5:15 PM - 7:15 PM
[ACG39-P14] The selection of the optimal analytical method for determining the mass concentration of black carbon in precipitation samples.
Keywords:black carbon, climate, climatically active substances, environmental monitoring
Black carbon is a type of particle with a size of 2.5 microns or less, which consists mainly of pure carbon and is formed as a result of the incomplete combustion of fossil fuels, biofuels, and biomass. These particles have a high absorption coefficient for solar radiation and can affect the climate system by changing the albedo of snow and ice.
Since 2022, Russia has been monitoring black carbon levels in atmospheric air and precipitation. The main observation points are located in the Arctic region, but there are also monitoring stations in other parts of the country. In the early years of the monitoring network's operation, soot concentrations were measured using a photocolorimetric method. Samples of precipitation taken in 2022 and 2023 were filtered and analyzed using a photometric method to determine the concentration of black carbon.
In the Arctic regions, the highest recorded concentrations of soot occurred on March 1st, 2022 and February 24th, 2023, with concentrations of 0.36 mg/L and 1.21 mg/L, respectively. The average annual concentrations for these dates were 0.09 mg/L and 0.23 mg/L in the Murmansk region. On February 9th, 2022, a peak concentration of 4.76 mg/L was recorded, with an average annual concentration of 0.53 mg/L for the Arkhangelsk region. For the central part of Russia, the peak soot concentration was 0.57 mg/L on September 19th, 2022 and 1.73 mg/L on September 14th, 2023. The average annual concentrations in 2022 and 2023 were 0.17 and 0.19 mg/L respectively.
Based on these soot concentrations, black carbon concentrations in the studied samples were calculated. Due to the complexity of sample preparation and the inaccuracy of the photocolorimetric method, measurements using the non-particulate organic carbon (NPOC) method with the thermocatalytic oxidation technique began in 2024.
In the Murmansk region, the peak and average annual concentrations were 3.05 and 0.83 mg/l on March 2, 2024. In the Moscow region, the peak concentration was 9.25 mg/l, and the average concentration for all samples was 1.35 mg/l.
The Arkhangelsk region had the highest average annual concentration of black carbon in precipitation samples, at 2.91 mg/l with peaks of 7.77 on September 29 and 7.61 on October 22.
This increase in peak and average concentrations is likely due to the use of a more sensitive method for determining black carbon levels.
Since 2022, Russia has been monitoring black carbon levels in atmospheric air and precipitation. The main observation points are located in the Arctic region, but there are also monitoring stations in other parts of the country. In the early years of the monitoring network's operation, soot concentrations were measured using a photocolorimetric method. Samples of precipitation taken in 2022 and 2023 were filtered and analyzed using a photometric method to determine the concentration of black carbon.
In the Arctic regions, the highest recorded concentrations of soot occurred on March 1st, 2022 and February 24th, 2023, with concentrations of 0.36 mg/L and 1.21 mg/L, respectively. The average annual concentrations for these dates were 0.09 mg/L and 0.23 mg/L in the Murmansk region. On February 9th, 2022, a peak concentration of 4.76 mg/L was recorded, with an average annual concentration of 0.53 mg/L for the Arkhangelsk region. For the central part of Russia, the peak soot concentration was 0.57 mg/L on September 19th, 2022 and 1.73 mg/L on September 14th, 2023. The average annual concentrations in 2022 and 2023 were 0.17 and 0.19 mg/L respectively.
Based on these soot concentrations, black carbon concentrations in the studied samples were calculated. Due to the complexity of sample preparation and the inaccuracy of the photocolorimetric method, measurements using the non-particulate organic carbon (NPOC) method with the thermocatalytic oxidation technique began in 2024.
In the Murmansk region, the peak and average annual concentrations were 3.05 and 0.83 mg/l on March 2, 2024. In the Moscow region, the peak concentration was 9.25 mg/l, and the average concentration for all samples was 1.35 mg/l.
The Arkhangelsk region had the highest average annual concentration of black carbon in precipitation samples, at 2.91 mg/l with peaks of 7.77 on September 29 and 7.61 on October 22.
This increase in peak and average concentrations is likely due to the use of a more sensitive method for determining black carbon levels.