MADS Cloud Fields
The cloud information (percentage and location) for a MADS is obtained directly from the eta field data sets.
To determine cloud type in the MADS the following logic is used.
If the liquid water content is greater than 0 and less than or equal to 0.01 and if temperature is less than 273 K, then the cloud is a thin cirrus cloud. If the temperature is greater than 273 K, it is a fog/haze.
If the liquid water content is greater than 0.01 and less than or equal to 0.05, then the cloud is a thick cirrus.
If the liquid water content is greater than 0.05, then the following logic is used.
If liquid water content is greater than or equal to 0.05 and less than 1.00, then the cloud is non-convective. If liquid water content is greater than or equal to 1.00, then the cloud is convective.
If pressure is greater than or equal to 850 mb, it is a low cloud. If pressure is greater than or equal to 300 mb and less than 850 mb, it is middle cloud. If pressure is less than 300 mb, it is a high cloud.
MADS Cloud Optical Property Models
The cirrus cloud backscatter computed for the MADS is the same method used for the GADS. For cirrus cloud attenuation, the AGM uses the liquid water content (LWC) to estimate geometric thickness, as shown below.
| Liquid Water Content (gm/m3) | Geometric Thickness (km) |
| 1e-4 | 0.1 |
| 1e-3 | 0.5 |
| 1e-2 | 4. |
| 5e-2 | 10. |
The AGM uses a simple AFGL cirrus model to define the cirrus attenuation as 0.14 * the geometric thickness.
| This page managed by Sidney A. Wood | Last modified: 21 Feb. 1998 |