UNFCCC Technical Workshop on Collaboration among Regional Centres / Networks

Transcription

1 UNFCCC Technical Workshop on Collaboration among Regional Centres / Networks Apia, Samoa, 2-5 March 2010 Perspectives: Climate Modelling, Scenarios and Downscaling R. Krishnan Centre for Climate Change Research Indian Institute of Tropical Meteorology Pune , India krish@tropmet.res.in

2 Acknowledgements: UNFCCC Secretariat Apia, Samoa Host of the UNFCCC Technical Workshop Ministry of Environment and Forests, New Delhi, Government of India Ministry of Earth Sciences, New Delhi, Government of India Indian Institute of Tropical Meteorology, Pune, India

3 Background Climate Change is being recognized as a major threat to present day society because of its adverse impacts on ecosystem, agricultural productivity, water resources, socio-economy and sustainability in a global as well as regional basis. In India, efforts are ongoing to address the science issues related to climate change. Inadequate understanding of the science of climate change; insufficient capacity in climate modelling and also lack of integration and networking. In this regard, a Brainstorming Workshop on National Program on Climate Change Research was organized by the Ministry of Earth Sciences, New Delhi on 1st June Addressed by the Honorable Minister for Science & Technology and Earth Sciences and attended by senior scientists, policy makers, and representatives from several other ministries and industries. Establishment of a dedicated centre for undertaking research on science aspects of Climate Change at IITM, Pune was strongly endorsed by the panelists and participants of this Brainstorming Workshop. Consequent upon the recommendation, a proposal for a Centre for Climate Change Research was submitted to the Ministry of Earth Sciences, and received approval on 7th January 2009 under the Program on Global and Regional Climate Change as one of the schemes of the 11th Five Year Plan.

4 Science of Climate Change and the Monsoon Objectives:! Development of in-house capacity in global and regional climate modeling to address issues of National interest relating to climate change particularly the South Asian monsoon! Estimation of change & uncertainties in the South Asian summer monsoon rainfall under different climate change scenarios based on dynamic downscaling of monsoon rainfall using regional climate models; conduct impact assessment studies! Observational and modeling studies of radiative forcing due to green-house gases and aerosols. Understand cloud-aerosol interactions in the monsoon environment! Understand past changes in monsoon climate using multiple proxy records. Reconstruction of an iconic monsoon rainfall index going back to a few thousand years! Outreach and training for capacity building in climate change research; and dissemination of information

5 CCCR Administration Scientific Research Outreach Generation of Climate Change Scenarios for Indian Monsoon region Quantification of Uncertainties & Impact Assessment Studies Global Climate Modeling Towards Earth System Modelling for Climate Change Observational & modelling studies on Radiative Forcing -Green-house gases And Aerosol Understanding Past Climate Change from proxy records Outreach, Training for Capacity Building in Climate Change Research, Dissemination of Information

6 Road Map: Regional climate modeling! Estimate the uncertainty in Projections of monsoon by Regional Climate Models. Ensemble of simulations using regional climate models with boundary conditions from a number of global coupled climate models! Contribute to IPCC AR5 through this activity! As the resolution of the global coupled models taking part in IPCC AR5 will still be 100 km or poorer, IPCC has decided to add a section on projections downscaled by regional models. The regional downscaling for the South Asian monsoon region will be conducted at CCCR, IITM.

7 Road Map: Impacts of regional climate change! Projections from modeling simulations is the input for all impact assessment studies! Carry out impact on water resources and hydrological disasters at IITM using climate model outputs to drive hydrological models! For impacts on agriculture, environment, health etc, we shall be networking with other expert groups similar to what we did during NATCOM-I I project

8 Road Map : Global coupled modeling! Develop in-house capacity in global ocean-atmosphere atmosphere coupled modeling! Conduct coupled model simulations and make long term projections of the Indian monsoon under different scenarios & participate in AR-6! Explore possibility of participating in AR-5. Collaborate with an existing IPCC modeling group that is willing to extend long-term support for model development. Design and conduct special simulations focusing on the South Asian monsoon for AR5! Improve representation of physical processes in the model so that the simulation of the South Asian monsoon as well as the global climate is improved. Reduce uncertainty of these projections through model development! Understand the internal (natural) variability of the climate system. tem. For. eg., decadal variability (30-year samples) of the climate system! Better quantification of physical processes over the tropics water vapor feedback, cloud interaction, aerosol interaction etc.! Bio-geochemistry and carbon cycle modeling

9 Road Map: Observational programme! Establish a High Altitude Cloud Physics Monitoring Laboratory at Mahabaleshwar. Long-term monitoring of cloud-aerosol interactions and study of aerosol indirect effects in the monsoon environment! Observations for estimating aerosol direct radiative forcing in different spectral regions using optical and chemical composition data; together with radiative transfer models! Contribute to the modeling effort for understanding the influence e of aerosol and greenhouse gas radiative forcing on the monsoon climate! Greenhouse gas monitoring over India. Transport modeling and inverse modeling to estimate regional carbon sources and sinks! Reconstruction of monsoon climate proxies (eg., Monsoon rainfall index going back to at least a few thousand years). Establishment of a Stable Isotope Mass Spectrometer Laboratory.

10 Road Map for Outreach, Training and Capacity building! Training and Capacity Building! Recruit new climate scientists, modelers! Run a sustained in house Training Program! Get trained scientists at centres of excellence! Enhancing scientific awareness of climate change and monsoon related issues, popularise climate science through - (Interactions with Universities, Schools, Indian Meteorological Society, Audio-Visual demonstration programmes, organise campaigns, workshops, invited lectures etc for enhancing environmental awareness; Climate News letters etc).! Develop diagnostic tools for dissemination of climate information (eg., interactive graphical web-site, database systems for archival & dissemination of climate model outputs)

11 What are Monsoons? Monsoon means season Describes complete reversal of wind regimes during the seasonal cycle Driven by changes in the distribution of heating driven primarily by the solar seasonal cycle Requires a thermal contrast between land and sea to set up a monsoon Once established, positive feedback between circulation and latent heat release maintains the monsoon Characterised by pronounced rainy seasons

12 Winds at 925hPa DJF JJA West African Monsoon Asian Monsoon Austral Monsoon

13 Land/Sea Temperature contrasts Nov./Dec. May/June West African Monsoon Asian Monsoon Austral Monsoon

14 Rainfall (mm/day) DJF West African Monsoon Asian Monsoon Austral Monsoon JJA

15 Long term climatology of total rainfall over India during (1 Jun 30 Sep) summer monsoon season ( ALL-INDIA SUMMER MONSOON RAINFALL Mean = mm Std. Dev. = 83.4 mm Excess years - 20 Drought years Normal Deficient Excess Years Percentage departure normal from

16 All India summer monsoon rainfall variability Climatological Mean (JJAS) Interannual Variability Goswami et al., Science, 2006

17 Time series of count over CI Low & Moderate events Heavy events (>10cm) V. Heavy events (>15cm)

18 Simulation of the South Asian monsoon rainfall by AR4 models Kripalani et al. 2007

19 Annual Cycles: South Asia Kripalani et al. 2007

20 Projections of Annual Cycles over South Asia:

21 Monsoon simulation in AR4 coupled models!the boreal summer monsoon is basically a convectively coupled phenomenon.!uncertainties about changes in regional distribution of South Asian monsoon rainfall due to global warming (A1B scenario). Wide variations among the AR4 models in capturing the mean monsoon rainfall and its variability!increases in summer monsoon precipitation over South Asia have been noted; despite weakening of the low-level monsoon cross-equatorial flow.!reliable assessment of future changes monsoon climate require that the present monsoon climate is realistically captured by the models Mean monsoon rainfall and circulation Monsoon synoptic systems (eg. Lows, Depressions, MTC) Monsoon intraseasonal variability (eg. active / break spells)....

22 PRECIS Runs at IITM Evaluation experiment using LBCs derived from ERA-15 ( ) 93) LBCs from Hadley Centre Models Baseline ( ) 90) 3 members A2 scenario ( ) 2100) -33 members B2 scenario ( ) 2100) QUMP ( ) A1b 3 Members (Quantifying Uncertainty in Model Predictions QUMP: Single model; Perturbations introduced through physical parameterisation schemes in the model) BCs from ECHAM Baseline (Resolution: 50km) 2 Scenario: Team Leader: K. Krishna Kumar

23 Assessment of Climate Change Impacts on the Indian Climate IPCC AR4 Simulations (23 models) QUMP Ensemble simulations (17 Models) High resolution regional model simulations Team Leader: K. Krishna Kumar

24 Observed rainfall compared with QUMP simulations Team Leader: K. Krishna Kumar

25 Temperature changes in Future scenarios Rainfall changes in future Scenarios

26 Current thinking on Coordinated Regional Projection Experiment framework The regional climate change information in Chapter 10 of the TAR and AR4 was essentially based on AOGCM simulations The resolution of CMIP5 simulations that will form the main input for IPCC-AR5 are not going to be very different in the resolution compared to CMIP-3 (IPCC-AR4) Resulting in the relevance & usefulness of high-resolution regional Scenarios using RCMs for the IPCC-AR5 (Source: Fillippo Georgi, ICTP)

27 Regional Inter comparison Projects PIRCS NARCCAP SGMIP ARCMIP PRUDENCE ENSEMBLES NEWBALTIC AMMA AFRMIP AIACC RMIP PLATIN ARC

28 Long term climatology of total rainfall over India during (1 Jun 30 Sep) summer monsoon season ( Interannual variability of the Indian Summer Monsoon Rainfall

29 M O N S O O N A L D R O U G H T S Land Surface Process Surface Boundary Conditions SST Eurasian Snow Cover Complex Interactive Mechanisms of Monsoon Droughts Interactive Dynamics ENSO Cycle Other Possible Causes Low Frequency Intra-seasonal day scale Solar Volcanic Anthropogenic S.H. mid Latitudes Synoptic Scale <One Week North Ward Moving Episodes Indian and West Pacific Ocean East Ward Moving Episodes N.H. mid Latitudes Stratospheric? Source: Sikka, 1999

30 Monsoon droughts emanate from prolonged breaks in the monsoon rainfall Total seasonal rainfall (mm) (1 Jun - 30 Sep) Intraseasonal variability of monsoon rainfall over India (Active / Break spells) 2002 Monsoon rainfall anomaly: 2002 Monsoon rainfall anomaly:

31 OLR Climatology (June September)

32 Monsoon synoptic disturbances: Monsoon depressions Streamlines at 850 hpa and TMI (3B42) rainfall (mm / hr) during 1-8 August 2006 d b e c f g h i

33 Summary and Recommendations Science of Monsoon Climate Change: Regional downscaling of climate change information for the South Asian monsoon region. Highresolution atmospheric GCMs (eg., PRECIS, HadGEM, RegCM, LMD model with regional zooming capability). Model simulations will be conducted on the HPC system at CCCR, IITM, Pune. The high resolution regional model outputs are expected to be ready by early Understand the projected changes and estimate the uncertainties of projections in the mean-monsoon climate, monsoon Synoptic systems and intra-seasonal variability, extreme events Understand the natural and human-induced variations of the monsoon Develop diagnostic online tools for dissemination of climate information (eg., interactive graphical website, database systems for archival and dissemination of climate model outputs & observed data).

34 Summary and Recommendations (contd) In-house Training and National Capacity Building: Recruitment of climate scientists. Sustained In-house Education and Training Program (Ph.D. fellowships). Get the scientists trained at centers of excellence. Facilitating Knowledge Sharing and Knowledge Support: Develop online resources, User-friendly knowledge products Conduct climate related training programs in the region (eg. Climate Modelling, Analysis of Climate Model Outputs, Assessment of Climate Change and its Impacts, etc). Share climate information for impact assessment on agriculture, water-resources, environment and health by networking and developing regional and global collaborations with countries, expert groups, universities and communities. This will be important for building adaption strategies in different sectors.

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