Temperature/Levels » Thickness Definition
Definition: Thickness
Thickness refers to the vertical distance between two constant pressure surfaces (isobars).
Thickness refers to the vertical distance between two constant pressure surfaces (isobars).
The thickness of a layer is related to the mean virtual temperature (Tv) according to the formula:

Where:
- ΔZ = thickness (m)
- Rd = gas constant for dry air
-
= mean virtual temperature for the layer
- p1 = pressure at the bottom of the layer
- p2 = pressure at the top of the layer
- g = gravitational acceleration
Note for a given pair of pressures, the thickness is proportional to the mean virtual temperature (Tv) in the layer. The 1000-500 hPa thickness is perhaps the most commonly used because it corresponds to the mean temperature in the lower half of the troposphere. It is typically plotted on weather charts with 60-meter contours. In this case, each contour reflects a mean virtual temperature change of about 3°C.
Note for a given pair of pressures, the thickness is proportional to the mean virtual temperature (Tv) in the layer. The 1000-500 hPa thickness is perhaps the most commonly used because it corresponds to the mean temperature in the lower half of the troposphere. It is typically plotted on weather charts with 60-meter contours. In this case, each contour reflects a mean virtual temperature change of about 3°C.