Articles | Volume 25, issue 1
https://doi.org/10.5194/acp-25-511-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-25-511-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
16 Jan 2025
Research article |
| 16 Jan 2025
| 16 Jan 2025
Valley floor inclination affecting valley winds and transport of passive tracers in idealised simulations
Johannes Mikkola
CORRESPONDING AUTHOR
Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
Alexander Gohm
Department of Atmospheric and Cryospheric Sciences, University of Innsbruck, Innsbruck, Austria
Victoria A. Sinclair
Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
Federico Bianchi
Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
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Local winds in four valleys located in the Nepal Himalayas are studied by means of high-resolution meteorological modelling. Well-defined daytime up-valley winds are simulated in all of the valleys with some variation in the flow depth and strength among the valleys and their parts. Parts of the valleys with a steep valley floor inclination (2–5°) are associated with weaker and shallower daytime up-valley winds compared with the parts that have nearly flat valley floors (< 1°).
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Arto Heitto, Cheng Wu, Diego Aliaga, Luis Blacutt, Xuemeng Chen, Yvette Gramlich, Liine Heikkinen, Wei Huang, Radovan Krejci, Paolo Laj, Isabel Moreno, Karine Sellegri, Fernando Velarde, Kay Weinhold, Alfred Wiedensohler, Qiaozhi Zha, Federico Bianchi, Marcos Andrade, Kari E. J. Lehtinen, Claudia Mohr, and Taina Yli-Juuti
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Particle growth at the Chacaltaya station in Bolivia was simulated based on measured vapor concentrations and ambient conditions. Major contributors to the simulated growth were low-volatility organic compounds (LVOCs). Also, sulfuric acid had major role when volcanic activity was occurring in the area. This study provides insight on nanoparticle growth at this high-altitude Southern Hemispheric site and hence contributes to building knowledge of early growth of atmospheric particles.
Giancarlo Ciarelli, Sara Tahvonen, Arineh Cholakian, Manuel Bettineschi, Bruno Vitali, Tuukka Petäjä, and Federico Bianchi
Geosci. Model Dev., 17, 545–565, https://doi.org/10.5194/gmd-17-545-2024, https://doi.org/10.5194/gmd-17-545-2024, 2024
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The terrestrial ecosystem releases large quantities of biogenic gases in the Earth's Atmosphere. These gases can effectively be converted into so-called biogenic aerosol particles and, eventually, affect the Earth's climate. Climate prediction varies greatly depending on how these processes are represented in model simulations. In this study, we present a detailed model evaluation analysis aimed at understanding the main source of uncertainty in predicting the formation of biogenic aerosols.
Diego Aliaga, Santeri Tuovinen, Tinghan Zhang, Janne Lampilahti, Xinyang Li, Lauri Ahonen, Tom Kokkonen, Tuomo Nieminen, Simo Hakala, Pauli Paasonen, Federico Bianchi, Doug Worsnop, Veli-Matti Kerminen, and Markku Kulmala
Aerosol Research, 1, 81–92, https://doi.org/10.5194/ar-1-81-2023, https://doi.org/10.5194/ar-1-81-2023, 2023
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We introduce a novel method for evaluating days when small particles are formed in the atmosphere. Instead of the traditional binary division between event and non-event days, our method, known as "nano ranking analysis", provides a continuous, non-categorical metric for each day. By utilizing data from Hyytiälä, Finland, we show that our approach effectively quantifies these events. This innovative method paves the way for a deeper understanding of the factors influencing particle formation.
Steven Job Thomas, Toni Tykkä, Heidi Hellén, Federico Bianchi, and Arnaud P. Praplan
Atmos. Chem. Phys., 23, 14627–14642, https://doi.org/10.5194/acp-23-14627-2023, https://doi.org/10.5194/acp-23-14627-2023, 2023
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The study employed total ozone reactivity to demonstrate how emissions of Norway spruce readily react with ozone and could be a major ozone sink, particularly under stress. Additionally, this approach provided insight into the limitations of current analytical techniques that measure the compounds present or emitted into the atmosphere. The study shows how the technique used was not enough to measure all compounds emitted, and this could potentially underestimate various atmospheric processes.
Victoria A. Sinclair and Jennifer L. Catto
Weather Clim. Dynam., 4, 567–589, https://doi.org/10.5194/wcd-4-567-2023, https://doi.org/10.5194/wcd-4-567-2023, 2023
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We studied the relationship between the strength of mid-latitude cyclones and their precipitation, how this may change in the future, and whether it depends of the type of cyclone. The relationship between cyclone strength and precipitation increases in warmer climates and depends strongly on the type of cyclone. For some cyclone types there is no relation between cyclone strength and precipitation. For all cyclone types, precipitation increases with uniform warming and polar amplification.
Rujing Yin, Xiaoxiao Li, Chao Yan, Runlong Cai, Ying Zhou, Juha Kangasluoma, Nina Sarnela, Janne Lampilahti, Tuukka Petäjä, Veli-Matti Kerminen, Federico Bianchi, Markku Kulmala, and Jingkun Jiang
Atmos. Chem. Phys., 23, 5279–5296, https://doi.org/10.5194/acp-23-5279-2023, https://doi.org/10.5194/acp-23-5279-2023, 2023
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Atmospheric cluster ions are important constituents in the atmosphere. However, the quantitative research on their compositions is still limited, especially in urban environments. Here we demonstrate the feasibility of an in situ quantification method of cluster ions measured by a high-resolution mass spectrometer and reveal their governing factors, sources, and sinks in urban Beijing through quantitative analysis of cluster ions, reagent ions, neutral molecules, and condensation sink.
Qiaozhi Zha, Wei Huang, Diego Aliaga, Otso Peräkylä, Liine Heikkinen, Alkuin Maximilian Koenig, Cheng Wu, Joonas Enroth, Yvette Gramlich, Jing Cai, Samara Carbone, Armin Hansel, Tuukka Petäjä, Markku Kulmala, Douglas Worsnop, Victoria Sinclair, Radovan Krejci, Marcos Andrade, Claudia Mohr, and Federico Bianchi
Atmos. Chem. Phys., 23, 4559–4576, https://doi.org/10.5194/acp-23-4559-2023, https://doi.org/10.5194/acp-23-4559-2023, 2023
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We investigate the chemical composition of atmospheric cluster ions from January to May 2018 at the high-altitude research station Chacaltaya (5240 m a.s.l.) in the Bolivian Andes. With state-of-the-art mass spectrometers and air mass history analysis, the measured cluster ions exhibited distinct diurnal and seasonal patterns, some of which contributed to new particle formation. Our study will improve the understanding of atmospheric ions and their role in high-altitude new particle formation.
Wiebke Scholz, Jiali Shen, Diego Aliaga, Cheng Wu, Samara Carbone, Isabel Moreno, Qiaozhi Zha, Wei Huang, Liine Heikkinen, Jean Luc Jaffrezo, Gaelle Uzu, Eva Partoll, Markus Leiminger, Fernando Velarde, Paolo Laj, Patrick Ginot, Paolo Artaxo, Alfred Wiedensohler, Markku Kulmala, Claudia Mohr, Marcos Andrade, Victoria Sinclair, Federico Bianchi, and Armin Hansel
Atmos. Chem. Phys., 23, 895–920, https://doi.org/10.5194/acp-23-895-2023, https://doi.org/10.5194/acp-23-895-2023, 2023
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Dimethyl sulfide (DMS), emitted from the ocean, is the most abundant biogenic sulfur emission into the atmosphere. OH radicals, among others, can oxidize DMS to sulfuric and methanesulfonic acid, which are relevant for aerosol formation. We quantified DMS and nearly all DMS oxidation products with novel mass spectrometric instruments for gas and particle phase at the high mountain station Chacaltaya (5240 m a.s.l.) in the Bolivian Andes in free tropospheric air after long-range transport.
Johannes Mikkola, Victoria A. Sinclair, Marja Bister, and Federico Bianchi
Atmos. Chem. Phys., 23, 821–842, https://doi.org/10.5194/acp-23-821-2023, https://doi.org/10.5194/acp-23-821-2023, 2023
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Local winds in four valleys located in the Nepal Himalayas are studied by means of high-resolution meteorological modelling. Well-defined daytime up-valley winds are simulated in all of the valleys with some variation in the flow depth and strength among the valleys and their parts. Parts of the valleys with a steep valley floor inclination (2–5°) are associated with weaker and shallower daytime up-valley winds compared with the parts that have nearly flat valley floors (< 1°).
Matthew Boyer, Diego Aliaga, Jakob Boyd Pernov, Hélène Angot, Lauriane L. J. Quéléver, Lubna Dada, Benjamin Heutte, Manuel Dall'Osto, David C. S. Beddows, Zoé Brasseur, Ivo Beck, Silvia Bucci, Marina Duetsch, Andreas Stohl, Tiia Laurila, Eija Asmi, Andreas Massling, Daniel Charles Thomas, Jakob Klenø Nøjgaard, Tak Chan, Sangeeta Sharma, Peter Tunved, Radovan Krejci, Hans Christen Hansson, Federico Bianchi, Katrianne Lehtipalo, Alfred Wiedensohler, Kay Weinhold, Markku Kulmala, Tuukka Petäjä, Mikko Sipilä, Julia Schmale, and Tuija Jokinen
Atmos. Chem. Phys., 23, 389–415, https://doi.org/10.5194/acp-23-389-2023, https://doi.org/10.5194/acp-23-389-2023, 2023
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The Arctic is a unique environment that is warming faster than other locations on Earth. We evaluate measurements of aerosol particles, which can influence climate, over the central Arctic Ocean for a full year and compare the data to land-based measurement stations across the Arctic. Our measurements show that the central Arctic has similarities to but also distinct differences from the stations further south. We note that this may change as the Arctic warms and sea ice continues to decline.
Chao Yan, Yicheng Shen, Dominik Stolzenburg, Lubna Dada, Ximeng Qi, Simo Hakala, Anu-Maija Sundström, Yishuo Guo, Antti Lipponen, Tom V. Kokkonen, Jenni Kontkanen, Runlong Cai, Jing Cai, Tommy Chan, Liangduo Chen, Biwu Chu, Chenjuan Deng, Wei Du, Xiaolong Fan, Xu-Cheng He, Juha Kangasluoma, Joni Kujansuu, Mona Kurppa, Chang Li, Yiran Li, Zhuohui Lin, Yiliang Liu, Yuliang Liu, Yiqun Lu, Wei Nie, Jouni Pulliainen, Xiaohui Qiao, Yonghong Wang, Yifan Wen, Ye Wu, Gan Yang, Lei Yao, Rujing Yin, Gen Zhang, Shaojun Zhang, Feixue Zheng, Ying Zhou, Antti Arola, Johanna Tamminen, Pauli Paasonen, Yele Sun, Lin Wang, Neil M. Donahue, Yongchun Liu, Federico Bianchi, Kaspar R. Daellenbach, Douglas R. Worsnop, Veli-Matti Kerminen, Tuukka Petäjä, Aijun Ding, Jingkun Jiang, and Markku Kulmala
Atmos. Chem. Phys., 22, 12207–12220, https://doi.org/10.5194/acp-22-12207-2022, https://doi.org/10.5194/acp-22-12207-2022, 2022
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Atmospheric new particle formation (NPF) is a dominant source of atmospheric ultrafine particles. In urban environments, traffic emissions are a major source of primary pollutants, but their contribution to NPF remains under debate. During the COVID-19 lockdown, traffic emissions were significantly reduced, providing a unique chance to examine their relevance to NPF. Based on our comprehensive measurements, we demonstrate that traffic emissions alone are not able to explain the NPF in Beijing.
Benjamin Foreback, Lubna Dada, Kaspar R. Daellenbach, Chao Yan, Lili Wang, Biwu Chu, Ying Zhou, Tom V. Kokkonen, Mona Kurppa, Rosaria E. Pileci, Yonghong Wang, Tommy Chan, Juha Kangasluoma, Lin Zhuohui, Yishou Guo, Chang Li, Rima Baalbaki, Joni Kujansuu, Xiaolong Fan, Zemin Feng, Pekka Rantala, Shahzad Gani, Federico Bianchi, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, Yongchun Liu, and Pauli Paasonen
Atmos. Chem. Phys., 22, 11089–11104, https://doi.org/10.5194/acp-22-11089-2022, https://doi.org/10.5194/acp-22-11089-2022, 2022
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This study analyzed air quality in Beijing during the Chinese New Year over 7 years, including data from a new in-depth measurement station. This is one of few studies to look at long-term impacts, including the outcome of firework restrictions starting in 2018. Results show that firework pollution has gone down since 2016, indicating a positive result from the restrictions. Results of this study may be useful in making future decisions about the use of fireworks to improve air quality.
Cornelius Immanuel Weiß, Alexander Gohm, Mathias Walter Rotach, and Thomas Torora Minda
Weather Clim. Dynam., 3, 1003–1019, https://doi.org/10.5194/wcd-3-1003-2022, https://doi.org/10.5194/wcd-3-1003-2022, 2022
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Two gap flow events in the Great Rift Valley in Ethiopia were investigated based on observations, ERA5 reanalysis data, and simulations with the numerical weather prediction model WRF. The main focus was on strong winds in the area around Lake Abaya since the winds may generate waves on the lake which help to sustain the lake's ecology. That is important in terms of food supply for the local population. The gap winds exhibit a diurnal cycle and a seasonal dependence.
Yishuo Guo, Chao Yan, Yuliang Liu, Xiaohui Qiao, Feixue Zheng, Ying Zhang, Ying Zhou, Chang Li, Xiaolong Fan, Zhuohui Lin, Zemin Feng, Yusheng Zhang, Penggang Zheng, Linhui Tian, Wei Nie, Zhe Wang, Dandan Huang, Kaspar R. Daellenbach, Lei Yao, Lubna Dada, Federico Bianchi, Jingkun Jiang, Yongchun Liu, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 22, 10077–10097, https://doi.org/10.5194/acp-22-10077-2022, https://doi.org/10.5194/acp-22-10077-2022, 2022
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Gaseous oxygenated organic molecules (OOMs) are able to form atmospheric aerosols, which will impact on human health and climate change. Here, we find that OOMs in urban Beijing are dominated by anthropogenic sources, i.e. aromatic (29 %–41 %) and aliphatic (26 %–41 %) OOMs. They are also the main contributors to the condensational growth of secondary organic aerosols (SOAs). Therefore, the restriction on anthropogenic VOCs is crucial for the reduction of SOAs and haze formation.
Helen Claire Ward, Mathias Walter Rotach, Alexander Gohm, Martin Graus, Thomas Karl, Maren Haid, Lukas Umek, and Thomas Muschinski
Atmos. Chem. Phys., 22, 6559–6593, https://doi.org/10.5194/acp-22-6559-2022, https://doi.org/10.5194/acp-22-6559-2022, 2022
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This study examines how cities and their surroundings influence turbulent exchange processes responsible for weather and climate. Analysis of a 4-year observational dataset for the Alpine city of Innsbruck reveals several similarities with other (flat) city centre sites. However, the mountain setting leads to characteristic daily and seasonal flow patterns (valley winds) and downslope windstorms that have a marked effect on temperature, wind speed, turbulence and pollutant concentration.
Victoria Anne Sinclair, Jenna Ritvanen, Gabin Urbancic, Irene Erner, Yurii Batrak, Dmitri Moisseev, and Mona Kurppa
Atmos. Meas. Tech., 15, 3075–3103, https://doi.org/10.5194/amt-15-3075-2022, https://doi.org/10.5194/amt-15-3075-2022, 2022
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We investigate the boundary-layer (BL) height and surface stability in southern Finland using radiosondes, a microwave radiometer and ERA5 reanalysis. Accurately quantifying the BL height is challenging, and the diagnosed BL height can depend strongly on the method used. Microwave radiometers provide reliable estimates of the BL height but only in unstable conditions. ERA5 captures the BL height well except under very stable conditions, which occur most commonly at night during the warm season.
Hanna K. Lappalainen, Tuukka Petäjä, Timo Vihma, Jouni Räisänen, Alexander Baklanov, Sergey Chalov, Igor Esau, Ekaterina Ezhova, Matti Leppäranta, Dmitry Pozdnyakov, Jukka Pumpanen, Meinrat O. Andreae, Mikhail Arshinov, Eija Asmi, Jianhui Bai, Igor Bashmachnikov, Boris Belan, Federico Bianchi, Boris Biskaborn, Michael Boy, Jaana Bäck, Bin Cheng, Natalia Chubarova, Jonathan Duplissy, Egor Dyukarev, Konstantinos Eleftheriadis, Martin Forsius, Martin Heimann, Sirkku Juhola, Vladimir Konovalov, Igor Konovalov, Pavel Konstantinov, Kajar Köster, Elena Lapshina, Anna Lintunen, Alexander Mahura, Risto Makkonen, Svetlana Malkhazova, Ivan Mammarella, Stefano Mammola, Stephany Buenrostro Mazon, Outi Meinander, Eugene Mikhailov, Victoria Miles, Stanislav Myslenkov, Dmitry Orlov, Jean-Daniel Paris, Roberta Pirazzini, Olga Popovicheva, Jouni Pulliainen, Kimmo Rautiainen, Torsten Sachs, Vladimir Shevchenko, Andrey Skorokhod, Andreas Stohl, Elli Suhonen, Erik S. Thomson, Marina Tsidilina, Veli-Pekka Tynkkynen, Petteri Uotila, Aki Virkkula, Nadezhda Voropay, Tobias Wolf, Sayaka Yasunaka, Jiahua Zhang, Yubao Qiu, Aijun Ding, Huadong Guo, Valery Bondur, Nikolay Kasimov, Sergej Zilitinkevich, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 22, 4413–4469, https://doi.org/10.5194/acp-22-4413-2022, https://doi.org/10.5194/acp-22-4413-2022, 2022
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We summarize results during the last 5 years in the northern Eurasian region, especially from Russia, and introduce recent observations of the air quality in the urban environments in China. Although the scientific knowledge in these regions has increased, there are still gaps in our understanding of large-scale climate–Earth surface interactions and feedbacks. This arises from limitations in research infrastructures and integrative data analyses, hindering a comprehensive system analysis.
Manuel Saigger and Alexander Gohm
Weather Clim. Dynam., 3, 279–303, https://doi.org/10.5194/wcd-3-279-2022, https://doi.org/10.5194/wcd-3-279-2022, 2022
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In this work a special form of a foehn wind in an Alpine valley with a large-scale northwesterly flow is investigated. The study clarifies the origin of the air mass and the mechanisms by which this air enters the valley. A trajectory analysis shows that the location where the main airstream passes the crest line is more suitable for a foehn classification than the local or large-scale wind direction. Mountain waves and a lee rotor were crucial for importing air into the valley.
Jing Cai, Cheng Wu, Jiandong Wang, Wei Du, Feixue Zheng, Simo Hakala, Xiaolong Fan, Biwu Chu, Lei Yao, Zemin Feng, Yongchun Liu, Yele Sun, Jun Zheng, Chao Yan, Federico Bianchi, Markku Kulmala, Claudia Mohr, and Kaspar R. Daellenbach
Atmos. Chem. Phys., 22, 1251–1269, https://doi.org/10.5194/acp-22-1251-2022, https://doi.org/10.5194/acp-22-1251-2022, 2022
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This study investigates the connection between organic aerosol (OA) molecular composition and particle absorptive properties in autumn in Beijing. We find that the molecular properties of OA compounds in different episodes influence particle light absorption properties differently: the light absorption enhancement of black carbon and light absorption coefficient of brown carbon were mostly related to more oxygenated OA (low C number and four O atoms) and aromatics/nitro-aromatics, respectively.
Terhi K. Laurila, Hilppa Gregow, Joona Cornér, and Victoria A. Sinclair
Weather Clim. Dynam., 2, 1111–1130, https://doi.org/10.5194/wcd-2-1111-2021, https://doi.org/10.5194/wcd-2-1111-2021, 2021
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We create a climatology of mid-latitude cyclones and windstorms in northern Europe and investigate how sensitive the minimum pressure and maximum gust of windstorms are to four precursors. Windstorms are more common in the cold season than the warm season, whereas the number of mid-latitude cyclones has no annual cycle. The low-level temperature gradient has the strongest impact of all considered precursors on the intensity of windstorms in terms of both the minimum pressure and maximum gust.
Diego Aliaga, Victoria A. Sinclair, Marcos Andrade, Paulo Artaxo, Samara Carbone, Evgeny Kadantsev, Paolo Laj, Alfred Wiedensohler, Radovan Krejci, and Federico Bianchi
Atmos. Chem. Phys., 21, 16453–16477, https://doi.org/10.5194/acp-21-16453-2021, https://doi.org/10.5194/acp-21-16453-2021, 2021
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We investigate the origin of air masses sampled at Mount Chacaltaya, Bolivia. Three-quarters of the measured air has not been influenced by the surface in the previous 4 d. However, it is rare that, at any given time, the sampled air has not been influenced at all by the surface, and often the sampled air has multiple origins. The influence of the surface is more prevalent during day than night. Furthermore, during the 6-month study, one-third of the air masses originated from Amazonia.
Shahzad Gani, Lukas Kohl, Rima Baalbaki, Federico Bianchi, Taina M. Ruuskanen, Olli-Pekka Siira, Pauli Paasonen, and Hanna Vehkamäki
Geosci. Commun., 4, 507–516, https://doi.org/10.5194/gc-4-507-2021, https://doi.org/10.5194/gc-4-507-2021, 2021
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In this article, we present authorship guidelines which also include a novel authorship form along with the documentation of the formulation process for a multidisciplinary and interdisciplinary center with more than 250 researchers. Our practical approach promotes fair authorship practices and, by focusing on clear, transparent, and timely communication, helps avoid late-stage authorship conflict.
Mao Xiao, Christopher R. Hoyle, Lubna Dada, Dominik Stolzenburg, Andreas Kürten, Mingyi Wang, Houssni Lamkaddam, Olga Garmash, Bernhard Mentler, Ugo Molteni, Andrea Baccarini, Mario Simon, Xu-Cheng He, Katrianne Lehtipalo, Lauri R. Ahonen, Rima Baalbaki, Paulus S. Bauer, Lisa Beck, David Bell, Federico Bianchi, Sophia Brilke, Dexian Chen, Randall Chiu, António Dias, Jonathan Duplissy, Henning Finkenzeller, Hamish Gordon, Victoria Hofbauer, Changhyuk Kim, Theodore K. Koenig, Janne Lampilahti, Chuan Ping Lee, Zijun Li, Huajun Mai, Vladimir Makhmutov, Hanna E. Manninen, Ruby Marten, Serge Mathot, Roy L. Mauldin, Wei Nie, Antti Onnela, Eva Partoll, Tuukka Petäjä, Joschka Pfeifer, Veronika Pospisilova, Lauriane L. J. Quéléver, Matti Rissanen, Siegfried Schobesberger, Simone Schuchmann, Yuri Stozhkov, Christian Tauber, Yee Jun Tham, António Tomé, Miguel Vazquez-Pufleau, Andrea C. Wagner, Robert Wagner, Yonghong Wang, Lena Weitz, Daniela Wimmer, Yusheng Wu, Chao Yan, Penglin Ye, Qing Ye, Qiaozhi Zha, Xueqin Zhou, Antonio Amorim, Ken Carslaw, Joachim Curtius, Armin Hansel, Rainer Volkamer, Paul M. Winkler, Richard C. Flagan, Markku Kulmala, Douglas R. Worsnop, Jasper Kirkby, Neil M. Donahue, Urs Baltensperger, Imad El Haddad, and Josef Dommen
Atmos. Chem. Phys., 21, 14275–14291, https://doi.org/10.5194/acp-21-14275-2021, https://doi.org/10.5194/acp-21-14275-2021, 2021
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Experiments at CLOUD show that in polluted environments new particle formation (NPF) is largely driven by the formation of sulfuric acid–base clusters, stabilized by amines, high ammonia concentrations or lower temperatures. While oxidation products of aromatics can nucleate, they play a minor role in urban NPF. Our experiments span 4 orders of magnitude variation of observed NPF rates in ambient conditions. We provide a framework based on NPF and growth rates to interpret ambient observations.
Yongchun Liu, Zemin Feng, Feixue Zheng, Xiaolei Bao, Pengfei Liu, Yanli Ge, Yan Zhao, Tao Jiang, Yunwen Liao, Yusheng Zhang, Xiaolong Fan, Chao Yan, Biwu Chu, Yonghong Wang, Wei Du, Jing Cai, Federico Bianchi, Tuukka Petäjä, Yujing Mu, Hong He, and Markku Kulmala
Atmos. Chem. Phys., 21, 13269–13286, https://doi.org/10.5194/acp-21-13269-2021, https://doi.org/10.5194/acp-21-13269-2021, 2021
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The mechanisms and kinetics of particulate sulfate formation in the atmosphere are still open questions although they have been extensively discussed. We found that uptake of SO2 is the rate-determining step for the conversion of SO2 to particulate sulfate. NH4NO3 plays an important role in AWC, the phase state of aerosol particles, and subsequently the uptake kinetics of SO2 under high-RH conditions. This work is a good example of the feedback between aerosol physics and aerosol chemistry.
Nahid Atashi, Dariush Rahimi, Victoria A. Sinclair, Martha A. Zaidan, Anton Rusanen, Henri Vuollekoski, Markku Kulmala, Timo Vesala, and Tareq Hussein
Hydrol. Earth Syst. Sci., 25, 4719–4740, https://doi.org/10.5194/hess-25-4719-2021, https://doi.org/10.5194/hess-25-4719-2021, 2021
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Dew formation potential during a long-term period (1979–2018) was assessed in Iran to identify dew formation zones and to investigate the impacts of long-term variation in meteorological parameters on dew formation. Six dew formation zones were identified based on cluster analysis of the time series of the simulated dew yield. The distribution of dew formation zones in Iran was closely aligned with topography and sources of moisture. The dew formation trend was significantly negative.
Zhuohui Lin, Yonghong Wang, Feixue Zheng, Ying Zhou, Yishuo Guo, Zemin Feng, Chang Li, Yusheng Zhang, Simo Hakala, Tommy Chan, Chao Yan, Kaspar R. Daellenbach, Biwu Chu, Lubna Dada, Juha Kangasluoma, Lei Yao, Xiaolong Fan, Wei Du, Jing Cai, Runlong Cai, Tom V. Kokkonen, Putian Zhou, Lili Wang, Tuukka Petäjä, Federico Bianchi, Veli-Matti Kerminen, Yongchun Liu, and Markku Kulmala
Atmos. Chem. Phys., 21, 12173–12187, https://doi.org/10.5194/acp-21-12173-2021, https://doi.org/10.5194/acp-21-12173-2021, 2021
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We find that ammonium nitrate and aerosol water content contributed most during low mixing layer height conditions; this may further trigger enhanced formation of sulfate and organic aerosol via heterogeneous reactions. The results of this study contribute towards a more detailed understanding of the aerosol–chemistry–radiation–boundary layer feedback that is likely to be responsible for explosive aerosol mass growth events in urban Beijing.
Xiaolong Fan, Jing Cai, Chao Yan, Jian Zhao, Yishuo Guo, Chang Li, Kaspar R. Dällenbach, Feixue Zheng, Zhuohui Lin, Biwu Chu, Yonghong Wang, Lubna Dada, Qiaozhi Zha, Wei Du, Jenni Kontkanen, Theo Kurtén, Siddhart Iyer, Joni T. Kujansuu, Tuukka Petäjä, Douglas R. Worsnop, Veli-Matti Kerminen, Yongchun Liu, Federico Bianchi, Yee Jun Tham, Lei Yao, and Markku Kulmala
Atmos. Chem. Phys., 21, 11437–11452, https://doi.org/10.5194/acp-21-11437-2021, https://doi.org/10.5194/acp-21-11437-2021, 2021
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We observed significant concentrations of gaseous HBr and HCl throughout the winter and springtime in urban Beijing, China. Our results indicate that gaseous HCl and HBr are most likely originated from anthropogenic emissions such as burning activities, and the gas–aerosol partitioning may play a crucial role in contributing to the gaseous HCl and HBr. These observations suggest that there is an important recycling pathway of halogen species in inland megacities.
Wei Huang, Haiyan Li, Nina Sarnela, Liine Heikkinen, Yee Jun Tham, Jyri Mikkilä, Steven J. Thomas, Neil M. Donahue, Markku Kulmala, and Federico Bianchi
Atmos. Chem. Phys., 21, 8961–8977, https://doi.org/10.5194/acp-21-8961-2021, https://doi.org/10.5194/acp-21-8961-2021, 2021
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We show full characterization of gaseous organic compounds in a boreal forest. Molecular composition and volatility of gaseous organic compounds with different oxidation extents (from volatile organic compounds to highly oxygenated organic molecules) were investigated and discussed. We provide a more comprehensive understanding of atmospheric organic compounds in this boreal forest and new insights into interpreting ambient measurements or testing and improving parameterizations in models.
Yishuo Guo, Chao Yan, Chang Li, Wei Ma, Zemin Feng, Ying Zhou, Zhuohui Lin, Lubna Dada, Dominik Stolzenburg, Rujing Yin, Jenni Kontkanen, Kaspar R. Daellenbach, Juha Kangasluoma, Lei Yao, Biwu Chu, Yonghong Wang, Runlong Cai, Federico Bianchi, Yongchun Liu, and Markku Kulmala
Atmos. Chem. Phys., 21, 5499–5511, https://doi.org/10.5194/acp-21-5499-2021, https://doi.org/10.5194/acp-21-5499-2021, 2021
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Fog, cloud and haze are very common natural phenomena. Sulfuric acid (SA) is one of the key compounds forming those suspended particles, technically called aerosols, through gas-to-particle conversion. Therefore, the concentration level, source and sink of SA is very important. Our results show that ozonolysis of alkenes plays a major role in nighttime SA formation under unpolluted conditions in urban Beijing, and nighttime cluster mode particles are probably driven by SA in urban environments.
Johannes Horak, Marlis Hofer, Ethan Gutmann, Alexander Gohm, and Mathias W. Rotach
Geosci. Model Dev., 14, 1657–1680, https://doi.org/10.5194/gmd-14-1657-2021, https://doi.org/10.5194/gmd-14-1657-2021, 2021
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This process-based evaluation of the atmospheric model ICAR is conducted to derive recommendations to increase the likelihood of its results being correct for the right reasons. We conclude that a different diagnosis of the atmospheric background state is necessary, as well as a model top at an elevation of at least 10 km. Alternative boundary conditions at the top were not found to be effective in reducing this model top elevation. The results have wide implications for future ICAR studies.
Haiyan Li, Manjula R. Canagaratna, Matthieu Riva, Pekka Rantala, Yanjun Zhang, Steven Thomas, Liine Heikkinen, Pierre-Marie Flaud, Eric Villenave, Emilie Perraudin, Douglas Worsnop, Markku Kulmala, Mikael Ehn, and Federico Bianchi
Atmos. Chem. Phys., 21, 4123–4147, https://doi.org/10.5194/acp-21-4123-2021, https://doi.org/10.5194/acp-21-4123-2021, 2021
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For the first time, we performed binPMF analysis on the complex mass spectra acquired with the Vocus PTR-TOF in two European pine forests and identified various primary emission sources and secondary oxidation processes of atmospheric organic vapors, i.e., terpenes and their oxidation products, with varying oxidation degrees. Further insights were gained regarding monoterpene and sesquiterpene reactions based on the interpretation results.
Runlong Cai, Chao Yan, Dongsen Yang, Rujing Yin, Yiqun Lu, Chenjuan Deng, Yueyun Fu, Jiaxin Ruan, Xiaoxiao Li, Jenni Kontkanen, Qiang Zhang, Juha Kangasluoma, Yan Ma, Jiming Hao, Douglas R. Worsnop, Federico Bianchi, Pauli Paasonen, Veli-Matti Kerminen, Yongchun Liu, Lin Wang, Jun Zheng, Markku Kulmala, and Jingkun Jiang
Atmos. Chem. Phys., 21, 2457–2468, https://doi.org/10.5194/acp-21-2457-2021, https://doi.org/10.5194/acp-21-2457-2021, 2021
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Based on long-term measurements, we discovered that the collision of H2SO4–amine clusters is the governing mechanism that initializes fast new particle formation in the polluted atmospheric environment of urban Beijing. The mechanism and the governing factors for H2SO4–amine nucleation in the polluted atmosphere are quantitatively investigated in this study.
Yongchun Liu, Yusheng Zhang, Chaofan Lian, Chao Yan, Zeming Feng, Feixue Zheng, Xiaolong Fan, Yan Chen, Weigang Wang, Biwu Chu, Yonghong Wang, Jing Cai, Wei Du, Kaspar R. Daellenbach, Juha Kangasluoma, Federico Bianchi, Joni Kujansuu, Tuukka Petäjä, Xuefei Wang, Bo Hu, Yuesi Wang, Maofa Ge, Hong He, and Markku Kulmala
Atmos. Chem. Phys., 20, 13023–13040, https://doi.org/10.5194/acp-20-13023-2020, https://doi.org/10.5194/acp-20-13023-2020, 2020
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Understanding of the chemical and physical processes leading to atmospheric aerosol particle formation is crucial to devising effective mitigation strategies to protect the public and reduce uncertainties in climate predictions. We found that the photolysis of nitrous acid could promote the formation of organic and nitrate aerosol and that traffic-related emission is a major contributor to ambient nitrous acid on haze days in wintertime in Beijing.
Jing Cai, Biwu Chu, Lei Yao, Chao Yan, Liine M. Heikkinen, Feixue Zheng, Chang Li, Xiaolong Fan, Shaojun Zhang, Daoyuan Yang, Yonghong Wang, Tom V. Kokkonen, Tommy Chan, Ying Zhou, Lubna Dada, Yongchun Liu, Hong He, Pauli Paasonen, Joni T. Kujansuu, Tuukka Petäjä, Claudia Mohr, Juha Kangasluoma, Federico Bianchi, Yele Sun, Philip L. Croteau, Douglas R. Worsnop, Veli-Matti Kerminen, Wei Du, Markku Kulmala, and Kaspar R. Daellenbach
Atmos. Chem. Phys., 20, 12721–12740, https://doi.org/10.5194/acp-20-12721-2020, https://doi.org/10.5194/acp-20-12721-2020, 2020
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By applying both OA PMF and size PMF at the same urban measurement site in Beijing, similar particle source types, including vehicular emissions, cooking emissions and secondary formation-related sources, were resolved by both frameworks and agreed well. It is also found that in the absence of new particle formation, vehicular and cooking emissions dominate the particle number concentration, while secondary particulate matter governed PM2.5 mass during spring and summer in Beijing.
Martin Heinritzi, Lubna Dada, Mario Simon, Dominik Stolzenburg, Andrea C. Wagner, Lukas Fischer, Lauri R. Ahonen, Stavros Amanatidis, Rima Baalbaki, Andrea Baccarini, Paulus S. Bauer, Bernhard Baumgartner, Federico Bianchi, Sophia Brilke, Dexian Chen, Randall Chiu, Antonio Dias, Josef Dommen, Jonathan Duplissy, Henning Finkenzeller, Carla Frege, Claudia Fuchs, Olga Garmash, Hamish Gordon, Manuel Granzin, Imad El Haddad, Xucheng He, Johanna Helm, Victoria Hofbauer, Christopher R. Hoyle, Juha Kangasluoma, Timo Keber, Changhyuk Kim, Andreas Kürten, Houssni Lamkaddam, Tiia M. Laurila, Janne Lampilahti, Chuan Ping Lee, Katrianne Lehtipalo, Markus Leiminger, Huajun Mai, Vladimir Makhmutov, Hanna Elina Manninen, Ruby Marten, Serge Mathot, Roy Lee Mauldin, Bernhard Mentler, Ugo Molteni, Tatjana Müller, Wei Nie, Tuomo Nieminen, Antti Onnela, Eva Partoll, Monica Passananti, Tuukka Petäjä, Joschka Pfeifer, Veronika Pospisilova, Lauriane L. J. Quéléver, Matti P. Rissanen, Clémence Rose, Siegfried Schobesberger, Wiebke Scholz, Kay Scholze, Mikko Sipilä, Gerhard Steiner, Yuri Stozhkov, Christian Tauber, Yee Jun Tham, Miguel Vazquez-Pufleau, Annele Virtanen, Alexander L. Vogel, Rainer Volkamer, Robert Wagner, Mingyi Wang, Lena Weitz, Daniela Wimmer, Mao Xiao, Chao Yan, Penglin Ye, Qiaozhi Zha, Xueqin Zhou, Antonio Amorim, Urs Baltensperger, Armin Hansel, Markku Kulmala, António Tomé, Paul M. Winkler, Douglas R. Worsnop, Neil M. Donahue, Jasper Kirkby, and Joachim Curtius
Atmos. Chem. Phys., 20, 11809–11821, https://doi.org/10.5194/acp-20-11809-2020, https://doi.org/10.5194/acp-20-11809-2020, 2020
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With experiments performed at CLOUD, we show how isoprene interferes in monoterpene oxidation via RO2 termination at atmospherically relevant concentrations. This interference shifts the distribution of highly oxygenated organic molecules (HOMs) away from C20 class dimers towards C15 class dimers, which subsequently reduces both biogenic nucleation and early growth rates. Our results may help to understand the absence of new-particle formation in isoprene-rich environments.
Lubna Dada, Ilona Ylivinkka, Rima Baalbaki, Chang Li, Yishuo Guo, Chao Yan, Lei Yao, Nina Sarnela, Tuija Jokinen, Kaspar R. Daellenbach, Rujing Yin, Chenjuan Deng, Biwu Chu, Tuomo Nieminen, Yonghong Wang, Zhuohui Lin, Roseline C. Thakur, Jenni Kontkanen, Dominik Stolzenburg, Mikko Sipilä, Tareq Hussein, Pauli Paasonen, Federico Bianchi, Imre Salma, Tamás Weidinger, Michael Pikridas, Jean Sciare, Jingkun Jiang, Yongchun Liu, Tuukka Petäjä, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 20, 11747–11766, https://doi.org/10.5194/acp-20-11747-2020, https://doi.org/10.5194/acp-20-11747-2020, 2020
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We rely on sulfuric acid measurements in four contrasting environments, Hyytiälä, Finland; Agia Marina, Cyprus; Budapest, Hungary; and Beijing, China, representing semi-pristine boreal forest, rural environment in the Mediterranean area, urban environment, and heavily polluted megacity, respectively, in order to define the sources and sinks of sulfuric acid in these environments and to derive a new sulfuric acid proxy to be utilized in locations and during periods when it is not measured.
Cited articles
Bianchi, F., Junninen, H., Bigi, A., Sinclair, V., Dada, L., Hoyle, C., Zha, Q., Yao, L., Ahonen, L., Bonasoni, P., Buenrostro Mazon, S., Hutterli, M., Laj, P., Lehtipalo, K., Kangasluoma, J., Kerminen, V., Kontkanen, J., Marinoni, A., Mirme, S., Molteni, U., Petaja, T., Riva, M., Rose, C., Sellegri, K., Yan, C., Worsnop, D., Kulmala, M., Baltensperger, U., and Dommen, J.: Biogenic particles formed in the Himalaya as an important source of free tropospheric aerosols, Nat. Geosci., 14, 4–9, https://doi.org/10.1038/s41561-020-00661-5, 2021. a, b, c, d
Bollasina, M., Bertolani, L., and Tartari, G.: Meteorological observations at high altitude in the Khumbu Valley, Nepal Himalayas, 1994–1999, Bull. Glaciol. Res., 19, 1–11, 2002. a
Bonasoni, P., Laj, P., Marinoni, A., Sprenger, M., Angelini, F., Arduini, J., Bonafè, U., Calzolari, F., Colombo, T., Decesari, S., Di Biagio, C., di Sarra, A. G., Evangelisti, F., Duchi, R., Facchini, MC., Fuzzi, S., Gobbi, G. P., Maione, M., Panday, A., Roccato, F., Sellegri, K., Venzac, H., Verza, GP., Villani, P., Vuillermoz, E., and Cristofanelli, P.: Atmospheric Brown Clouds in the Himalayas: first two years of continuous observations at the Nepal Climate Observatory-Pyramid (5079 m), Atmos. Chem. Phys., 10, 7515–7531, https://doi.org/10.5194/acp-10-7515-2010, 2010. a, b
Farina, S. and Zardi, D.: Understanding Thermally Driven Slope Winds: Recent Advances and Open Questions, Bound.-Lay. Meteorol., 189, 5–52, https://doi.org/10.1007/s10546-023-00821-1, 2023. a, b, c
Göbel, M., Serafin, S., and Rotach, M. W.: Numerically consistent budgets of potential temperature, momentum, and moisture in Cartesian coordinates: application to the WRF model, Geosci. Model Dev., 15, 669–681, https://doi.org/10.5194/gmd-15-669-2022, 2022. a, b
Göbel, M., Serafin, S., and Rotach, M. W.: Adverse impact of terrain steepness on thermally driven initiation of orographic convection, Weather Clim. Dynam., 4, 725–745, https://doi.org/10.5194/wcd-4-725-2023, 2023. a
Gohm, A., Harnisch, F., Vergeiner, J., Obleitner, F., Schnitzhofer, R., Hansel, A., Fix, A., Neininger, B., Emeis, S., and Schaefer, K.: Air Pollution Transport in an Alpine Valley: Results From Airborne and Ground-Based Observations, Bound.-Lay. Meteorol., 131, 441–463, https://doi.org/10.1007/s10546-009-9371-9, 2009. a, b
Gordon, H., Kirkby, J., Baltensperger, U., Bianchi, F., Breitenlechner, M., Curtius, J., Dias, A., Dommen, J., Donahue, N. M., Dunne, E. M., Duplissy, J., Ehrhart, S., Flagan, R. C., Frege, C., Fuchs, C., Hansel, A., Hoyle, C. R., Kulmala, M., Kürten, A., Lehtipalo, K., Makhmutov, V., Molteni, U., Rissanen, M. P., Stozkhov, Y., Tröstl, J., Tsagkogeorgas, G., Wagner, R., Williamson, C., Wimmer, D., Winkler, P. M., Yan, C., and Carslaw, K. S.: Causes and importance of new particle formation in the present-day and preindustrial atmospheres, J. Geophys. Res.-Atmos., 122, 8739–8760, https://doi.org/10.1002/2017JD026844, 2017. a
Henne, S., Furger, M., Nyeki, S., Steinbacher, M., Neininger, B., de Wekker, S. F. J., Dommen, J., Spichtinger, N., Stohl, A., and Prévôt, A. S. H.: Quantification of topographic venting of boundary layer air to the free troposphere, Atmos. Chem. Phys., 4, 497–509, https://doi.org/10.5194/acp-4-497-2004, 2004. a
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz-Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmons, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., De Chiara, G., Dahlgren, P., Dee, D., Diamantakis, M., Dragani, R., Flemming, J., Forbes, R., Fuentes, M., Geer, A., Haimberger, L., Healy, S., Hogan, R. J., Hólm, E., Janisková, M., Keeley, S., Laloyaux, P., Lopez, P., Lupu, C., Radnoti, G., de Rosnay, P., Rozum, I., Vamborg, F., Villaume, S., and Thépaut, J.-N.: The ERA5 global reanalysis, Q. J. Roy. Meteor. Soc., 146, 1999–2049, https://doi.org/10.1002/qj.3803, 2020. a
Hindman, E. E. and Upadhyay, B. P.: Air pollution transport in the Himalayas of Nepal and Tibet during the 1995–1996 dry season, Atmos. Environ., 36, 727–739, https://doi.org/10.1016/S1352-2310(01)00495-2, 2002. a
Hong, S. and Lim, J.-O. J.: The WRF Single-Moment 6-Class Microphysics Scheme (WSM6), Asia-Pac. J. Atmos. Sci., 42, 129–151, 2006. a
Jiménez, P. A., Dudhia, J., González-Rouco, J. F., Navarro, J., Montávez, J. P., and García-Bustamante, E.: A Revised Scheme for the WRF Surface Layer Formulation, Mon. Weather Rev., 140, 898–918, https://doi.org/10.1175/MWR-D-11-00056.1, 2012. a
Lang, M. N., Gohm, A., and Wagner, J. S.: The impact of embedded valleys on daytime pollution transport over a mountain range, Atmos. Chem. Phys., 15, 11981–11998, https://doi.org/10.5194/acp-15-11981-2015, 2015. a
Leukauf, D., Gohm, A., and Rotach, M. W.: Toward Generalizing the Impact of Surface Heating, Stratification, and Terrain Geometry on the Daytime Heat Export from an Idealized Valley, J. Appl. Meteorol. Clim., 56, 2711–2727, https://doi.org/10.1175/JAMC-D-16-0378.1, 2017. a
Li, J.-G. and Atkinson, B. W.: Transition Regimes in Valley Airflows, Bound.-Lay. Meteorol., 91, 385–411, https://doi.org/10.1023/A:1001846005338, 1999. a
Mikkola, J.: Data for “Valley floor inclination affecting valley winds and transport of passive tracers in idealised simulations”, University of Helsinki [data set], https://doi.org/10.23729/234cb096-eec7-4f9b-b37b-435228df3996, 2024a. a
Mikkola, J.: Model and analysis code for “Valley floor inclination affecting valley winds and transport of passive tracers in idealised simulations”, https://doi.org/10.5281/zenodo.12178614, Zenodo [code], 2024b. a
Rotach, M. W., Wohlfahrt, G., Hansel, A., Reif, M., Wagner, J., and Gohm, A.: The World is Not Flat: Implications for the Global Carbon Balance, B. Am. Meteorol. Soc., 95, 1021–1028, https://doi.org/10.1175/BAMS-D-13-00109.1, 2014. a
Schmidli, J.: Daytime Heat Transfer Processes over Mountainous Terrain, J. Atmos. Sci., 70, 4041–4066, https://doi.org/10.1175/JAS-D-13-083.1, 2013. a, b, c
Schmidli, J. and Rotunno, R.: Mechanisms of Along-Valley Winds and Heat Exchange over Mountainous Terrain, J. Atmos. Sci., 67, 3033–3047, https://doi.org/10.1175/2010JAS3473.1, 2010. a, b
Schmidli, J. and Rotunno, R.: The Quasi-Steady State of the Valley Wind System, Front. Earth Sci., 3, 79, https://doi.org/10.3389/feart.2015.00079, 2015. a, b
Schumann, U.: Large-eddy simulation of the up-slope boundary layer, Q. J. Roy. Meteor. Soc., 116, 637–670, https://doi.org/10.1002/qj.49711649307, 1990. a
Serafin, S., Adler, B., Cuxart, J., De Wekker, S., Gohm, A., Grisogono, B., Kalthoff, N., Kirshbaum, D., Rotach, M., Schmidli, J., Stiperski, I., Vecenaj, Z., and Zardi, D.: Exchange Processes in the Atmospheric Boundary Layer Over Mountainous Terrain, Atmosphere, 9, 102, https://doi.org/10.3390/atmos9030102, 2018. a, b
Skamarock, C., Klemp, B., Dudhia, J., Gill, O., Liu, Z., Berner, J., Wang, W., Powers, G., Duda, G., Barker, D. M., and Huang, X.: A Description of the Advanced Research WRF Model Version 4, NCAR Technical Notes, NCAR/TN-556+STR, National Center for Atmospheric Research, https://doi.org/10.5065/1dfh-6p97, 2019. a, b
Venzac, H., Sellegri, K., Laj, P., Villani, P., Bonasoni, P., Marinoni, A., Cristofanelli, P., Calzolari, F., Fuzzi, S., Decesari, S., Facchini, M.-C., Vuillermoz, E., and Verza, G. P.: High frequency new particle formation in the Himalayas, P. Natl. Acad. Sci. USA, 105, 15666–15671, https://doi.org/10.1073/pnas.0801355105, 2008. a
Wagner, A.: Theorie und Beobachtung der periodischen Gebirgswinde (Theory and observation of periodic mountain winds), Gerl. Beitr. Geophys, 52, 408–449, [English translation: Whiteman, C. D., and E. Dreiseitl, 1984: Alpine Meteorology: Translations of Classic Contributions by A. Wagner, E. Ekhart and F. Defant, PNL-5141/ASCOT-84-3, Pacific Northwest Laboratory, 11–43], 1938. a, b
Wagner, J. S., Gohm, A., and Rotach, M. W.: The Impact of Horizontal Model Grid Resolution on the Boundary Layer Structure over an Idealized Valley, Mon. Weather Rev., 142, 3446–3465, https://doi.org/10.1175/MWR-D-14-00002.1, 2014. a
Wagner, J. S., Gohm, A., and Rotach, M. W.: The impact of valley geometry on daytime thermally driven flows and vertical transport processes, Q. J. Roy. Meteor. Soc., 141, 1780–1794, https://doi.org/10.1002/qj.2481, 2015b. a, b
Weigel, A., Chow, F., Rotach, M., Street, R., and Xue, M.: High-Resolution Large-Eddy Simulations of Flow in a Steep Alpine Valley. Part II: Flow Structure and Heat Budgets, J. Appl. Meteorol. Clim., 45, 87–107, https://doi.org/10.1175/JAM2323.1, 2006. a, b
Whiteman, C.: Mountain Meteorology: Fundamentals and Applications, Oxford University Press, https://doi.org/10.1093/oso/9780195132717.001.0001, 2000. a, b, c
Whiteman, C. D. and Doran, J. C.: The Relationship between Overlying Synoptic-Scale Flows and Winds within a Valley, J. Appl. Meteorol. Clim., 32, 1669–1682, https://doi.org/10.1175/1520-0450(1993)032<1669:TRBOSS>2.0.CO;2, 1993. a
Whiteman, C. D. and Dreiseitl, E.: Alpine meteorology: translations of classic contributions by A. Wagner, E. Ekhart, and F. Defant, https://doi.org/10.2172/6665518, 1984. a
Whiteman, C. D., Hoch, S. W., Horel, J. D., and Charland, A.: Relationship between particulate air pollution and meteorological variables in Utah's Salt Lake Valley, Atmos. Environ., 94, 742–753, https://doi.org/10.1016/j.atmosenv.2014.06.012, 2014. a
Yu, Y., Cai, X., King, J. C., and Renfrew, I. A.: Numerical simulations of katabatic jumps in Coats Land, Antarctica, Bound.-Lay. Meteorol., 114, 413–437, https://doi.org/10.1007/s10546-004-9564-1, 2005. a
Zängl, G., Egger, J., and Wirth, V.: Diurnal Winds in the Himalayan Kali Gandaki Valley. Part II: Modeling, Mon. Weather Rev., 129, 1062–1080, https://doi.org/10.1175/1520-0493(2001)129<1062:DWITHK>2.0.CO;2, 2001. a
Zardi, D. and Whiteman, C. D.: Diurnal Mountain Wind Systems, Springer Netherlands, https://doi.org/10.1007/978-94-007-4098-3_2, 2013. a
Short summary
This study investigates the influence of valley floor inclination on diurnal winds and passive tracer transport within idealised mountain valleys using numerical simulations. The valley inclination strengthens the daytime up-valley winds but only up to a certain point. Beyond that critical angle, the winds weaken again. The inclined valleys transport the tracers higher up in the free troposphere, which would, for example, lead to higher potential for long-range transport.
This study investigates the influence of valley floor inclination on diurnal winds and passive...
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