Upper-air Water Vapour
ECV Products and Requirements
These products and requirements reflect the Implementation Plan 2022 (GCOS-244).
The requirements are found in the complete 2022 ECVs Requirements document as well: ECV Upper-air Water Vapour.
| Products | Water Vapour Mixing Ratio in the | ||||
| Upper Troposphere and Lower Stratosphere | Middle and Upper Stratosphere | Mesosphere | |||
| (*) | Unit | Values | Values | Values | |
| Horizontal Resolution | G | km | 15 | 50 | 50 |
| B | 100 | 500 | 500 | ||
| T | 500 | 1500 | 1500 | ||
| Vertical Resolution | G | km | 0.01 | 0.5 | 0.5 |
| B | 0.1 | 1 | 1 | ||
| T | 0.25 | 3 | 3 | ||
| Temporal Resolution | G | h | 3 | 3 | 3 |
| B | 6 | 6 | 6 | ||
| T | 24 | 72 | 72 | ||
| Timeliness | G | h | 1 | 1 | 1 |
| B | 120 | 168 | 168 | ||
| T | 720 | 720 | 720 | ||
| Required Measurement Uncertainty (2-sigma) | G | ppmv | 0.1 | 0.1 | 0.1 |
| B | 0.25 | 0.25 | 0.25 | ||
| T | 0.5 | 0.5 | 0.5 | ||
| Stability | G | ppmv/decade | <0.1 | <0.2 | <0.2 |
| B | 0.1 | 0.2 | 0.2 | ||
| T | 0.25 | 0.5 | 0.5 | ||
| Products | Relative Humiditiy in the | ||||||
| Boundary Layer | Free Troposphere | Upper Troposphere and Lower Stratosphere | |||||
| (*) | Unit | Values | Unit | Values | Values | ||
| Horizontal Resolution | G | km | 15 | km | 15 | 15 | |
| B | 100 | 100 | 100 | ||||
| T | 500 | 1000 | 500 | ||||
| Vertical Resolution | G | m | 1 | km | 0.01 | 0.01 | |
| B | 10 | 0.1 | 0.1 | ||||
| T | 100 | 1 | 0.25 | ||||
| Temporal Resolution | G | h | <1 | h | <1 | 3 | |
| B | 6 | 6 | 6 | ||||
| T | 12 | 12 | 24 | ||||
| Timeliness | G | h | 1 | h | 1 | 1 | |
| B | 120 | 120 | 120 | ||||
| T | 720 | 720 | 720 | ||||
| Required Measurement Uncertainty (2-sigma) | G | %RH | 0.1 | %RH | 0.1 | 0.5 | |
| B | 0.5 | 0.5 | 1 | ||||
| T | 1 | 1 | 2 | ||||
| Stability | G | %RH/ decade | 0.1 | %RH/ decade | 0.1 | <0.5 | |
| B | 0.5 | 0.5 | 0.5 | ||||
| T | 1 | 1 | 2 | ||||
| Products | Specific Humidity in the | Integrated Water Vapour | |||||||
| Boundary Layer | Free Troposphere | ||||||||
| (*) | Unit | Values | Unit | Values | Unit | Values | |||
| Horizontal Resolution | G | km | 15 | km | 15 | km | 25 | ||
| B | 100 | 100 | 250 | ||||||
| T | 500 | 1000 | 1000 | ||||||
| Vertical Resolution | G | m | 1 | km | 0.01 | - | |||
| B | 10 | 0.1 | - | ||||||
| T | 100 | 1 | - | ||||||
| Temporal Resolution | G | h | <1 | h | <1 | h | 0.2 | ||
| B | 1 | 1 | 1 | ||||||
| T | 3 | 3 | 24 | ||||||
| Timeliness | G | h | 1 | h | 1 | h | 24 | ||
| B | 120 | 120 | 120 | ||||||
| T | 720 | 720 | 720 | ||||||
| Required Measurement Uncertainty (2-sigma) | G | g Kg-1 | 0.1 | g Kg-1 | 0.1 | Kg m-3 | 0.1 | ||
| B | 0.5 | 0.5 | 0.5 | ||||||
| T | 1 | 1 | 1 | ||||||
| Stability | G | g Kg-1/ decade | 0.01 | g Kg-1/ decade | 0.01 | Kg m-3/ decade | 0.1 | ||
| B | 0.05 | 0.05 | 0.2 | ||||||
| T | 0.1 | 0.1 | 0.5 | ||||||
(*) Goal (G): an ideal requirement above which further improvements are not necessary. Breakthrough (B): an intermediate level between threshold and goal which, if achieved, would result in a significant improvement for the targeted application. The breakthrough value may also indicate the level at which specified uses within climate monitoring become possible. It may be appropriate to have different breakthrough values for different uses. Threshold (T): the minimum requirement to be met to ensure that data are useful
Data sources
This list provides sources for openly accessible data sets with worldwide coverage for which metadata is available. It is curated by the respective GCOS ECV Steward(s). The list does not claim to be complete. Anyone with a suitable dataset who wishes it to be added to this list should contact the abombelli
wmo [dot] int (GCOS Secretariat).
In Situ:
- NOAA Earth System Research Laboratory Global Monitoring Data
- Network for the Detection of Atmospheric Composition Change (NDACC)
- Integrated Global Radiosonde Archive (IGRA)
- GCOS Reference Upper-Air Network (GRUAN)
- GEWEX Water Vapour Assessment
Reanalysis:
- REANALYSES.ORG (Inventory for Reanalysis)
Satellite:
