| چکیده انگلیسی مقاله |
Extended Abstract
Introduction
Land surface temperature is one of the key parameters in the study of climate change, which helps in the real assessment of the environmental situation at local to global scales. Investigating the land surface temperature and its changes is necessary to evaluate the climate processes in arid and semi-arid regions. Also, based on the results of the researchers, the observation of the land surface temperature at midday, when its values reach the maximum, has more information about the distribution of energy among the turbulent heat rays, which is due to the key role of the maximum surface temperature in describing its daily cycle. Occurs the actual distribution of the land surface temperature is attributed to the magnitude, the daily range and its relationship with the solar radiation and the thermal radiation of the soil (Bhumralkar, 1975). Braganza et al. (2004) investigated changes in the diurnal temperature range (DTR) as an indicator of global climate change in the 20th century. Their results show that the decrease observed in this index is very high. Will experience Wang et al. (2020) in investigating the relationship between daily temperature range and daily hospitalization for exacerbation of chronic respiratory diseases in 21 Chinese cities showed that the trend of hospitalization increases with the increase of day-to-day temperature difference. According to the research of Xi et al. (2023), the average land surface temperature in the Kilingdaba Mountains in the Central China region during the period of 2000-2020 is estimated to be about 18.2 degrees Celsius. Also, while heating is revealed in the studied area, its rate is stronger at night than during the day, and subsequently the difference between night and day temperatures is decreasing. In addition, in the region of Kiling Daba Mountains, the height factor was the most important factor in the spatial distribution of the surface temperature, and the influence of the mentioned variable on daytime and nighttime temperatures was determined to be 63% and 92%, respectively. In Iran, many researches have been conducted on the changes in the range of the land surface temperature on a local and macro scale (Rahimzadeh and Askari, 2004; Sabziparvar et al., 2011; Salahi et al., 2016; Mozasi et al., 2023).
Materials & Methods
The MODIS sensor was successfully launched by NASA on December 18, 1999. This sensor is installed on two satellites Terra and Aqua. These two satellites image the entire surface of the earth twice a day and collect data in 36 spectral bands (wavelengths of 0.4-14.4 micrometers) with a resolution of 250, 500 and 1000 meters. In this research, day and night data of MYD11A1 product with a spatial resolution of 1000 meters were extracted from the NASA website for 7305 days between 01/01/2003 and 12/31/2022. With the selection of this product and the Aqua satellite, due to the convenient time of its passage over the region, a more detailed investigation of the surface temperature of the Daranjir desert basin was carried out. Since Terra's Khursheed satellite passes over Iran at 10:30 am and 10:30 pm, it cannot provide an accurate picture of the energy balance, for this reason, the Aqua satellite monitors Iran at 1:30 pm and 1:30 pm. is selected. The main reason for this choice is the high energy balance in the middle of the day and the middle of the night. Since the statistical period of Terra is longer than that of Aqua, this satellite should have been chosen for Al-Qaeda, but Aqua satellite data is used more for the reasons described (Wan, 2013).
Results & Discussion
Examining the long-term average surface temperature of Daranjir desert during the last two decades shows that the range of maximum and minimum surface temperature of Daranjir desert is between 15.5 to 51 and -4 to 17.5 degrees Celsius, respectively. If we compare the average maximum temperature (40 degrees Celsius) and minimum temperature (9 degrees Celsius) of the basin, we will find a difference of 31 degrees in day and night temperature, which also shows the characteristic of the basin being a desert. Also, the findings showed that the maximum and minimum temperature of Daranjir desert depends on the altitude; Due to various types of industrial uses, the expansion of urbanization and the increase of heat islands, the highest surface temperature is seen in the northern and western lowland areas of the basin. Also, in lowland and desert areas, due to the presence of barren, sandy, and unvegetated lands, a large part of energy is absorbed and causes an increase in land surface temperature. The lowest land surface temperature is observed at high altitudes. In general, the fluctuation range of 31 degrees annually indicates an increase in heat. Factors such as climate change and global warming and subtropical high pressure in the hot period of the year and successive droughts, reduction of snow cover, reduction of vegetation and increase of barren lands play a major role in heating and cooling of Daranjir basin.
Conclusion
The results of average land surface temperature on a seasonal scale showed that the highest and lowest surface temperatures are seen respectively in the lowlands, especially Chale Bafaq and the highlands, which indicates the effect of altitude on the surface temperature of the Daranjir desert basin. In addition, the results show that the day-to-day difference in the surface temperature of Daranjir desert in the hot period of the year (spring and summer seasons) is more than the cold period of the year (autumn and winter seasons). On an annual scale, it also showed that the average daily surface temperature is 40 degrees Celsius and the average night temperature is 9 degrees Celsius, in which case the day-night difference in surface temperature will be 31 degrees. This significant difference in day and night temperature of the surface can challenge the environment and agricultural production of these areas, which depend on the surface and subsurface water bodies. |