1. Sandy Deserts Negligible Evaporation Q*  Q H + Q G Not terribly high Instability in afternoon

2. Very High Surface Temps (despite high albedo) Shallow layer of extremely high instability High winds Strong heat flux convergence Lower atmosphere very unstable Mirage due to density variation Huge diurnal air temperature range

3. Snow and Ice Snow and ice permit transmission of some solar radiation

4. Notice the difference between K  and Q* Why ? High Albedo Magnitudes of longwave fluxes are small due to low temperature

5. Surface Energy Balance for Snow and Ice Q* = Q H + Q E +  Q S +  Q M  Q S Convergence or divergence of sensible heat fluxes  Q M Latent heat storage change due to melting and refreezing Negligible Q E (sublimation possible) Low heat conduction Q* is negative Q* = Q H + Q E +  Q S +  Q M - Q R COLDMELTING Rainfall adds heat too Percolation and refreezing transfers heat  Q M >  Q S Condensation at surface is common (snow pack temperature can only rise to 0  C) - Q E can be important ! Why ? K V >L F  Q M = L F   r

6. Surface Radiation Balance for Melting Snow Latent heat storage change due to melting or freezing (negligible Q E, Q M and small Q S if ‘cold’ snow) Q* can be negative for nold snow Isothermal snow Turbulent transfer Raise temp

7. Surface Radiation Balance for Melting Glacier Higher  Continual receipt of Q H and Q E from atmosphere

8. Surface Radiation Balance for a Lake

10. Surface Radiation Balance for a Plant Canopy