A5082192352- Atmospheric chemistry and aerosols
- Atmospheric aerosols and clouds
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Air Quality and Health Impacts
- Arctic and Antarctic ice dynamics
- Aeolian processes and effects
- Vehicle emissions and performance
- Climate variability and models
- Plant responses to elevated CO2
- Air Quality Monitoring and Forecasting
- Particle Dynamics in Fluid Flows
- Oceanographic and Atmospheric Processes
- Methane Hydrates and Related Phenomena
- Per- and polyfluoroalkyl substances research
- Marine and coastal ecosystems
- Industrial Gas Emission Control
- Ocean Acidification Effects and Responses
- Maritime Transport Emissions and Efficiency
- Odor and Emission Control Technologies
- Meteorological Phenomena and Simulations
- Indoor Air Quality and Microbial Exposure
- Coastal and Marine Dynamics
- Wind and Air Flow Studies
- Geophysics and Gravity Measurements
Stockholm University
2014-2024
Bolin Centre for Climate Research
2015-2024
Aarhus University
2020
Lund University
2020
Netherlands Organisation for Applied Scientific Research
2012
Leibniz Institute for Tropospheric Research
2007
National Institute of Meteorology
2001-2002
Uganda National Meteorological Authority
2001-2002
University of Helsinki
1984-2001
Helsinki Institute of Physics
1998
A major source of the primary marine aerosol is bursting air bubbles produced by breaking waves. Several parameterizations are available from literature, usually limited to particles with a dry diameter D p > 1 μm. The objective this work extend current knowledge submicrometer particles. Bubbles were generated in synthetic seawater using sintered glass filter, size spectra that only partly same as measured field. Bubble spectra, and distributions resulting (0.020–20.0 μm ) aerosol, for...
The chemical properties of sea‐spray aerosol particles produced by artificially generated bubbles using oceanic waters were investigated during a phytoplankton bloom in the North Atlantic. Spray exhibited progressive increase organic matter (OM) content from 3 ± 0.4% up to 77 5% with decreasing particle diameter 8 0.125 μ m. Submicron OM was almost entirely water insoluble (WIOM) and consisted colloids aggregates exuded phytoplankton. Our observations indicate that size dependent transfer...
Abstract. The objective of this study is to document and evaluate recent changes updates the module for aerosols aerosol–cloud–radiation interactions in atmospheric CAM4-Oslo core version Norwegian Earth System Model (NorESM), NorESM1-M. Particular attention paid role natural organics, sea salt, mineral dust determining gross aerosol properties as well anthropogenic contribution these associated direct indirect radiative forcing. extended from earlier versions that have been published,...
Aerosol formation and subsequent particle growth in ambient air have been frequently observed at a boreal forest site (SMEAR II station) Southern Finland. The EU funded project BIOFOR (Biogenic aerosol the forest) has focused on: (a) determination of mechanisms particles site; (b) verification emissions secondary organic aerosols from (c) quantification amount condensable vapours produced photochemical reactions biogenic volatile compounds (BVOC) leading to formation. approach was combine...
Abstract. Aerosol physical and chemical properties trace gas concentrations were measured during the QUEST field campaign in March–April 2003, Hyytiälä, Finland. Our aim was to understand role of oxidation products VOC's such as mono- sesquiterpenes atmospheric nucleation events. Particle compositions using Aerodyne Mass Spectrometer, aerosol samples collected with low-pressure impactors a high volume sampler analysed number techniques. The results indicate that after new particle formation,...
An eddy‐covariance flux system was successfully applied over open sea, leads and ice floes during the Arctic Ocean Expedition in July‐August 1996. Wind‐driven upward aerosol number fluxes were observed sea pack ice. These particles must originate from droplets ejected into air at bursting of small bubbles water surface. The source F (in 10 6 m −2 s −1 ) had a strong dependency on wind speed, , leads, respectively (where is local speed about height). Over wind‐driven consisted film drop mode...
Aerosol nucleation events occurring in the continental boundary layer over boreal forest region Finland, during BIOFOR experiment, have been examined to elucidate rôle of micrometeorology promoting such events. Invariably, spring campaign 1999, occurred Arctic and polar air masses cold outbreaks. Under clear-sky conditions, typical these synoptic meteorological patterns, evolution was characterized by rapid growth a mixed layer, convection strong entrainment, first from residual later free...
The presence of bacteria in aerosols has been known for centuries, but information on their identity and role dispersing microbial traits is still limited. This study monitored the airborne bacterial community during an annual survey using samples collected from a 25-m tower near Baltic Sea coast. number CFU was estimated agar plates while most probable (MPN) viable dilution-to-extinction culturing assays (DCAs). MPN values produced quantitatively similar results, displaying pronounced...
Abstract Breaking waves on the ocean surface produce bubbles which, upon bursting, deliver seawater constituents into atmosphere as sea spray aerosol particles. One way of investigating this process in laboratory is to generate a bubble plume by continuous plunging jet. We performed series experiments elucidate role temperature production from artificial free organic contamination using The was varied −1.3°C 30.1°C, while volume air entrained jet, size distributions, and distribution...
Abstract. We have developed an inorganic sea spray source function that is based upon state-of-the-art measurements of aerosol production using a temperature-controlled plunging jet chamber. The size-resolved particle was measured between 0.01 and 10 μm dry diameter. Particle decreased non-linearly with increasing seawater temperature (between −1 30 °C) similar to previous findings. In addition, we observed the effective radius, as well surface, volume mass, increased due particles diameters...
Sea spray aerosols can act as a vector for sea-to-land transport of perfluorinated alkyl acids<italic>via</italic>the atmosphere.
Abstract Sea spray aerosol particles are an integral part of the Earth's radiation budget. To date, inorganic composition nascent sea has widely been assumed to be equivalent seawater. Here we challenge this assumption using a laboratory chamber containing both natural and artificial seawater, as well with ambient samples collected over central Arctic Ocean during summer. We observe significant enrichment calcium in submicrometer (<1 μm diameter) when generated from seawater sources...
The formation of sulfate aerosol particles due to atmospheric mixing processes is investigated using a classical model for binary nucleation. nucleation rate seen be enhanced when two air parcels with different temperature and relative humidity mix each other. This the curvature on vapor pressure diagram, whole process more in H 2 SO 4 ‐ O system compared unary case. If differences are, example, 8 K 60%, can increase by 3 orders magnitude if they are mixed. A brief survey situations that...
Nucleation of near nm sized aerosol particles and subsequent growth to ~100 in 1–2 days has recent years been frequently observed the continental boundary layer at several European locations. In 1998–99, this was focus BIOFOR experiment Hyytiälä boreal Finnish forest. occurred arctic some extent polar air masses, with a preference for maritime transition never sub-tropical air. The masses originated north by paths from southwest northeast sector. nucleation also associated cold advection...
Eddy covariance aerosol flux measurements were conducted at the Mace Head coastal station in North East Atlantic. Footprint and micrometeorological analysis under clean marine air mass conditions indicated that fluxes representative of open ocean could be derived during high tide an oceanic fetch. Sea‐spray for total particle sizes larger than 10 nm 100 (i.e. covering Aitken Accumulation mode). The source ( F ) found to strongly correlated with both wind speed U friction velocity u *),...
Abstract. Understanding Arctic climate change requires knowledge of both the external and local drivers as well feedbacks within system. An feedback mechanism relating changes in sea ice extent to an alteration emission salt aerosol consequent radiative balance is examined. A set idealized model simulations were performed quantify effects emissions induced by prescribed extent. The was forced using concentrations consistent with present day conditions projections for 2100. Sea increase...
Bubbles bursting from whitecaps are considered to be the most effective mechanism for particulate matter ejected into atmosphere Earth's oceans. To realistically predict climate effect of marine aerosols, global models require process‐based understanding particle formation bubble bursting. During a cruise on highly biologically active waters northeastern Atlantic Ocean in summer 2006, submicrometer primary aerosol produced by jet seawater impinging surface was investigated. The size spectra...
Sea spray particles ejected as a result of bubbles bursting from artificial seawater containing salt and organic matter in stainless steel tank were sampled for size distribution, morphology, cloud condensation nucleus (CCN) activity. Bubbles generated either by aeration through diffuser or water jet impingement on the surface. Three objectives addressed this study. First, CCN activities NaCl two types sea only inorganic components measured to establish baseline further measurements mixed...
Abstract. The Nordic Centre of Excellence CRAICC (Cryosphere–Atmosphere Interactions in a Changing Arctic Climate), funded by NordForsk the years 2011–2016, is largest joint research and innovation initiative to date, aiming strengthen regarding climate change issues region. gathered more than 100 scientists from all countries virtual centre with objectives identifying quantifying major processes controlling warming related feedback mechanisms, outlining strategies mitigate warming,...
Abstract To improve our understanding of the impact sea salt aerosols (SSA) on Earth's climate, it is critical to understand physical mechanisms which determine size‐resolved SSA production flux. Of factors affecting emissions, seawater salinity has perhaps received least attention in literature and previous studies have produced conflicting results. Here, we present a series laboratory experiments designed investigate role aerosol from artificial using continuous plunging jet. During these...
Abstract. To compare in situ and laboratory estimates of sea spray aerosol (SSA) production fluxes, we conducted two research campaigns the vicinity an eddy covariance (EC) flux tower on island Östergarnsholm Baltic Sea during May August 2021. accomplish this, performed EC measurements for particles with diameters between 0.25 2.5 µm simultaneously using a plunging jet simulation chamber containing local seawater sampled close to footprint tower. We observed log-linear relationship wind...
A 3 week measurement campaign was undertaken to study the effect of local weather parameters, transportation from an urban area, structure boundary layer, and precipitation on submicron (8–450 nm in mobility diameter) aerosol particles background area Finland. Also, concentrations NO x , O SO 2 were monitored. The most important meteorological factor affecting shown be wind direction. It also seen that diurnal behavior layer plays role for particle concentration size distribution gas phase...