گرمایش جهانی و ستبرای نیمۀ زیرین هواسپهر

Most scientists believe that the phenomenon of global warming occurred, however, in the case of the occurrence of this phenomenon by some environmental scientists have raised doubts. They are questioning global warming by arguing that the temperature recorded at the weather stations cannot be representative of the occurrence of the temperature rise. Because with the passage of time and the increase in population and a stronger urban heat island, temperature, weather stations indicate heat island is not global warming. In order to remove this doubt, we can evaluate this with a different approach and instead assessment of temperature, global warming from the atmospheric thickness changes examined. For this purpose, geopotential height data network for level of five hundred and thousand hPa, from date 1.01.1979 to 30.12.2013 the Northern Hemisphere for 12,782 days on the Web site of the NCEP / DOE was extracted. Thickness maps were calculated for each day and then maps the average thickness was provided every day for the whole hemisphere. This calculation was performed for all 12,782 days. Thus, the weighted average time-series of the northern hemisphere atmospheric thickness was prepared. This Time series, in addition to the northern hemisphere, was calculated to Iran and its behavior with time series average minimum and maximum temperatures of Iran was investigated. Studies show that during the period studied (2013-1979) the average thickness of the bottom half of the northern hemisphere atmospheric increased about 13 meters. Year of 1998 is a turning point in the northern hemisphere atmospheric thickness changes. This year has seen a jump in the time series of the northern hemisphere atmospheric thickness. Studies show that changes in all latitudes of the Northern Hemisphere atmospheric thickness is not uniform. In tropical areas is very low and at high latitudes, is more severe and has significantly increased. The relationship between the thickness of the northern hemisphere atmospheric and Iran show that atmospheric thickness of Iran about 2.7 m during 35 years period more than the average thickness of the northern hemisphere has increased. This means that the rate of increase in Iran, is higher than the average northern hemisphere. Studies show that the minimum temperature time series have stronger relationship with time series average thickness of the northern hemisphere atmospheric. While the maximum temperature time series with time series of a stronger relationship between atmospheric thicknesses of Iran. Evaluation of minimum temperature time series with atmospheric thickness time series indicated that the minimum temperature behavior before and after 1992 has changed. This may indicate that the increase in minimum temperature variability is in the second phase. In total, the investigation showed that with one degree rise in average temperature Iran, atmospheric thickness of about 17 meters has increased.