Use the SBDART software http://arm.mrcsb.com/sbdart to design your own experiments to explore scattering of solar radiation in the atmosphere. Decide which input variables you will hold constant throughout all of the simulations for each experiment, and which you will vary.
1. Explore the sensitivity of the upwelling flux at the top of the atmosphere to aerosol characteristics. Note that visibility is inversely proportional to the volume scattering coefficient.
a) Which of shortwave spectral bands show the strongest signals for aerosols?
b) Is it easier to retrieve from satellite aerosol optical depth?
c) If a cloud is present, can you retrieve aeosol optical depth?
d) For the same visibility, how does the flux at the top of the atmosphere vary with aerosol composition?
2. Explore the sensitivity of the upwelling flux at the top of the atmosphere to cloud properties.
a) Put a cloud layer at 2 km, over a sea water surface. For the same optical depth and effective radius, how does the reflectivity at the top of the atmosphere vary for liquid vs ice cloud?
b) Put a cloud layer at 2 km, over a sea water surface For the same optical depth, compare the reflectivity at the top of the atmosphere for a water cloud with re=10 microns, and an ice cloud with re=106 microns.
c) For the same clouds in b), redo the calculations over a snow surface. Compare the reflectivities of the ice and liquid cloud over the snow and sea water surfaces.
d) For the same clouds in b), vary the solar zenith angle from 70o to 10o. Which solar zenith angles provide the clearest signal of the cloud properties?