Light snow precipitation and effects on weather and climate

• Other Authors: Gultepe, Ismael (author), Rabin, R. (author), Ware, Randolph (author), Pavolonis, M. (author), Nielsen, Lars (editor)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2016
• Subjects: Arctic; Canada; Newfoundland
• Online Access: https://doi.org/10.1016/bs.agph.2016.09.001

The objective of this work is to better understand light snow (LSN) precipitation measurements (precipitation rate (PR) < 0.5 mm/h) collected by optical present weather sensors (OPWS), weighing gauges, and spectral probes that are important for meteorological and hydrometeorological applications. Observations collected during the Satellite Applications for Arctic Weather and Search and rescue (SAR) Operations (SAAWSO) project that took place over Goose Bay, Newfoundland (NFL), Canada were studied to assess LSN characteristics and instrument sensitivities. Two case studies representing extreme environmental conditions temperature between 0 and −35°C, and snow occurrence for the SAAWSO project are presented. The ice crystal size and shape of LSN using a new platform called Ground Cloud Imaging Probe (GCIP) were obtained between 7.5 and 930 μm over 60 channels at 15 μm intervals. The measurements from the GCIP, Laser Precipitation Monitor (LPM), weighing gauges, and OPWS were used in the analysis. The results suggested the following: (1) LSN occurs at about 80% of time over the Arctic regions; (2) LSN can play a significant role in cooling at the surface and dehydration of the upper levels; and (3) OPWS can respond to LSN conditions better than weighing gauges. It is concluded that OPWS and spectral probes can improve measurement of LSN, including snow particle shape and size distribution with sizes <0.5 mm. Further research on LSN impact on weather and climate simulations is needed.