جستجوی مقالات مرتبط با کلیدواژه "دماهای حداقل" در نشریات گروه "جغرافیا"

Today, long-term forecasting of climate variables has received much attention in order to be aware of the extent of change and, consequently, to take the necessary measures to mitigate the adverse effects of climate change. In this study, minimum temperatures in Kurdistan province were predicted using LARS-WG6 downscaling for the next three 20-year periods (2040-2021, 2060-2041, 2080-2061). For this purpose, the HadGEM2-ES general circulation model and three scenarios of RCP8.5, RCP4.5 and RCP2.6 were used. To generate the time series of future periods, daily data for the statistical period 1989-2019 were used and the trend of its changes was analyzed using Mann-Kendall test. The results showed that LARS-WG6 software simulates the minimum values of the minimum temperature well with low error indicators. Also, based on the results of the HadGM2-ES global model output in the study area, the minimum temperature in the future period will be higher than the base period in all scenarios and periods. The intensity of this increase under the RCP8.5 scenario is related to the last period of the century (2080-2061) and its lesser extent is related to the period (2060-2041) under the RCP4.5 scenario. Examination of seasonal averages also shows that spring has a lower temperature increase and autumn has a higher temperature increase. The trend of changes shows that the trend is positive and negative in both directions, so that in most stations and scenarios in different forecast periods, spring will have the most positive trend and autumn will have the most negative trend. Therefore, it can be concluded that the temperature will increase in future periods and the effect of cold waves will decrease.

An AO is an example of teleconnection pattern in the northern hemisphere’s winter. In this study, the effect of AO on the monthly minimum temperatures in the North-East region of Iran is investigated. The required statistics, including statistics monthly minimum temperatures for 17 synoptic stations of the under study area was provided from Iran Meteorological Organization’s (IRMO). Pearson correlation analysis as the main method used in this study Show an inverse relationship between minimum temperatures and most selected stations and AO index.The results of this study shows that there is a significant relationship between the AO teleconnection pattern and minimum temperatures of north-east of Iran during the cold season of the year. This shows decrease of temperature in positive phase of the AO and rise of temperature is negative phase. In terms of time correlation coefficients were calculated showed a significant negative correlation between the temperature of stations and the AO Among the studied stations, the relationship between the minimum and average monthly temperatures in Birjand and Bojnoord station more than other stations, affected by the AO pattern, has been fluctuated and significant correlation coefficients between the minimum and average temperature of Birjand and Bojnoord Stations with AO has been calculated. The effect of Arctic oscillation on mean temperature of the studied area, north-east of Iran, during the three months, January to march, and ,two months, January to February, is very distinctive against any other periods of time.