Document Type
Article
Publication Date
12-6-2017
Abstract
The sensitivity of Global Precipitation Measurement (GPM) Microwave Imager (GMI) high-frequency channels to snowfall at higher latitudes (around 60◦N/S) is investigated using coincident CloudSat observations. The 166 GHz channel is highlighted throughout the study due to its ice scattering sensitivity and polarization information. The analysis of three case studies evidences the important combined role of total precipitable water (TPW), supercooled cloud water,and background surface composition on the brightness temperature (TB) behavior for different snow-producing clouds. A regression tree statistical analysis applied to the entire GMI-CloudSat snowfall dataset indicates which variables influence the 166 GHz polarization difference (166∆TB)and its relation to snowfall. Critical thresholds of various parameters (sea ice concentration (SIC), TPW, ice water path (IWP)) are established for optimal snowfall detection capabilities. The 166∆TB can identify snowfall events over land and sea when critical thresholds are exceeded (TPW > 3.6 kg·m−2, IWP > 0.24 kg·m−2 over land, and SIC > 57%, TPW > 5.1 kg·m−2 over sea). The complex combined 166∆TB-TB relationship at higher latitudes and the impact of supercooled water vertical distribution are also investigated. The findings presented in this study can be exploited to improve passive microwave snowfall detection algorithms.
Publication Title
Remote Sensing
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Panegrossi, Giulia; Rysman, Jean-François; Casella, Daniele; Marra, Anna Cinzia; and Kulie, Mark, "CloudSat-based assessment of GPM Microwave Imager snowfall observation capabilities" (2017). Department of Geological and Mining Engineering and Sciences Publications. 184.
http://digitalcommons.mtu.edu/geo-fp/184
Version
Publisher's PDF
Publisher's Statement
© 2017 by the authors. Licensee MDPI, Basel, Switzerland. Article deposited here in compliance with publisher policies. Publisher's version of record: 10.3390/rs9121263