Connection between Upstream Atmosphere and Cloud Formation at Whiteface Mountain

The Chemical Processing of Organics within Clouds (CPOC) field campaign at Whiteface Mountain (WFM) in Upstate New York from 11-25 August 2017. The primary goal was to investigate aqueous chemical processing within clouds, which is a key process in the formation of secondary organic aerosol mass. There is significant uncertainty regarding the organic chemical reactions occurring within clouds and what conditions are favorable for the reactions to occur. Predicting when the summit of WFM was in clouds and the height of the cloud base was a key concern throughout the project. We collected temperature and relative humidity data at 10 locations along the highway to the summit and at the weather station on the summit. There were 18 radiosondes launched throughout the seven intensive operation periods upstream of WFM at the Northwood School outside of Lake Placid, New York. Other in-situ measurements taken during the project included Cloud Condensation Nuclei concentration at the summit and below cloud level, cloud Liquid Water Content at the summit, and cloud particle counts at the summit. Using the relative humidity data along the topography of WFM as well as a camera upstream of WFM we were able to estimate the height of the cloud base as it progressively moves up the mountain during cloudy days. By plotting and analyzing data from the soundings, we characterize how the changes in upstream air relate to the changes in cloud properties and cloud base elevation at WFM. Knowing the parameters upstream of WFM, we are more able to understand why our measurements behave how they do. Additionally, this allows us to make better forecast of clouds base and properties, for future projects on cloud chemistry research.