ECV Products and Requirements for Upper-air Water Vapour
These products and requirements reflect the Implementation Plan 2016 (GCOS-200). GCOS is reviewing and will update the requirements until 2022. More information on: gcos.wmo.int.
| PRODUCT | DEFINITION | FREQ. | RESOLUTION | REQUIRED MEASUREMENT UNCERTAINTY | STABILITY | STANDARDS/ REFERENCES |
| Total column water vapour | Total mass of water vapour present in a vertical atmospheric column (kg/m2) | 4hr | 25 km/ NA | 2% | 0.30% | |
| Tropospheric profiles of water vapour | 3D field of the relative humidity in the troposphere. Relative humidity is the ratio of the amount of atmospheric moisture present relative to the amount that would be present if the air were saturated with respect to water or ice to be specified in the metadata (%) | 4hr (troposphere) | 25 km/ 2 km | 5% | 0.30% | |
| Lower-stratospheric profiles of water vapour | 3D field of the relative humidity in the Lower stratosphere (%) | daily (stratosphere) | 100-200 km/ 2 km | 5% | 0.30% | |
| Upper tropospheric humidity | 3D field of the relative humidity in the upper troposphere (%) | 1hr | 25 km/ NA | 5% | 0.30% |
