Spatial analysis of dew point temperature trend changes in Iran

Document Type : Original Article

Authors

1 PhD student of Climatology, Zanjan University, Zanjan, Iran

2 Associate Professor of Climatology, Department of Geography, Zanjan University, Zanjan, Iran,

3 Assistant Professor of Climatology, Department of Geography, University of Zanjan, Zanjan,

Abstract

Dew point temperature is one of the most important atmospheric variables and its long-term changes can lead to changes in the climatic characteristics of an area. In order to spatially analyze the trend of dew point temperature changes in Iran, the annual and monthly average data of this variable in 109 synoptic meteorological stations during the statistical period of 1990-2022 have been used. In order to investigate the effect of changes in other atmospheric variables on dew point temperature, the data of average annual relative humidity, average minimum and average maximum temperature, and average total annual precipitation have been used. In order to investigate the change process using the Mann-Kendall method and to identify the patterns governing the spatial changes of the dew point temperature in Iran, the spatial autocorrelation models of Global Moran and Getis-Ord General G statistic have been used. The results of investigating the trend of dew point temperature changes show that this variable has an increasing trend in the areas around the north and South Seas and the northwest region, and a decreasing trend in the central, eastern and northeastern regions of Iran. Spatial analysis of areas with high dew point temperature shows a severe cluster pattern, which means that areas with high dew point temperature are mainly spread in parts of the coasts of the Caspian Sea and many parts of the coasts of the Persian Gulf and Oman Sea, parts of northern Azerbaijan and Ardabil. This shows that the temperature of the dew point increases as it approaches moisture sources. Also, the spatial analysis of the areas with low dew point temperature also shows that these types of temperatures are generally concentrated in a large part of the central areas of the south of Khorasan province and the east and southeast of Iran.

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Ali, H., Fowler, H.J., & Mishra, V., 2018, Global observational evidence of strong linkage between dew point temperature and precipitation extremes. Geophys. Res. Lett, 45, pp. 320–30.
20.Arikan, B. B., Jiechen, L., Sabbah, I. I., Ewees, A., Homsi, R., & Sulaiman, S. O. 2021, Dew point time series forecasting at the North Dakota. Knowledge-Based Engineering and Sciences2(2), 24-34.
21.Bui, A., Johnson, F., & Wasko, C. 2019, The relationship of atmospheric air temperature and dew point temperature to extreme rainfall. Environmental Research Letters, 14(7), 1-10.
22.Dario, P., & Leonardo, V. N., 2021, Exploring the linkage between dew point temperature and precipitation extremes: A multi-time-scale analysis on a semi-arid Mediterranean region, Atmospheric Research, 254, pp. 1045-1061.
23.Famiglietti, C. A., Fisher, J. B., Halverson, G., & Borbas, E. E. 2018, Global validation of MODIS near‐surface air and dew point temperatures. Geophysical Research Letters, 45(15), 7772-7780.
24.Górnicki, K., Winiczenko, R., Kaleta, A., & Choińska, A. 2017, Evaluation of models for the dew point temperature determination. Technical Sciences, 20(3), 241-257.
25.Hubbard, K. G., Mahmood, R., & Carlson, C. 2003, Estimating daily dew point temperature for the northern Great Plains using maximum and minimum temperature. Agronomy Journal, 95(2), 323-328.
26.Kim, S., Singh, V. P., Lee, C. J., & Seo, Y. 2015, Modeling the physical dynamics of daily dew point temperature using soft computing techniques. KSCE Journal of Civil Engineering, 19, 1930-1940.
27.Lawrence.M.G 2005, The Relationship between Relative Humidity and the Dew point Temperature in Moist Air. Bulletin of the American Meteorological Society. Volume 86: Issue 2: PP 225–234.
28.Lenderink, G., & Meijgaard, E.V. 2010, Linking increases in hourly precipitation extremes to atmospheric temperature and moisture changes, Environ. Res. Lett, 5 , PP.1-9.
29.Mortuza, M.R., Selmi, S., Khudri, M. M., Ankur, A. K., & Rahman, M. M. 2014, Evaluation of temporal and spatial trends in relative humidity and dew point temperature in Bangladesh. Arabian Journal of Geosciences7, 5037-5050.
30.Robinson, P. J. 2000, Temporal trends in United States dew point temperatures. International Journal of Climatology: A Journal of the Royal Meteorological Society, 20(9), 985-1002.
31.Sein, Z. M. M., Ullah, I., Iyakaremye, V., Azam, K., Ma, X., Syed, S., & Zhi, X. 2022. Observed spatiotemporal changes in air temperature, dew point temperature and relative humidity over Myanmar during 2001–2019, Meteorology and Atmospheric Physics134, 1-17.
32.Wasko, C., & Sharma, A. 2015. Steeper temporal distribution of rain intensity at higher temperatures within Australian storms, Nat. Geosci, 8, pp. 527–9.
33.Wasko, C., Lu, W. T., & Mehrotra, R. 2018, Relationship of extreme precipitation, dry-bulb temperature, and dew point temperature across Australia. Environmental Research Letters13(7), 074031.
34.Wermter, J., Noble, S., & Brian, V., 2022, Impacts of the Thermal Gradient on Inland Advecting Sea Breezes in the Southeastern United States, Atmosphere, 13, pp. 1-13.
35.Yao, F., Sun, J., & Dong, J. 2022, Estimating Daily Dew Point Temperature Based on Local and Cross-Station Meteorological Data Using CatBoost Algorithm. cmes-computer modeling in engineering & sciences, 130(2), 671-700.
36.Zounemat-Kermani, M. 2012, Hourly predictive Levenberg–Marquardt ANN and multi linear regression models for predicting of dew point temperature. Meteorology and Atmospheric Physics, 117(3-4), 181-192.