Key characteristics of organic carbon in precipitation in Seoul, South Korea

Precipitation is a component of the global carbon cycle through which organic carbon enters terrestrial and aquatic ecosystems from the atmosphere. We measured Δ14C-DOC (dissolved organic carbon) and Δ14C-POC (particulate organic carbon) in bulk precipitation from Dec. 30, 2015 to Feb. 21, 2017 in Seoul, South Korea

An empirical study of climatic controls on riverine C logy 512 (2014) 195–205export from three major U.S. watersheds. Global Biogeochem

[1] The correlations between annual precipitation, evaporation, temperature, and annual carbon export (bicarbonate, dissolved organic carbon, and particulate organic carbon) are established for the Ohio, upper Mississippi, and Missouri watersheds and coefficients that predict C export on the basis of precipitation, evapotranspiration, and seasonal temperature are provided. Interannual variation in carbon export is controlled by the level of precipitation and evapotranspiration, the discharge to precipitation ratio (D:P), the concentration of the major carbon pool, the rating curve (discharge versus carbon concentration plots), and seasonal temperature. Within a watershed, precipitation has the strongest correlation with annual carbon export for all carbon pools. In the upper Mississippi and Ohio, levels of evapotranspiration can predict the majority of the residuals of precipitation versus carbon export. Bicarbonate demonstrates the largest response in yield to annual precipitation variation for each watershed. Rating curves, however, indicate that dissolved organic carbon and particulate organic carbon generally increase with increasing discharge, while bicarbonate decreases, causing a larger percentage response to precipitation for the organic carbon pools. Across watersheds the discharge to precipitation (D:P) ratio is the dominant determinant of how carbon yields respond to changes in precipitation, and watersheds with a high D:P ratio should demonstrate large changes in carbon yields with forecasted changes to precipitation. Citation: Raymond, P. A., and N.-H. Oh (2007), An empirical study of climatic controls on riverine C export from three major U.S. watersheds, Global Biogeochem. Cycles, 21, GB2022

Photochemical characteristics of dissolved organic matter in precipitation from Seoul, South Korea

Precipitation is a component of the global carbon cycle through which organic carbon enters terrestrial and aquatic ecosystems from the atmosphere. We measured photochemical characteristics of dissolved organic matter in precipitation from Dec. 30, 2015 to Feb. 21, 2017 in Seoul, South Korea

Loads and ages of carbon from the five largest rivers in South Korea in 2012-2013

Understanding the quantity and quality of riverine carbon is crucial to predict the changes of the global carbon cycle and to efficiently manage drinking water quality. We investigated the loads and 14C ages of carbon exported by the five largest rivers in South Korea using water samples collected seasonally and daily water discharge data in 2012–2013

A Study on the Change in Properties by Using an Additive with Water-Soluble Rubber-Asphalt-Based Waterproof Coating Materials

Water-soluble rubber-asphalt-based waterproof coating materials are mainly used for the purpose of preventing leakage from the inside of a structure to the outside or to the lower floor. In this study, water-soluble rubber-asphalt-based waterproof coating materials were prepared based on different mixture ratios to develop a new method to improve the physical properties of the materials. In order to improve the overall physical properties, additives were added to the coating material and analyzed for the change in performance, and the analyzed additives were used in combination to improve the physical properties of waterproofing materials. In particular, in the quality standards, ‘Attachment performance and fatigue resistance performance are the performance required for the outside of the structure’, but in the rubber asphalt category, the value of the adhesion performance quality standard was excluded, so it was limited to external use as a waterproofing material. The degree of improvement was compared and analyzed according to the quality standards of the Korean Industrial Standard KS F 3211-‘15’ Paint Waterproofing Materials for Construction. Therefore, in this study, a total of 27 complex additive tests were conducted, and among them, basic property evaluation was performed on 14 items, excluding 13 items that had defects in the drying process. As a result, in the test conducted with complex additives, about 98% to 104% of the quality standard was obtained, and it was judged that stable waterproofing performance would appear if additional quality improvements were made based on this combination in the future

A Study on the Change in Properties by Using an Additive with Water-Soluble Rubber-Asphalt-Based Waterproof Coating Materials

Water-soluble rubber-asphalt-based waterproof coating materials are mainly used for the purpose of preventing leakage from the inside of a structure to the outside or to the lower floor. In this study, water-soluble rubber-asphalt-based waterproof coating materials were prepared based on different mixture ratios to develop a new method to improve the physical properties of the materials. In order to improve the overall physical properties, additives were added to the coating material and analyzed for the change in performance, and the analyzed additives were used in combination to improve the physical properties of waterproofing materials. In particular, in the quality standards, ‘Attachment performance and fatigue resistance performance are the performance required for the outside of the structure’, but in the rubber asphalt category, the value of the adhesion performance quality standard was excluded, so it was limited to external use as a waterproofing material. The degree of improvement was compared and analyzed according to the quality standards of the Korean Industrial Standard KS F 3211-‘15’ Paint Waterproofing Materials for Construction. Therefore, in this study, a total of 27 complex additive tests were conducted, and among them, basic property evaluation was performed on 14 items, excluding 13 items that had defects in the drying process. As a result, in the test conducted with complex additives, about 98% to 104% of the quality standard was obtained, and it was judged that stable waterproofing performance would appear if additional quality improvements were made based on this combination in the future

Canopy Leaching Rather than Desorption of PM2.5 From Leaves Is the Dominant Source of Throughfall Dissolved Organic Carbon in Forest

Abstract Dissolved organic carbon (DOC) in throughfall plays a vital role in providing carbon and energy to organisms in forests. We utilized carbon isotope analysis to allocate the sources of throughfall DOC, including leaching from plant tissues, PM2.5 deposition on plant foliage, and precipitation. Rainwater, PM2.5, and throughfall samples were collected from pine and oak forests between March and November 2021. The mean concentration of throughfall DOC was 7.9 mg L−1, approximately six times higher than that of rainfall. The mean Δ14C of throughfall DOC was −38.2‰, ∼200‰ higher than that of rainwater or PM2.5. Mass balance estimates revealed that canopy leaching contributed to ∼83% of throughfall DOC, while desorption of PM2.5 and rainwater accounted for only ∼3% and ∼14% of throughfall DOC, respectively. These results clearly highlight canopy leaching as the primary source of carbon input to the forest floor, with a relatively minor contribution from PM2.5 desorption on leaves