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The productivity of terrestrial ecosystems is determined, among other things, by solar radiation and its degree of scattering can increase or reduce it. The intensity of scattering is determined by the optical properties of the atmosphere due to the presence of particles suspended in the atmosphere, i.e. clouds and aerosols. Additionally, the amount of these substances and also the physical properties affect the radiation transfer and thus the plants ability of CO2 absorption. In the presented research, an attempt to quantify the impact of the different types of aerosols presence in the atmosphere on the amount of gross ecosystem production (GEP) in a transitional peatland in northwestern Poland was made. Three classes of cloudiness were assumed in the simulations: cloudless, medium and full cloud conditions, and an atmosphere-ecosystem model was used to assess the peatland productivity under these conditions. It was found that changes in the physical parameters of aerosols in the atmosphere can both increase and decrease the amount of CO2 uptake by peatlands by up to 8.2% and 6%, respectively. Thus, the research is extremely relevant to the global carbon balance, as peatlands are one of the largest reservoirs of organic carbon in the biosphere.

The soil CO2 emission is one of the most important parts of forest carbon balance, and accurate estimation of this flux is fundamental for appropriate forest management aimed at adaptation and mitigation of climate change. The soil carbon dioxide flux density is determined by different factors, e.g. soil temperature, humidity, and C-content. The Polish forest habitats classification (based on the climate and soil conditions) provides the practical basis for the effective extrapolation of local carbon dioxide emission observations to larger areas. Thus, the main goal of this study was the estimation of the annual dynamics of the soil CO2 emission at three of the most common forest habitats and to select the most reliable model that can be commonly applied to managed forests. There were three experimental sites selected for this study, and they represented the following forest habitats: optimal conditions for pine forest (OP), rich conditions for pine forest (RP) optimal conditions for mixed oak and pine forest (OOP). These three habitats represent 66% of forested areas in Poland. The sites were located in Oborniki Forest Inspectorate in the Greater Poland Voivodship, Western Poland. The CO2 emission was measured by means of the manual dynamic opaque chamber attached to the infrared gas analyzer (LI-840 LI-COR, USA). There were 3 collars (25 cm diameter) inserted about 15 cm depth into the ground at each site, and the measurement campaigns were carried out from 16th of March 2022 8th of March 2023, at 3-week intervals. The soil measurement system (TMS-4, TOMST, Czechia) was applied for discrete (15-minute interval) measurements of the air and soil temperature and soil water content at each collar. Additionally, soil analysis was made at each site. The initial analysis of obtained results shows that the model based on both soil temperature and soil water content can be considered the most accurate and reliable. The richest forest habitat (OOP) with the highest soil C-content is characterized by the highest annual soil CO2 emission.

Peatlands are ecosystems with relatively low net productivity but a long-term carbon storage period (thousands of years). This carbon stock is continuously related to its hydrogenic origin, resulting in the high sensitivity of peatlands to hygrothermal factors such as temperature and precipitation. Changing the balance of temperature and wetness in peatlands may stimulate higher ecosystem respiration and/or reduce the photosynthetic capacity of plants and consequently shift the peatland from net sinks to sources of CO2 to the atmosphere. Thus, the peatland-climate interaction study is crucial for understanding and predicting their faith in the future.Since July 2019, the eddy covariance (EC) technique has been used to monitor CO2/H2O net fluxes at a baltic raised bog in Bagno Kusowo Nature Reserve, northern Poland (53.82 N, 16.59 E, 144 m a.s.l.). This peatland started formatting thousands of years ago and currently reaches up to 8 m of peat depth. The measurement tower works in collocation with the meteorological station, thus the standard meteorological parameters are measured along with flux observations. These common measurements were the basis for estimating peatland carbon dioxide balance and its relation to biophysical factors.An early start of vegetation (March-April) on the baltic raised bog was noted, as well as predominant emissions from the peatland in mid-summer (August). During 2.5 years of measurements, the peatland in Kusowo was both a net sink and a source of CO2 on an annual basis. The negative impact of lowering the water table level on the CO2 balance (higher emissions) is more noticeable during the growing season when higher temperatures intensify the respiration processes.

Peatlands are among the largest stocks of soil carbon, which can be stored for thousands of years under well-wetted conditions. The main goals of the study were to assess annual and seasonal CO2 balances of a temperate peatland and the main biophysical factors affecting these CO2 fluxes. The studied peatland was usually a CO2 sink with a mean annual net ecosystem production (NEP) of 110±83 gCO2-C·m^−2·yr^−1 and extreme balances in 2006 (-17 gCO2-C·m^−2·yr^−1) and 2011 (194 gCO2-C·m^−2·yr^−1). Annual fluxes were not significantly correlated with biophysical variables, unlike seasonal data. Furthermore, the average air temperature in spring and summer was related to NEP at r^2=0.65 and r^2=0.61, respectively (warmer spring increased NEP while hot summer decreased NEP in these seasons). A decrease in daytime measured NEP during the summer period (June-August) was observed when TA exceeded 25 °C or VPD was above 15 hPa, respectively, due to the growing Reco and possibly plant photorespiration. These findings suggest a negative impact of ongoing global warming on temperate peatland CO2 balances.

The Poland-AOD aerosol research network was established in 2011 to improve aerosol–climate interaction knowledge and provide a real-time and historical, comprehensive, and quantitative database for the aerosol optical properties distribution over Poland. The network consists of research institutions and private owners operating 10 measurement stations and an organization responsible for aerosol model transport simulations. Poland-AOD collaboration provides observations of spectral aerosol optical depth (AOD), Ångstrom Exponent (AE), incoming shortwave (SW) and longwave (LW) radiation fluxes, vertical profiles of aerosol optical properties and surface aerosol scattering and absorption coefficient, as well as microphysical particle properties. Based on the radiative transfer model (RTM), the aerosol radiative forcing (ARF) and the heating rate are simulated. In addition, results from GEM-AQ and WRF-Chem models (e.g., aerosol mass mixing ratio and optical properties for several particle chemical components), and HYSPLIT back-trajectories are used to interpret the results of observation and to describe the 3D aerosol optical properties distribution. Results of Poland-AOD research indicate progressive improvement of air quality and at mospheric turbidity during the last decade. The AOD was reduced by about 0.02/10 yr (at 550 nm), which corresponds to positive trends in ARF. The estimated clear-sky ARF trend is 0.34 W/m2/10 yr and 0.68 W/m2/10 yr, respectively, at TOA and at Earth’s surface. Therefore, reduction in aerosol load observed in Poland can significantly contribute to climate warming.

The Atmospheric Boundary Layer (ABL) over two middle-latitude rural sites was characterized in terms of mean horizontal wind and turbulence sources using a standard classification methodology based on Doppler lidar. The first location was an irrigated olive orchard in Úbeda (Southern Spain), representing one of the most important crops in the Mediterranean basin and a typical site with Mediterranean climate. The second location was PolWET peatland site in Rzecin (Northwestern Poland), representing one of the largest natural terrestrial carbon storages that have a strong interaction with the climate system. The results showed typical situations for non cloud-topped ABL cases, where ABL is fully developed during daytime due to convection, with high turbulent activity and strong positive skewness indicating frequent and powerful updrafts. The cloud-topped cases showed the strong influence that clouds can have on ABL development, preventing it to reach the same maximum height and introducing top-down movements as an important contribution to mixing. The statistical analysis of turbulent sources allowed for finding a common diurnal cycle for convective mixing at both sites, but nocturnal wind shear driven turbulence with marked differences in its vertical distribution. This analysis demonstrates the Doppler lidar measurements and the classification algorithm strong potential to characterize the dynamics of ABL in its full extent and with high temporal resolution. Moreover, some recommendations for future improvement of the classification algorithm were provided on the basis of the experience gained., Fundacion Ramon Areces, European Space Agency 4000119961/16/NL/FF/mg, Polish National Science Centre (NCN) 2021/40/C/ST10/00023, Spanish Government CGL2015-73250-JIN CGL201681092-R CGL2017-83538-C3-1-R CGL2017-90884-REDT PID2020117825GB-C21 PID2020-120015RB-100, Andalusian Regional Government P18-RT-3820, FEDER-UGR program ARNM-430-UGR20, University of Granada, ACTRIS-2 Research Infrastructure Project of the European Union's Horizon 2020 research and innovation program 654109, European Cooperation in Science and Technology (COST) CA18235, Universidad de Granada/CBUA

There is the need of integration of atmospheric and ecosystem research in order to assess the habitats reaction in the future since the recent climate changes. Peatlands due to their vulnerability are important ecosystems since their strong interaction with the climate system. In stable climatic conditions, they are atmospheric carbon sinks. The study of the atmosphere properties in the context of peatlands productivity requires the application of the multidimensional strategy of field measurements. These kind of measurements are conducted using the following sensors: sun photometer, cloud radar, Raman lidar and eddy covariance (EC) system. They are located and operated at the Rzecin peatland in the framework of the POLIMOS project. So far, aerosols presence in the air was found as a factor that increases the peatland production. This presents the novel strategy of extensive atmospheric studies in order to identify the selected particles type impact on peatlands carbon uptake capabilities.

During August 2016, a quasi-stationary high-pressure system spreading over Central and North-Eastern Europe, caused weather conditions that allowed for 24/7 observations of aerosol optical properties by using a complex multi-wavelength PollyXT lidar system with Raman, polarization and water vapour capabilities, based at the European Aerosol Research Lidar Network (EARLINET network) urban site in Warsaw, Poland. During 24–30 August 2016, the lidar-derived products (boundary layer height, aerosol optical depth, Angstrom exponent, lidar ratio, depolarization ratio) were analysed in terms of air mass transport (HYSPLIT model), aerosol load (CAMS data) and type (NAAPS model) and confronted with active and passive remote sensing at the ground level (PolandAOD, AERONET, WIOS-AQ networks) and aboard satellites (SEVIRI, MODIS, CATS sensors). Optical properties for less than a day-old fresh biomass burning aerosol, advected into Warsaw’s boundary layer from over Ukraine, were compared with the properties of long-range transported 3–5 day-old aged biomass burning aerosol detected in the free troposphere over Warsaw. Analyses of temporal changes of aerosol properties within the boundary layer, revealed an increase of aerosol optical depth and Angstrom exponent accompanied by an increase of surface PM10 and PM2.5. Intrusions of advected biomass burning particles into the urban boundary layer seem to affect not only the optical properties observed but also the top height of the boundary layer, by moderating its increase.