Authors: H Athar
Publish Date: 2013/03/06
Volume: 119, Issue: 2, Pages: 333-344
Abstract
Variability in the observed daily temperature for the 31year period 1978–2008 is studied for northern Saudi Arabia nSA by computing the probability distribution functions PDFs on a seasonal basis The 31year base period is divided into three decades and the results for the first 1978–1987 and the last decade 1999–2008 are presented When averaged over all seasons mean values of the observed decadal PDFs depict a positive shift from the first to last decade in the minimum mean and maximum temperature of 081 °C 103 °C and 125 °C respectively The daily temperature datasets from a regional climate model RCM and two versions of a coupled atmosphereocean general circulation model AOGCM are compared with the observed daily temperature datasets The RCM is driven by reanalysis data for the historical period and by the HadCM3 model for the future while the AOGCMs used are the GFDL CM20 and 21 models with both HadCM3 and the GFDL simulations corresponding to the SRES A1B scenario The average shifts from 1978–1987 to 1999–2008 in the mean value of the PDFs for the minimum mean and maximum temperature are 063 °C 054 °C and 045 °C respectively for the RCM and 097 °C 097 °C and 096 °C respectively for the AOGCM Thus the RCM shows a smaller shift in the mean of PDF for maximum temperature than for mean or minimum temperature the AOGCM shows a comparable shift for all three and the observations show a greater shift in the PDF for maximum temperature For the period 2070–2099 relative to 1978–2008 the three average shifts are 411 °C 387 °C and 344 °C for the RCM and 363 °C 374 °C and 384 °C for the AOGCMThe author thanks Presidency of Meteorology and Environment PME Jeddah Saudi Arabia and Dr Mansour Almazroui for providing the observed dataset The PRECIS simulation results were made available by Dr Panos Hadjinicolaou The GFDL based AOGCM datasets were obtained from the following website http//data1gfdlnoaagov/ The author also thanks Dr Danny Harvey and the three anonymous reviewers for their appreciation and useful comments
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