Transcript Presentation - Geospatial World Forum

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
Centre for Climate Change Research
Indian Institute of Tropical Meteorology, Pune
An Elegant Science Question:
Are increases in greenhouse gases responsible for
increase in global mean temperature (global warming)?
14.6
Global Temperature & Carbon Dioxide 1860-2008
14.4
14.2
14.0
13.8
395
0.76°C (1.4°F) since 1900
0.55°C (1.0°F) since 1979
365
335
305
13.6
13.4
275
Hypothesis
• Greenhouse gases increase due to human activities.
• Global warming is due to increases in greenhouse gases.
• Global warming is due to human activities.
Alternative Hypothesis
• Global warming is due to natural variations of climate.
How do you test such hypotheses?
Climate Models; IPCC
What is a Climate Model?
• 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
Increase in Surface Temperature
Observations
Predictions with Anthropogenic/Natural forcings
Predictions with Natrual forcings
1.0º C
IPCC 2007
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 precipitation
Observed rainfall (JJAS)
IPCC models: 20C3M
1979-1998
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)
JJAS cumulative rainfall (1951-2009)
Area average (90E – 97E ; 20N – 30N)
IMD gridded rainfall dataset
http://www.tropmet.res.in
Long-term mean of
JJAS rainfall (mm)
1999
2005
Interannual variability of monsoon rainfall over Northeast India
2000
2006
2001
2002
2007
2008
2003
2009
2004
2010
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?
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)
• Increase in
intensity of
extreme events
Goswami et al
2006
•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

Possible causes for the decreasing trend in the moderate
rainfall events ?

Long-term trends in the large-scale monsoon circulation ?

Indications of weakening of the low-level monsoon flow
(Joseph and Simon 2005)

Increasing frequency of “breaks” in monsoon rainfall
(Ramesh Kumar et al. 2009)
Zonal wind
averaged over
(12.5N – 17.5N;
70 E – 85 E)
1950-2002
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
Strategy on Regional Climate Change Research at IITM
Centre 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


To provide reliable input for Impact Assessment studies


Earth System Model (ESM)
Dynamic downscaling of regional monsoon climate using high
resolution models; quantification of uncertainties
Observational monitoring: Network with other Institutions
CCCR
Administration
Scientific Research
Modelling Program
Outreach
Observational Program
Objectives
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)
 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
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
Monthly mean annual cycle of surface air temperature over Indian land region
Jan
CRU
CRU
ERAIM
ERAIM
WRF – KF2
WRF – BM
CRU
CRU
ERAIM
ERAIM
RegCM - EML
RegCM - GRL
CRU
CRU
ERAIM
ERAIM
PRECIS
LMDZ
Apr
Jul
Oct
Jan
Apr
Jul
Oct
Monthly mean annual cycle of precipitation (mm/day) over Indian land region
IMD
IMD
CMAP
CMAP
WRF – BM
WRF – KF2
Jan
Apr
IMD
IMD
CMAP
CMAP
RegCM - EML
RegCM - GRL
IMD
IMD
CMAP
CMAP
PRECIS
LMDZ
Jul
Oct
Jan
Apr
Jul
Oct
High resolution monsoon simulations: Global model with zoom over monsoon domain
JJAS rainfall
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 hPa
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 05
Day 06
Day 09
Day 10
Day 13
Day 14
Day 03
Day 07
Day 04
Day 08
Day 11
Day 12
Day 15
Day 16
LMDZ simulation: Evolution of SLP anomalies during a typical monsoon depression
Day 01
Day 02
Day 03
Day 05
Day 06
Day 07
Day 09
Day 10
Day 11
Day 14
Day 15
Day 13
Day 04
Day 08
Day 12
Day 16
Earth System Model (ESM)
development

Start with an atmosphere-ocean coupled model which has
a realistic mean climate – eg. NCEP CFS



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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

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


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
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
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 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
CCCR Climate Data Web Portal
http://www.cccr.res.in
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
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
Quantify
Also
to IPCC AR5 report through its activity
uncertainties in regional monsoon projections using results from multiple models
employ bias correction techniques for reducing model errors
Share
model data & conduct inter-disciplinary collaborative research towards impact
assessment, vulnerability and adaptation.
Hydrological
Long
Modeling to be started at CCCR soon
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).