An extensive data set for in situ microphysical characterization of low-level clouds in a Finnish sub-Arctic site

Doulgeris, Konstantinos; Lihavainen, Heikki; Hyvärinen, Anti-Pekka; Kerminen, Veli‐Matti; Brus, David

doi:10.5194/essd-14-637-2022

Cited by 5 publications

(9 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Wind speed ranges during the PaCEs were approximately from 0 to 10 m s -1 and the average wind speed during each campaign was around 7 m s -1 . These values were lower in comparison to the probe air speed of both cloud ground-based spectrometers (Doulgeris et al, 2022).…”

Section: Local Meteorological Conditionsmentioning

confidence: 62%

“…Their main difference was that the CAPS was fixed and always heading to the main wind direction of the station (southwest, ∼ 225), whereas the FSSP-100 was deployed on a rotating platform to continuously face the wind. A description of both ground setups, installation, limitations and the methodology that was used is documented in Doulgeris et al (2020) and Doulgeris et al (2022). The instrument that monitored the cloud base was a lidar ceilometer (model CT25K, Vaisala Oyj, Vaisala 150 users guide, 2002;Emeis et al, 2004), except in 2019 when it was replaced by a model CL31, Vaisala Oyj.…”

Section: Instrumentationmentioning

confidence: 99%

“…The cloud probes and meteorological data used here are available in the Finnish Meteorological Institute (FMI) open data repository for each campaign and each cloud spectrometer ground setup individually (Doulgeris et al, 2021;Doulgeris et al, 2022). The FLEXPART simulations and the ceilometer dataset 445 are available upon request to the corresponding author (konstantinos.doulgeris@fmi.fi).…”

Section: Data Availabilitymentioning

confidence: 99%

See 2 more Smart Citations

Influence of air mass origin on microphysical properties of low-level clouds in a subarctic environment

Doulgeris

Vakkari

O’Connor

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. In this work, an analysis was performed to investigate how different long-range transport air masses can affect the occurrence and the microphysical properties of low-level clouds in a clean subarctic environment. The cloud measurements comprised in-situ and ground-based and were conducted during eight Pallas Cloud Experiments (PaCE) held in the autumn between 2004 and 2019. Each PaCE was carried out at the Pallas Atmosphere – Ecosystem Supersite, located in the Finnish subarctic region. Two cloud spectrometer ground setups were installed on the roof of the station to measure cloud microphysical properties: the Cloud, Aerosol and Precipitation Spectrometer probe (CAPS) and the Forward Scattering Spectrometer Probe (FSSP). Air mass histories were analyzed using the Lagrangian particle dispersion model FLEXPART in order to investigate the differences between five distinct source regions (Arctic, Eastern, Southern, Western and Local). The results showed that there was a connection between the microphysical properties of the clouds we sampled during PaCEs and the air mass source region. The occurrence of clouds at the measuring station was mainly connected with air masses coming from the continental regions. Higher values of cloud droplet number concentrations (Nc) were related to air masses coming from the Southern and Eastern regions (continental), whereas the lowest values of Nc were related to Arctic and Western air masses (marine). In addition, the marine air masses were characterized by larger cloud droplets (median volume diameter approximately from 15 to 20 µm), in comparison to continental air masses that were mainly characterized by cloud droplets with median volume diameters of approximately from 8 to 12 µm. Finally, there was an indication that cloud droplets were more prone to grow in warm liquid clouds.

show abstract

Section: Local Meteorological Conditionsmentioning

confidence: 62%

Section: Instrumentationmentioning

confidence: 99%

Section: Data Availabilitymentioning

confidence: 99%

See 1 more Smart Citation

Influence of air mass origin on microphysical properties of low-level clouds in a subarctic environment

Doulgeris

Vakkari

O’Connor

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…Their main difference was that the CAS was fixed and always heading to the main wind direction of the station (southwest, ∼ 225), whereas the FSSP-100 was deployed on a rotating platform to continuously face the wind. A description of both ground setups, installation, limitations and the methodology that was used is documented in Doulgeris et al ( , 2022. The in-strument that monitored the cloud base was a lidar ceilometer that was deployed at the Kenttärova site (model CT25K, Vaisala Oyj, 2002;, except in 2019 when it was replaced by a CL31 model, Vaisala Oyj.…”

Section: Instrumentationmentioning

confidence: 99%

“…Measurements used in this study were conducted during the Pallas Cloud Experiments (PaCEs). A description of the dataset (microphysical properties of clouds along with meteorological variables) that was obtained during PaCEs is available in Doulgeris et al (2022). The PaCEs were approximately 2-month-long field campaigns conducted in the Finnish subarctic region at the Sammaltunturi station during autumn and lasted approximately from the beginning of September until the end of November.…”

Section: Sampling Campaignsmentioning

confidence: 99%

Experimental studies on cloud condensation nuclei activation and cloud microphysical properties

Doulgeris¹

View full text Add to dashboard Cite

Atmospheric aerosol particles have the ability to affect climate through cloud interactions and direct scattering and absorption of radiation. These aerosol particles can also affect human health through respiratory system. Aerosol particles are emitted to the atmosphere through direct sources or they can be formed through chemical processes from gas phase precursors. The different atmospheric processes and climate feedbacks of aerosol particles can be studied using process-scale models as well as larger global-scale models. In recent years, it has been found out that certain aerosol species lack information on their thermodynamic properties, causing uncertainties in process-scale modelling as well as global-scale modelling. In addition, transport of aerosols to remote regions, where emissions of aerosol particles are low, is poorly modelled in global-scale models. Furthermore, sources for formed secondary organic aerosol (SOA) include uncertainties in global aerosol-climate models, which causes uncertainty to estimating the radiative forcing (RF). In this thesis, these aspects relating to uncertainties are addressed using process and global-scale modelling. This was done first by evaluating the capability of thermodynamic equilibrium model to reproduce observed hygroscopicity in terms of dimethylamine, sulfuric acid and ammonia containing particles. Second, an in-cloud wet deposition scheme was developed (hereafter referred to as the newly-developed scheme) for global models which use sectional aerosol description. The newlydeveloped wet deposition scheme was tested using ECHAM-HAMMOZ global aerosol-climate model with Sectional Aerosol model for Large-Scale Applications (SALSA) in terms of aerosol vertical distributions and lifetimes. Third, the biotic stress effects to trees over boreal region and their effects to SOA formation, clouds and radiative effects were studied using ECHAM-HAMMOZ with SALSA. The results showed that when the thermodynamic equilibrium model was used to model particles with sizes of the order of couple of tens of nanometers, it was inadequate in estimating the hygroscopic growth of dimethylamine (DMA), sulfuric acid (SA) and ammonia containing particles. Thus, more investigation is needed in terms of thermodynamics of DMA containing systems to properly evaluate its effects to climate. Global aerosol-climate models are very complex and thus making aerosol processes more physically sound can even impair the results. This was seen in the results of the newly-developed, more physical, in-cloud wet deposition scheme as it produced spurious vertical profiles and atmospheric black carbon lifetime when compared to the preexisting scheme. Especially, the atmospheric lifetime of black carbon, in the newly-developed scheme, was 1.6 times longer than in the pre-existing scheme and over 2.6 times longer than has been suggested by experimental studies. Thus, the sensitivity of the newly-developed scheme was tested in terms of internal mixing and emission size distribution of black carbon as well as ageing of aerosol species. These results showed that mixing black carbon with soluble substances produced best results in comparison with the observations as well as atmospheric lifetimes of aerosol species when compared to AEROCOM model means. Lastly, the results studying the biotic stress effects on climate showed that increasing the extent of stress in boreal trees enhanced SOA formation as the emissions of volatile organic compounds (VOCs) were increased. The enhanced SOA formation increased cloud droplet number concentration (CDNC) at cloud top and caused stronger negative RF in both all-sky and clear-sky cases. In the future, aerosol model development should investigate further on the thermodynamic properties of aerosol species, especially with respect to DMA. The wet removal and extent of internal mixing of different aerosol species, especially black carbon, should be further investigated and revised, in global climate models, to properly evaluate the transport of aerosol particles. In addition, sources of atmospheric SOA needs further investigation to properly describe its behaviour in the atmosphere as well as the effects on the climate.

show abstract

Influence of air mass origin on microphysical properties of low-level clouds in a subarctic environment

Doulgeris¹,

Vakkari²,

O’Connor³

et al. 2023

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. In this work, an analysis was performed to investigate how different long-range transport air masses can affect the microphysical properties of low-level clouds in a clean subarctic environment. The cloud measurements included in situ and remote sensing ground-based techniques and were conducted during eight Pallas Cloud Experiments (PaCEs) held in the autumn between 2004 and 2019. Each PaCE was carried out at the Pallas Atmosphere-Ecosystem Supersite, located in the Finnish subarctic region. Two cloud spectrometer ground setups were installed on the roof of the station to measure cloud microphysical properties: the cloud, aerosol and precipitation spectrometer (CAPS) and the forward-scattering spectrometer probe (FSSP). Air mass histories were analyzed using the Lagrangian FLEXible PARTicle dispersion model (FLEXPART) in order to investigate the differences between five distinct source regions (“Arctic”, “Eastern”, “Southern”, “Western” and “Local”). We observed clear differences in the cloud microphysical properties for the air mass source regions. Arctic air masses were characterized by low liquid water content (LWC), low cloud droplet number concentration (Nc) and comparatively large median volume and effective droplet diameter. The Western region (marine North Atlantic) differed from the Arctic by both higher Nc and LWC. The Eastern region (continental Eurasia) only had a little higher LWC than the Arctic but substantially higher Nc and a smaller droplet diameter. The Southern region (continental Europe) had high Nc and LWC and a very similar droplet diameter to the Eastern region. Finally, the relationship between Nc and droplet size (i.e., the Twomey effect) was characterized for the different source regions, indicating that all region clouds were sensitive to increases in Nc.

show abstract

An extensive data set for in situ microphysical characterization of low-level clouds in a Finnish sub-Arctic site

Cited by 5 publications

References 48 publications

Influence of air mass origin on microphysical properties of low-level clouds in a subarctic environment

Influence of air mass origin on microphysical properties of low-level clouds in a subarctic environment

Experimental studies on cloud condensation nuclei activation and cloud microphysical properties

Influence of air mass origin on microphysical properties of low-level clouds in a subarctic environment

Contact Info

Product

Resources

About