Analysis of the trends of solar radiation change in Basra and Karbala stations for the period (2009-2010/2019-2020) by using the Mann-Kendall equation

Abstract

The Mann-Kendall equation was used to analyze the seasonal time series of solar brightness values ​​at the Basra and Karbala climatic stations for the period (2009 - 2010 / 2019 - 2020). This test is one of the nonlinear tests widely used to verify the existence of a potential significance in the direction of the time series. The results showed a downward trend in both stations for the fall and winter seasons, while the results of an analysis of the change direction of the actual sun’s brightness showed an upward trend in the summer and spring for both stations for the same time period.

Keywords: actual solar brightness, analysis of the trend of change, statistical significance.