Universität zu Köln

Souverijns, N., Gossart, A., Lhermitte, S., Gorodetskaya, I. V., Kneifel, S., Maahn, M., Bliven, F. L. and van Lipzig, N. P. M. (2017). Estimating radar reflectivity - Snowfall rate relationships and their uncertainties over Antarctica by combining disdrometer and radar observations. Atmos. Res., 196. S. 211 - 224. NEW YORK: ELSEVIER SCIENCE INC. ISSN 1873-2895

Full text not available from this repository.

Abstract

Snowfall rate (SR) estimates over Antarctica are sparse and characterised by large uncertainties. Yet, observations by precipitation radar offer the potential to get better insight in Antarctic SR. Relations between radar reflectivity (Ze) and snowfall rate (Ze-SR relations) are however not available over Antarctica. Here, we analyse observations from the first Micro Rain Radar (MRR) in Antarctica together with an optical disdrometer (Precipitation Imaging Package; PIP), deployed at the Princess Elisabeth station. The relation Ze = A*SRB was derived using PIP observations and its uncertainty was quantified using a bootstrapping approach, randomly sampling within the range of uncertainty. This uncertainty was used to assess the uncertainty in snowfall rates derived by the MRR. We find a value of A = 18 [11-43] and B = 1.10 [0.97-1.17]. The uncertainty on snowfall rates of the MRR based on the Ze-SR relation are limited to 40%, due to the propagation of uncertainty in both Ze as well as SR, resulting in some compensation. The prefactor (A) of the Ze-SR relation is sensitive to the median diameter of the snow particles. Larger particles, typically found closer to the coast, lead to an increase of the value of the prefactor (A = 44). Smaller particles, typical of more inland locations, obtain lower values for the prefactor (A = 7). The exponent (B) of the Ze-SR relation is insensitive to the median diameter of the snow particles. In contrast with previous studies for various locations, shape uncertainty is not the main source of uncertainty of the Ze-SR relation. Parameter uncertainty is found to be the most dominant term, mainly driven by the uncertainty in mass-size relation of different snow particles. Uncertainties on the snow particle size distribution are negligible in this study as they are directly measured. Future research aiming at reducing the uncertainty of Ze-SR relations should therefore focus on obtaining reliable estimates of the mass-size relations of snow particles.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Souverijns, N. UNSPECIFIED UNSPECIFIED UNSPECIFIED Gossart, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Lhermitte, S. UNSPECIFIED UNSPECIFIED UNSPECIFIED Gorodetskaya, I. V. UNSPECIFIED UNSPECIFIED UNSPECIFIED Kneifel, S. UNSPECIFIED UNSPECIFIED UNSPECIFIED Maahn, M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Bliven, F. L. UNSPECIFIED UNSPECIFIED UNSPECIFIED van Lipzig, N. P. M. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-213305
DOI:	10.1016/j.atmosres.2017.06.001
Journal or Publication Title:	Atmos. Res.
Volume:	196
Page Range:	S. 211 - 224
Date:	2017
Publisher:	ELSEVIER SCIENCE INC
Place of Publication:	NEW YORK
ISSN:	1873-2895
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language RAYLEIGH-GANS APPROXIMATION; ATMOSPHERIC ICE CRYSTALS; SURFACE MASS-BALANCE; EAST ANTARCTICA; PRECIPITATION PARTICLES; SNOWDRIFT SUBLIMATION; SIZE DISTRIBUTIONS; VIDEO DISDROMETER; MEAN DENSITY; FALL SPEEDS Multiple languages Meteorology & Atmospheric Sciences Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/21330