1. Regional Climate Model Version 4.1 (RegCM4.1) Centre for Oceans, Rivers, Atmosphere and Land Sciences Indian Institute of Technology Kharagpur Kharagpur 721302, INDIA 7 th February 2011 S. Maity, S. Nayak, M. Mandal EPIKH CHAIN School, 7 th -17 th February, 2011, VECC, Kolkata

2. Outline….. Aspects of the Study Model Description Customization of Model Prerequisites Key Notes Data

3. Aspects of the study  Impact of Land Use Land Cover Changes on the Climate over the Indian Region using RegCM4.1  Simulation of Indian Summer Monsoon using RegCM4.1

4. Model Description RegCM4.1 is  The latest version of RegCM  Designed by International Center for Theoretical Physics (ICTP), Trieste, Italy  A non-hydrostatic, σ-coorindate, primitive equation model  Developed by Fortran-95 language  Having four components such as Terrain, ICBC, RegCM, and Postprocessor  Terrain and ICBC are the two components of RegCM preprocessor

5. Customization of the model RegCM4 will be implemented over Taking Indian region centrally 30 o E - 120 o E and 15 o S - 45 o N Grid resolution of 30 Km

6. Prerequisites Operating System (OS) Any suitable version of LINUX/UNIX Compilers The model can be run with the following compilers: 1.gfortran/sunf90 These are general fortran-95 compiler on different Linux distribution gfortran compiler version should be > 4.2 These compilers are not sufficient to compile all the module of the model (Serial Part only) Compilers Contd…

7. Prerequisites ( Contd….) 2. pgi compiler(pgf90/pgcc) Portland Group Fortran compiler It is not freely available The version should be >= 10 3. Intel Fortran Compiler (ifort/icc) This is a very popular fortran compiler It is freely available For our case this is the most efficient one Python This is required for some utility tools of the model The version should be >= 2.5

8. Libraries 1. NetCDF libraries with HDF5 and zlib or szlib Input/Output of RegCM 4.1 stored in NetCDF format Can take advantage of NetCDF-4 features Includes data compression through HDF file format & compression library(zlib or szlib) All the package should be installed with same compiler Libraries Contd… Prerequisites ( Contd….)

9. 2. Message Passing Interface (MPI) RegCM 4.1 supports Parallel execution through MPI interface To run the parallel version of the model system must be equipped with a MPI implementation Offers libraries, compiler wrappers and program that execute parallel code Generally, openmpi-1.4.3 is used Installation should be done by same fortran compiler Prerequisites ( Contd….)

10. Key Notes Note 1: RegCM 4.1 has two versions  Serial  Parallel To use the RegCM with CLM3.5 coupler parallel version is required Note 2: CLM currently compiles with only PGI compilers(pgf90) or Intel compilers(ifort) cmpilers due to the limitation in the CLM3.5 code itself For our purpose we want to use RegCM with CLM3.5 coupler

11. Data Terrain heights and land use data are obtained from a global data set at 30 minute resolution. Meteorological parameters: The initial and boundary conditions necessary for the model integration will be taken from the NCEP/NCAR reanalysis (NNRP1). Sea Surface Temperature (SST) which is an important parameter for providing lower boundary condition to the model is provided using Global Sea Surface Temperature (GISST) 1 o monthly gridded data obtained from the Hadley Centre of UK Met Office.

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