modelling of climatic parameters in province of southern khorasan

introductionclimate change has played an important role in all aspects of human life. therefore, climatepredictions in atmospheric general circulation models (gcm) will have particular importance.in this study, downscaling by a1b scenarios, ipcm4 and bcm2 of atmosphere generalcirculation models in lars-wg model are used for analysis of climate change impacts onmaximum and minimum temperature, solar radiation and precipitation. the data have beengathered from 7 synoptic stations in province of southern khorasan. for this purpose,assessment process of simulation and observation data are conducted by three steps, includingcalibration, validation and modelling. to evaluate the agreement between the observed andsimulated data, two indexes were used; root mean square error (rmse) and coefficient ofdetermination (cd). the results of analysis in makesens, sin’s estimator and mann-kendallshowed that minimum temperature, maximum temperature and evapotranspiration in all stationswill be increased in years of 2011-2060. the results have shown that rainfall in all stations(except ghaen station) will be decreased and solar radiation in all stations (except ghaen andferdous station) will also be increased. increasing trend in temperature in birjand and ghaenstation will be lower and in tabas station will be higher. it may be appeared that weak changesin climatic parameters in some stations are related to specific geographical conditions andtopography of this region.climate change in the past and today would change the pattern of human life and it seemsthat humans and their activities are causing the global climate change. uncontrolled growth ofpopulation, transportation and other human activities, particularly pollution resulted fromindustries lead to major changes in climate. after the industrial revolution changes in globalclimate such as increases in extreme climatic events have appeared due to the excessive use offossil fuels and land use change. at present, this variability has become a major concern ofclimatologists and weathermen. therefore, attention to researcher long term forecast aboutclimate parameters for change value help decrease the effects of ill climate change.atmospheric general circulation models to assess future climate is one of the common methods.meanwhile, lars-wg model as one of the general circulation models of the atmosphere isimportant for future climate change and has led to some efforts by many scholars. the highaccuracy of climate data modelling in different climatic stations has been confirmed by manyresearchers.methodologyin this study at first, daily statistics including minimum temperature, maximum temperature,rainfall and radiation related to 7 synoptic stations in province of southern khorasan wereobtained from meteorological organization of iran (table: 1).table 1: geographical characteristics of the sample stationsstations lon lat elebirjand 59 12 32 52 1491boshruyeh 57 27 33 54 885ferdous 58 10 34 10 1293ghaen 55 05 33 47 845khour 58 28 32 56 1117nehbandan 58 48 36 16 1213tabas 56 55 33 36 711in second step, some weather data have been produced by using parameters listed in larsmodels. two bcm2 ipcm4 models for each synoptic station in south khorasan are used in thisstudy to arrive target modeling data under scenario a1b. after entering data into the modellars-wg and getting the trends in the observed time series data, we have attempted to reproducethe data at the stations during 2011- 2060.. finally, the simulated data are compared withobserved data using statistical analysis and graphing. they have also examined the ability of themodel to simulate meteorological data in stations. the root mean square error (rmse) andcoefficient of determination (cd)have also been applied. if the rmse values are closer to zero,this indicates the observed and simulated values are closer to each other and to be more preciseanswers in each step.results and discussionthe results of the research showed that bcm2-a1b models in birjand, boshruyeh, ferdous,nehbandan and tabas and ipcm4-a1b models in ghaen, have the lowest simulated values.distribution of annual minimum temperature simulated for the period 2011-2060 shows that thephysical geography research quarterly, 46 (3), fall 2014 11minimum temperature in southern khorasan province is 0.02 per year and the coefficient ofdetermination of 0.09 is increasing and that the minimum temperature during the five decadescan be changed between 11.4 to 12.9 degrees. the simulations conducted by lars-wg modelsover the next fifty years will change in the average of minimum temperature among thesynoptic stations of provinces, from 7.5 degrees in ghaen to 17 degrees in tabas. the averageof maximum temperature will also change from 23 degrees in ghaen to 30 degrees in tabas. inprovince of south khorasan, the average of minimum temperature is 12 degrees and the averageof maximum temperature is 26.6 degrees. increasing trend of temperature in birjand and ghaenstations will be lower and in tabas station higher. obviously, due to the lower temperature, thecities of ghaen and birjand will experience more precipitation. nehbandan, tabas and khorwill have the highest mean radiation in cities and birjand will receive the lowestevapotranspiration and radiation and tabas the highest rates of evapotranspiration.conclusionfrom the results this can be concluded that bcm2-a1b models in birjand boshruyeh, ferdous,nehbandan and tabas and ipcm4-a1b models in ghaen have the lowest differences imulatedvalues with observed values. results of lars model simulations for the next fifty yearsshowed an average low temperature in ghaen and birjand cities. the birjand has the lowestrates of evapotranspiration and tabas the highest temperature and the least amount ofprecipitation. ghaen had not seen much rain, but relative to other stations it will have weakincreasing trend. the results of analysis of makesens, sin’s estimator and mann-kendallshowed that in the years from 2011 to 2060 we will experience an increase in the minimumtemperature, maximum temperature and evapotranspiration in all the stations and also adecrease in all (except ghaen station). it will also observe an increasing trend in radiation in allstations except for ghaen and ferdous.