...
| Info | ||||
|---|---|---|---|---|
| ||||
|
| Easy Heading Macro | ||
|---|---|---|
|
History of modifications
| Expand | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||||||||||
|
Related Documents
|
Related Documents
| Expand | ||||||
|---|---|---|---|---|---|---|
| ||||||
| ||||||
| Expand | ||||||
| ||||||
|
...
Table 1: Main variables and note on adjustments Anchor table1 table1
Origin | Variable | Units | Time period for | Time period for | Base line period for | Adjustments |
ERA5 | 0-7cm volumetric soil moisture | m3m-3 | 1979 - present | 1979 - present | 1981-2010 | Yes, see here |
ERA5 | Total precipitation | m day-1 | 1979 - present | 1979 - present | 1981-2010 | No |
ERA5 | Sea-ice cover | (0 - 1) | 1979 - present | 1979 - present | 1981-2010 | No |
ERA5 | Surface air relative humidity | % | 1979 - present | 1979 - present | 1981-2010 | No |
ERA5 | Surface air temperature | K | 1979 - present | 1979 - present | 1981-2010 | Yes, see here |
ERA-Interim | 0-7cm volumetric soil moisture | m3m-3 | 1979 - present | 1979 - present | 1981-2010 | Yes, see here |
ERA-Interim | Total precipitation | m day-1 | 1979 - present | 1979 - present | 1981-2010 | No |
ERA-Interim | Sea-ice cover | (0 - 1) | 1979 - present | 1979 - present | 1981-2010 | No |
ERA-Interim | Surface air relative humidity | % | 1979 - present | 1979 - present | 1981-2010 | Yes, see here |
ERA-Interim | Surface air temperature | K | 1979 - present | 1979 - present | 1981-2010 | Yes, see here |
ERA5
Surface air temperature Anchor era5surftempadj era5surftempadj
...
In v01 of the data set fields with the wrong processing were made available. V02 rectifies this, see more here.
Surface air relative humidity
...
Table 2: Information about GRIB codes, version numbers and differences between version numbers.
Origin | Variable | GRIB | Grid | Version number | Difference between v01 | Difference between |
ERA5 | 0-7cm volumetric soil moisture | 39 | .25/.25 | v02 | 12 m running mean statistics reprocessed | |
ERA5 | Total precipitation | 228 | .25/.25 | v02 | 12 m running mean statistics reprocessed | |
ERA5 | Sea-ice cover | 31 | .25/.25 | v02 | 12 m running mean statistics reprocessed | |
ERA5 | Surface air relative humidity | 157 | .25/.25 | v02 | 12 m running mean statistics reprocessed | |
ERA5 | Surface air temperature | 167 | .25/.25 | v02 | Reprocessing adjustment over Great Lakes only, updated interpolation package for regridding to regular grid.* 12 m running mean statistics reprocessed | |
ERA-Interim | 0-7cm volumetric soil moisture | 39 | .25/.25 | v02/v03 | Applied masking over sea, ice sheets and deserts; | 12 m running mean statistics reprocessed |
ERA-Interim | Total precipitation | 228 | .25/.25 | v02/v03 | Grid changed to regular | 12 m running mean statistics reprocessed |
ERA-Interim | Sea-ice cover | 31 | .25/.25 | v02/v03 | Grid changed to .25/.25 | 12 m running mean statistics reprocessed |
ERA-Interim | Surface air | 157 | .25/.25 | v02/v03 | Grid changed to regular; GRIB code changed | 12 m running mean statistics reprocessed |
ERA-Interim | Surface air temperature | 167 | .25/.25 | v02/03 | Adjustments over ice-free seas applied; GRIB code changed | 12 m running mean statistics reprocessed |
Known issues
- Update from v01 to v02 of ERA5 surface air temperature:
...
"Essential climate variables for assessment of climate variability from 1979 to present" constitutes the basis for the C3S monthly Climate Bulletin. For the months of September, October, November and December 2021, erroneously large values of soil moisture, and to a lesser extent, of 2m temperature and of humidity became noticeable in the timely ERA5 product (ERA5T) for central Asia. A full description of the issue and how it has been addressed can be found here.
After correction, the timely published "Essential climate variables for assessment of climate variability from 1979 to present" have been replaced for each of the affected months with a newly post-processed version based on the corrected, consolidated ERA5 (rather than ERA5T, which bore the erroneous values). Graphics and time-series data of the monthly climate bulletin have been accordingly updated and replaced for the affected months in the respective bulletin. The table of the bottom of the page outlines which months have been updated to date.
...
The outdated and new maps of hydrological variables for Europe for October highlight the main difference between the dataset containing the erroneous values and the new one based on the consolidated ERA5. The issue is very apparent in Central Asia in the soil moisture maps and, to some extent, for the other variables too.
| Old erroneous | New corrected |
|---|---|
|
|
Figure 1: Anomalies in precipitation, the relative humidity of surface air, the volumetric moisture content of the top 7 cm of soil and surface air temperature for October 2021 with respect to October averages for the period 1991-2020. The darker grey shading denotes where soil moisture is not shown due to ice cover or climatologically low precipitation. Data source: Left ERA5T (erroneous), Right: ERA5 consolidated (new & corrected) Credit: Copernicus Climate Change Service/ECMWF.
...
Table 3: Original erroneous and the new corrected versions of data and graphics.Anchor table3 table3
| September | October | November | December | |
|---|---|---|---|---|
| Old erroneous | Zip-file of data and graphics (1981-2010, 1991-2020) | Zip-file of data and graphics (1981-2010, 1991-2020) | ||
| New corrected graphics and time-series data | September monthly summary | November monthly summary | December monthly summary | |
| Corrected spatial data available in the CDS entry? | yes | yes | yes | yes |
| Date of correction | 07/01/2022 | 07/01/2022 | 07/01/2022 | 02/02/2022 |
- Incomplete retrieval of ERA5 during DHS move affecting RH used in the Climate bulletin
The “Essential climate variables for assessment of climate variability from 1979 to present" dataset constitutes the basis for the C3S monthly Climate Bulletin.
In the frame of a major hardware change at ECMWF, and for a limited period, the services usually provided by the Data Handling System, from which this dataset is retrieved, were distributed across different systems. For this, a bespoke retrieval script was developed, within which an error led to the incomplete retrieval of surface air relative humidity data for the month of September 2022. Instead of covering the period 1-30 September, the retrieved files only contained the data for the period 07-30 September. This one-off problem, had an impact on all data and information derived from those, namely the data for September and October 2022. Upon publication of data for November 2022, the problem was identified and the data for the month of September 2022 correctly retrieved. As of mid-December 2022, the published "Essential climate variables for assessment of climate variability from 1979 to present" data have thus been replaced on the CDS for each of the affected months with a new version.
In turn, related maps, time-series and data of the monthly climate bulletin have been accordingly updated and replaced for the affected months in the respective bulletin. The table of the bottom of the page outlines which months have been updated to date.
Table 4: Original erroneous and the new corrected versions of data and graphics. Anchor table4 table4
| September | October |
Old erroneous |
New corrected graphics and time-series data | September monthly summary | October monthly summary |
| ||
Corrected spatial data available in the CDS entry? | yes | yes |
|
Date of correction |
22/ |
12/2022 |
22/ |
12/2022 |
|
| Anchor | ||||
|---|---|---|---|---|
|
...
Philippe Lopez 2013: Experimental 4D-Var Assimilation of SYNOP Rain Gauge Data at ECMWF, https://doi.org/10.1175/MWR-D-12-00024.1 
| Info | ||
|---|---|---|
| ||
This document has been produced in the context of the Copernicus Climate Change Service (C3S). The activities leading to these results have been contracted by the European Centre for Medium-Range Weather Forecasts, operator of C3S on behalf of the European Union (Delegation agreementAgreement signed on 11/11/2014 and Contribution Agreement signed on 22/07/2021). All information in this document is provided "as is" and no guarantee or warranty is given that the information is fit for any particular purpose. The users thereof use the information at their sole risk and liability. For the avoidance of all doubt , the European Commission and the European Centre for Medium - Range Weather Forecasts have no liability in respect of this document, which is merely representing the author's view. |
Related articles
| Content by Label | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|