INFLUENCE OF COMPOSITION OF ATMOSPHERE OVER BULGARIA ON SURFACE RADIATION FLUXES AND AIR TEMPERATURE
Problems of Geography, 2017, Vol.4, DOI: https://doi.org/10.35101/PRG-2017.4.5
Peter Nojarov
Abstract:
This study determines the influence of greenhouse gases and aerosols in the atmosphere over Bulgaria on different radiation fluxes at Earth‘s surface, and on near surface air temperature. The research period is 09.2002 – 12.2015. Data for observed air temperature in Bulgaria, specific humidity at different levels, content of CO2 and CH4 in atmosphere, aerosol optical depth and different radiation fluxes at surface level were processed using statistical methods. The results show that air temperature in near surface layer is determined mainly by upward longwave radiation. This radiation flux in turn depends on downward shortwave and longwave radiation fluxes. Greenhouse gases determine downward longwave radiation flux and aerosols – the two shortwave radiation fluxes (downward and upward). The influence of aerosols on air temperature is complex and greater than assumed so far, their effect being prolonged in time covering a period of at least two months. Thus, aerosols are the second most important factor that influences air temperature. The main greenhouse gas is water vapor, but based on the available data it is difficult to estimate how much it affects air temperature and how much air temperature affects water vapor content in atmosphere. The second most important greenhouse gas is CO2 , but it is the third factor influencing air temperature. The role of CH4 in the greenhouse effect remains difficult to assess due to the revealed significant inversely proportional relationship between this gas and water vapor. Increased content of water vapor leads to an increased content of hydroxyl radical in atmosphere, which in turn significantly reduces the content of CH4 in the air.
Keywords:
greenhouse gases, aerosols, air temperature, radiation fluxes, Bulgaria
Author information:
Author: Peter Nojarov
E-mail: pnojarov@abv.bg
Affiliation: National Institute of Geophysics, Geodesy and Geography – BAS, str. Acad. G. Bonchev, bl. 3, Sofia 1113, Bulgaria
How to cite:
Nojarov, P. (2017). INFLUENCE OF COMPOSITION OF ATMOSPHERE OVER BULGARIA ON SURFACE RADIATION FLUXES AND AIR TEMPERATURE. Problems of Geography, 2017, Vol.4, p. 57-78. https://doi.org/10.35101/PRG-2017.4.5