matthew shupe von walden ed eloranta taneil uttal james campbell masataka shiobara
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Cloud Occurrence and Phase at Arctic Atmospheric Observatories: Further progress towards understanding Arctic clouds. Matthew Shupe Von Walden Ed Eloranta Taneil Uttal James Campbell Masataka Shiobara Sandy Starkweather. AMS Polar Met. & Ocean. 2009 Madison, WI. Observatories. - PowerPoint PPT PresentationTRANSCRIPT
Matthew Shupe Von Walden Ed Eloranta Taneil UttalJames CampbellMasataka ShiobaraSandy Starkweather
Cloud Occurrence and Phase at Arctic Atmospheric Observatories:
Further progress towards understanding Arctic clouds
AMS Polar Met. & Ocean. 2009Madison, WI
Observatories
Site Instruments DatesAtqasuk, AK, USA Ceilometer 1999 – Present
Barrow, AK, USA Radar, lidar, mwr, ceilometer, soundings
1998 – Present
Ny’Alesund, Norway Lidar 2002 – Present
Eureka, Canada Radar, lidar, mwr, soundings
2005 – Present
SHEBA, Arctic Ocean Radar, lidar, mwr, ceilometer, soundings
1997-1998
Summit, Greenland Ceilometer 2001-2002
Methods and Details
• “What is a Cloud?” It depends on your perspective and objective
• Clouds identified using thresholds for each sensor that aim to distinguish cloudy from clear sky signals.
• Different sensors at each site impact the results
• Phase classification requires radar, lidar, mwr, and radiosonde (only available at 3 sites)
Cloud Occurrence Fraction
Variability in time and space
Cloud “Phase” Type Fraction
All (black)Ice (blue)Mixed-Phase (orange)Liquid (red)Liquid present (red dash)
Barrow SHEBA Eureka
Vertical Distribution
Diurnal Cycle
AN
OM
AL
Y [
%]
Cloud Occurrence Fraction
C
loud
Fra
ctio
n A
nom
aly
[%]
Cloud “Persistence”
Phase vs. Temperature
• Detailed perspective from the surface complements satellite climatologies and in situ campaigns.
• Results are appropriate for model evaluation and comparisons with satellite retrievals.
• Need more observations to better establish baselines and to detect change. Needs: E. Arctic, over the sea-ice, longer records.
• Much of data used in this analysis is available at CADIS archive (www.eol.ucar.edu/projects/aon-cadis)
To Conclude