ccn-hygroscopicity-predicted-cloud-droplet-numbers-weissfluhjoch
1.0
CCN, hygroscopicity, predicted cloud droplet numbers Weissfluhjoch
Athanasios Nenes, Paraskevi Georgakaki, Aikaterini Bougiatioti
Athanasios Nenes
CCN, hygroscopicity, predicted cloud droplet numbers Weissfluhjoch
2020
Birmensdorf, Switzerland
EnviDat
1.0
csv
DOI
doi:10.16904/envidat.198
https://www.envidat.ch/dataset/ccn-hygroscopicity-predicted-cloud-droplet-numbers-weissfluhjoch
TECHNICAL CONTACT
Athanasios
Nenes
athanasios.nenes@epfl.ch
EARTH SCIENCE
CLIMATE INDICATORS
LAND SURFACE/AGRICULTURE INDICATORS
environment
CCN
CLOUD DROPLETS
CLOUD MODELING
DMT CCN CHAMBER
HYGROSCOPICITY
RACLETS
SIGMA-W
SUPERSATURATION
WEISSFLUHJOCH
Not provided
Not provided
Not provided
2020-01-01
COMPLETE
CARTESIAN
CARTESIAN
9.806475
46.832964
46.832964
46.832964
9.806475
9.806475
9.806475
46.832964
Not provided
Public access to the data
Usage constraintes defined by the license "ODbL with Database Contents License (DbCL)", see https://opendefinition.org/licenses/odc-odbl
English
LAPI
DISTRIBUTOR
WSL
Swiss Federal Institute for Forest, Snow and Landscape Research WSL
https://www.wsl.ch
DATA CENTER CONTACT
EnviDat
envidat@wsl.ch
https://www.envidat.ch/envidat_thumbnail.png
__Cloud Condensation Nuclei (CCN) data:__ A Droplet Measurement Technologies (DMT) single-column continuous-flow streamwise thermal gradient chamber (CFSTGC; Roberts and Nenes, 2005) was deployed at the measurement site Weissfluhjoch (2700 m a.s.l., LON: 9.806475, LAT: 46.832964) to record the in-situ CCN number concentrations between February 24 and March 8 2019 for different supersaturations (SS). To account for the difference between the ambient (~735 mbar) and the calibration pressure (~800 mbar), the SS reported by the instrument is adjusted by a factor of 0.92. The CFSTGC was cycled between 6 discrete SS values ranging from 0.09% to 0.74%, producing a full CCN spectrum every hour. The raw CCN measurements are filtered to discount periods of transient operation and whenever the room temperature housing the instrument changed sufficiently to induce a reset in column temperature. Additional information can be found in Section 2.1.2 [here](https://acp.copernicus.org/preprints/acp-2020-1036/). __Hygroscopicity data:__ The CCN number concentration measurements were directly related to the size distribution and total aerosol concentration data measured by the Scanning Mobility Particle Size Spectrometer (SMPS) instrument at the same station (https://www.envidat.ch/dataset/aerosol-data-weissfluhjoch) to infer the particles hygroscopicity parameter (kappa). For each SMPS scan, the particles critical dry diameter (Dcr) is estimated by integrating backward the SMPS size distribution, until the aerosol number matches the CCN concentration observed for the same time period as the SMPS scan. Assuming the particle chemical composition is internally mixed, the kappa is determined from Dcr and SS, applying Köhler theory. Additional information can be found in Section 2.2 [here](https://acp.copernicus.org/preprints/acp-2020-1036/). __Predicted cloud droplet numbers:__ Droplet calculations are carried out with the physically based aerosol activation parameterization of Morales and Nenes (2014), employing the “characteristic velocity” approach of Morales and Nenes (2010). Aerosol size distribution observations required to predict the cloud droplet numbers and maximum in-cloud supersaturation are obtained from the SMPS instrument deployed at Weissfluhjoch. The required vertical velocity measurements are derived from the wind Doppler Lidar (https://www.envidat.ch/dataset/lidar-wind-profiler-data) deployed at Davos Wolfgang and are extracted for the altitude of interest, being 1100 m above ground level for Weissfluhjoch. Additional information can be found in Section 2.3 [here](https://acp.copernicus.org/preprints/acp-2020-1036/).
https://www.envidat.ch/dataset/ccn-hygroscopicity-predicted-cloud-droplet-numbers-weissfluhjoch
gcmd_dif
VERSION 10.2
2020-12-06T15:37:23.421545
2020-12-17T09:38:51.454396
2020-12-06T15:37:23.421545
2020-12-17T09:38:51.454396
False
Geographic Location
String
46 49’58.670”N 9 48’23.309”E
parent
String
RACLETS Field Campaign