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The Study of Temperature Variation in the Plain of Mashhad as the index of Climate Change in the Region

Climate change and temperature increase are considered as important ecological issues on which a lot of studies have been done in recent years. The increase in average global tempereture and its variations, which are a part of all climate change theories, act as indicators of climate change. Climate changes in a region can be traced through the examination of average temperature variation. Estimates suggests that the average temperature of earth will show an increase of 017 to 2 degrees centigrade up to the year 2030. According to different climate change models, the increase in temperature results from the variations in climate conditions and different predictions and conclusions have been made in many parts of the world. Keeping with these predictions, the average temperature in the global scale will bring about a change of climate between 3.5 to 5 degrees centigrade in dfferent settings up the year 2050. Furthermore, rapid change of temperature in different regions will also show great differences in different regions. The present essay is a part of a research titled: The study of climate change in the plain of Mashhad. The studied region is located in the 580-20ʹ longitude and 60°-8ʹ eastern and 36°-0ʹ latitude and 37°-5ʹ northern in Khorasan Razavi Province which, according to the existing data, has an average annual temperature of 12.4 and an average precipitation of 27816. The synoptic stations of Mashhad and Golmakan and 8 vapor estimation stations and 25 precipitation stations located in the plain were used to obtain the required meteorological data. The periodical temperature variation is a distinct phenomenon in any climate. The study of climate change and global heating deal with temperature changes during long term data gathering periods. The simplest study method for temperature changes is the regression method between temperatures and the time of their occurrence. The Mankendal and Letenmyer methods are two data gathering methods that were used to study the process of temperature change in the plain of Mashhad. The temperature change process was studied at two possible levels of 1 and 5. Letenmyer and Mankendal methods in the levels of 1 and 5 percent were used to study temperature change process every month. The results indicated that an increasing course was presented in most of the months. Through linear, symbolic and type two regression method an increasing curse was determined for every one of the three parameters (Minimum, average and maximum). This increasing temperature process was especially more obvious in minimum temperature. Temperatures were compared with each other in different data gathering periods and the triple average of temperature at the levels of I and 5 percent showed a meaningful difference in the last 25 years. This difference was more remarkable in the last ten years with long term average. In the Letenmyer and Mankendal methods in the levels of I and 5 percent, the process of temperature change was studied for every month and the results indicated an increasing process in most of the months. The temperature change in each year was calculated by the long term average and the results showeda positive and increasing change process in every month. The annual temperature change average in the plain of Mashhad was studied during the data gathering period with the long term average of a 50 year period. In this case the temperature data indicatesa positive process in the region and on the whole temperature changes were remarkable in the plain of Mashhad. These changes can be named as an index of climate change.