1. CHARACTERIZING COLD AIR POOL DYNAMICS USING THERMAL IMAGERY PRESENTED BY CHRIS JOHNSON BIOMICROMETEOROLOGY GROUP

2. Photo Credit: The University of Utah

3. DESIGN OF EXPERIMENT SODAR

4. THERMAL IMAGERY TO MAP COLD AIR POOL DYNAMICS Each pixel of temperature information will be associated with a position on the Earth and an elevation. But first the thermal imagery must be filtered, georeferenced, and orthorectified.

5. GEOREFERENCING THERMAL IMAGERY Identify objects in the image Obtain accurate locations Use known objects as Ground Control Points Ground Control Point Known Object and Location

6. ORTHORECTIFICATION Data Gap

7. VALIDATION – Temperature Profile Basic Functions: Emits a sound pulse Measures properties of sound backscattered from turbulent fluctuations Emitted pulse frequency Backscattered sound frequency Intensity of backscattered sound Relationship to IR Measurements: Atmospheric Structure Parameters Refractive Index Structure Parameter(C N 2 ) Temperature Structure Parameter (C T 2 ) Intensity related to C N 2 C N 2 related to C T 2 C T 2 directly calculated from temperature gradient

8. VALIDATION – Cold Air Pool Depth Plot Credit: Beyrich, F., 1997. Mixing Height Estimation from SODAR Data. Atmospheric Environment 31, 3941-3953. Assumption: The depth of the cold air pool is equal to the inversion height. ABL Conditions for Plot: Weak wind, surface radiatively cooling. Potential Temperature Backscatter Intensity

9. DESIGN OF EXPERIMENT SODAR