The great dun fell cloud experiment 1993: An overview

Choularton, T. W.; Colvile, R. N.; Bower, Keith; Gallagher, Martin; Wells, Marcella A.; Beswick, K.M.; Arends, B. G.; Möls, J.J.; Kos, G.P.A.; Fuzzi, S.; Lind, John A.; Orsi, G.; Facchini, M. C.; Laj, Paolo; Gieray, R.; Wieser, P.; Engelhardt, Thomas; Berner, A.; Kruisz, C.; Möller, Detlev; Acker, K.; Wieprecht, W.; Lüttke, Jens; Levsen, K.; Bizjak, M.; Hansson, H.‐C.; Cederfelt, Sven-Inge; Frank, Göran; Mentes, Besim; Martinsson, Bengt G.; Orsini, D.; Svenningsson, Birgitta; Swietlicki, Erik; Wiedensohler, Alfred; Noone, Kevin J.; Pahl, S.; Winkler, P.; Seyffer, E.; Helas, G.; Jaeschke, W.; Georgii, H. W.; Wobrock, W.; Preiss, M.; Maser, R.; Schell, D.; Dollard, G. J.; Jones, Brian M.; Davies, Trevor J.; Sedlak, David L.; David, Margaret M.; Wendisch, Manfred; Cape, J. N.; Hargreaves, K. J.; Sutton, Mark A.; Storeton-West, Robert; Fowler, D.; Hallberg, A.; Harrison, Roy M.; Peak, John D.

doi:10.1016/s1352-2310(96)00316-0

Cited by 72 publications

(25 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Smallest droplets are around 3 µm, while larger droplets up to 40 µm are always present, and the size range of the FSSP limits the detection of larger droplets. These values lie in a size range that has been reported from many previous hill cap cloud experiments (e.g., Wobrock et al, 1994;Cederfelt et al, 1997;Choularton et al, 1997;Hallberg et al, 1997;Wieprecht et al, 2005). Conversion of the number size distribution to total volume density and thereby to liquid cloud water content (LWC) yielded fair agreement with the PVM data (slope = 0.80, r 2 = 0.66), but the conversion of a number size distribution to a total mass concentration is always subject to uncertainties.…”

Section: Cloud Propertiessupporting

confidence: 67%

Uptake of nitric acid, ammonia, and organics in orographic clouds: mass spectrometric analyses of droplet residual and interstitial aerosol particles

et al. 2017

View full text Add to dashboard Cite

Abstract. Concurrent in situ analyses of interstitial aerosol and cloud droplet residues have been conducted at the Schmücke mountain site during the Hill Cap Cloud Thuringia campaign in central Germany in September and October 2010. Cloud droplets were sampled from warm clouds (temperatures between −3 and +16 • C) by a counterflow virtual impactor and the submicron-sized residues were analyzed by a compact time-of-flight aerosol mass spectrometer (C-ToF-AMS), while the interstitial aerosol composition was measured by an high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). During cloud-free periods, the submicron out-of-cloud aerosol was analyzed using both instruments, allowing for intercomparison between the two instruments. Further instrumentation included black carbon measurements and optical particle counters for the aerosol particles as well as optical sizing instrumentation for the cloud droplets. The results show that, under cloud conditions, on average 85 % of the submicron aerosol mass partitioned into the cloud liquid phase. Scavenging efficiencies of nitrate, ammonium, sulfate, and organics ranged between 60 and 100 %, with nitrate having, in general, the highest values. For black carbon, the scavenging efficiency was markedly lower (about 24 %). The nitrate and ammonium mass fractions were found to be markedly enhanced in cloud residues, indicating uptake of gaseous nitric acid and ammonia into the aqueous phase. This effect was found to be temperature dependent: at lower temperatures, the nitrate and ammonium mass fractions in the residues were higher. Also, the oxidation state of the organic matter in cloud residues was found to be temperature dependent: the O : C ratio was lower at higher temperatures. A possible explanation for this observation is a more effective uptake and/or higher concentrations of low-oxidized water-soluble volatile organic compounds, possibly of biogenic origin, at higher temperatures. Organic nitrates were observed in cloud residuals as well as in the out-of-cloud aerosol, but no indication of a preferred partitioning of organic nitrates into the aqueous phase or into the gas phase was detected. Assuming the uptake of nitric acid and ammonia in cloud droplets will be reversible, it will lead to a redistribution of nitrate and ammonium among the aerosol particles, leading to more uniform, internally mixed particles after several cloud passages.

show abstract

Section: Cloud Propertiessupporting

confidence: 67%

Uptake of nitric acid, ammonia, and organics in orographic clouds: mass spectrometric analyses of droplet residual and interstitial aerosol particles

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Bower et al, 1999;Herrmann et al, 2005). The use of hill cap clouds as a natural flow-through reactor was for example realised successfully on Great Dun Fell (UK) (Bower et al, 1999;Choularton et al, 1997;, on the German mountain Kleiner Feldberg (Wobrock et al, 1994), during the cap cloud experiment of the 2nd Aerosol Characterisation Experiment (ACE-2 HILLCLOUD) at Teneriffe, Spain (Bower et al, 2000) and during FEBUKO (Field Investigations of Budgets and Conversions of Particle Phase Organics in Tropospheric Cloud Processes) at Mt. Schmücke .…”

Section: Introductionmentioning

confidence: 99%

Influence of cloud processing on CCN activation behaviour in the Thuringian Forest, Germany during HCCT-2010

et al. 2014

Self Cite

View full text Add to dashboard Cite

Abstract. Within the framework of the "Hill Cap Cloud Thuringia 2010" (HCCT-2010) international cloud experiment, the influence of cloud processing on the activation properties of ambient aerosol particles was investigated. Particles were probed upwind and downwind of an orographic cap cloud on Mt Schmücke, which is part of a large mountain ridge in Thuringia, Germany. The activation properties of the particles were investigated by means of size-segregated cloud condensation nuclei (CCN) measurements at 3 to 4 different supersaturations. The observed CCN spectra together with the total particle spectra were used to calculate the hygroscopicity parameter κ for the upwind and downwind stations. The upwind and downwind critical diameters and κ values were then compared for defined cloud events (FCE) and noncloud events (NCE). Cloud processing was found to increase the hygroscopicity of the aerosol particles significantly, with an average increase in κ of 50 %. Mass spectrometry analysis and isotopic analysis of the particles suggest that the observed increase in the hygroscopicity of the cloud-processed particles is due to an enrichment of sulfate and possibly also nitrate in the particle phase.

show abstract

“…The role of clouds in the transport, transformation, and delivery of chemical pollutants has recently received increased attention especially in temperate regions (e.g., Choularton 1997;Acker et al 2002). In tropical latitudes, however, there are few studies examining either the inorganic (Gordon et al 1994;Clark et al 1998) or organic (Sanhueza et al 1992) composition of cloud water.…”

Section: Introductionmentioning

confidence: 99%

Chemical Composition of Cloud Water in the Puerto Rican Tropical Trade Wind Cumuli

Gioda

Mayol-Bracero

Morales-García

et al. 2008

Water Air Soil Pollut

View full text Add to dashboard Cite

As part of the Rain In Cumulus over the Ocean Experiment (RICO) and the Puerto Rico Aerosol and Cloud Study (PRACS), cloud water was collected at East Peak (EP) in Puerto Rico. The main objective of this study was to determine the concentrations of water-soluble species (Cl liquid phase concentrations of all inorganic substances were similar to those found in clouds in other clean maritime environments.

show abstract

The great dun fell cloud experiment 1993: An overview

Cited by 72 publications

References 40 publications

Uptake of nitric acid, ammonia, and organics in orographic clouds: mass spectrometric analyses of droplet residual and interstitial aerosol particles

Uptake of nitric acid, ammonia, and organics in orographic clouds: mass spectrometric analyses of droplet residual and interstitial aerosol particles

Influence of cloud processing on CCN activation behaviour in the Thuringian Forest, Germany during HCCT-2010

Chemical Composition of Cloud Water in the Puerto Rican Tropical Trade Wind Cumuli

Contact Info

Product

Resources

About