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- ItemA review of coarse mineral dust in the Earth system(Amsterdam [u.a.] : Elsevier, 2022) Adebiyi, Adeyemi; Kok, Jasper F.; Murray, Benjamin J.; Ryder, Claire L.; Stuut, Jan-Berend W.; Kahn, Ralph A.; Knippertz, Peter; Formenti, Paola; Mahowald, Natalie M.; Pérez García-Pando, Carlos; Klose, Martina; Ansmann, Albert; Samset, Bjørn H.; Ito, Akinori; Balkanski, Yves; Di Biagio, Claudia; Romanias, Manolis N.; Huang, Yue; Meng, JunMineral dust particles suspended in the atmosphere span more than three orders of magnitude in diameter, from <0.1 µm to more than 100 µm. This wide size range makes dust a unique aerosol species with the ability to interact with many aspects of the Earth system, including radiation, clouds, hydrology, atmospheric chemistry, and biogeochemistry. This review focuses on coarse and super-coarse dust aerosols, which we respectively define as dust particles with a diameter of 2.5–10 µm and 10–62.5 µm. We review several lines of observational evidence indicating that coarse and super-coarse dust particles are transported farther than previously expected and that the abundance of these particles is substantially underestimated in current global models. We synthesize previous studies that used observations, theories, and model simulations to highlight the impacts of coarse and super-coarse dust aerosols on the Earth system, including their effects on dust-radiation interactions, dust-cloud interactions, atmospheric chemistry, and biogeochemistry. Specifically, coarse and super-coarse dust aerosols produce a net positive direct radiative effect (warming) at the top of the atmosphere and can modify temperature and water vapor profiles, influencing the distribution of clouds and precipitation. In addition, coarse and super-coarse dust aerosols contribute a substantial fraction of ice-nucleating particles, especially at temperatures above –23 °C. They also contribute a substantial fraction to the available reactive surfaces for atmospheric processing and the dust deposition flux that impacts land and ocean biogeochemistry by supplying important nutrients such as iron and phosphorus. Furthermore, we examine several limitations in the representation of coarse and super-coarse dust aerosols in current model simulations and remote-sensing retrievals. Because these limitations substantially contribute to the uncertainties in simulating the abundance and impacts of coarse and super-coarse dust aerosols, we offer some recommendations to facilitate future studies. Overall, we conclude that an accurate representation of coarse and super-coarse properties is critical in understanding the impacts of dust aerosols on the Earth system.
- ItemVariability of black carbon mass concentrations, sub-micrometer particle number concentrations and size distributions: results of the German Ultrafine Aerosol Network ranging from city street to High Alpine locations(Amsterdam [u.a.] : Elsevier Science, 2018) Sun, J.; Birmili, W.; Hermann, M.; Tuch, T.; Weinhold, K.; Spindler, G.; Schladitz, A.; Bastian, S.; Löschau, G.; Cyrys, J.; Gu, J.; Flentje, H.; Briel, B.; Asbac, C.; Kaminski, H.; Ries, L.; Sohme, R.; Gerwig, H.; Wirtz, K.; Meinhardt, F.; Schwerin, A.; Bath, O.; Ma, N.; Wiedensohler, A.This work reports the first statistical analysis of multi-annual data on tropospheric aerosols from the German Ultrafine Aerosol Network (GUAN). Compared to other networks worldwide, GUAN with 17 measurement locations has the most sites equipped with particle number size distribution (PNSD) and equivalent black carbon (eBC) instruments and the most site categories in Germany ranging from city street/roadside to High Alpine. As we know, the variations of eBC and particle number concentration (PNC) are influenced by several factors such as source, transformation, transport and deposition. The dominant controlling factor for different pollutant parameters might be varied, leading to the different spatio-temporal variations among the measured parameters. Currently, a study of spatio-temporal variations of PNSD and eBC considering the influences of both site categories and spatial scale is still missing. Based on the multi-site dataset of GUAN, the goal of this study is to investigate how pollutant parameters may interfere with spatial characteristics and site categories. © 2019 The Authors
- ItemMapping the aerosol over Eurasia from the Zotino tall tower(Milton Park : Taylor & Francis, 2013) Heintzenberg, Jost; Birmili, Wolfram; Seifert, Patric; Panov, Alexey; Chi, Xuguang; Andreae, Meinrat O.The present study covers more than 5 yr corresponding to more than 40 000 hours of particle and gas data measured at the Siberian tall tower Zotino Tall Tower (ZOTTO) (60.8°N; 89.35°E). Extrapolated along 10-d back trajectories, the ZOTTO measurements cover large parts of the Eurasian land mass. Mapping the extrapolated ZOTTO data points to major anthropogenic source regions and Siberian fire regions, consistent with emission data for CO and vegetation fires. Middle East mid-latitude sources stand out strongly and possibly emissions from Northern China may be seen at times from ZOTTO. The maps of measured light scattering and absorption characteristics support the interpretation of different source types. Three clusters of substantially different submicrometer particle size distributions were found, the maps of which also could be related to major aerosol source regions.