Megha Tropiques

(GP Retrieval and Applications plan)

Vijay K. Agarwal, MOG/SAC

Oct. 17-20, 2005

MT- Utilization Plan: Themes• Geo-Physical Retrievals and validations• Synergy of data from different sources & value addition• Scientific Studies

– Convective systems

– Cloud-Radiation interaction

– Data assimilation in models

– Air-sea interaction

• Applications on semi-operational level– Synoptic studies– Near real time applications in weather forecast– Ocean state forecast– Land applications

Geo-physical Retrieval Components

• MADRAS – Simulation studies using Radiative Transfer– Basic algorithms for retrieval of rainfall and other GPP– Validation experiments using TRMM

• SAPHIR– Simulations using RT– Experiments with AMSR, ATOVS data

• ScaRAB– Experiments with ERBE data– Experiments with NOAA derived radiative fluxes

MADRAS Retrievals• RT simulations continued using a data base from

TRMM and PR for more than three years on optimum spatial and temporal scales.

• First version of rainfall using integrated Scattering Index (SI) and Polarization Corrected Temperature (PCT) methods in final stages of testing using DWR observations.

• Work has been initiated for blending Geo-St. IR and polar orbiting MW observations from INSAT & TRMM.

• Algorithm for inversion of MT measurements for WV and other geo-physical parameters based on Bayesian approach

COMPARISON OF RAINFALL FROM NASA, PR & PRESENT ALGORITHMS

NASA TMI RAINRATE NASA PR RAINRATE

TMI RAINRATE (PRESENT ALGORITHM)

OCTOBER 10, 2002

VALIDATIONS: TRMM VS. DWR RAINFALL

0 10 20 30 40 50 60D WR R ain R ate (m m / h)

0

10

20

30

40

50

60

TM

I R

ain

Rat

e (m

m/h

)

C om parison of T M I and D WR rain rates (17 O ctober 2002)R (TM I) = 0 .68 R (DWR) - 3 .83N o. of P ts.= 460r=0.80bias= -7 .99 m m / hrm s diff=10.12 m m / hrm s after bias rem oval=6.31 m m / h

OCTOBER 17, 2002

NASA-GPR OF RAINFALL PRODUCT

TMI DERIVED GEOPHYSICAL PARAMETERS) OVER LAND (03/06/2003-15GMT)

SAPHIR: Humidity profile

• Emission based RT simulations using simulated atmospheres

• Retrievals using Statistical & EOF techniques

• Improvement in lower level humidity profile through total water vapour content

• Impact of viewing geometry & surface contamination on retrievals

•At nadir view with dry atmosphere, the low freq channels are contaminated by surface contributions

•At oblique view with moist atmosphere, the low freq channels are less sensitive to boundary layer humidity which contributes the most to many meteorological & oceanographic processes

SAPHIR CHANNELS’ RESPONSE (NADIR VIEW)

At nadir view with dry atmosphere, the low freq channels are contaminated by surface contributions

Dry Atmosphere Moist Atmosphere

SAPHIR CHANNELS’ RESPONSE (OBLIQUE VIEW)

At oblique view with moist atmosphere, the low freq channels are less sensitive to boundary layer humidity which contributes the most to many meteorological & oceanographic processes

Moist AtmosphereDry Atmosphere

ATMOSPHERIC HUMIDITY PROFILE FROM AMSU-B DATA

}{ .exp1

,,0 i

Ni

i

pipp TBLARH AA

RETRIEVAL MODEL FOR LAYER AVERAGED RELATIVE HUMIDITY

Date: 9 June, 2002: 0711 GMT

Utilization for science studies

• Atmospheric Studies – Assimilation in GCM & RCM

– Cloud radiative forcing studies

– Studies of severe convective system

• Oceanographic Studies– Impact of Soil moisture & vegetation cover on Asian Monsoon

region

– Inter-annual variability of Asian Monsoon

– Study of Indian Ocean Dipole

• Climate studies– Impact of Indonesian Through Flow over thermodynamics of Indian

Ocean– Impact of land-surface observations on regional climate

Atmospheric studies

Data Assimilation in Atmospheric Models

NCEP Analysis

Assimilation of MSMR-derived soil moisture in ERMP model

(July 2001)

Control Run SM assimilation

Rainrate (mm/day)

Assimilation of scatterometer winds in MM5

(PSLV-C3 Launch October 2001)

Control

Quikscat

Analysis

CMV & Q-Scat winds in GCM & MM5

Rainfall in GCM

Soil moisture in GCM

(Singh et al)

-25 -20 -15 -10 -5 0 5

-80

-60

-40

-20

0

20Y = -5.95 +1.8 X

R = 0.48

NCRF

Velocity (ms-1)

0

30

60

90

120

150

180Y = 51.3 - 1.2 X

R = -0.37

LCRF

Clo

ud R

adia

tive

Forc

ing

(Wm

-2)

-180

-150

-120

-90

-60

-30

0Y = -56.6 + 3.03 X

R = 0.56

SCRF

SCRF Vs Wind

LCRF Vs Wind

NCRF Vs Wind

Association between Jet speed and Cloud Radiative Forcing

For a 10 m/s increase in the speed of jet

SCRF increases by 30Wm-2

LCRF increases by 12 Wm-2

NCRF increases by18 Wm-2

Oceanographic studies

Studies of IO, El-Nino

Fresh water flux

Radiative & heat fluxes

Data Assimilation in Ocean Models

• Ocean state using SACMOM

• Monsoon variability using AGCM

•Cyclone simulations using MM5

•Coupled ocean-atmosphere models

SST ANOMALY SEP-DEC 1997

Relative performance of the model using the two wind products

From 1997 till 1999 The model is forcedwith NCEP and then till 2004 with scatterometer winds

Buoy

Model

SST

D20 Isotherm

Errors in SW Fluxes: NCEP (61 watts/m2 ),

LY (37 watts/m2 ) and OLR-based (45 watts/m2)

Wa

tts/

m2

LY

OLR

NCEP

Time Variation of SW Radiation in central Bay of Bengal

Experiment 2: Impact of Shortwave Radiation on model simulations

Climatic studies

Impact of land usage

Model Simulated Rainfall (cm) For July 1998

TRMM Observed Rainfall (cm)Model Simulated Rainfall (cm) For July 1998

TRMM Observed Rainfall (cm)

Applications Demonstration

• Synoptic studies– Weather forecast– cyclone studies

• Ocean State Forecast• Land applications

– Applications in agro-meteorology– Variation of land surface emissivities

Cyclone studies (Disaster Management System)

• Cyclone track & storm surge prediction

•Tsunami generation & propagation

•Coastal inundation

-40 -30 -20 -10 0 10 20 30 40 50 60Predicted 24-H In tensity C hange ( K t)

-40

-30

-20

-10

0

10

20

30

40

50

60

Obs

erve

d 24

-H In

tens

ity C

hang

e (

Kt)

T ra in ing ( N = 180 )

Validation ( N = 49 )

Cyclone Intensity Change prediction: Genetic approach

5

10

15

20

25

30

75 80 85 90 95 100

Longitude

Latit

ude

Observed Track BOG3 NBOG

27

28

30

29

27,27

2828

29

29

3030

PredictorsPattern-Based

PredictorsPattern-Based

Minimum PCT in inner coreAverage PCT in inner coreAverage 10V BT inner coreAverage 10V BT in outer core

Convective SHEAR ( angular shift b/w high density region of high BT(37H) and that of low PCT in 85 GHz image.

BT (37-H)

PCT

OCEAN WAVE FORECASTComponents are:

• Ocean waves• Ocean surface winds• Sea Surface temperature• Ocean currents• Ocean Eddies• Mixed Layer depth• Ocean heat content and• Lower level currents

Applications:

• Optimal Ship routing• Design of off-shore structures• Ocean disaster management (e.g. Tsunami run-off, storm

surge distribution etc.)

Tsunami Propagation (26 Dec)

24 Hr Wave F/c for Coasts

Uses Satellite & Buoys data, and

Ocean numerical models

Animation of SSH for 1997-98