The dynamics of the radiation budget and its components in Moscow according to the new RAD-MSU complex of the BSRN standard

Monitoring of the radiation budget and its components is necessary for the assessment and forecasting of climate change. In August 2021, high-quality Kipp&Zonen instruments recommended for measurement on the BSRN network were installed at the Moscow State University Meteorological Observatory (MSU MO), and the RAD-MSU (BSRN) complex was established [Chubarova et al., 2022; Piskunova et al., 2024]. The instruments measure all components of the radiation budget: upward and downward shortwave and longwave radiation, direct and diffuse shortwave radiation, erythemal UV radiation, and UV-A radiation with minute time resolution. During the monitoring, a system for evaluating data quality criteria was developed, and software for automated data processing was created. 

We analyze the dynamics of the components of the radiation budget during the entire measurement period for clear and cloudy conditions from August 2021 to March 2025. The influence of various geophysical factors on shortwave and longwave radiation is considered. The role of surface albedo, moisture content, and cloud cover was evaluated for the shortwave radiation. The amount of cloud transmission for global shortwave radiation was estimated, depending on the cloud cover, separately for snow and snow-free conditions. For the components of the net longwave radiation, the quantitative characteristics of the relationship with surface temperature, the lower and total cloud cover, and moisture content were evaluated. 

It was revealed that in the period from November to March, the net longwave radiation prevails in absolute magnitude over the net shortwave radiation due to the low sun elevation, high surface albedo, and frequent occurrence of overcast conditions.

The analysis of the conditions for observing positive values of the net longwave radiation is continued. Several numerical experiments with the ICON model confirm the possibility of the transition of net longwave radiation values through zero under the conditions of advection of warm air onto a snow surface.

Additionally, we analyze the influence of the temporary transfer of equipment on data quality due to the repair at the Moscow State University. Comparisons with the data of standard actinometric observations at the Moscow State University have been carried out.

Литература

Chubarova N.E. et al. New radiation complex at the Moscow State University Meteorological Observatory of the BSRN standard: methodological aspects and first measurement results // OAO. 2022. V. 35. № 8. P. 670–678.

Piskunova D. et al. Radiative Regime According to the New RAD-MSU(BSRN) Complex in Moscow: The Roles of Aerosol, Surface Albedo, and Sunshine Duration // Atmosphere (Basel). 2024. V. 15. № 2. P. 1–19.