Tuesday, December 14, 2010

Lake breeze captured during glider flight

Yesterday December 13, 2010 part of the PCAPS team and volunteers headed out again to the Great Salt Lake for more glider "sounding" data. With a strong possibility for lake breeze development, we hoped to capture at least some of the event mid-day. Meeting around solar noon allowed for time to setup and train our volunteers in initializing GRAW sondes and configuring radios for communications.

Some of the Team: Erik Crossman, Chris Santacroce, Chris Ander, David Reim, Neil Lareau

Our pilot, Chris Santacroce, met us shortly after noon. Surface winds were strangely calm at the lake's edge, and after waiting for several minutes, Chris decided to make a no-wind launch with his powered paraglider.

Chris setting up the powered paraglider

The flight plan was to fly long north-south cross sections, stepping up 100m each leg. Half way through the 50 minute flight we noticed a strong increase in surface winds pushing off the lake. Temps dropped rapidly and rh values spiked. We managed to capture the lake breeze as Chris was sampling data at the inversion top, so changed plan and sampled an east-west cross section at the mixing level as the lake breeze persisted inland. No one anticipated the lake breeze to penetrate deep into the Salt Lake Valley, but within the hour it had channeled across the length of the valley into Sandy. This helped strengthen the inversion and justified one more sounding transect the next day at 12 and 18 UTC across the valley before ending sub IOP 3 operations.

Chris flying north over the GSL at 6000 ft MSL.

More analysis is needed on the data collected, and we hope to review this last glider data-set during the upcoming downtime as the next series of troughs move through northern Utah.

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