dBZ (meteorology)

From Wikipedia, the free encyclopedia

The scale of dBZ values can be seen along the bottom of the image.
The scale of dBZ values can be seen along the bottom of the image.

dBZ stands for decibels of Z. It is a meteorological measure of equivalent reflectivity (Z) of a radar signal reflected off a remote object.[1] The reference level for Z is 1 mm6 m-3, which is equal to 1 μm3.

Reflectivity of a cloud is dependent on the number and type of hydrometeors, which includes rain, snow, and hail, and the hydrometeors' size. A large number of small hydrometeors will reflect the same as one large hydrometeor. The signal returned to the radar will be equivalent in both situations, so a group of small hydrometeors is virtually indistinguishable from one large hydrometeor on the resulting radar image.

A meteorologist can determine the difference between one large hydrometeor and a group of small hydrometeors as well as the type of hydrometeor through knowledge of local weather condition contexts.

One dBZ-scale of rain: > 40 heavy, 24-39 moderate and 8-23 light

[edit] See also

[edit] References