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Seminar on Socio Economic Implications of Climate Change Initiatives: Priorities and Implications for India Geospatial World Forum Hyderabad 18 – 21 January, 2011. High-resolution modelling of regional climate change scenario over South Asia R. Krishnan - PowerPoint PPT Presentation
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High-resolution modelling of regional climate change scenario over South Asia
R. Krishnan Centre for Climate Change Research
Indian Institute of Tropical Meteorology, Pune
Seminar on Socio Economic Implications of Climate Change Initiatives:
Priorities and Implications for India
Geospatial World ForumHyderabad
18 – 21 January, 2011
An Elegant Science Question: An Elegant Science Question: Are increases in greenhouse gases responsible for
increase in global mean temperature (global warming)?
0.76°C (1.4°F) since 1900
0.55°C (1.0°F) since 1979
395
365
335
305
275
14.6
14.4
14.0
13.8
13.4
14.2
13.6
Global Temperature & Carbon Dioxide 1860-2008
• Greenhouse gases increase due to human activities.
• Global warming is due to increases in greenhouse gases.
• Global warming is due to human activities.
HypothesisHypothesis
Alternative HypothesisAlternative Hypothesis
• Global warming is due to natural variations of climate.
How do you test such hypotheses?
Climate Models; IPCC
• Equations of motions and laws of thermodynamics to predict rate of change of:
T, P, V, q, etc. (A, O, L, CO2, etc.)
• 10 Million Equations: 100,000 Points × 100 Levels × 10 Variables
• With Time Steps of: ~ 10 Minutes
• Use Supercomputers
What is a Climate Model?What is a Climate Model?
IPCC 2007
1.0º C1.0º C
Increase in Surface TemperatureIncrease in Surface Temperature
ObservationsPredictions with Anthropogenic/Natural forcingsPredictions with Natrual forcings
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
South Asia
(5-35N, 65-95E))
Source: Kripalani et al. 2010
Summer monsoon precipitationSummer monsoon precipitation
IPCC models: 20C3M1979-1998Observed 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)
1999 2000
2005
2001 2002 2003 2004
2007 20082006 2009 2010
Long-term mean of JJAS rainfall (mm)
JJAS cumulative rainfall (1951-2009) Area average (90E – 97E ; 20N – 30N)IMD gridded rainfall dataset
http://www.tropmet.res.in
Interannual variability of monsoon rainfall over Northeast India
Questions : On Attribution?Questions : On Attribution?
How much of the observed variability of the mean Indian How much of the observed variability of the mean Indian Summer Monsoon rainfall due to Climate Change?Summer Monsoon rainfall due to Climate Change?
How much of the observed increase in temperature over India How much of the observed increase in temperature over India been decreased by increasing presence of aerosols?been decreased by increasing presence of aerosols?
Questions : On Projections of Questions : On Projections of MonsoonMonsoon
What will happen to the monsoon hydrological cycle 50-100 What will happen to the monsoon hydrological cycle 50-100 years from now under different scenarios? In particular, will the years from now under different scenarios? In particular, will the quantum of seasonal mean rainfall increase or decrease and if so quantum of seasonal mean rainfall increase or decrease and if so by how much?by how much?
What is the uncertainty in these projections? Can we quantify What is the uncertainty in these projections? Can we quantify this uncertainty?this uncertainty?
How can we reduce this uncertainty?How can we reduce this uncertainty?
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?
All India summer monsoon rainfall variability
Climatological Mean (JJAS)
Interannual Variability
Goswami et al., Science, 2006
Time series of count over CI
Low & Moderate events
Heavy events (>10cm)
V. Heavy events (>15cm)
•Frequency as well as intensity of heavy & very-heavy rainfall events have significantly increased over Central India
•Low and moderate events have significant decreasing trend over Central India
•The seasonal mean does not have a trend because decreasing contribution from low and moderate events are compensated by increasing contribution from heavy events
• Increase in intensity of extreme events
Goswami et al 2006
Possible causes for the decreasing trend in the moderate Possible causes for the decreasing trend in the moderate rainfall events ?rainfall events ?
Long-term trends in the large-scale monsoon circulation ?Long-term trends in the large-scale monsoon circulation ?
Indications of weakening of the low-level monsoon flow Indications of weakening of the low-level monsoon flow (Joseph and Simon 2005)(Joseph and Simon 2005)
Increasing frequency of “breaks” in monsoon rainfall Increasing frequency of “breaks” in monsoon rainfall (Ramesh Kumar et al. 2009)(Ramesh Kumar et al. 2009)
Zonal wind averaged over (12.5N – 17.5N; 70 E – 85 E)
1950-2002
•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
Time series of frequency of monsoon depressions
Strategy on Regional Strategy on Regional Climate Change Research at IITMClimate Change Research at IITM
Centre for Climate Change Research (CCCR)Centre for Climate Change Research (CCCR)Ministry of Earth Sciences, Govt. of IndiaMinistry of Earth Sciences, Govt. of India
To build capacity in the country in high resolution coupled To build capacity in the country in high resolution coupled ocean-atmosphere modelling to address issues on ocean-atmosphere modelling to address issues on Attribution Attribution and Projection and Projection of regional Climate Changeof regional Climate Change
Earth System Model (ESM)Earth System Model (ESM)
To provide reliable input for Impact Assessment studies To provide reliable input for Impact Assessment studies Dynamic downscaling of regional monsoon climate using high Dynamic downscaling of regional monsoon climate using high
resolution models; quantification of uncertaintiesresolution models; quantification of uncertainties
Observational monitoring: Network with other Institutions Observational monitoring: Network with other Institutions
CCCR
Administration Scientific Research Outreach
Modelling Program Observational Program
To establish a High Altitude Cloud Physics Observatory for monitoring cloud-aerosol interactions – (Long-term)
To understand Past Changes in Monsoon Climate using Multiple Proxy Records. Reconstruction of an iconic monsoon index going back to a few thousand years – (Long-term)
To promote Outreach and Training for Capacity Building in Climate Change Research and Dissemination of Information – Long-term cont
To build a Global High-resolution Earth System
Model to address the Attribution & Projection of
regional climate change – (Long-term)
To generate regional climate change scenarios for
South Asia using Ultra High-resolution Regional
Climate Models and quantify uncertainties.
Provide reliable inputs for impact assessments.
Contribute to IPCC AR5 – (Short-term)
Objectives
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
CRU
ERAIM
WRF – KF2
CRU
ERAIM
WRF – BM
CRU
ERAIM
RegCM - EML
CRU
ERAIM
RegCM - GRL
CRU
ERAIM
PRECIS
CRU
ERAIM
LMDZ
Jan Apr Jul Oct Jan Apr Jul Oct
Monthly mean annual cycle of surface air temperature over Indian land region
Jan Apr Jul Oct Jan Apr Jul Oct
IMD
CMAP
WRF – KF2
IMD
CMAP
WRF – BM
IMD
CMAP
RegCM - EML
IMD
CMAP
RegCM - GRL
IMD
CMAP
PRECIS
IMD
CMAP
LMDZ
Monthly mean annual cycle of precipitation (mm/day) over Indian land region
LMD model
1 degree (Global)
LMDZ model
1/3 degree zoom for
Monsoon Domain
(40-110E; 15S-30N)
&
1 degree outside
Initial runs made at CCCR on PRITHVI, IITM
JJAS SLP and winds 850 hPaJJAS rainfall
High resolution monsoon simulations: Global model with zoom over monsoon domain
LMDZ monsoon simulation at 50 km zoomed resolution – 10 year mean
Mean SLP and 850 hPa winds (JJAS) Mean rainfall (JJAS)
•Large scale structure of winds and SLP is well captured
•Monsoon Trough has strong southward dip over eastern India and Bay of Bengal – Bias
•Precipitation along West Coast and Central - Eastern India is reasonably well simulated
•Rainfall over north Bay of Bengal is underestimated. Excessive rain over central Bay of Bengal
•Rainfall over Equatorial Eastern Indian Ocean is underestimated
Example of a monsoon depression in a typical synoptic chart
LMDZ simulation: Rainfall and 850 hPa streamlines during a typical monsoon low / depression
Day 01 Day 02 Day 03 Day 04
Day 05 Day 06 Day 07 Day 08
Day 09 Day 10 Day 11 Day 12
Day 13 Day 14 Day 15 Day 16
LMDZ simulation: Evolution of SLP anomalies during a typical monsoon depression
Day 01 Day 02 Day 03 Day 04
Day 05 Day 06 Day 07 Day 08
Day 09 Day 10 Day 11 Day 12
Day 13 Day 14 Day 15 Day 16
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) Sea-ice module … .
Climatological (JJAS) mean monsoon rainfall from CFS model – 100 year free run
Climatological (JJAS) mean SST from CFS model – 100 year free run
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
CFS modelJJAS 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
Interannual variability of summer monsoon rainfall in the CFS model – 100 year free runDomain: 70E-90E; 10N-30N
Time in years
CFSv2 precip JJAS 10 yr mean CMAP precip JJAS (1980-2009)
CFSv1 precip JJAS 100 yr mean
CFSv2 runs on PRITHVI by CCCR
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 modelPlan to include ESM components in the CFS-2 coupled ocean-atmosphere model
CFS-2 coupled ocean-atmosphere model simulations on HPC initiatedCFS-2 coupled ocean-atmosphere model simulations on HPC initiated
Ocean Biogeochemistry Module coupled to MOM4. Runs are ongoing on HPCOcean Biogeochemistry Module coupled to MOM4. Runs are ongoing on HPC
Aerosol Transport Module coupled to AGCM. Runs are ongoing on HPCAerosol Transport Module coupled to AGCM. Runs are ongoing on HPC
Basic structure
of ESM
CCCR
Features of Dynamic Climate Data Portal
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.hpc:8080/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
CCCR Climate Data Web Portalhttp://www.cccr.res.in
Summary Dynamic downscaling of regional monsoon climate using high resolution models. Efforts have been initiated at CCCR.
Downscaling simulations of present day and future monsoon climate scenarios will be completed by early 2012 (PRECIS, WRF, RegCM, LMDZ)
Contribute to IPCC AR5 report through its activity
Quantify uncertainties in regional monsoon projections using results from multiple models
Also employ bias correction techniques for reducing model errors
Share model data & conduct inter-disciplinary collaborative research towards impact assessment, vulnerability and adaptation.
Hydrological Modeling to be started at CCCR soon
Long term plans (~ 3-4 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).
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