The Trend of Sea Level Pressure Changes in Iran with Emphasis on Climate Hazards

The occurrence of climatic hazards is one of the main characteristics of the climate of Iran, which it always has economic, social, and financial losses. Undoubtedly, the first step in reducing the climate impact of the country is to identify the causes of these hazards. Sea level pressure is one of the most important climatic elements that can affect important climatic factors such as temperature, rainfall and wind that cause climate hazards. Increase or decrease severity and the expansion of the eastern and northern levels of sea level pressure centers is one of major determinants of dry and humid periods in Iran. The study of published works and resources shows that a comprehensive study is required on changes in Iranian sea surface pressure in different seasons. Therefore, the purpose of this study is to reveal the trend of sea level pressure changes in different seasons. For this purpose, sea level data with NC format at 12 GMT Obtained from the NCEP / NCAR database from 1948 to 2016. Afterward, to obtain the seasonal categorization and mapping, the next steps were converted to TXT, Matlab, EXCEL, and GIS formats. Then, long-term changes in sea surface pressure were revealed. Study of time series trend diagram as well as values of mean, average, minimum, and average of maximum sea level pressure with the Mann Kendall test in different seasons showed that the level of significance level in all cases is smaller than 0.05, and the average annual pressure level of the Iranian sea has a significant upward trend, which is increasing by 0.047 hpa per year. The average 10-year map of Iran's surface pressure was similar in different seasons, and the average pressure dropped from the north of Iran to the south. Anomalous maps of the mean of ten years of sea-surface pressure showed that anomalous amounts have reached their highest positive levels in recent decades. Considering the importance of the issue and the vulnerability of the country to environmental hazards, it is clear that climate risk management will have a higher chance of success and credibility with increasing sea-level pressure.