Cloud Scattering and Enhanced Path Lengths


This applet simulates photons being scattered in a non-absorbing cloud using a variety of cloud geometries and scattering functions. The profiles of the clouds are largely user configurable with the plot on the left side of the panel. The clouds occupy a region of one unit length. The left plot shows the scattering optical density as a function of altitude. When the mouse is positioned near a data point you can click and drag that point to other values. Note the scale labels as the region automatically resizes as the data points move.

The middle section shows a graphical representation of the cloud and every tenth path through it when the applet is running. The brightness is given by the exponential of minus the local optical depth. Zero optical depth results in blue regions while optical depths near or above 100 are shown as essentially white.

The far right graph displays the number of paths that have resulted in different path lengths for both reflected and transmitted paths.

Below the figures are the selections for cloud structure, scattering function, and incident angle (not used for 1D model). There is also a button to start or stop the simulation. Below those are displays showing the optical depth of the cloud, the number of photons tested, the average transmitted path length, the average reflected path length, and the percentage of photons relfected. Note that when you stop a simulation all the tallies for it are cleared.


You need to have either IE 4.x, Netscape 4.x, or HotJava (from Sun) to view this page properly.