Solar Cycle Influence on Wind, Temperature, and Surface Pressure During 1981–2021 Over Indian Region

Abstract

A solar cycle linkage is investigated on wind, temperature and surface pressure throughout 1981 to 2021 using The Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA2) data. Sunspot data were obtained from the Royal Observatory of Belgium (solar cycles 21 to early 25). It is determined from the analysis that solar cycle intensity decreased gradually in the last four decades; wind data at six stations (metropolitan cities) over India showed a consistent decrease by an amount of 0.3 to 0.6 m/s, on average 0.5 m/s. A strong association is evident between the solar cycle and wind variability, this is more evident while approaching closer to the equator from northern tropics. Wind speed declined more clearly near and around 10°N latitudes. This consistent decline assumes a strong significance during winter in Northern India i.e., the climatic trend is unfavourable for dispersing the pollutants and will harm the air quality in future. On the other hand, temperature and pressure data showed a climatic increasing trend (~ 0.9 °C and ~ 1.5–2.0 mb) most prominently seen from 2000 to 2021 over the tropical region; which became slightly weak in extra tropical region (Delhi). Temperature and pressure data did not show a relationship with sunspot numbers. It is determined that solar cycle variability has influenced windspeed (positive correlation ~ 0.5, with 95% confidence level) near ground level.