Towards Earth System Modelling for Monsoon Projections Under Changing Climate

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National Monsoon Mission Scoping Workshop Indian
Institute of Tropical Meteorology 11 15 April,
2011
Towards Earth System Modelling for Monsoon
Projections Under Changing Climate Based on
CFS R. Krishnan Centre for Climate Change
Research Indian Institute of Tropical
Meteorology, Pune
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Increase in Surface Temperature
Observations Predictions with Anthropogenic/Natura
l forcings Predictions with Natrual forcings
1.0º C
IPCC 2007
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Challenges in assessment of future changes in
South Asian monsoon rainfall

• Wide variations and uncertainties among the IPCC
  AR4 models in capturing the mean monsoon rainfall
  over South Asia (eg., Kripalani et al. 2007,
  Annamalai et al. 2007).
• Systematic biases in simulating the spatial
  pattern of present-day mean monsoon rainfall
  (eg., Gadgil and Sajani, 1998 Kripalani et al.
  2007)
• Realism of present-day climate simulation is an
  essential requirement for reliable assessment of
  future changes in monsoon

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South Asia (5-35N, 65-95E))
Source Kripalani et al. 2010
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Summer monsoon precipitation
IPCC models 20C3M 1979-1998
Observed rainfall (JJAS)
The 20c3m simulations attempt to replicate the
overall climate variations during the period
1850-present by imposing each modeling groups
best estimates of natural (eg., solar irradiance
and volcanic aerosols) and anthropogenic (eg.
GHG, sulfate aerosols and ozone) during this
period. Seven 20C3M models (GFDL CM2.0,
GFDL-CM2.1, MPI-ECHAM5, MRI, MIROC3-HIRES,
HadCM3, NCAR-PCM Source J. Shukla)
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Questions On Attribution?

• How much of the observed variability of the mean
  Indian Summer Monsoon rainfall due to Climate
  Change?
• How much of the observed increase in temperature
  over India been decreased by increasing presence
  of aerosols?

Questions On Projections of Monsoon

• What will happen to the monsoon hydrological
  cycle 50-100 years from now under different
  scenarios? In particular, will the quantum of
  seasonal mean rainfall increase or decrease and
  if so by how much?
• What is the uncertainty in these projections? Can
  we quantify this uncertainty?
• How can we reduce this uncertainty?

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• Some indicators of regional monsoon climate
• Observed changes in frequency of monsoon
  depressions during the last century
• Changes in the observed extreme rainfall events
  during the 20th century
• Question
• Attribution How much of the observed regional
  monsoon variability is due to global warming?

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All India summer monsoon rainfall variability
Climatological Mean (JJAS)
Interannual Variability
Goswami et al., Science, 2006
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Time series of count over CI
Low Moderate events
Heavy events (gt10cm)
V. Heavy events (gt15cm)
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Time series of frequency of monsoon depressions

• Decreasing frequency of monsoon depressions
  during last 2-3 decades (eg., Rajeevan et al.,
  2000 Amin and Bhide, 2003 Dash et al., 2004)
• Recovery in the activity of monsoon depressions
  during the recent years (2005 2007)
• Activity of monsoon depressions modulated by
  low-frequency variability of atmospheric
  large-scale circulation on inter-decadal
  time-scales

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Strategy on Regional Climate Change Research at
IITMCentre for Climate Change Research
(CCCR)Ministry of Earth Sciences, Govt. of India

• To build capacity in the country in high
  resolution coupled ocean-atmosphere modelling to
  address issues on Attribution and Projection of
  regional Climate Change
• Earth System Model (ESM)
• To provide reliable input for Impact Assessment
  studies
• Dynamic downscaling of regional monsoon climate
  using high resolution models quantification of
  uncertainties
• Observational monitoring Network with other
  Institutions

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Earth System Model (ESM) development

• Start with an atmosphere-ocean coupled model
  which has a realistic mean climate eg. NCEP CFS
• Fidelity in capturing the global and monsoon
  climate
• Realistic representation of monsoon interannual
  variability
• Features of ocean-atmosphere coupled interactions
  
• Include components of the ESM
• Aerosol and Chemistry Transport Module
• Biogeochemistry Module (Terrestrial and Marine)
• .

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• Ongoing efforts towards development of Earth
  System Model (ESM) to address the Scientific
  Challenges of Global Climate Change and the Asian
  Monsoon System

• Plan to include ESM components in the CFS-2
  coupled ocean-atmosphere model
• CFS-2 coupled ocean-atmosphere model simulations
  on HPC initiated
• Ocean Biogeochemistry Module coupled to MOM4.
  Runs are ongoing on HPC
• Aerosol Transport Module coupled to AGCM. Runs
  are ongoing on HPC

Basic structure of ESM
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Climatological (JJAS) mean monsoon rainfall from
CFS model 100 year free run
Climatological (JJAS) mean SST from CFS model
100 year free run
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Taylor diagram of spatial pattern of
climatological seasonal mean (JJAS) rainfall
CFS Model High pattern correlation with
observed rainfall over India (IMD gridded
Dataset)
Source Seasonal Prediction Group, IITM
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Source Roxy Mathew
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(No Transcript)
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Interannual variability of summer monsoon
rainfall in the CFS model 100 year free
run Domain 70E-90E 10N-30N
Time in years
CFS model JJAS climatological mean rain rate
5.80 mm / day (red line) Standard Deviation
of JJAS rain rate 0.82 mm / day Observed
rainfall (IMD) JJAS climatological mean rain
rate 7.5 mm /day Standard Deviation
0.85 mm / day
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M O N S O O N A L D R O U G H T S
Complex Interactive Mechanisms of Monsoon
Droughts
Surface Boundary Conditions
Land Surface Process
SST
Eurasian Snow Cover
ENSO Cycle
Interactive Dynamics
Other Possible Causes
Low Frequency Intra-seasonal 30-50 day scale
Anthropogenic
Solar
Volcanic
North Ward Moving Episodes
Stratospheric
East Ward Moving Episodes
?
Synoptic Scale ltOne Week
Source Sikka, 1999
S.H. mid Latitudes
Indian and West Pacific Ocean
N.H. mid Latitudes
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Monsoon droughts in CFS model

• Atmosphere Ocean coupling in the tropical
  Indo-Pacific sector
• Tropical central-eastern Pacific (El Nino /
  Modoki)
• Eastern equatorial Indian Ocean (Negative IOD)
• Monsoon and mid-latitude interactions

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Monsoon drought composites in CFS model
Rainfall and wind (850 hPa) anomalies
SST and wind (850 hPa) anomalies in the CFS model

• Anomalous warming of
• the tropical Indo-Pacific
• Atmosphere Ocean Coupled Interaction
• Bjerknes-type feedback
• El Nino - Modoki
• Negative IOD

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Anomaly composites during monsoon droughts CFS
model
Monsoon and Mid-latitude Interactions
Krishnan et al. J. Atmos. Sci., 2009
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ESM components

• Strong Monsoon Seasonal Cycle Unique feature of
  tropical Indian Ocean
• Aerosols transport
• Terrestrial and Marine Ecosystem
• Quantify the effects of aerosol variability on
  the South Asian Monsoon - Aerosol transport
  module
• Quantify the climate response to variations in
  the regional ecosystem - Ecosystem and
  biogeochemical modeling

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Marine ecosystem and biogeochemistry modelling

• Marine phytoplankton absorb sunlight within the
  350 - 700 nm spectral range and thereby modulate
  heat flux in the upper ocean
• Ecosystem response in the tropical Indian Ocean
  is linked with the seasonal cycle of monsoon
  winds and Indian Ocean circulation
• Variations in ocean biology influenced by climate
  phenomena - El Nino, IOD

Phytoplankton Zooplankton Detrius Nutrient
food web model
(Doney et al. 1996, Fasham et al. 2001, Moore et
al. 2001, 2004)
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MOM4p1 forced ocean simulation 120 year spin up
Physical and Biogeochemical Parameters for
Tropical Indian Ocean
January
July
January
July
Source Aparna, Swapna
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Source John Dunne, GFDL
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Verification of MOM4p1 forced runs for Tropical
Pacific CORE forcing (1959 2004) Reproducibil
ity of the simulated SST and Chlorophyll
variability
Analysis of MOM4P1 runs by Raghu Loop 5 (1959
2004)
SST Anomaly, EOF1, (59.89 ) (1948 1992)
MOM4p1 runs and analysis made at CCCR Aparna
and Swapna
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Analysis of MOM4P1 runs by Raghu
MOM4p1 runs and analysis made at CCCR Aparna
and Swapna
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Modeling the effects of aerosols on the South
Asian monsoon

• GHG have contributed to a total of 2.7 Wm-2 to
  the greenhouse effect since 1850. The
  contribution of aerosols other non-greenhouse
  factors is less certain (IPCC AR4, 2007)
• Contrasting views on the impact of anthropogenic
  aerosols on South Asian monsoon climate
• Weakening of monsoon circulation via., solar
  dimming (eg. Ramanathan et al. 2005)
• Elevated Heat Pump (EHP) theory Aerosol heating
  over Tibetan Plateau during pre-monsoon months
  would intensify the monsoon Hadley circulation
  (eg. Lau et al. 2006)
• EHP hypothesis is not supported in CALIPSO Lidar
  satellite observations (Kuhlmann and Quass, 2010)

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Desert air and aerosol incursions during dry
Indian monsoon spells - TN Krishnamurti et al.
2010
Vertically integrated lower tropospheric (950
700 hPa) specific humidity (kg / kg)
Dry monsoon spell 10 19 June, 2009
Wet monsoon spell 14 20 July, 2009
Dry air
01 Aug 2004
18 June 2009
14 Aug 2005
16 July 2002
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Advection of dry air aerosols from
extra-tropics into Indian region TN Krishnamurti
et al. 2010
Composite of AOD _at_ 550 nm during monsoon breaks
MODIS Terra / Aqua
West Asia Blocking High
V. Ravi Kiran, M. Rajeevan, V.B. Rao and N.P.
Rao, GRL, 2009
Break monsoon
Active monsoon
High AOD over Arabian Sea
High AOD Indo Gangetic plains
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Modeling the effects of Aerosols on the South
Asian Monsoon
HAM (Hamburg Aerosol Module) Predicts evolution
of an ensemble of 7 interacting internally and
externally-mixed aerosol modes. Compounds
considered are Sulfate, Black Carbon, Organic
Carbon, Sea Salt, Mineral Dust

• Main Components
• Microphysical core (coagulation of aerosols,
  condensation of gas-phase SO2 on aerosol surface)
• Aerosol radiative properties sink processes
• Aerosol wet deposition
• Emissions of mineral-dust (based on 10 m winds)
• Sea salt emissions (based on 10 m winds)
• Sulfur cycle (Inputs monthly oxidant fields )
• Emissions of DMS (Inputs DMS sea-water
  concentrations calculations using 10m winds,
  SST)
• Terrestrial biogenic DMS emissions are prescribed
• AeroCom inventory for all other compounds

Experiment Boundary and Initial conditions
Control AGCM Climatological SST. Ensemble runs (22 members) starting from 22 perturbed IC of March and runs go through December
Aerosol AGCM Aerosol Module (HAM) Climatological SST. Ensemble runs (22 members) starting from 22 perturbed IC of March and runs go through December
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AGCM with aerosol transport
Rainfall low level winds (JJAS)
Aerosol minus Control
Very slight increase in precipitation over
monsoon trough region
Simulations of HAM coupled to an AGCM on
PRITHVI ,CCCR, IITM
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AOD and 850 hPa winds
JJAS temperature anomaly at 925 hPa Aerosol
minus Control
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Time series of the JJAS seasonal mean monsoon
rainfall averaged over the region (70E 100 E
10N 30N) based on the 22 member ensemble
realizations for the two AGCM experiments (a)
With aerosols (b) No aerosols
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Frequency distribution of rainfall over monsoon
region (70E 95E 10N 30N)
Frequency
Rainfall (mm / day)
Spatial map of difference in frequency of
rainfall events ( lt 50 mm / day) between the
Aerosol and Control simulations. The daily
rainfall at each grid point covers the June to
September monsoon season for 22 years
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Break monsoon anomaly composites
Summary Conducted two sets of 22 member
ensemble AGCM runs with and without aerosols.
Both runs use prescribed monthly climatological
SST The frequency of low moderate rainfall
events over the Indo-Gangetic plains shows very
slight increase in Aerosol run as compared to
no-aerosol simulation Interannual variability
of monsoon rainfall in the 2 experiments is
uncorrelated AOD changes during break monsoons
in the GCM are broadly consistent with the
observed AOD anomaly pattern Monsoon internal
dynamics is dominantly seen. Role of aerosols in
affecting the monsoon rainfall and circulation is
being investigated.
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High resolution regional climate change
scenarios and quantification of uncertainties
Provide reliable inputs for impact assessments
and contribute to IPCC AR5

• High resolution dynamic downscaling of monsoon
  Baseline climate runs using WRF, RegCM and LMDZ
  partially completed. Future climate scenario
  runs to be initiated in January 2011.
• Two member 19 year (1989 2007) run of WRF (50
  km) model completed. ERA Interim LBC
• One member 19 year (1989 2007) run of RegCM (50
  km) model completed. ERA Interim LBC
• One member 10 year (1979 1988) run of LMDZ (50
  km) model completed

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LMDZ global atmospheric model Variable
resolution with zooming capability
Source Sabin, CCCR
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Source Sabin
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High resolution ( 35 km) dynamical downscaling
simulations using LMDZ over South Asia Proposed
at CCCR
Historical (1890-2005) Includes natural and
anthropogenic (GHG, aerosols, land cover etc)
climate forcing during the historical period
(1890 2005) 106 years Historical Natural
(1890 2005) Includes only natural climate
forcing during the historical period (1890
2005) 106 years
RCP 4.5 scenario (2006-2100) Future projection
run which includes both natural and anthropogenic
forcing based on the IPCC AR5 RCP 4.5 climate
scenario . The evolution of GHG and
anthropogenic aerosols in RCP 4.5 scenario
produces a global radiative forcing of 4.5 W
m-2 by 2100
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Hydrologic Impacts of Climate Change

• Large scale hydrologic impacts
• Continental water balance projections
• Water resource projections for India
• Large scale water mass variation
• River discharge projections
• Runoff computation from GCMs with global river
  channel network
• Lateral movement of water
• River flow model for river routing
• Runoff and discharge projections using macroscale
  hydrologic models Eg. Water Gap Global
  Hydrology Model (WGHM)
• Global datasets for landuse, soil types,
  vegetation cover
• River routing linear models
• Validation with global datasets Global Runoff
  Data Center (GRDC)
• Uncertainty modeling and decision support
• Multimodel ensemble of GCM simulations
• Uncertainty quantification of key hydrologic
  parameters at large scales
• Exploring adaptation and mitigation measures

Source Deepashree Raje
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Macroscale hydrologic modelingHydrologic Impacts
of Climate Change

• Variable infiltration capacity (VIC) macroscale
  model (Liang et al., 1994) at 1 deg. by 1 deg.
  resolution over Indian region
• subgrid variability in land surface vegetation
  classes
• subgrid variability in the soil moisture storage
  capacity, which is represented as a spatial
  probability distribution
• subgrid variability in topography through the use
  of elevation bands
• spatial subgrid variability in precipitation
• Simulation of water balances for 1 deg x 1 deg
  grids
• Inputs are time series of daily or sub-daily
  meteorological drivers (e.g. precipitation, air
  temperature, wind speed)
• Land-atmosphere fluxes, and the water and energy
  balances at the land surface, are simulated at a
  daily or sub-daily time step
• Daily runoff and baseflow routed using
  independent routing model (Lohmann et al., 1996)
• Calibration and validation of model using current
  meteorologic forcings and observed discharge data
  in three river basins (Narmada, Ganga, Krishna)

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Data sources

• Digital elevation data at 1 km (USGS)
• Land cover classification (UMD) at 1 km (UMD)
• Soil texture mapping at 0.0833 deg (FAO)
• Hydrologic data analysis using GIS
• Basin delineations
• Flow directions and accumulations at fine and
  coarse resolution (1 deg) grids
• Area-weighted derived soil property maps at 1 deg
• Area-weighted landcover maps at 1 deg
• Discharge validation with global datasets
  Global runoff data center (GRDC)

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DEM for study region
River routing for study basins
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Soil Mapping Unit (SMU) classification
Land cover classification
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Preliminary results Calibration
Observed discharge m3s-1

• Calibration using data from four discharge
  stations Farakka (Ganga), Jamtara (Narmada),
  Garudeshwar (Narmada), Vijayawada (Krishna) for
  years 1965-1970

Source Deepashree Raje
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Preliminary results Testing
Observed discharge m3s-1

• Testing for years 1971 - 1975

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Features of Dynamic Climate Data Portal
CCCR Climate Data Web Portal http//www.cccr.res.i
n

• Visualize data with on-the-fly graphic
• Easy and user friendly analysis of climate data
  through graphical display on the browser with one
  click
• Example IMD daily rainfall (1951 to 2009)
• URL http//cccr.hpc8080/CCCR
• Step 1 Click on the above URL
• Centre for Climate Change Research
• Indian Institute of Tropical Meteorology, Pashan
  , Pune 411 008
• Ministry of Earth Sciences, Govt. of India

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Summary

• Long term plans ( 3 years) to develop an Earth
  System Model (ESM)
• A global atmosphere-ocean coupled model (CFS) is
  operational. A century long simulation and
  several other runs have been performed
• Aspects of global and regional monsoon climate
  are realistically captured by CFS model
• Realistic features of monsoon interannual
  variability is seen from the CFS simulations
  (e.g., Atmosphere-ocean coupling over tropical
  Indo-Pacific, Monsoon and mid-latitude
  interactions, etc)
• Plans to improve the simulation of present day
  monsoon climate in the CFS model. Need to reduce
  model systematic biases.
• Ongoing efforts to include ESM components in CFS
  model (ie., Aerosol transport module, Marine and
  Terrestrial Ecosystem and Biogeochemistry
  module, Sea-Ice module, etc).
• Dynamic downscaling of regional monsoon climate
  using high resolution models
• Downscaling simulations of present day and
  future monsoon climate scenarios will be
  completed by early 2012
• Contribute to IPCC AR5 report through its
  activity

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Thank you