Document Type : Original Article
Authors
1
Graduated from Master's Degree in Meteorology, Climate Change, Faculty of Geographical Sciences, Khwarazmi University, Tehran, Iran
2
Professor Department of Climatology Faculty of Geographical Sciences, Kharazmi University, Tehran, Iran.
3
Assistant Professor Department of Climatology Faculty of Geographical Sciences, Kharazmi University, Tehran, Iran
Abstract
The spatial distribution and trends of cloudy days, particularly during the cold season, carry significant importance for environmental planning and water resource management in arid and semi-arid regions. Clouds, as a crucial component of the hydrological cycle, play a vital role in regulating precipitation patterns, temperature, and evapotranspiration. This research aims to investigate the trends in cloud cover during the winter season and identify the influencing factors in southeastern Iran. By utilizing data from 23 synoptic stations and reanalysis data from the European Centre for Medium-Range Weather Forecasts (ERA5) covering the period from 1989 to 2022, this study employed statistical analyses, including the spatiotemporal distribution of low-level cloud cover (LCC), the Mann-Kendall trend test, and linear regression modeling, to assess long-term changes. The results indicate that the spatial distribution of cloud cover in the study area is influenced by geographical factors such as latitude, longitude, altitude, and atmospheric patterns. Furthermore, trend analysis using the Mann-Kendall test and regression on both observational and ERA5 reanalysis data reveals a decreasing trend in cloud cover during the months of December, January, and February. The most significant decrease in cloudiness was observed in December. The findings of this research can enhance our understanding of regional climate change and improve climate prediction models. Moreover, the results can contribute to water resource management, as well as agricultural and energy-related planning in southeastern Iran
Keywords
Subjects