Understanding Atmospheric Heating in the GPM Era Robert Houze University of Washington 6 th GPM...
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Transcript of Understanding Atmospheric Heating in the GPM Era Robert Houze University of Washington 6 th GPM...
Understanding Atmospheric Heating in the GPM Era
Robert HouzeUniversity of Washington
6th GPM International Planning Workshop, 6-8 November 2006, Annapolis, Maryland, USA
Heating algorithms are expected to be an important product of GPM
Relationship of Cloud Water Relationship of Cloud Water Budgets to Heating Profile Budgets to Heating Profile
CalculationsCalculations
Austin and Houze 1973Houze et al. 1980Houze 1982, 1989
Takayabu 2002Shige et al. 2006
Relationship of Cloud Water Relationship of Cloud Water Budgets to Heating Profile Budgets to Heating Profile
CalculationsCalculations
Austin and Houze 1973Houze et al. 1980Houze 1982, 1989
Takayabu 2002Shige et al. 2006
Latent heating only
Total heating
Houze 1982
PREMISEPREMISE
Can also relate eddy & radiative heating profiles to water budget to obtain
Total Heating = Latent + Eddy + Radiative
Houze 1982
PREMISEPREMISE
Can also relate eddy & radiative heating profiles to water budget to obtain
Total Heating = Latent + Eddy + Radiative
Tropical MCSs inject lots of hydrometeors into upper troposphereTropical MCSs inject lots of hydrometeors into upper troposphere
Idealized life cycle of tropical MCS as proposed by Houze 1982
Conv. LH Strat. LH
Rad.Conv. Eddy Strat. Eddy
Contributions to Total Heating by Convective Cloud System Contributions to Total Heating by Convective Cloud System
Details from Houze 1982
TOTAL HEATING
These combine to give “top-heavy” heating profile These combine to give “top-heavy” heating profile
Houze 1982 idealized case
“Top Heavy” profile.
Includes latent, eddy, and radiative heating.
Think of the following schematic as a composite of the water budget of an MCS over its whole life cycle
Think of the following schematic as a composite of the water budget of an MCS over its whole life cycle
After Houze et al. (1980)
AcAs
As
Csu+CT =Rs + Esd + As
Rs=εs Csu +CT( )
Esd =a Csu +CT( )
As =b Csu +CT( )
where
εs + a+b=1
Stratiform water budget equation
As
Ac
Rain not simply related to condensation
AsAs
Ac
Rs=εs Csu +CT( )
Esd =a Csu +CT( )
As =b Csu +CT( )
where
εs + a+b=1±error
Water budget parameters: As , Rs , Csu, CT
Need to be determined empirically Field projects, CloudSat,…
AsAs
Ac
Ccu=Rc + Ecd + Ac +CT
Convective region water budget equation
AsAs
Ac
R = Rcii∑
Ccu = Ccuii∑
Ecd = Ecdii∑
CT = CTii∑
Ac = Acii∑
Rci=ε iCci
Esdi =α iCci
Aci =βiCci
CTi =ηiCci
ε i +α i + βi +ηi =1
Sum over all cloud height categories i
For each height category i
with the constraint
(each height cat.)
AsAs
Ac
Dimensions and hydrometeor content of anvils are determined by the cloud dynamics and are related to the
radiative heating profiles
These also need to be determined empirically
XAC
ZAC
Using empirically derived values of the water
budget parameters b and εs, the stratiform
regions’ anvil mass is proportional to the stratiform rain
As =(bRs)/εs
200 hPa streamfunction response to CRF assumed proportional to TRMM rain by Schumacher et al. (2004)
400 hPaK/day
SummarySummary
•Profiles of latent heating estimated by spectral methods are not independent of eddy and radiative heating profiles.
•Latent, eddy and radiative heating are interrelated through the water budget of the precipitating cloud system.
•Cloud water budget provides a means to establish the internal consistency of latent and radiative heating profiles and hence allows us to link radiative and eddy heating to latent heating
•Global patterns of heating estimated from GPM data can be extended to include radiative and eddy heating.
•Water budget parameters will need to be determined empirically in field studies aimed at understanding the anvil cirrus generation, and/or in conjunction with CloudSat .
•Profiles of latent heating estimated by spectral methods are not independent of eddy and radiative heating profiles.
•Latent, eddy and radiative heating are interrelated through the water budget of the precipitating cloud system.
•Cloud water budget provides a means to establish the internal consistency of latent and radiative heating profiles and hence allows us to link radiative and eddy heating to latent heating
•Global patterns of heating estimated from GPM data can be extended to include radiative and eddy heating.
•Water budget parameters will need to be determined empirically in field studies aimed at understanding the anvil cirrus generation, and/or in conjunction with CloudSat .
Final ThoughtFinal Thought
•Too ambitious?
•Think 15 years from now!
•Too ambitious?
•Think 15 years from now!
Thank you!
Extra Slides:
13˚S
11˚S
12˚S
130˚E 132˚E131˚E
60534639322518114
dBZ
20 January 2006 0000UTC
6 km
13˚S
11˚S
12˚S
130˚E 132˚E131˚E
60534639322518114
dBZ
20 January 2006 0900UTC
6 km
13˚S
11˚S
12˚S
130˚E 132˚E131˚E
60
53
46
39
32
25
18
11
4
dBZ20 January 2006 1800UTC
6 km
Example from TWP-ICE
dBZ20
220019Jan06
000020Jan06
020020Jan06
040020Jan06
060020Jan06
080020Jan06
100020Jan06
120020Jan06
140020Jan06
160020Jan06
180020Jan06
200020Jan06
28
21
14
7
0
-7
-14
-21
-28
ATTENUATED
Hei
gh
t (k
m)
4
8
12
16
0
Cloud Radar
Precipitation Radar
TWP-ICE Precipitation
Radar Rain Rate(~20 % stratiform)
TWP-ICE Cloud Radar Anvil Frequency
Longer-term records of the water budget parameters also are being derived.
Figures here are for duration of TWP-ICE.
This will also be done for a longer-term climatology.
We will use cloud & precipitation radars permanently located at Darwin.
AsAs
Ac
Rs=εs Csu +CT( )
Esd =a Csu +CT( )
As =b Csu +CT( )
where
εs + a+b=1±error
Cloud radar As
Precip radar Rs
Doppler & soundings As, Csu, CT
Water budget parameters empirical
Field projects, CloudSat,…