Articles | Volume 14, issue 4
https://doi.org/10.5194/os-14-617-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/os-14-617-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
11 Jul 2018
Research article |
| 11 Jul 2018
| 11 Jul 2018
100 years of atmospheric and marine observations at the Finnish Utö Island in the Baltic Sea
Lauri Laakso
CORRESPONDING AUTHOR
Finnish Meteorological Institute, Erik Palménin aukio 1, Helsinki, Finland
Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
Santtu Mikkonen
Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
Achim Drebs
Finnish Meteorological Institute, Erik Palménin aukio 1, Helsinki, Finland
Anu Karjalainen
Finnish Meteorological Institute, Erik Palménin aukio 1, Helsinki, Finland
Pentti Pirinen
Finnish Meteorological Institute, Erik Palménin aukio 1, Helsinki, Finland
Pekka Alenius
Finnish Meteorological Institute, Erik Palménin aukio 1, Helsinki, Finland
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Atmos. Chem. Phys., 25, 2443–2457, https://doi.org/10.5194/acp-25-2443-2025, https://doi.org/10.5194/acp-25-2443-2025, 2025
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The Baltic Sea's designation as a sulfur emission control area in 2006, with subsequent regulations, significantly reduced sulfur emissions from shipping. Our study analysed air quality data from 2003 to 2020 on the island Utö and employed modelling, showing a continuous decrease in SO2 concentrations since 2003 and thus evidencing the effectiveness of such regulations in improving air quality. It also underscored the importance of long-term, high-resolution monitoring at remote marine sites.
Martti Honkanen, Mika Aurela, Juha Hatakka, Lumi Haraguchi, Sami Kielosto, Timo Mäkelä, Jukka Seppälä, Simo-Matti Siiriä, Ken Stenbäck, Juha-Pekka Tuovinen, Pasi Ylöstalo, and Lauri Laakso
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Heidi Hellén, Rostislav Kouznetsov, Kaisa Kraft, Jukka Seppälä, Mika Vestenius, Jukka-Pekka Jalkanen, Lauri Laakso, and Hannele Hakola
Atmos. Chem. Phys., 24, 4717–4731, https://doi.org/10.5194/acp-24-4717-2024, https://doi.org/10.5194/acp-24-4717-2024, 2024
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Mixing ratios of C2-C5 NMHCs and methanethiol were measured on an island in the Baltic Sea using an in situ gas chromatograph. Shipping emissions were found to be an important source of ethene, ethyne, propene, and benzene. High summertime mixing ratios of methanethiol and dependence of mixing ratios on seawater temperature and height indicated the biogenic origin to possibly be phytoplankton or macroalgae. These emissions may have a strong impact on SO2 production and new particle formation.
Matti Räsänen, Mika Aurela, Ville Vakkari, Johan P. Beukes, Juha-Pekka Tuovinen, Pieter G. Van Zyl, Miroslav Josipovic, Stefan J. Siebert, Tuomas Laurila, Markku Kulmala, Lauri Laakso, Janne Rinne, Ram Oren, and Gabriel Katul
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The productivity of semiarid grazed grasslands is linked to the variation in rainfall and transpiration. By combining carbon dioxide and water flux measurements, we show that the annual transpiration is nearly constant during wet years while grasses react quickly to dry spells and drought, which reduce transpiration. The planning of annual grazing strategies could consider the early-season rainfall frequency that was linked to the portion of annual transpiration.
Martti Honkanen, Jens Daniel Müller, Jukka Seppälä, Gregor Rehder, Sami Kielosto, Pasi Ylöstalo, Timo Mäkelä, Juha Hatakka, and Lauri Laakso
Ocean Sci., 17, 1657–1675, https://doi.org/10.5194/os-17-1657-2021, https://doi.org/10.5194/os-17-1657-2021, 2021
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The exchange of carbon dioxide (CO2) between the sea and the atmosphere is regulated by the gradient of CO2 partial pressure (pCO2) between the sea and the air. The daily variation of the seawater pCO2 recorded at the fixed station Utö in the Baltic Sea was found to be mainly biologically driven. Calculation of the annual net exchange of CO2 between the sea and atmosphere based on daily measurements of pCO2 carried out using the same sampling time every day could introduce a bias of up to 12 %.
Matti Räsänen, Mika Aurela, Ville Vakkari, Johan P. Beukes, Juha-Pekka Tuovinen, Pieter G. Van Zyl, Miroslav Josipovic, Stefan J. Siebert, Tuomas Laurila, Markku Kulmala, Lauri Laakso, Janne Rinne, Ram Oren, and Gabriel Katul
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2019-651, https://doi.org/10.5194/hess-2019-651, 2020
Revised manuscript not accepted
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The annual ET is approximately equal to precipitation during six measured years for grazed savanna grassland. The computed annual transpiration was highly constrained when rainfall was near or above the long-term mean but was reduced during severe drought year. The developed methodologies can be used in a wide range of arid and semi-arid ecosystems.
Tracey Leah Laban, Pieter Gideon van Zyl, Johan Paul Beukes, Ville Vakkari, Kerneels Jaars, Nadine Borduas-Dedekind, Miroslav Josipovic, Anne Mee Thompson, Markku Kulmala, and Lauri Laakso
Atmos. Chem. Phys., 18, 15491–15514, https://doi.org/10.5194/acp-18-15491-2018, https://doi.org/10.5194/acp-18-15491-2018, 2018
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Surface O3 was measured at four sites in the north-eastern interior of South Africa, which revealed that O3 is a regional problem in continental South Africa, with elevated O3 levels found at rural background and industrial sites. Increased O3 concentrations were associated with high CO levels predominantly related to regional biomass burning, while the O3 production regime was established to be predominantly VOC limited. Increased O3 is associated with strong seasonality of precursor sources.
Ulpu Leijala, Jan-Victor Björkqvist, Milla M. Johansson, Havu Pellikka, Lauri Laakso, and Kimmo K. Kahma
Nat. Hazards Earth Syst. Sci., 18, 2785–2799, https://doi.org/10.5194/nhess-18-2785-2018, https://doi.org/10.5194/nhess-18-2785-2018, 2018
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The coastal flooding risks based on the combined effect of sea level variations and wind-generated waves are estimated for the present, 2050 and 2100. The variability of the wave conditions between the two case study locations in the Helsinki archipelago leads to a difference in the safe building levels of up to 1 m. The rising mean sea level in the Gulf of Finland and the uncertainty of the associated scenarios contribute to the flooding risks notably in 2100.
Tuomo Nieminen, Veli-Matti Kerminen, Tuukka Petäjä, Pasi P. Aalto, Mikhail Arshinov, Eija Asmi, Urs Baltensperger, David C. S. Beddows, Johan Paul Beukes, Don Collins, Aijun Ding, Roy M. Harrison, Bas Henzing, Rakesh Hooda, Min Hu, Urmas Hõrrak, Niku Kivekäs, Kaupo Komsaare, Radovan Krejci, Adam Kristensson, Lauri Laakso, Ari Laaksonen, W. Richard Leaitch, Heikki Lihavainen, Nikolaos Mihalopoulos, Zoltán Németh, Wei Nie, Colin O'Dowd, Imre Salma, Karine Sellegri, Birgitta Svenningsson, Erik Swietlicki, Peter Tunved, Vidmantas Ulevicius, Ville Vakkari, Marko Vana, Alfred Wiedensohler, Zhijun Wu, Annele Virtanen, and Markku Kulmala
Atmos. Chem. Phys., 18, 14737–14756, https://doi.org/10.5194/acp-18-14737-2018, https://doi.org/10.5194/acp-18-14737-2018, 2018
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Atmospheric aerosols have diverse effects on air quality, human health, and global climate. One important source of aerosols is their formation via nucleation and growth in the atmosphere. We have analyzed long-term observations of regional new particle formation events around the globe and provide a comprehensive view on the characteristics of this phenomenon in diverse environments. The results are useful in developing more realistic representation of atmospheric aerosols in global models.
Martti Honkanen, Juha-Pekka Tuovinen, Tuomas Laurila, Timo Mäkelä, Juha Hatakka, Sami Kielosto, and Lauri Laakso
Atmos. Meas. Tech., 11, 5335–5350, https://doi.org/10.5194/amt-11-5335-2018, https://doi.org/10.5194/amt-11-5335-2018, 2018
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The exchange rate of carbon dioxide (CO2) between the atmosphere and the sea is typically small compared to the fluxes observed in the terrestrial ecosystems, causing technical challenges for the measurements of the CO2 sea–air fluxes. In this paper, we examine CO2 sea–air flux measurements carried out on a fixed station on an island. The problems generated by water vapor interference and unmet theoretical assumptions of the eddy covariance method are addressed.
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Andrew D. Venter, Pieter G. van Zyl, Johan P. Beukes, Micky Josipovic, Johan Hendriks, Ville Vakkari, and Lauri Laakso
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Size-resolved trace metal concentrations were determined at a regional background site impacted by the major pollutant source regions in the interior of South Africa, which include a region holding a large number of pyrometallurgical smelters. ≥70% of trace metal species were in the smaller size fractions, indicating the influence of industrial activities, while the influence of wind-blown dust was reflected in the PM2.5–10 size fraction. Annual average Ni and As exceeded European standards.
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This study presents measurements of carbon dioxide exchange between the atmosphere and a grazed savanna grassland ecosystem for 3 years. We find that the yearly variation in carbon dioxide balance is largely determined by the changes in the early wet season balance (September to November) and in the mid-growing season balance (December to January).
Kerneels Jaars, Pieter G. van Zyl, Johan P. Beukes, Heidi Hellén, Ville Vakkari, Micky Josipovic, Andrew D. Venter, Matti Räsänen, Leandra Knoetze, Dirk P. Cilliers, Stefan J. Siebert, Markku Kulmala, Janne Rinne, Alex Guenther, Lauri Laakso, and Hannele Hakola
Atmos. Chem. Phys., 16, 15665–15688, https://doi.org/10.5194/acp-16-15665-2016, https://doi.org/10.5194/acp-16-15665-2016, 2016
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Biogenic volatile organic compounds (BVOCs) – important in tropospheric ozone and secondary organic aerosol formation – were measured at a savannah grassland in South Africa. Results presented are the most extensive for this type of landscape. Compared to other parts of the world, monoterpene levels were similar, while very low isoprene levels led to significantly lower total BVOC levels. BVOC levels were an order of magnitude lower compared to anthropogenic VOC levels measured at Welgegund.
J.-V. Björkqvist, H. Pettersson, L. Laakso, K. K. Kahma, H. Jokinen, and P. Kosloff
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We identified a previously unknown artefact in the Datawell DWR-G4 wave buoy, which measures the GPS signal to resolve surface water waves. The artefact interferes with the part of the measurements containing information about the longer waves and must be removed to obtain accurate readings. We presented a correction method and found it to be accurate based on a comparison to measurements from a larger wave buoy that measures the movements of the device without using the GPS signal.
F. Kuik, A. Lauer, J. P. Beukes, P. G. Van Zyl, M. Josipovic, V. Vakkari, L. Laakso, and G. T. Feig
Atmos. Chem. Phys., 15, 8809–8830, https://doi.org/10.5194/acp-15-8809-2015, https://doi.org/10.5194/acp-15-8809-2015, 2015
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The numerical model WRF-Chem is used to estimate the contribution of anthropogenic emissions to BC, aerosol optical depth and atmospheric heating rates over southern Africa. An evaluation of the model with observational data including long-term BC measurements shows that the basic meteorology is reproduced reasonably well but simulated near-surface BC concentrations are underestimated by up to 50%. It is found that up to 100% of the BC in highly industrialized regions is of anthropogenic origin.
E. Giannakaki, A. Pfüller, K. Korhonen, T. Mielonen, L. Laakso, V. Vakkari, H. Baars, R. Engelmann, J. P. Beukes, P. G. Van Zyl, M. Josipovic, P. Tiitta, K. Chiloane, S. Piketh, H. Lihavainen, K. E. J. Lehtinen, and M. Komppula
Atmos. Chem. Phys., 15, 5429–5442, https://doi.org/10.5194/acp-15-5429-2015, https://doi.org/10.5194/acp-15-5429-2015, 2015
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In this study we summarize 1 year of Raman lidar observations over South Africa. The analyses of lidar measurements presented here could assist in bridging existing gaps in the knowledge of vertical distribution of aerosols above South Africa, since limited long-term data of this type are available for this region. For the first time, we have been able to cover the full seasonal cycle on geometrical characteristics and optical properties of free tropospheric aerosol layers in the region.
A.-M. Sundström, A. Nikandrova, K. Atlaskina, T. Nieminen, V. Vakkari, L. Laakso, J. P. Beukes, A. Arola, P. G. van Zyl, M. Josipovic, A. D. Venter, K. Jaars, J. J. Pienaar, S. Piketh, A. Wiedensohler, E. K. Chiloane, G. de Leeuw, and M. Kulmala
Atmos. Chem. Phys., 15, 4983–4996, https://doi.org/10.5194/acp-15-4983-2015, https://doi.org/10.5194/acp-15-4983-2015, 2015
J. Backman, A. Virkkula, V. Vakkari, J. P. Beukes, P. G. Van Zyl, M. Josipovic, S. Piketh, P. Tiitta, K. Chiloane, T. Petäjä, M. Kulmala, and L. Laakso
Atmos. Meas. Tech., 7, 4285–4298, https://doi.org/10.5194/amt-7-4285-2014, https://doi.org/10.5194/amt-7-4285-2014, 2014
K. Jaars, J. P. Beukes, P. G. van Zyl, A. D. Venter, M. Josipovic, J. J. Pienaar, V. Vakkari, H. Aaltonen, H. Laakso, M. Kulmala, P. Tiitta, A. Guenther, H. Hellén, L. Laakso, and H. Hakola
Atmos. Chem. Phys., 14, 7075–7089, https://doi.org/10.5194/acp-14-7075-2014, https://doi.org/10.5194/acp-14-7075-2014, 2014
K. Korhonen, E. Giannakaki, T. Mielonen, A. Pfüller, L. Laakso, V. Vakkari, H. Baars, R. Engelmann, J. P. Beukes, P. G. Van Zyl, A. Ramandh, L. Ntsangwane, M. Josipovic, P. Tiitta, G. Fourie, I. Ngwana, K. Chiloane, and M. Komppula
Atmos. Chem. Phys., 14, 4263–4278, https://doi.org/10.5194/acp-14-4263-2014, https://doi.org/10.5194/acp-14-4263-2014, 2014
P. Tiitta, V. Vakkari, P. Croteau, J. P. Beukes, P. G. van Zyl, M. Josipovic, A. D. Venter, K. Jaars, J. J. Pienaar, N. L. Ng, M. R. Canagaratna, J. T. Jayne, V.-M. Kerminen, H. Kokkola, M. Kulmala, A. Laaksonen, D. R. Worsnop, and L. Laakso
Atmos. Chem. Phys., 14, 1909–1927, https://doi.org/10.5194/acp-14-1909-2014, https://doi.org/10.5194/acp-14-1909-2014, 2014
A. I. Partanen, A. Laakso, A. Schmidt, H. Kokkola, T. Kuokkanen, J.-P. Pietikäinen, V.-M. Kerminen, K. E. J. Lehtinen, L. Laakso, and H. Korhonen
Atmos. Chem. Phys., 13, 12059–12071, https://doi.org/10.5194/acp-13-12059-2013, https://doi.org/10.5194/acp-13-12059-2013, 2013
A. Hirsikko, V. Vakkari, P. Tiitta, J. Hatakka, V.-M. Kerminen, A.-M. Sundström, J. P. Beukes, H. E. Manninen, M. Kulmala, and L. Laakso
Atmos. Chem. Phys., 13, 5523–5532, https://doi.org/10.5194/acp-13-5523-2013, https://doi.org/10.5194/acp-13-5523-2013, 2013
V. Vakkari, J. P. Beukes, H. Laakso, D. Mabaso, J. J. Pienaar, M. Kulmala, and L. Laakso
Atmos. Chem. Phys., 13, 1751–1770, https://doi.org/10.5194/acp-13-1751-2013, https://doi.org/10.5194/acp-13-1751-2013, 2013
L. Riuttanen, M. Dal Maso, G. de Leeuw, I. Riipinen, L. Sogacheva, V. Vakkari, L. Laakso, and M. Kulmala
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acpd-13-4289-2013, https://doi.org/10.5194/acpd-13-4289-2013, 2013
Revised manuscript has not been submitted
J. Leppä, S. Gagné, L. Laakso, H. E. Manninen, K. E. J. Lehtinen, M. Kulmala, and V.-M. Kerminen
Atmos. Chem. Phys., 13, 463–486, https://doi.org/10.5194/acp-13-463-2013, https://doi.org/10.5194/acp-13-463-2013, 2013
A.-P. Hyvärinen, V. Vakkari, L. Laakso, R. K. Hooda, V. P. Sharma, T. S. Panwar, J. P. Beukes, P. G. van Zyl, M. Josipovic, R. M. Garland, M. O. Andreae, U. Pöschl, and A. Petzold
Atmos. Meas. Tech., 6, 81–90, https://doi.org/10.5194/amt-6-81-2013, https://doi.org/10.5194/amt-6-81-2013, 2013
V.-M. Kerminen, M. Paramonov, T. Anttila, I. Riipinen, C. Fountoukis, H. Korhonen, E. Asmi, L. Laakso, H. Lihavainen, E. Swietlicki, B. Svenningsson, A. Asmi, S. N. Pandis, M. Kulmala, and T. Petäjä
Atmos. Chem. Phys., 12, 12037–12059, https://doi.org/10.5194/acp-12-12037-2012, https://doi.org/10.5194/acp-12-12037-2012, 2012
Antti Vartiainen, Santtu Mikkonen, Ville Leinonen, Tuukka Petäjä, Alfred Wiedensohler, Thomas Kühn, and Tuuli Miinalainen
EGUsphere, https://doi.org/10.5194/egusphere-2025-774, https://doi.org/10.5194/egusphere-2025-774, 2025
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
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Global climate models, commonly used for climate predictions, struggle at capturing local-scale variations in air quality. We have used measurements of ultrafine particles (UFPs), a less understood air pollutant with potentially significant health implications, for training machine learning models that can substantially reduce the inaccuracy in UFP concentrations predicted by a climate model. This approach could aid epidemiological studies of ultrafine particles by extending exposure records.
Henri Oikarinen, Anni Hartikainen, Pauli Simonen, Miska Olin, Ukko-Ville Mäkinen, Petteri Marjanen, Laura Salo, Ville Silvonen, Sampsa Martikainen, Jussi Hoivala, Mika Ihalainen, Pasi Miettinen, Pasi Yli-Pirilä, Olli Sippula, Santtu Mikkonen, and Panu Karjalainen
EGUsphere, https://doi.org/10.5194/egusphere-2025-540, https://doi.org/10.5194/egusphere-2025-540, 2025
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
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Fuel-operated auxiliary heaters are used in vehicles to provide extra heating to improve passenger comfort and vehicle functionality in cold climates. Currently heater emissions are not regulated as part of vehicle emissions, so this research was done to assess harmful gaseous and airborne particle emissions from them. Heaters were found to be major source of particles, especially when particles formed after combustion were accounted for, and large carbon monoxide emissions were also observed.
Androniki Maragkidou, Tiia Grönholm, Laura Rautiainen, Juha Nikmo, Jukka-Pekka Jalkanen, Timo Mäkelä, Timo Anttila, Lauri Laakso, and Jaakko Kukkonen
Atmos. Chem. Phys., 25, 2443–2457, https://doi.org/10.5194/acp-25-2443-2025, https://doi.org/10.5194/acp-25-2443-2025, 2025
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The Baltic Sea's designation as a sulfur emission control area in 2006, with subsequent regulations, significantly reduced sulfur emissions from shipping. Our study analysed air quality data from 2003 to 2020 on the island Utö and employed modelling, showing a continuous decrease in SO2 concentrations since 2003 and thus evidencing the effectiveness of such regulations in improving air quality. It also underscored the importance of long-term, high-resolution monitoring at remote marine sites.
Matti Niskanen, Aku Seppänen, Henri Oikarinen, Miska Olin, Panu Karjalainen, Santtu Mikkonen, and Kari Lehtinen
EGUsphere, https://doi.org/10.5194/egusphere-2024-1898, https://doi.org/10.5194/egusphere-2024-1898, 2024
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Particle size is a key factor determining the properties of aerosol particles, which have a major influence on the climate and on human health. When measuring the particle sizes, however, sometimes the sampling lines that transfer the aerosol to the measurement device distort the size distribution, making the measurement unreliable. We propose a method to correct for the distortions and estimate the true particle sizes, improving measurement accuracy.
Martti Honkanen, Mika Aurela, Juha Hatakka, Lumi Haraguchi, Sami Kielosto, Timo Mäkelä, Jukka Seppälä, Simo-Matti Siiriä, Ken Stenbäck, Juha-Pekka Tuovinen, Pasi Ylöstalo, and Lauri Laakso
Biogeosciences, 21, 4341–4359, https://doi.org/10.5194/bg-21-4341-2024, https://doi.org/10.5194/bg-21-4341-2024, 2024
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The exchange of CO2 between the sea and the atmosphere was studied in the Archipelago Sea, Baltic Sea, in 2017–2021, using an eddy covariance technique. The sea acted as a net source of CO2 with an average yearly emission of 27.1 gC m-2 yr-1, indicating that the marine ecosystem respired carbon that originated elsewhere. The yearly CO2 emission varied between 18.2–39.2 gC m-2 yr-1, mostly due to the yearly variation of ecosystem carbon uptake.
Heidi Hellén, Rostislav Kouznetsov, Kaisa Kraft, Jukka Seppälä, Mika Vestenius, Jukka-Pekka Jalkanen, Lauri Laakso, and Hannele Hakola
Atmos. Chem. Phys., 24, 4717–4731, https://doi.org/10.5194/acp-24-4717-2024, https://doi.org/10.5194/acp-24-4717-2024, 2024
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Mixing ratios of C2-C5 NMHCs and methanethiol were measured on an island in the Baltic Sea using an in situ gas chromatograph. Shipping emissions were found to be an important source of ethene, ethyne, propene, and benzene. High summertime mixing ratios of methanethiol and dependence of mixing ratios on seawater temperature and height indicated the biogenic origin to possibly be phytoplankton or macroalgae. These emissions may have a strong impact on SO2 production and new particle formation.
Ville Leinonen, Miska Olin, Sampsa Martikainen, Panu Karjalainen, and Santtu Mikkonen
Atmos. Meas. Tech., 16, 5075–5089, https://doi.org/10.5194/amt-16-5075-2023, https://doi.org/10.5194/amt-16-5075-2023, 2023
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Emission factor calculation was studied to provide models that do not use traditional CO2-based calculation in exhaust plume analysis. Two types of models, one based on the physical dependency of dilution of the exhaust flow rate and speed and two based on the statistical, measured dependency of dilution of the exhaust flow rate, acceleration, speed, altitude change, and/or wind, were developed. These methods could possibly be extended to also calculate non-exhaust emissions in the future.
Matti Räsänen, Mika Aurela, Ville Vakkari, Johan P. Beukes, Juha-Pekka Tuovinen, Pieter G. Van Zyl, Miroslav Josipovic, Stefan J. Siebert, Tuomas Laurila, Markku Kulmala, Lauri Laakso, Janne Rinne, Ram Oren, and Gabriel Katul
Hydrol. Earth Syst. Sci., 26, 5773–5791, https://doi.org/10.5194/hess-26-5773-2022, https://doi.org/10.5194/hess-26-5773-2022, 2022
Short summary
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The productivity of semiarid grazed grasslands is linked to the variation in rainfall and transpiration. By combining carbon dioxide and water flux measurements, we show that the annual transpiration is nearly constant during wet years while grasses react quickly to dry spells and drought, which reduce transpiration. The planning of annual grazing strategies could consider the early-season rainfall frequency that was linked to the portion of annual transpiration.
Ville Leinonen, Harri Kokkola, Taina Yli-Juuti, Tero Mielonen, Thomas Kühn, Tuomo Nieminen, Simo Heikkinen, Tuuli Miinalainen, Tommi Bergman, Ken Carslaw, Stefano Decesari, Markus Fiebig, Tareq Hussein, Niku Kivekäs, Radovan Krejci, Markku Kulmala, Ari Leskinen, Andreas Massling, Nikos Mihalopoulos, Jane P. Mulcahy, Steffen M. Noe, Twan van Noije, Fiona M. O'Connor, Colin O'Dowd, Dirk Olivie, Jakob B. Pernov, Tuukka Petäjä, Øyvind Seland, Michael Schulz, Catherine E. Scott, Henrik Skov, Erik Swietlicki, Thomas Tuch, Alfred Wiedensohler, Annele Virtanen, and Santtu Mikkonen
Atmos. Chem. Phys., 22, 12873–12905, https://doi.org/10.5194/acp-22-12873-2022, https://doi.org/10.5194/acp-22-12873-2022, 2022
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We provide the first extensive comparison of detailed aerosol size distribution trends between in situ observations from Europe and five different earth system models. We investigated aerosol modes (nucleation, Aitken, and accumulation) separately and were able to show the differences between measured and modeled trends and especially their seasonal patterns. The differences in model results are likely due to complex effects of several processes instead of certain specific model features.
Sini Isokääntä, Paul Kim, Santtu Mikkonen, Thomas Kühn, Harri Kokkola, Taina Yli-Juuti, Liine Heikkinen, Krista Luoma, Tuukka Petäjä, Zak Kipling, Daniel Partridge, and Annele Virtanen
Atmos. Chem. Phys., 22, 11823–11843, https://doi.org/10.5194/acp-22-11823-2022, https://doi.org/10.5194/acp-22-11823-2022, 2022
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This research employs air mass history analysis and observations to study how clouds and precipitation affect atmospheric aerosols during transport to a boreal forest site. The mass concentrations of studied chemical species showed exponential decrease as a function of accumulated rain along the air mass route. Our analysis revealed in-cloud sulfate formation, while no major changes in organic mass were seen. Most of the in-cloud-formed sulfate could be assigned to particle sizes above 200 nm.
Verónica González-Gambau, Estrella Olmedo, Antonio Turiel, Cristina González-Haro, Aina García-Espriu, Justino Martínez, Pekka Alenius, Laura Tuomi, Rafael Catany, Manuel Arias, Carolina Gabarró, Nina Hoareau, Marta Umbert, Roberto Sabia, and Diego Fernández
Earth Syst. Sci. Data, 14, 2343–2368, https://doi.org/10.5194/essd-14-2343-2022, https://doi.org/10.5194/essd-14-2343-2022, 2022
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We present the first Soil Moisture and Ocean Salinity Sea Surface Salinity (SSS) dedicated products over the Baltic Sea (ESA Baltic+ Salinity Dynamics). The Baltic+ L3 product covers 9 days in a 0.25° grid. The Baltic+ L4 is derived by merging L3 SSS with sea surface temperature information, giving a daily product in a 0.05° grid. The accuracy of L3 is 0.7–0.8 and 0.4 psu for the L4. Baltic+ products have shown to be useful, covering spatiotemporal data gaps and for validating numerical models.
Antti Westerlund, Elina Miettunen, Laura Tuomi, and Pekka Alenius
Ocean Sci., 18, 89–108, https://doi.org/10.5194/os-18-89-2022, https://doi.org/10.5194/os-18-89-2022, 2022
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Water exchange through the Åland Sea (in the Baltic Sea) affects the conditions in the neighbouring Gulf of Bothnia. Pathways and variability of flows were studied with a high-resolution hydrodynamic model. Our analysis showed a northward transport in the deep layer and net transport towards the south in the surface layer. While on the southern edge of the Åland Sea the primary route of deep-water exchange is through Lågskär Deep, some deep water still bypasses it to the Åland Sea.
Martti Honkanen, Jens Daniel Müller, Jukka Seppälä, Gregor Rehder, Sami Kielosto, Pasi Ylöstalo, Timo Mäkelä, Juha Hatakka, and Lauri Laakso
Ocean Sci., 17, 1657–1675, https://doi.org/10.5194/os-17-1657-2021, https://doi.org/10.5194/os-17-1657-2021, 2021
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The exchange of carbon dioxide (CO2) between the sea and the atmosphere is regulated by the gradient of CO2 partial pressure (pCO2) between the sea and the air. The daily variation of the seawater pCO2 recorded at the fixed station Utö in the Baltic Sea was found to be mainly biologically driven. Calculation of the annual net exchange of CO2 between the sea and atmosphere based on daily measurements of pCO2 carried out using the same sampling time every day could introduce a bias of up to 12 %.
Antti Ruuskanen, Sami Romakkaniemi, Harri Kokkola, Antti Arola, Santtu Mikkonen, Harri Portin, Annele Virtanen, Kari E. J. Lehtinen, Mika Komppula, and Ari Leskinen
Atmos. Chem. Phys., 21, 1683–1695, https://doi.org/10.5194/acp-21-1683-2021, https://doi.org/10.5194/acp-21-1683-2021, 2021
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The study focuses mainly on cloud-scavenging efficiency of absorbing particulate matter (mainly black carbon) but additionally covers cloud-scavenging efficiency of scattering particles and statistics of cloud condensation nuclei. The main findings give insight into how black carbon is distributed in different particle sizes and the sensitivity to cloud scavenged. The main findings are useful for large-scale modelling for evaluating cloud scavenging.
Santtu Mikkonen, Zoltán Németh, Veronika Varga, Tamás Weidinger, Ville Leinonen, Taina Yli-Juuti, and Imre Salma
Atmos. Chem. Phys., 20, 12247–12263, https://doi.org/10.5194/acp-20-12247-2020, https://doi.org/10.5194/acp-20-12247-2020, 2020
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We determined decennial statistical time trends and diurnal statistical patterns of atmospheric particle number concentrations in various relevant size fractions in the city centre of Budapest in an interval of 2008–2018. The mean overall decrease rate of particles in different size fractions was approximately −5 % scaled for the 10-year measurement interval. The decline can be interpreted as a consequence of the decreased anthropogenic emissions in the city.
Havu Pellikka, Terhi K. Laurila, Hanna Boman, Anu Karjalainen, Jan-Victor Björkqvist, and Kimmo K. Kahma
Nat. Hazards Earth Syst. Sci., 20, 2535–2546, https://doi.org/10.5194/nhess-20-2535-2020, https://doi.org/10.5194/nhess-20-2535-2020, 2020
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Meteotsunamis are long waves created by atmospheric disturbances travelling over the sea. These waves can be hazardous in rare cases. Their occurrence in the Baltic Sea has been poorly known, which is why we examine century-long sea level records from the Gulf of Finland to identify these waves. In total, 121 potential meteotsunamis were found. The strong connection between meteotsunami occurrence and lightning observations indicates that meteotsunamis in this region occur during thunderstorms.
Sini Isokääntä, Eetu Kari, Angela Buchholz, Liqing Hao, Siegfried Schobesberger, Annele Virtanen, and Santtu Mikkonen
Atmos. Meas. Tech., 13, 2995–3022, https://doi.org/10.5194/amt-13-2995-2020, https://doi.org/10.5194/amt-13-2995-2020, 2020
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Online mass spectrometry produces large amounts of data. These data can be interpreted with statistical methods, enabling scientists to more easily understand the underlying processes. We compared these techniques on car exhaust measurements. We show differences and similarities between the methods and give recommendations on applicability of the methods on certain types of data. We show that applying multiple methods leads to more robust results, thus increasing reliability of the findings.
Ville Leinonen, Petri Tiitta, Olli Sippula, Hendryk Czech, Ari Leskinen, Juha Karvanen, Sini Isokääntä, and Santtu Mikkonen
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2020-13, https://doi.org/10.5194/gmd-2020-13, 2020
Revised manuscript not accepted
Matti Räsänen, Mika Aurela, Ville Vakkari, Johan P. Beukes, Juha-Pekka Tuovinen, Pieter G. Van Zyl, Miroslav Josipovic, Stefan J. Siebert, Tuomas Laurila, Markku Kulmala, Lauri Laakso, Janne Rinne, Ram Oren, and Gabriel Katul
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2019-651, https://doi.org/10.5194/hess-2019-651, 2020
Revised manuscript not accepted
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The annual ET is approximately equal to precipitation during six measured years for grazed savanna grassland. The computed annual transpiration was highly constrained when rainfall was near or above the long-term mean but was reduced during severe drought year. The developed methodologies can be used in a wide range of arid and semi-arid ecosystems.
Santtu Mikkonen, Mikko R. A. Pitkänen, Tuomo Nieminen, Antti Lipponen, Sini Isokääntä, Antti Arola, and Kari E. J. Lehtinen
Atmos. Chem. Phys., 19, 12531–12543, https://doi.org/10.5194/acp-19-12531-2019, https://doi.org/10.5194/acp-19-12531-2019, 2019
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Atmospheric measurement data never come without measurement error. Too often, these errors are neglected when researchers make inferences from their data. We applied multiple line-fitting methods to simulated data mimicking two central variables in aerosol research. Our results show that an ordinary least squares fit, typically used to describe relationships, underestimates the slope of the fit and that methods taking the measurement uncertainty into account performed significantly better.
Terhikki Manninen, Tuula Aalto, Tiina Markkanen, Mikko Peltoniemi, Kristin Böttcher, Sari Metsämäki, Kati Anttila, Pentti Pirinen, Antti Leppänen, and Ali Nadir Arslan
Biogeosciences, 16, 223–240, https://doi.org/10.5194/bg-16-223-2019, https://doi.org/10.5194/bg-16-223-2019, 2019
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The surface albedo time series CLARA-A2 SAL was used to study trends in the timing of the melting season of snow and preceding albedo value in Finland during 1982–2016 to assess climate change. The results were in line with operational snow depth data, JSBACH land ecosystem model, SYKE fractional snow cover and greening-up data. In the north a clear trend to earlier snowmelt onset, increasing melting season length, and decrease in pre-melt albedo (related to increased stem volume) was observed.
Liqing Hao, Olga Garmash, Mikael Ehn, Pasi Miettinen, Paola Massoli, Santtu Mikkonen, Tuija Jokinen, Pontus Roldin, Pasi Aalto, Taina Yli-Juuti, Jorma Joutsensaari, Tuukka Petäjä, Markku Kulmala, Kari E. J. Lehtinen, Douglas R. Worsnop, and Annele Virtanen
Atmos. Chem. Phys., 18, 17705–17716, https://doi.org/10.5194/acp-18-17705-2018, https://doi.org/10.5194/acp-18-17705-2018, 2018
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An aerosol mass spectrometer was used to characterize aerosol chemical composition during new particle formation periods. The time profiles of mass concentrations and chemical composition of observed aerosol particles are subjected to joint effects of boundary layer dilution, atmospheric chemistry and aerosol mixing in different boundary layers. During the nighttime, the increase in organic aerosol mass correlated well with the increase in condensed highly oxygenated organic molecules' mass.
Tracey Leah Laban, Pieter Gideon van Zyl, Johan Paul Beukes, Ville Vakkari, Kerneels Jaars, Nadine Borduas-Dedekind, Miroslav Josipovic, Anne Mee Thompson, Markku Kulmala, and Lauri Laakso
Atmos. Chem. Phys., 18, 15491–15514, https://doi.org/10.5194/acp-18-15491-2018, https://doi.org/10.5194/acp-18-15491-2018, 2018
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Surface O3 was measured at four sites in the north-eastern interior of South Africa, which revealed that O3 is a regional problem in continental South Africa, with elevated O3 levels found at rural background and industrial sites. Increased O3 concentrations were associated with high CO levels predominantly related to regional biomass burning, while the O3 production regime was established to be predominantly VOC limited. Increased O3 is associated with strong seasonality of precursor sources.
Ulpu Leijala, Jan-Victor Björkqvist, Milla M. Johansson, Havu Pellikka, Lauri Laakso, and Kimmo K. Kahma
Nat. Hazards Earth Syst. Sci., 18, 2785–2799, https://doi.org/10.5194/nhess-18-2785-2018, https://doi.org/10.5194/nhess-18-2785-2018, 2018
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The coastal flooding risks based on the combined effect of sea level variations and wind-generated waves are estimated for the present, 2050 and 2100. The variability of the wave conditions between the two case study locations in the Helsinki archipelago leads to a difference in the safe building levels of up to 1 m. The rising mean sea level in the Gulf of Finland and the uncertainty of the associated scenarios contribute to the flooding risks notably in 2100.
Tuomo Nieminen, Veli-Matti Kerminen, Tuukka Petäjä, Pasi P. Aalto, Mikhail Arshinov, Eija Asmi, Urs Baltensperger, David C. S. Beddows, Johan Paul Beukes, Don Collins, Aijun Ding, Roy M. Harrison, Bas Henzing, Rakesh Hooda, Min Hu, Urmas Hõrrak, Niku Kivekäs, Kaupo Komsaare, Radovan Krejci, Adam Kristensson, Lauri Laakso, Ari Laaksonen, W. Richard Leaitch, Heikki Lihavainen, Nikolaos Mihalopoulos, Zoltán Németh, Wei Nie, Colin O'Dowd, Imre Salma, Karine Sellegri, Birgitta Svenningsson, Erik Swietlicki, Peter Tunved, Vidmantas Ulevicius, Ville Vakkari, Marko Vana, Alfred Wiedensohler, Zhijun Wu, Annele Virtanen, and Markku Kulmala
Atmos. Chem. Phys., 18, 14737–14756, https://doi.org/10.5194/acp-18-14737-2018, https://doi.org/10.5194/acp-18-14737-2018, 2018
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Atmospheric aerosols have diverse effects on air quality, human health, and global climate. One important source of aerosols is their formation via nucleation and growth in the atmosphere. We have analyzed long-term observations of regional new particle formation events around the globe and provide a comprehensive view on the characteristics of this phenomenon in diverse environments. The results are useful in developing more realistic representation of atmospheric aerosols in global models.
Martti Honkanen, Juha-Pekka Tuovinen, Tuomas Laurila, Timo Mäkelä, Juha Hatakka, Sami Kielosto, and Lauri Laakso
Atmos. Meas. Tech., 11, 5335–5350, https://doi.org/10.5194/amt-11-5335-2018, https://doi.org/10.5194/amt-11-5335-2018, 2018
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The exchange rate of carbon dioxide (CO2) between the atmosphere and the sea is typically small compared to the fluxes observed in the terrestrial ecosystems, causing technical challenges for the measurements of the CO2 sea–air fluxes. In this paper, we examine CO2 sea–air flux measurements carried out on a fixed station on an island. The problems generated by water vapor interference and unmet theoretical assumptions of the eddy covariance method are addressed.
Jorma Joutsensaari, Matthew Ozon, Tuomo Nieminen, Santtu Mikkonen, Timo Lähivaara, Stefano Decesari, M. Cristina Facchini, Ari Laaksonen, and Kari E. J. Lehtinen
Atmos. Chem. Phys., 18, 9597–9615, https://doi.org/10.5194/acp-18-9597-2018, https://doi.org/10.5194/acp-18-9597-2018, 2018
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New particle formation (NPF) in the atmosphere is globally an important source of aerosol particles. NPF events are typically identified and analyzed manually by researchers from particle size distribution data day by day, which is time consuming and might be inconsistent. We have developed an automatic analysis method based on deep learning for NPF event identification. The developed method can be easily utilized to analyze any long-term datasets more accurately and consistently.
Ari Venäläinen, Mikko Laapas, Pentti Pirinen, Matti Horttanainen, Reijo Hyvönen, Ilari Lehtonen, Päivi Junila, Meiting Hou, and Heli M. Peltola
Earth Syst. Dynam., 8, 529–545, https://doi.org/10.5194/esd-8-529-2017, https://doi.org/10.5194/esd-8-529-2017, 2017
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The rapidly growing forest-based bioeconomy calls for increasing wood harvesting intensity, and an increase in thinning and a final felling area. This may increase wind damage risks at the upwind edges of new cleared felling areas and thinned stands. Efficient wind risk assessment is needed. We demonstrate a pragmatic and computationally feasible method for identifying at a high spatial resolution those locations having the highest forest wind damage risks.
Sami Romakkaniemi, Zubair Maalick, Antti Hellsten, Antti Ruuskanen, Olli Väisänen, Irshad Ahmad, Juha Tonttila, Santtu Mikkonen, Mika Komppula, and Thomas Kühn
Atmos. Chem. Phys., 17, 7955–7964, https://doi.org/10.5194/acp-17-7955-2017, https://doi.org/10.5194/acp-17-7955-2017, 2017
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Surface topography affects aerosol–cloud interactions in boundary layer clouds. Local topography effects should be screened out from in situ observations before results can be generalised into a larger scale. Here we present modelling and observational results from a measurement station residing in a 75 m tower on top of a 150 m hill, and analyse how landscape affects the cloud formation, and which factors should be taken into account when aerosol effect on cloud droplet formation is studied.
Kgaugelo Euphinia Chiloane, Johan Paul Beukes, Pieter Gideon van Zyl, Petra Maritz, Ville Vakkari, Miroslav Josipovic, Andrew Derick Venter, Kerneels Jaars, Petri Tiitta, Markku Kulmala, Alfred Wiedensohler, Catherine Liousse, Gabisile Vuyisile Mkhatshwa, Avishkar Ramandh, and Lauri Laakso
Atmos. Chem. Phys., 17, 6177–6196, https://doi.org/10.5194/acp-17-6177-2017, https://doi.org/10.5194/acp-17-6177-2017, 2017
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This paper presents atmospheric black carbon (BC) data collected in South Africa (SA). In general, BC level were higher than in the developed world. At one site, five sources were identified, with household combustion as well as savannah and grassland fires the most significant sources during winter and spring, while coal-fired power stations, pyrometallurgical smelters and traffic contributed year round.
Andrew D. Venter, Pieter G. van Zyl, Johan P. Beukes, Micky Josipovic, Johan Hendriks, Ville Vakkari, and Lauri Laakso
Atmos. Chem. Phys., 17, 4251–4263, https://doi.org/10.5194/acp-17-4251-2017, https://doi.org/10.5194/acp-17-4251-2017, 2017
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Size-resolved trace metal concentrations were determined at a regional background site impacted by the major pollutant source regions in the interior of South Africa, which include a region holding a large number of pyrometallurgical smelters. ≥70% of trace metal species were in the smaller size fractions, indicating the influence of industrial activities, while the influence of wind-blown dust was reflected in the PM2.5–10 size fraction. Annual average Ni and As exceeded European standards.
Matti Räsänen, Mika Aurela, Ville Vakkari, Johan P. Beukes, Juha-Pekka Tuovinen, Pieter G. Van Zyl, Miroslav Josipovic, Andrew D. Venter, Kerneels Jaars, Stefan J. Siebert, Tuomas Laurila, Janne Rinne, and Lauri Laakso
Biogeosciences, 14, 1039–1054, https://doi.org/10.5194/bg-14-1039-2017, https://doi.org/10.5194/bg-14-1039-2017, 2017
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This study presents measurements of carbon dioxide exchange between the atmosphere and a grazed savanna grassland ecosystem for 3 years. We find that the yearly variation in carbon dioxide balance is largely determined by the changes in the early wet season balance (September to November) and in the mid-growing season balance (December to January).
Kerneels Jaars, Pieter G. van Zyl, Johan P. Beukes, Heidi Hellén, Ville Vakkari, Micky Josipovic, Andrew D. Venter, Matti Räsänen, Leandra Knoetze, Dirk P. Cilliers, Stefan J. Siebert, Markku Kulmala, Janne Rinne, Alex Guenther, Lauri Laakso, and Hannele Hakola
Atmos. Chem. Phys., 16, 15665–15688, https://doi.org/10.5194/acp-16-15665-2016, https://doi.org/10.5194/acp-16-15665-2016, 2016
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Biogenic volatile organic compounds (BVOCs) – important in tropospheric ozone and secondary organic aerosol formation – were measured at a savannah grassland in South Africa. Results presented are the most extensive for this type of landscape. Compared to other parts of the world, monoterpene levels were similar, while very low isoprene levels led to significantly lower total BVOC levels. BVOC levels were an order of magnitude lower compared to anthropogenic VOC levels measured at Welgegund.
Aki Pajunoja, Weiwei Hu, Yu J. Leong, Nathan F. Taylor, Pasi Miettinen, Brett B. Palm, Santtu Mikkonen, Don R. Collins, Jose L. Jimenez, and Annele Virtanen
Atmos. Chem. Phys., 16, 11163–11176, https://doi.org/10.5194/acp-16-11163-2016, https://doi.org/10.5194/acp-16-11163-2016, 2016
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The phase state of ambient particles was inferred from bounce measurements conducted at a rural site in central Alabama during the SOAS campaign. The organic-dominated ambient particles are mostly in the liquid phase at summertime conditions but they turn semisolid when dried in the measurement setup. Bounce humidograms reveal that the hygroscopicity and oxidation of the particles decreases the liquefying RH. The effect of oxidation is emphasized by oxidation flow reactor measurements.
Elham Baranizadeh, Benjamin N. Murphy, Jan Julin, Saeed Falahat, Carly L. Reddington, Antti Arola, Lars Ahlm, Santtu Mikkonen, Christos Fountoukis, David Patoulias, Andreas Minikin, Thomas Hamburger, Ari Laaksonen, Spyros N. Pandis, Hanna Vehkamäki, Kari E. J. Lehtinen, and Ilona Riipinen
Geosci. Model Dev., 9, 2741–2754, https://doi.org/10.5194/gmd-9-2741-2016, https://doi.org/10.5194/gmd-9-2741-2016, 2016
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The molecular mechanisms through which new ultrafine (< 100 nm) aerosol particles are formed in the atmosphere have puzzled the scientific community for decades. In the past few years, however, significant progress has been made in unraveling these processes through laboratory studies and computational efforts. In this work we have implemented these new developments to an air quality model and study the implications of anthropogenically driven particle formation for European air quality.
Jani Huttunen, Harri Kokkola, Tero Mielonen, Mika Esa Juhani Mononen, Antti Lipponen, Juha Reunanen, Anders Vilhelm Lindfors, Santtu Mikkonen, Kari Erkki Juhani Lehtinen, Natalia Kouremeti, Alkiviadis Bais, Harri Niska, and Antti Arola
Atmos. Chem. Phys., 16, 8181–8191, https://doi.org/10.5194/acp-16-8181-2016, https://doi.org/10.5194/acp-16-8181-2016, 2016
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For a good estimate of the current forcing by anthropogenic aerosols, knowledge in past is needed. One option to lengthen time series is to retrieve aerosol optical depth from solar radiation measurements. We have evaluated several methods for this task. Most of the methods produce aerosol optical depth estimates with a good accuracy. However, machine learning methods seem to be the most applicable not to produce any systematic biases, since they do not need constrain the aerosol properties.
J.-V. Björkqvist, H. Pettersson, L. Laakso, K. K. Kahma, H. Jokinen, and P. Kosloff
Geosci. Instrum. Method. Data Syst., 5, 17–25, https://doi.org/10.5194/gi-5-17-2016, https://doi.org/10.5194/gi-5-17-2016, 2016
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We identified a previously unknown artefact in the Datawell DWR-G4 wave buoy, which measures the GPS signal to resolve surface water waves. The artefact interferes with the part of the measurements containing information about the longer waves and must be removed to obtain accurate readings. We presented a correction method and found it to be accurate based on a comparison to measurements from a larger wave buoy that measures the movements of the device without using the GPS signal.
J. Joutsensaari, P. Yli-Pirilä, H. Korhonen, A. Arola, J. D. Blande, J. Heijari, M. Kivimäenpää, S. Mikkonen, L. Hao, P. Miettinen, P. Lyytikäinen-Saarenmaa, C. L. Faiola, A. Laaksonen, and J. K. Holopainen
Atmos. Chem. Phys., 15, 12139–12157, https://doi.org/10.5194/acp-15-12139-2015, https://doi.org/10.5194/acp-15-12139-2015, 2015
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Global warming will induce large-scale insect outbreaks in boreal forests. Our results from field and laboratory experiments, satellite observations and global-scale modelling suggest that more frequent insect outbreaks, in addition to temperature-dependent increases in VOC emissions, could result in substantial increases in biogenic SOA formation and therefore affect both aerosol direct and indirect forcing of climate at regional scales. This should be considered in future climate predictions.
F. Kuik, A. Lauer, J. P. Beukes, P. G. Van Zyl, M. Josipovic, V. Vakkari, L. Laakso, and G. T. Feig
Atmos. Chem. Phys., 15, 8809–8830, https://doi.org/10.5194/acp-15-8809-2015, https://doi.org/10.5194/acp-15-8809-2015, 2015
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The numerical model WRF-Chem is used to estimate the contribution of anthropogenic emissions to BC, aerosol optical depth and atmospheric heating rates over southern Africa. An evaluation of the model with observational data including long-term BC measurements shows that the basic meteorology is reproduced reasonably well but simulated near-surface BC concentrations are underestimated by up to 50%. It is found that up to 100% of the BC in highly industrialized regions is of anthropogenic origin.
E. Giannakaki, A. Pfüller, K. Korhonen, T. Mielonen, L. Laakso, V. Vakkari, H. Baars, R. Engelmann, J. P. Beukes, P. G. Van Zyl, M. Josipovic, P. Tiitta, K. Chiloane, S. Piketh, H. Lihavainen, K. E. J. Lehtinen, and M. Komppula
Atmos. Chem. Phys., 15, 5429–5442, https://doi.org/10.5194/acp-15-5429-2015, https://doi.org/10.5194/acp-15-5429-2015, 2015
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In this study we summarize 1 year of Raman lidar observations over South Africa. The analyses of lidar measurements presented here could assist in bridging existing gaps in the knowledge of vertical distribution of aerosols above South Africa, since limited long-term data of this type are available for this region. For the first time, we have been able to cover the full seasonal cycle on geometrical characteristics and optical properties of free tropospheric aerosol layers in the region.
A.-M. Sundström, A. Nikandrova, K. Atlaskina, T. Nieminen, V. Vakkari, L. Laakso, J. P. Beukes, A. Arola, P. G. van Zyl, M. Josipovic, A. D. Venter, K. Jaars, J. J. Pienaar, S. Piketh, A. Wiedensohler, E. K. Chiloane, G. de Leeuw, and M. Kulmala
Atmos. Chem. Phys., 15, 4983–4996, https://doi.org/10.5194/acp-15-4983-2015, https://doi.org/10.5194/acp-15-4983-2015, 2015
E. M. Dunne, S. Mikkonen, H. Kokkola, and H. Korhonen
Atmos. Chem. Phys., 14, 13631–13642, https://doi.org/10.5194/acp-14-13631-2014, https://doi.org/10.5194/acp-14-13631-2014, 2014
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Marine clouds have a strong effect on the Earth's radiative balance. One proposed climate feedback is that, in a warming climate, marine aerosol emissions will change due to changing wind speeds. We have examined the processes that affect aerosol emissions and removal over 15 years, and high-temporal-resolution output over 2 months. We conclude that wind trends are unlikely to cause a strong feedback in marine regions, but changes in removal processes or transport from continental regions may.
J. Backman, A. Virkkula, V. Vakkari, J. P. Beukes, P. G. Van Zyl, M. Josipovic, S. Piketh, P. Tiitta, K. Chiloane, T. Petäjä, M. Kulmala, and L. Laakso
Atmos. Meas. Tech., 7, 4285–4298, https://doi.org/10.5194/amt-7-4285-2014, https://doi.org/10.5194/amt-7-4285-2014, 2014
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V. Vakkari, J. P. Beukes, H. Laakso, D. Mabaso, J. J. Pienaar, M. Kulmala, and L. Laakso
Atmos. Chem. Phys., 13, 1751–1770, https://doi.org/10.5194/acp-13-1751-2013, https://doi.org/10.5194/acp-13-1751-2013, 2013
L. Riuttanen, M. Dal Maso, G. de Leeuw, I. Riipinen, L. Sogacheva, V. Vakkari, L. Laakso, and M. Kulmala
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acpd-13-4289-2013, https://doi.org/10.5194/acpd-13-4289-2013, 2013
Revised manuscript has not been submitted
J. Leppä, S. Gagné, L. Laakso, H. E. Manninen, K. E. J. Lehtinen, M. Kulmala, and V.-M. Kerminen
Atmos. Chem. Phys., 13, 463–486, https://doi.org/10.5194/acp-13-463-2013, https://doi.org/10.5194/acp-13-463-2013, 2013
A.-P. Hyvärinen, V. Vakkari, L. Laakso, R. K. Hooda, V. P. Sharma, T. S. Panwar, J. P. Beukes, P. G. van Zyl, M. Josipovic, R. M. Garland, M. O. Andreae, U. Pöschl, and A. Petzold
Atmos. Meas. Tech., 6, 81–90, https://doi.org/10.5194/amt-6-81-2013, https://doi.org/10.5194/amt-6-81-2013, 2013
V.-M. Kerminen, M. Paramonov, T. Anttila, I. Riipinen, C. Fountoukis, H. Korhonen, E. Asmi, L. Laakso, H. Lihavainen, E. Swietlicki, B. Svenningsson, A. Asmi, S. N. Pandis, M. Kulmala, and T. Petäjä
Atmos. Chem. Phys., 12, 12037–12059, https://doi.org/10.5194/acp-12-12037-2012, https://doi.org/10.5194/acp-12-12037-2012, 2012
Related subject area
Approach: In situ Observations | Depth range: All Depths | Geographical range: Baltic Sea | Phenomena: Temperature, Salinity and Density Fields
Assessment of the three dimensional temperature and salinity observational networks in the Baltic Sea and North Sea
Density and Absolute Salinity of the Baltic Sea 2006–2009
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Short summary
Meteorological observations at Utö Atmospheric and Marine Research Station, the Baltic Sea, started in 1881 and seawater temperature and salinity observations in 1900. Based on the dataset of more than 100 years of observations, we see an increase in atmospheric temperature after the 1980s, in line with reduced sea ice cover. We also found an increase in seawater temperatures, modulated by changes in salinities. The results indicate that the climate at Utö may have shifted into a new phase.
Meteorological observations at Utö Atmospheric and Marine Research Station, the Baltic Sea,...
