1. Assessment of Future Change in Temperature and Precipitation over Pakistan (Simulated by PRECIS RCM for A2 Scenario) Siraj Ul Islam, Nadia Rehman

2.  Motivation and Objectives  Introduction to Downscaling and PRECIS System  Experiment Design  Data and methods  Results 1. Validation 2. Future Change  Conclusion  Future work Out Lines

3. To investigate and Validate PRECIS behaviors over South Asia particularly over Pakistan in a long simulation using nested RCM in GCM Based on this validation, predictability of future climate change over selected domains is calculated High resolution information is to be used in different crop and water models specially focusing over Pakistan Motivations and Objectives Overall assessment of PRECIS performance Future Change and its impacts on Sub Regions 1 2 Output to be used in Impact Studies 3

4. Introduction to Dynamical Downscaling RCM Model (Resolution ~ 50 Km) GCM Resolution ~ 500km Downscaling Adding Local Details Lateral Boundary Initial Conditions Other Forcing A Regional Climate Model is a tool to add small-scale detailed information of future climate change to the large-scale projections of a GCM. It is a comprehensive physical model, usually of the atmosphere and land surface, containing representations of the important processes in the climate system (e.g. clouds, radiation, rainfall, soil hydrology) as are found in a GCM.

5. HadAM3P GCM 150km PRECIS Regional Climate Model (RCM) 50km HADCM3 Coupled GCM (300km atmosphere) SST/sea-ice change from coupled GCM At its boundaries, an PRECIS is mainly driven by atmospheric winds, temperatures and humidity output from a GCM. Introduction to PRECIS System of Downscaling

6. HadAM3P PRECIS The third-generation Hadley Centre RCM (PRECIS) is based on the latest GCM, HadCM3. It has a horizontal resolution of 50 km with 19 levels in the atmosphere (from the surface to 30 km in the stratosphere) and four levels in the soil.

7. Surface and lateral boundary conditions 1.Surface boundary conditions are only required over water, where the model needs time series of surface temperatures and ice extents. 2.Lateral boundary conditions provide dynamical atmospheric information at the latitudinal and longitudinal edges of the model domain. There is no prescribed constraint at the upper boundary of the model. The lateral boundary conditions comprise the standard atmospheric variables of surface pressure, horizontal wind components and measures of atmospheric temperature and humidity. 3.These lateral boundary conditions are updated every 6 hours, surface boundary conditions are updated every day. Sulphur cycle 1.A certain configuration of the PRECIS RCM contain a full representation of the sulphur cycle then a set of boundary conditions (including sulphur dioxide, sulphate aerosols and associated chemical species) are also required for this. The model step forward every five minutes of model time (about four seconds of real time), calculating the new state of the climate system at each step.

8. Experiment Design Model UsedPRECIS (A Regional Climate Model of Hadley Center UK) Driving DataHadAM3P (A High Resolution (150 Km) GCM Derived from HadCM3 AOGCM ) Resolution50 Km (0.44°) Model DomainSouth Asia (Lat 5N to 50N, Lon 55E to 100E) Time Slices1961-90 (Base), 2071-2100 (Future) ScenarioA2 Analysis DomainPakistan (Divided into three Sub-regions) Output DataMonthly and Daily

9. A measure of the confidence to be placed on projections of climate change from a particular climate model (global or regional) comes in part from its ability to simulate recent climate. Needless to say, no model will give a perfect validation against climatology or observations. It is best to validate two or more climate models (GCM or RCM) as it will then enable a choice to be made of the most appropriate model to be used in scenario generation for that region. Validation Results

10. (a)South Asia domain topography showing values of altitude in meters (m). (b)The standard deviation (S.D) of elevation showing RCM elevations are averaged values for each grid box's area (so peaks will indeed be smoothed out), S.D. is calculated from the original 10 minute resolution global data and then averaged to the grid of the regional model (In meters). The topography of the domain

11. Bias over South Asia Base (1961-1990)

12. Correlation Maps TemperaturePrecipitation Base (1961-1990)

13. Model Bias over Pakistan Prec %change=[(base-cru)/cru]*100 Temp Diff =(base-cru) Base (1961-1990)

14. RMSE Maps TemperaturePrecipitation Base (1961-1990)

15. BOX A BOX B BOX C

16. Base (1961-1990)

17. Annual Cycle profile for scatter plots

18. Base (1961-1990) Monthly profile of Scatter plot for all three boxes (12 x 30 = 360 months)

19. PRECIPITATION TEMERATURE Monthly profile of Scatter plot for all three boxes (12 x 30 = 360 months) Base (1961-1990)

23. Annual Summer Winter Base (1961-1990)

24. PRECIPITATION CORRRMSE (mm/d) % diff (mm/d) (model-cru)/cru *100 BOX A0.3814721.9505696.1434 BOX B0.626881.38729-0.8917 BOX C0.5628211.0969894.0005 PAK0.61481.020349.8928 TEMPERATURE CORRRMSE (mm/d) Diff (°C) (model-cru) BOX A0.9662135.74479-4.1514 BOX B0.9251654.26976-0.4439 BOX C0.9464073.106950.7832 PAK0.95023.3034-0.3163 Base (1961-1990)

25. FUTURE CHANGE

26. Future Change over South Asia Future (2071-2100)

27. ANNUAL Prec %change=[(future-base)/base]*100 Temp Diff =(Future-base) Future (2071-2100)

31. Annual Summer Winter Future (2071-2100)

32. PRECIPITATION ΔP %(mm/d) AnnualSummer (JJAS)Winter (DJFM) BOX A11.35-0.8820.43 BOX B0.780.97-7.74 BOX C-0.51-3.37-24.53 PAK3.38-1.459.39 TEMPERATURE ΔT(°C) AnnualSummer (JJAS)Winter (DJFM) BOX A4.764.814.97 BOX B4.984.865.20 BOX C4.684.564.71 PAK4.774.684.88 Future (2071-2100)

33. Work in Progress Daily data analysis of minimum, maximum and mean temperatures for finding climate indices in future. (Paper to be presented in Young Scientist Conference in November) Future Work 1.Analysis of more downscaled variables like SLP, Solar Radiation flux etc for impact studies (on Monthly bases only) 2.Compassion of HadAM3P simulation with ERA40 downscaled data set. (instead of CRU) 3.Using these outputs in crop and hydrological models. 4.Comparison of PRECIS with RegCM3 output.