Richardson Number | Ellrod Index | Turbulence CAPE Index
Atmospheric Turbulence
Richardson Number
The Richardson number is the ratio of buoyancy and flow shear terms. It is expressed by a dimensionless number between 0 and 10. In aviation the Richardson Number can be used to assess atmospheric turbulence. This is also referred to as Clear Air Turbulence (CAT). Values below unity indicate significant turbulence.
richardson_number_<level>:idx
Available levels: 100hPa, 300hPa, 500hPa
Examples
- Show Richardson Number for the entire globe:
- Current situation: https://api.meteomatics.com/2022-07-01T06:00:00Z/richardson_number_500hPa:idx/global:1,1/html_map
Ellrod Index
The Ellrod Index is designed to detect regions of Clear-Air-Turbulence (CAT) in the atmosphere. It is computed based on horizontal deformation of air parcels and vertical wind shear. The unit is s-2.
- Especially suitable to detect turbulence near the jet stream; at upper level troughs and ridges, and the exit region of a jet
- Does NOT account for low level turbulence due to thunderstorms, mountain ranges, etc.
Range | Meaning |
0-2 | smooth conditions |
2-9 | light turbulence |
9-20 | moderate turbulence |
20-36 | severe turbulence |
> 36 | extreme turbulence |
turbulence_ellrod_<level>:s2
Available levels (global): 950hPa, 925hPa, 900hPa, 850hPa, 800hPa, 700hPa, 500hPa, 300hPa, 250hPa, 200hPa, 150hPa, 100hPa, 70hPa, 50hPa, 10hPa
Available flight levels (global): FL20, FL50, FL100, FL140, FL180, FL240, FL300, FL340, FL390, FL450
Examples
- Ellrod Index at 700 hPa around the globe:
- Current situation: https://api.meteomatics.com/2022-07-01T06:00:00Z/turbulence_ellrod_700hPa:s2/global:0.5,0.5/html_map
Turbulence CAPE Index
Turbulence index incorporating CAPE. The index is computed for the total atmospheric column and not for single layers. This index allows for checking if turbulence is present. The values range from 0 (no turbulence expected) to 1 (turbulence expected)
turbulence_cape:m23s
- Show turbulence CAPE for the entire globe:
- Current situation: https://api.meteomatics.com/2022-07-01T06:00:00Z/turbulence_cape:m23s/global:1,1/html_map