Long-term variability of the MERRA-2 radiation budget over Poland in Central Europe

• Published in: Acta geophysica 2024, Vol.72 (4), p.2907-2924
• Main Authors: Markowicz, Krzysztof M., Okraska, Igor, Chiliński, Michał T., Makuch, Przemysław, Nurowska, Katarzyna, Posyniak, Michał A., Rozwadowska, Anna, Sobolewski, Piotr, Zawadzka-Mańko, Olga
• Format: Article
• Language: English
• Subjects: Advection; Aerosols; Air masses; Air temperature; Albedo; Budgets; Carbon dioxide; Climate change; Cloud cover; Cloud optical depth; Clouds; Data analysis; Earth and Environmental Science; Earth Sciences; Earth surface; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Global warming; Greenhouse effect; Greenhouse gases; High temperature effects; Optical analysis; Optical thickness; Ozone; Radiation; Radiation budget; Review Article - Atmospheric & Space Sciences; Short wave radiation; Structural Geology; Sulfate particles; Sulfates; Surface temperature; Surface-air temperature relationships; Temperature changes; Temperature rise; Temporal variability; Trends; Variability; Warm seasons; Water vapor
• ISSN: 1895-7455; 1895-6572; 1895-7455
• DOI: 10.1007/s11600-023-01256-5

This paper discusses the radiation budget and its temporal variability over Poland. The data analysis is based on the MERRA-2 reanalysis for the years 1980–2020. During the last four decades, the enhancement of climate warming has been observed, which coincides with the changes in the radiation budget. Positive and statistically significant trends at the top of the atmosphere (TOA; 0.7 ± 0.2 W/m 2 /10 year) and on the Earth’s surface (1.5 ± 0.2 W/m 2 /10 year) radiation budget (net downward flux) are mainly a consequence of changes in the amount of aerosol and greenhouse gases (GHG). According to MERRA-2, the AOD during this period decreased by − 0.19 (at 550 nm), which is 87% of the long-term (1980–2021) mean value (0.22). The reduction of AOD is due mainly to the decline of non-absorbing sulfate particles, which leads to a reduction of single-scattering albedo (SSA) by − 0.008 per decade and Angstrom exponent (AE) by − 0.06 per decade (both trends statistically significant). On the other hand, the GHG concentration increased by 4.9%/10 year and 3%/10 year, respectively, for CO 2 and CH 4 . The total column of water vapor increased (1.3%/10 year), while ozone decreased (− 1%/10 year). Despite the fact that cloud cover and cloud optical depth (COD) decreased (− 1.8%/10 year and − 1.0%/10 year), the impact of cloud on temporal variability radiation budget is small. It can be explained by nearly compensated shortwave (SW) cooling and longwave (LW) heating effects. During the analysis period, near-surface air temperature increased by 2.0 °C. The estimated increase in SW net surface radiation (7.9 W/m 2 ) leads to climate warming by 0.8 °C, which is a consequence mainly of the reduction of aerosol (0.4 °C) and cloud cover (0.2 °C). The impact of the change of SW radiation on air temperature is more pronounced during the warm season, while during the cold, air temperature change is controlled mainly by the variability of air mass advection.