Precipitation regimes over central Greenland inferred from 5 years of ICECAPS observations
A novel method for classifying Arctic precipitation using ground based remote sensors is presented. Using differences in the spectral variation of microwave absorption and scattering properties of cloud liquid water and ice, this method can distinguish between different types of snowfall events...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-04-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/4715/2018/acp-18-4715-2018.pdf |
| Summary: | A novel method for classifying Arctic precipitation using
ground based remote sensors is presented. Using differences in the spectral
variation of microwave absorption and scattering properties of cloud liquid
water and ice, this method can distinguish between different types of
snowfall events depending on the presence or absence of condensed liquid
water in the clouds that generate the precipitation. The classification
reveals two distinct, primary regimes of precipitation over the Greenland
Ice Sheet (GIS): one originating from fully glaciated ice clouds and the
other from mixed-phase clouds. Five years of co-located, multi-instrument
data from the Integrated Characterization of Energy, Clouds, Atmospheric
state, and Precipitation at Summit (ICECAPS) are used to examine cloud and
meteorological properties and patterns associated with each precipitation
regime. The occurrence and accumulation of the precipitation regimes are
identified and quantified. Cloud and precipitation observations from
additional ICECAPS instruments illustrate distinct characteristics for each
regime. Additionally, reanalysis products and back-trajectory analysis show
different synoptic-scale forcings associated with each regime. Precipitation
over the central GIS exhibits unique microphysical characteristics due to
the high surface elevations as well as connections to specific large-scale
flow patterns. Snowfall originating from the ice clouds is coupled to deep,
frontal cloud systems advecting up and over the southeast Greenland coast to
the central GIS. These events appear to be associated with individual storm
systems generated by low pressure over Baffin Bay and Greenland lee
cyclogenesis. Snowfall originating from mixed-phase clouds is shallower and
has characteristics typical of supercooled cloud liquid water layers, and
slowly propagates from the south and southwest of Greenland along a quiescent
flow above the GIS. |
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| ISSN: | 1680-7316 1680-7324 |