Effects of the land surface on fluxes, turbulence, and boundary layer structure as shown by IHOP data

Dr. Margaret LeMone, NCAR/MMM

Data from Wyoming King Air Boundary Layer Heterogeneity Flights flown during the International H₂O Project between 19 May and 22 June 2002, show significant horizontal variability in fluxes, turbulent structure, and boundary layer depth. These changes often (but not always) correlate with land-surface features, including land cover (as revealed by videos and NDVI), soil moisture (as determined from rainfall patterns), and terrain.

This pattern was flown over three different tracks, one in SE Kansas (ample precipitation and vegetation), one in south central Kansas (intermediate conditions), and one in the Oklahoma panhandle (semiarid, with sparse vegetation), enabling isolation of the various mechanisms of land-atmosphere interaction and their effects. The results for the eastern track, which corresponds to a flight track flown during the 1997 springtime (21 April - 21 May) Cooperative Atmosphere Surface Exchange Study allow comparisons to fluxes associated with vegetation earlier in the year.