Title: Matthew Shupe
1Cloud 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
2Observatories
3Site Instruments Dates
Atqasuk, AK, USA Ceilometer 1999 Present
Barrow, AK, USA Radar, lidar, mwr, ceilometer, soundings 1998 Present
NyAlesund, 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
4Methods 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)
5Cloud Occurrence Fraction
6Variability in time and space
7Cloud Phase Type Fraction
Barrow
SHEBA
Eureka
All (black) Ice (blue) Mixed-Phase
(orange) Liquid (red) Liquid present (red dash)
8Vertical Distribution
9Diurnal Cycle
10Cloud Occurrence Fraction
Cloud Fraction Anomaly
11Cloud Persistence
12Phase vs. Temperature
13To Conclude
- 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-ca
dis)