Predicted cloud droplet numbers (kappa=0.25) Weissfluhjoch

Description

In-situ measurements of aerosol size distributions along with updraft velocities collected from a wind Doppler Lidar are coupled with a state-of-the art droplet activation parameterization (Morales and Nenes, 2014) to determine the cloud droplet number and maximum in-cloud supersaturation that can potentially form over the Davos Wolfgang station between February 24 and March 8 2019. For this, as a sensitivity test, a hygroscopicity parameter of 0.25 is assumed, which is the upper limit determined from the analysis carried out for Weissfluhjoch (https://www.envidat.ch/dataset/ccn-hygroscopicity-predicted-cloud-droplet-numbers-weissfluhjoch). The data file contains:

• Date and time (DD/MM/YYYY hh:mm:ss) in UTC
• The wind-lidar derived standard deviation of updraft velocities (sigma-w) in m/s, used to apply the parameterization employing a single characteristic velocity (Morales and Nenes, 2010)
• The maximum predicted cloud parcel supersaturation (Smax%)
• The total in-situ aerosol number concentration (Naer) in cmˉ³, measured by the SMPS
• The predicted cloud droplet numbers (Nd) in cmˉ³
• The activation fraction (%)