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     ICRP Field Experiments G. S.
Bhat Centre for Atmospheric Oceanic
Sciences Indian Institute of Science Bangalore
Celebrating the Monsoon 24-28 July,
2007 Indian Institute of Science, Bangalore
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Outline

• Past Monsoon Experiments
• ICRP Indian Climate Research Programme
• ICRP Field Experiments
• Completed BOBMEX, ARMEX
• Planned - CTCZ

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Monsoon Experiments

• IIOE International Indian Ocean Expedition
  
• 1960 1965
• multinational,20 countries
• 40 ships, aircraft
  (drop-sonde), etc.
• 2. ISMEX - Indian Summer Monsoon Experiment
• 1973
• Indo-Soviet
• 6 research ships (4 USSR, 2
  Indian)
• Arabian Sea, the equatorial
  region
• and southern
  Indian Ocean
• 3. MONSOON-77
• 1977
• Indo-Soviet
• Monsoon Onset, depression, etc.
• 4. MONEX-79, Monsoon Experiment (FGGE)
• 1979 (summer MONEX)
• Multinational

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Leadership External Indians
Participated Many benefits to India a. New
institutes (e.g., NIO ?IIOE) b. Infrastructure
development c. Man power training d. Data
over the Indian region (ocean land) e.
Indias own measurements started (MONEX-79)
Impetus to developing national field programmes
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5. MONTBLEX- Monsoon Trough
BL Experiment 1990
Indian
Northern India, BoB 6. LASPEX Land Surface
Proc. Ex. 1997-98
Indian
North-Western India land
surface processes in a semi-arid
area 7. BOBMEX - Bay of Bengal Monsoon
Experiment 1999
Indian
Bay of Bengal 8. ARMEX - Arabian Sea Monsoon
Experiment 2002-2005
Indian
Arabian Sea West Coast of India 9. JASMINE
Joint Air-Sea Monsoon Interaction Expt.
1999 (pre to onset, end)
International
Equatorial IO Central BoB
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Post 1980 Expts. - Indian, except for
JASMINE (Conceived, planned executed
by Indian Sci.) BOBMEX, ARMEX ? ICRP

Next CTCZ - Continental Trough Convergence Zone
(2008 2010)
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ICRP - Genesis
Early 1990s - Indian Scientists (a) What we
know about Indian Monsoon? (b) What needs to be
understood? Action plan to address outstanding
problems utilizing limited national resources

Science Plan Indian Climate Research Programme
(DST 1996) ICRP Implementation Plan, DST1998
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(No Transcript)
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ICRP
Main Focus Understanding monsoon variability on
timescales ranging from sub-seasonal to inter
annual and decadal, and its impact on critical
national resources

• Observational
• Modeling
• Data Analysis

• Inter-Agency Multi-Institutional
• Department of Science Technology (Lead)
• Department of Ocean Development
• Department of Space
• India Meteorology Department(MoES)
• Ministry of Defence
• Research Institutes
• Universities

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maximum impact from the limited resources
available in the country, a road map for monsoon
research in the country for the coming decade
with well focused programmes

• Observational
• Modeling
• Data Analysis
• Field Experiments 2 Executed 1 planned
• Focus Indian Region

• Strategy in Field Expts.
• Science objectives
• Test the hypothesis or
• Find answers to a burning question

• 
  
• Implementation Plan - Used all available national
  resources

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ICRP Experiments
Bay of Bengal Monsoon Experiment (BOBMEX)
1998-1999 Arabian Sea
Monsoon Experiment (ARMEX)
Jun-Aug 2002, Mar - June 2003 , April-May 2005
1998
July 26, 2005 Mumbai 940 mm
BOBMEX 1998-99 Air-sea Coupling Rapid SST
Recovery Northward Propagation North-South
gradients (Bhat et al, BAMS, 2001)

• ARMEX 2002-2003, 2005
• Intense Rainfall Events on WC
• Warm pool build up Collapse
• Monsoon Onset over Kerala
• Mausam Jan. 2005 (Special Issue)

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ORV Sagar Kanya
Indian Oceanographic Research Vessel 110 m
long 31 Scientists 65 Crew
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North Bay SST- maintenance
OLR, Rainfall (GPCP) (shaded) (cont.)
June-Sept. 1978-95

• Maximum Precipitation
• Region of highest clouding in the
  entire region
• Cloud systems - Cut off solar radiation
• Wind speed
  generally increases
• SST decreases
• How SST is
  maintained above the
• threshold
  level (28oC)
• Top fresh water layer shallow mixed layer
• (solar
  penetration, Debasis, et al.
• 
  GRL, 2002)

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ARMEX 1. Intense Rainfall
Events on West Coast 2. Warm pool dynamics
Year 1998
(Source NIOT Buoy data)
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Temp
salinity
Density
(ARMEX BOBMEX)
Differences in the Ocean Mixed Layer North Bay
and Arabian Sea (AS)
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Rainfall SST
CAPE
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Differences in the surface energy balance over
Bay AS (weak phase of
convection/ break monsoon) Net heat flux- Bay
140-180 W/m2 AS- zero!
IO (JASMINE) 80Wm-2.
WP(TOGA-COARE) 80 Wm-2
Bay Positive feedback between ocean
atmosphere AS - Low precipitation, stronger
winds, atmos. inversion
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BAY weak winds High RH
lower LHF NLW
AS Winds stronger Lower RH
High LHF
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Wind speed dependence of latent heat flux over
different basins
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ARMEX 2002 Temperature inversion at air-sea
interface
Theory (M-O similarity profile) measurement
Diurnal range SST lt0.2oC Tair gt1oC
Comparison of measured Monin-Obukhov similarity
profiles
(Bhat (2006), GRL)
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SST
Ta
Buoy data
(WHOI,1995 )
1. SSTltTair, over a period of a month! 2. Heat
lost to water 10-20 W m-2
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SST
Ta
(WHOI)
Absorption by Sea salt particles (Bhat, GRL,
2006)
Hydrodynamic instability
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Hydrodynamic instability Wind shear stable
stratification (Kelvin-Helmholtz) Wave breaking
takes place strong low level jet
can account for up to 30 W/m2 of
heat flux under the conditions
prevailing over the Arabian Sea
Atmos.
Ocean
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CTCZ Brief Background
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Monsoon Zone
Mean JuneSeptember rainfall over the Indian
region south of 30 N
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Too many issues to address All appear
important!
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• Observations Rainfall results from Propagation
• of monsoon
  systems
• Models - unable to simulate this propagation
• in the monsoon zone
• Monsoon rainfall simulation - Poor
• CTCZ - ?
• Can we understand the mechanism of
• propagation in nature?
• Better prediction of Monsoon rainfall

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Dynamic surface conditions
May
Jul
Jun
Aug
Pre-onset onset Hot dry Peak
monsoon (July-Aug) Wet moist
Cloud systems their propagation
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Land-surface processes complex terrain
varying vegetation
Land-atmosphere coupling strength diagnostic for
boreal summer (the difference,dimensionless,
describing the impact of soil moisture on
precipitation), averaged across the 12 models
participating in GLACE (after Koster et al
2004,2006).
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Aerosols cloud microphysics (High
concentration of Aerosols)
Enormous Aerosol loading East west
gradient Marine dry Aerosol cloud
interactions
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Clouds are important
Monsoon ? Clouds Rain Cloud scales
processes? Cloud microphysics?
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• CTCZ
• Coupled Land-Ocean-Biosphere-Atmosphere
  Experiment
• Modulation of monsoon by land hydrological
  processes
• Cloud scale processes
• Aerosols cloud microphysics
• Multi-year programme
• Planning Stage
• Science plan being prepared
• Pilot 2008
• Main 2009-10

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Super sites
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Global Teleconnections
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Some positive developments Indian 1.IMDs
expansion plans network of AWSs, DWRs, high
resolution radiosondes, raingauge network,
satellites, 2. IITM Cloud Seeding Expt -
Research aircraft 3. STORM Project
Infracture 4. Megha-Tropiques 5. Validation
sites, ship, etc.
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Weather knows no national boundaries Collaboratio
n with other Asian countries AMY08, MAHASRI YOTC
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Thank you