PENGARUH FENOMENA SUNSPOT TERHADAP VARIASI SUHU UDARA DAN KELEMBAPAN RELATIF DI KOTA MEDAN

The effect of solar activity on weather and climate has become a research topic after the 11-years sunspot cycle was discovered. This research is aimed to find the effect of sunspots on the variations of air temperature and relative humidity (RH) in Medan City. This research used the daily average of air temperature and RH data from 1985 – 2014 at Kualanamu Meteorological Station which was obtained from BMKG. Meanwhile, the daily sunspot number data within the same year period was obtained from the Solar Influences Data Analysis Center (SIDC) The Royal Observatory of Belgium (RWC). The method that was used in this study is a statistical method. The results of the study show that the coefficient of determination R² between the sunspot number and the parameters of air temperature and RH are 0.9 and 2.2, respectively. Meanwhile, the correlation coefficient between sunspot number and the parameters of air temperature and RH is -0.058 and 0.038, respectively. All variables showed p-value <0.05 which means statistically significant. Thus, the increase in the number of sunspots has significant effects on decreasing air temperature and increasing RH in Medan City.