Vertical%20Structure%20And%20Processes%20Revealed%20With%20Recent%20Satellite%20Data

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Vertical Structure And Processes Revealed With
Recent Satellite Data
Duane E. Waliser1, Baijun Tian12, and Xianan
Jiang12   1Jet Propulsion Laboratory, California
Institute of Technology, Pasadena, CA 2 Joint
Institute for Regional Earth System Science and
Engineering, University of California, Los
Angeles, CA
BIRS, 2009
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Motivation

• The MJO is the dominant form of intraseasonal
  variability in the Tropics, with impacts a wide
  range of phenomena.
• Our weather climate models have a relatively
  poor representation
• Aspects of Vertical Structure which may be
  important to initiation/maintenance have been
  difficult to evaluate via observations.
• Space-based observations now make it possible to
  examine aspects of vertical structure of the MJO
  hydrological cycle.

Figures E. Maloney, PMEL/TAO, M. Wheeler, J.
Lin, D. Waliser
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Question?
Using space-based observations, what can be said
about the hydrological cycle of the MJO?
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Hydrological Data

• CMAP Rainfall
• global, 2.5x2.5 lat-long, pentad,
  01/01/1979-02/22/2007. Xie and Arkin (1997)
• TRMM 3B42 Rainfall
• 40S-40N, 0.25 x 0.25, 3-hourly,
  01/01/1998-06/30/2007. Huffman et al. (2007)
• AIRS H2OVapMMR TotH2OVap
• V4, L3, global, 1.0 x 1.0, 2Xdaily,
  09/01/2002-04/30/2007. Chahine et al. (2006)
• QuikSCAT TMI Moisture Transport
• 40S-40N, 0.25 x 0.25, 2Xdaily,
  08/1999-12/31/2005. Liu and Tang (2005)
• OAFlux Evaporation
• 65S-65N, 1.0 x 1.0, daily,
  01/01/1981-12/31/2002. Yu and Weller (2007)
• SSMI Total Column H2O Vapor Total Cloud
  Liquid H2O
• V6, DMSP F13, global, 0.25 x 0.25,
  2Xdaily, 01/01/1996-06/30/2007.
• Wentz (1997), Wentz and Spencer (1998)
• MLS Ice Water Content
• 80S-80N, 4 x 8 lat-long, 2Xdaily,
  08/26/2004-02/22/2007. Wu et al. (2006)

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Spatial-temporal Pattern of the 1st EEOF Mode of
Rainfall Anomaly
MJO Event Selection
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MJO Events in Hydrological Time Series
Principal Component Time Series of 1st EEOF Mode
of Rainfall Anomaly
TRMM 18 CMAP 57 AIRS11 QuikSCATTMI 13
OAFlux 44 SSMI 23 MLS 5
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Rainfall Pattern Data Sensitivity
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Rainfall Moisture Convergence
Rainfall and Total Column Moisture Convergence
tend to be Correlated throughout Tropics - except
maybe over S. America
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Rainfall Surface Evaporation
Near-equatorial Evap anomalies tend to lag
precipitation anomalies
Largest Evap anomalies in the subtropics in
association with Rossby grye modulations of
tradewind regimes
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Composite Hydrological Cycle
Vertical Structure
Water Vapor
Cloud Ice
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MJO Hydrological Cycle - Troposphere
Upper Troposphere - See Other Diagram
-0.5 mg/m3
0.5 mg/m3
300 hPa
0.03 mm
-0.03 mm
-0.1 gm/kg
0.1 gm/kg
2 mm
-2 mm
600 hPa
-3 mm/day
3 mm/day
0.3 gm/kg
-0.3 gm/kg
900 hPa
-0.2 mm/day
0.2 mm/day
-3 mm/day
3 mm/day
Surface
45 days
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MJO Hydrological Cycle - UTLS
0.01 ppmv
100 hPa
0.01 ppmv
0.1 mg/m3
-0.1 mg/m3
-0.5 K
0.5 K
150 hPa
0.5 K
1 ppmv
1 ppmv
1 mg/m3
-1 mg/m3
250 hPa
100 ppmv
100 ppmv
Lower-Middle Troposphere - See Other Diagram
3 mm/day
-3 mm/day
Surface
45 days
Schwartz, M. J., D. E. Waliser, B. Tian, J. F.
Li, D. L. Wu, J. H. Jiang, and W. G. Read, 2008
MJO in EOS MLS cloud ice and water vapor. GRL.
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Total-column Moisture Budget
Moisture Convergence due to large-scale moisture
transport
Total column Moisture change Moistening
(gt0) Drying (lt0)
Surface Evaporation
Surface Rainfall
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Summary I

• Satellite Observations are now able to provide an
  estimate of the chief components of the
  Hydrological Cycle Associated with the MJO, in
  some cases with vertical structure information.
• However, calcululations of the Residual Term of
  the column-integrated values indicates closing
  the budget with current generation of satellite
  retrievals is difficult.
• Within the levels of uncertainty, Future plans
  involve applying the observed Hydrological Cycle
  of the MJO as a means to diagnose, evaluate and
  validate GCM simulations of the MJO or Evaluate
  Theoretical considerations.

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Question?
What Physical or Dynamical Mechanism is
Responsible for the Lower-tropospheric Moisture
Preconditioning of the MJO?
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Summary II

• significant moisture anomalies are located in
  the lower troposphere with maxima around 700 hPa
  during the transition phase total-column and
  lower-tropospheric moisture change anomalies are
  positively correlated.
• moisture change anomalies are positively
  correlated with moisture convergence anomalies
  but negatively correlated with rainfall and
  surface evaporation anomalies.
• moisture change anomaly is highly positively
  correlated with the difference between moisture
  convergence and rainfall anomalies.
• implication lower-tropospheric moisture
  preconditioning of the MJO is due to the small
  difference between moisture convergence and
  rainfall anomalies instead of surface evaporation
  anomaly.

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Question?
What types of clouds and cloud processes play a
role in the moist pre-conditioning? Considered
w.r.t. to boreal summer.
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Dataset

• Cloudsat (Jun Sep 2006, 2007)
• Horizontal resolution 1x1 degs
• Variables
• Cloud liquid water content (LWC)
• Ice water content (IWC)
• Cloud types
• High Cirrus
• Middle Altocumulus (Ac), Altostratus (As)
• Low Stratocumulus (Sc), Stratus (St),
  Nimbostratus (Ns)
• Vertical Cumulus (Cu)
• GPCP rainfall (1997-2007)
• horizontal resolution 1x1 deg., 20-70-day
  band-pass filtered

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Hovmöller diagram of GPCP precipitation
(20-70-day filtered 75-95oE)
2006
2007
(mm/day)
2006
2007







Time series of EEOF1 of 1-D 20-70d filtered GPCP
rainfall (5oS25oN, averaged over 75-95oE sector)
for MJJAS, 1996-2007. The EEOF12 basically
captures northward propagation of the BSISO.
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Composite BSISV Evolution (7 events)
-10day
GPCP rainfall
-5
0
Time-latitude evolution (75-85oE)
5
10
(mm/day)
15
20
(mm/day)
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Composite Cloud LWC (85-95oE average) (no
time-filtering, seasonal mean removed)
-5d
10d
hPa
Cloud LWC
(mm/day)
rainfall
15d
0d

• Vertical Tilting in LWC
• Low-level LWC leading
• the convection center

5d
20d
(mg/m3)
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-5d
10d
Composite Cloud IWC (mg/m3) (85-95oE)
hPa
15d
0d

• IWC generally in phase with convection

5d
20d
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Total Non-precip Conditions
Total Precipitating Conditions
LWC by Cloud Types

• LWC variation associated with BSISV mainly
  related to non-precipitating and drizzling
  mid-low clouds
• Altocumulus cloud are crucial for mid-level LWC
  variation
• Stratocumulus cloud important in the low-level
  with contribution from cumulus.

AC
AC
ScCu
Sc
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CloudSat Application MJO/ISVdriven Monsoon
Onset Breaks
80-90 E Bay of Bengal
Convective Center
Convective Center
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Summary III

• During the northward propagation of the BS MJO,
  the cloud ice water content (IWC) in upper
  troposphere tends to be in phase with convection.
  
• A marked vertical tilting is discerned in cloud
  liquid water content (LWC) with respect to the
  convection center. Increased LWC leads the
  convection, particularly in the lower
  troposphere.
• IWC variability is largely associated with deep
  convective clouds while LWC is mainly linked to
  non-precipitating Altocumulus at mid-level and
  drizzling Stratocumulus cloud at low-level with
  the latter two appearing to play a role in
  pre-conditioning for the northward propagation.

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Afternoon Constellation Instrument Footprints
(Source M. Schoeberl, 2003)
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YOTC A-Train Data Co-Location Possibilities for
Studying Modeling Cloud/Convection
MLS
CERES
UTLS T(p), q(p), qi(p), CO (p), O3(p), HNO3(p)
TOA and SFC radiative fluxes
P (hpa)
CALIPSO
Aerosol (p) Cloud (p)
t lt 3
qi(p)
AIRS q(p) T(p)
CloudSat
qi(p) IWP ql(p) LWP Cloud Type (p) Particle
Size (p) Light Precip
MODIS
ECMWF w(p) u(p) du/dp(p) divH(p)
Aerosol Opt Depth Cloud Top - Temperature
Pressure, Particle Size, etc
ql(p)
AMSR Precipitation SST Prec Water LWP Surf. Wind
Speed
Light Precip