Back to Search
Start Over
Retrieval of Normalized Gamma Size Distribution Parameters Using Precipitation Imaging Package (Pip) Snowfall Observations During Ice-Pop 2018
- Source :
- Journal of Applied Meteorology and Climatology. 62(5)
- Publication Year :
- 2023
- Publisher :
- United States: NASA Center for Aerospace Information (CASI), 2023.
-
Abstract
- Parameters of the normalized gamma particle size distribution (PSD) have been retrieved from the Precipitation Image Package (PIP) snowfall observations collected during the International Collaborative Experiment - PyeongChang Olympics and Paralympic (ICE-POP 2018). Two of the gamma PSD parameters, the mass weighted particle diameter (Dmass) and the normalized intercept parameter NW, have median values of 1.15-1.31 mm and 2.84-3.04 log(mm-1 m-3), respectively. This range arises from the choice of the relationship between the maximum versus equivalent diameter, Dmx-Deq, and the relationship between the Reynolds and Best numbers, Re-X. Normalization of snow water equivalent rate (SWER) and ice water content (W) by NW reduces the range in NW resulting in well fitted power law relationship, between SWER/NW and Dmass and between W/NW and Dmass. The bulk descriptors of snowfall are calculated from PIP observations and from the gamma PSD with values of the shape parameter (μ) ranging from -2 to 10. NASA’s Global Precipitation Measurement (GPM) mission, which adopted the normalized gamma PSD, assumes μ = 2 and μ = 3 in its two separate algorithms. The mean fractional bias (MFB) of the snowfall parameters changes with μ, where the functional dependence on μ depends on the specific snowfall parameter of interest. The MFB of the total concentration was underestimated by 0.23-0.34 when μ = 2 and by 0.29-0.40 when μ = 3, while the MFB of SWER had a much narrower range (-0.03 to 0.04) for the same μ values.
- Subjects :
- Meteorology and Climatology
Subjects
Details
- Language :
- English
- ISSN :
- 15588424 and 15588432
- Volume :
- 62
- Issue :
- 5
- Database :
- NASA Technical Reports
- Journal :
- Journal of Applied Meteorology and Climatology
- Notes :
- 378289, , 80NSSC22M0001, , 80NSSC23M0011, , NNX16AE88G
- Publication Type :
- Report
- Accession number :
- edsnas.20230008493
- Document Type :
- Report
- Full Text :
- https://doi.org/10.1175/JAMC-D-21-0266.1