WACCM 20
Limita'ons of a Microphysical Model
• How well do we understand the processes? – Meteor Influx – Ice Nuclea'on – Coagula'on – Gravity Waves – Temperature – Temperature Variability
• Cost to run = ~3 x SD-‐WACCM • Specified Dynamics
– Limited Al'tude Range (e.g. GEOS-‐5, MERRA) • Mix of Free Running vs. Nudged
– Full Al'tude Range (e.g. NOGAPS) • Does simula'ng variability imply ability to simulate trends?
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Ques'ons?
SD-‐WACCM4/CARMA, Ice Mass Default Tuning, Cloud Height Low
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CIPS SD-‐WACCM/CARMA
Days Since 01 Jan 2007