Climate Change Scenarios 2030s Ashwini Kulkarni ashwini@tropmet.res.in K Krishna Kumar, Ashwini Kulkarni, Savita Patwardhan, Nayana Deshpande, K Kamala, Koteswara Rao Indian Institute of Tropical Meteorology, Pune National Workshop India: Climate Change & India A 4x4 Assessment November 16, 2010, New Delhi
Observed Data Temperature of 121 meteorological stations for 1901-2007 and the geographical demarcation of macro-regions. Seasonal rainfall over 36 sub-divisions of India for 1901-2007 Model Data Output of 10 selected IPCC models : 1901-2000(20c3m) and 2001-2100 (SRESA1B) 3 QUMP simulations from PRECIS : 1961-1990 (Baseline) and 1951-2100 (SRESA1B)
Observed Trends in air temperature 1901-2007 1901-1950 1951-2007 1971-2007
1-day highest and lowest ever recorded temperature ( o C ) during 1970-2005
Annual temperature time series for 4 regions during 1901-2007. Trends are depicted for the period 1901-2007 as well as 1971-2007 The trend values are for per 100 yrs for the entire period and for per 10 yrs in case of the recent period
Trends in summer monsoon rainfall for 36 subdivisions over India
Threshold (mm) to define heavy rainfall events ( 99 th percentile of rain day) and trends in the number of heavy rain days (dark green color indicates significant increasing trend)
Highest recorded rainfall (cm) during 1951-2004 and trends in annual extreme rainfall ( dark green color indicates significant increasing trend).
Seasonal rainfall time series for 4 regions during 1901-2007. Red line indicates the linear trend
Long term trends in frequency, intensity of rainy days and extreme rainfall over the four regions. Red line depicts the linear trend.
Projected Changes in 2030s
IPCC AR4 Simulations Historical run: 20th Century simulation Future climate simulations (initial conditions from end of the 20th Century simulation): Committed Climate Change : : hold concentrations at year 2000 SRES A2 to 2100 SRES A1B to 2100 then fix concentrations (~720 ppm) for an additional century (with one realization extended to 2300) As above but with SRES B1 (~550 ppm) Global Mean Indian Region The model simulation data of the above runs are available through IPCC-DDC/ PCMDI, USA and has already exceeded 40TB
MME time series of annual average temperature and seasonal rainfall over South Asia for 20c3m (black) and a1b(red) scenario
Percentage change in seasonal precipitation projected by 10 models and their MME under scenario A1B (2021-2050) with respect to 20c3m (1961-1990)
MME change in seasonal rainfall projected by 10 models under scenario A1B (2021-2050) with respect to 20c3m (1961-1990)
Change in annual average temperature projected by 10 models and their MME under scenario A1B (2021-2050) with respect to 20c3m (1961-1990)
MME change in seasonal temperature projected by 10 models under scenario A1B (2021-2050) with respect to 20c3m (1961-1990)
PRECIS Runs at IITM (Resolution: 50km) Evaluation experiment using LBCs derived from ERA-15 (1979-93) LBCs from Hadley Centre Models Baseline (1961-90) 3 members A2 scenario (2071-2100) -3 members B2 scenario (2071-2100) 3 Members of QUMP (1951-2100) A1B
Percentage change in the summer monsoon precipitation by three PRECIS runs towards 2030s with respect to 1970s.
Changes in the annual surface air temperature in 2030s with respect 1970s.
The change in the frequency of rainy days in 2030s with respectto 1970s The change in the intensity of rainy days in 2030s with respect to 1970s
The change in the lowest minimum temperature in 2030s with respect to 1970s The change in the highest maximum temperature in 2030s with respect to 1970s
90 th percentile of maximum temperature for baseline and change in the 90 th percentile value in 2030s with respect to 1970s
The storms simulated by PRECIS QUMP ensembles for 1970s (upper panels) and 2030s (lower panels). The normal tracks for Jun and Sept (red) and Juland Aug ( green ) are also shown
Change in seasonal rainfall (%) and annual average temperature( o C) in three simulations (dots) and their ensemble mean (bars) for the four regions.
Ensemble mean of Q1, Q0 and Q14 simulations for 1970s and changein seasonal rainfall (%) and temperature (deg C) in 2030s for different regions.
Summary Observed changes: All-India summer monsoon rainfall is free from any long-term trend although on subdivisional scale there are regions of increasing/decreasing trends. All- India mean annual temperature shows a significant warming trend during 1901-2007. Mean annual maximum temperature shows significant warming trends during the periods 1901-2007. However, in the recent decade 1998-2007, the maximum temperature shows stagnation in trend. Mean annual minimum temperature has significantly increased by 0.27 C per 100 years during the period 1901-2007. Number of heavy rainfall events (those exceeding 99 th percentile) are increasing almost over the entire landmass. Also the frequency and intensity of extreme events defined as 1-day maximum precipitation shows increasing trend everywhere except some northern parts of the country.
Projected changes in 2030s: Coupled model simulations from IPCC AR4 show large uncertainty in simulating Indian summer monsoon rainfall, however a MME of 10 selected models give reasonably good representation of monsoon though with a dry bias. MME projects around 10% increase in the Indian monsoon rainfall over central and peninsular India in 2030s. The expected change in the rainfall is within the current monsoon variability and there are large model to model differences making these projected changes to be lesser confident. MME projects 1.5-2 o C warming in the annual mean temperature over the Indian landmass while winter (Jan-Feb) and spring (Mar-Apr-May) seasons show higher warming. High resolution regional climate model PRECIS shows good skill in representing smaller scale features of monsoon. The projections of PRECIS in 2030s indicate 3-7% increase in all-india summer monsoon rainfall. The annual mean surface air temperature may rise from 1.7 C to 2 C by 2030s as indicated by the three simulations The regional climate model simulations indicate that the cyclonic disturbances over Indian Oceans during summer monsoon are likely to be more intense and the systems may form slightly to the south of normal locations. The ensemble mean changes in the monsoon rainfall are in the range of 2 to 12% while the annual temperature changes are of the order of 1.4 to 1.9 o C, however the individual simulations show large differences.
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