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Cloud Occurrence at Arctic Atmospheric Observatories. Matthew Shupe, Taneil Uttal, Daniel Wolfe, David Welsh. Special Thanks for Ny’Alesund MPL Data : Masataka Shiobara, James Campbell. AMS Polar Meteorology and Oceanography 2007. Arctic Cloud Stations. Barrow. SHEBA. Tiksi. Radar.
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Cloud Occurrence at Arctic Atmospheric Observatories Matthew Shupe, Taneil Uttal, Daniel Wolfe, David Welsh Special Thanks for Ny’Alesund MPL Data: Masataka Shiobara, James Campbell AMS Polar Meteorology and Oceanography 2007
Arctic Cloud Stations Barrow SHEBA Tiksi Radar Lidar Eureka Alert An Example Station Ny’Alesund Summit
Data Processing Considerations • Use a combination of cloud radar and lidar, depending on station • “Cloud fraction” is from the perspective of vertically-pointing, surface-based instruments • All but SHEBA must be considered preliminary in nature, more detailed multi-instrument analyses will follow
Total Cloud Fraction Radar Lidar Surface observations • Very cloudy in general at all stations (~75% total) • Summer/Fall maximum?
Vertical Distribution Radar Lidar Bimodal Dist’n in Vertical Lots of Low-level Clouds
Cloud Type Classification • Instruments: radar, lidar, microwave radiometer, radiosonde. • Manually classified. Automated system has been developed but not yet applied to all observations at all sites. • 1 year of data at SHEBA and 7 years at Barrow.
Annual Cycles of Cloud Type • Mixed-phase clouds: Maxima in transition seasons. • Similar trends and magnitudes between SHEBA and Barrow
Occurrence of Cloud Liquid Liquid is present throughout the year more than half of the time!
Vertical Distributions of Cloud Type • Remarkable similarities • Slightly different balance at surface.
Conclusions • High annual fraction: ~75% • Remarkable similarities in vertical. • Similar dist’n of phase for W. Arctic sites. • Liquid is frequent (and important!) Future Work • Radar-lidar combination at all sites. • Classification work at all sites using new algorithm. • More detailed analysis of boundaries Thank You.