1. New observations of clouds, atmosphere, and precipitation at Summit, Greenland Matthew Shupe, Von Walden, David Turner Ryan Neely, Ben Castellani, Chris Cox, Penny Rowe, Nate Miller, Maria Cadeddu ICECAPS Special thanks to a large team of supporters and collaborators

2. How do clouds impact the Greenland Ice Sheet? Source: Precipitation => The Mass Budget Sink: Radiation => The Energy Budget

3. Introducing the Mobile Science Facility at Summit

4. Microwave Radiometers: PWV, LWP, T Spectral Infrared Interferometer: Cloud phase, microphysics, LW radiation, trace gases Cloud Radar: Cloud macrophysics, phase, microphysics, dynamics Ceilometer: Cloud base Depolarization Lidars: Cloud base, phase, microphysics, orientation Sodar: Boundary layer depth Radiosonde: T, RH Precip Sensor: Rate, PSD?

5. Continuous radiosonde measurements Tropopause height Signs of spring? Cold and dry

6. Thermodynamic profiles and clouds Surface-based T and q inversions at ~ 100-300m (almost always present) Atmosphere is relatively moist & warm with clouds (~15 C warmer, 4x moister) Need to distinguish impacts of clouds vs. water vapor on SEB & w/ season

7. “Cloud Roses” Cloud presence/depth determined by multi-sensor analysis 90% of SE flow is cloudy, frequent clouds in flow from 100-300° With winds, almost all clouds come from SW-S

8. “Precipitation Roses” Precipitation occurrence identified by ground-based radar Frequent precipitation in W flow Very little precipitation coming from N sector flows, most from SW.

9. Summit clouds compared to other Arctic locations Generally: Remarkable similarity with other locations

10. Summit clouds compared to other Arctic locations LWP derived from microwave radiometer brightness temperatures Most Arctic clouds are thin ( LWP < 50 g/m 2 ) “Thick” clouds are virtually non-existent at Summit

11. q EE High backscatter + low depol = liquid Detailed cloud microphysical-dynamical relations are also similar High reflectivity + high depol = ice precip Velocity variability

12. Cloud mixed-layer Detailed cloud microphysical-dynamical relations are similar! W-LWP-IWP correlation Cloud-generated turbulence Cloud ice nucleates in liquid

13. Mixed-phase environment w/ riming T top = -20 C Dendrites form around -15 C and generally above water saturation Plates, sector plates in same T range but do not need water saturation 21:40 22:35 Ice Precip, Crystal Habits

14. 17:40 Ice cloud. Poss. liquid near sfc. T = -40 to -18 C Bullets, hollow capped columns, assemblages of plates/side planes (all -20 to -30 C, Magono and Lee) Ice Precip, Crystal Habits

15. Summary New cloud-atmosphere observing capabilities at Summit, Greenland Many cloud characteristics are similar to elsewhere in the Arctic Good opportunities to study cloud interactions with meteorology, boundary layer, surface energy budget, and precipitation We welcome collaborations!