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The CAMS Global NRT service provides data on atmospheric composition, but does CAMS also provide data on temperature, precipitation and other meteorological parameters?

Meteorological forecasts are not in the scope of the CAMS Global NRT service, and meteorological variables are not provided on the CAMS Global Near-Real-Time FTP service.

However, after five days the CAMS Global NRT data is moved from the FTP server to the CAMS Global data archive. At this time, consistent meteorological variables are also made available (including temperature, winds, pressure, precipitation...). These meteorological variables are provided by ECMWF for the convenience of CAMS users and in accordance with ECMWF data policy.

 

Is meteorological data also available from other CAMS services, like the CAMS Regional (European) service?

No, other CAMS services do not provide meteorological forecasts. Meteorological forecasts can be obtained from National Weather Services, ECMWF or other providers. They are not in the scope of the Copernicus services.


What meteorological data is available in the CAMS Global archive?

For the actual parameters please see the CAMS Global archive data server. In particular for Surface Pressure see below for details.

As with all data in the CAMS global NRT archive, data is available with a 5-day delay, ie. up to five days before the current date.

The meteorological data is not listed in the CAMS catalogue because they are not a CAMS product.


How can I access the CAMS Global meteorological data?

Surface meteorological variables can be accessed in the same way as other CAMS Global surface data through the CAMS Global archive data server. For meteorological variables on pressure or model levels, please contact Copernicus Service Desk.

Meteorological variables are not available on the CAMS Global Near-Real-Time FTP service.

 

What is the source of the CAMS Global meteorological data?

The meteorological forecasts provided with CAMS Global data are spatially and temporally consistent with the CAMS Global data. They are produced with the same system as are ECMWF's weather forecasts, except this system is run at a coarser spatial resolution.


What support is provided?

CAMS does not provide formal support for the meteorological data.


Is the CAMS Global meteorological data validated?

The meteorological data is not a CAMS product, so CAMS does not validate it. But because the meteorological forecasts are produced with ECMWF's Integrated Forecasting System (IFS), which is extensively and continually validated, we assume validity of the CAMS meteorological variables. For more information on validation of the IFS please see see the ECMWF website.


Is surface pressure provided?

Surface pressure (sp, parameter 134) is provided since June 21, 2016, 06:00. Note that Surface pressure is not listed in the data archive web interface, so you have to download the surface pressure data through the ECMWF WebAPI.

For earlier time periods (from 5th July 2012, the start of the CAMS Global NRT archive, to 21st June 2016, 00:00), you can calculate surface pressure from the parameter lnsp (logarithm of surface pressure), which is provided on model levels.

To download and calculate sp from lnsp:

1. Download lnsp, either form the data archive web interface ('model levels' on the left) , or through the ECMWF WebAPI with the Python script below.  Note lnsp is listed as 'model level 1', which usually indicates the top of the atmosphere. Listing lnsp as 'model level 1' is only for technical reasons, lnsp is valid at the lower boundary of the bottom level, i.e. at the surface of the orography.

#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
server.retrieve({
    "class": "mc",
    "dataset": "cams_nrealtime",
    "date": "2017-01-01/to/2017-01-31",
    "expver": "0001",
    "levelist": "1",
    "levtype": "ml",
    "grid": "N256", # In CAMS Global NRT data the atmospheric composition fields are stored as grid point data (until 2016-06-21 00:00 on a N128 grid, from 2016-06-21 06:00 on a N256 grid), while lnsp is stored as spectral fields. To spatially match lnsp to atmospheric composition data, please specify here the grid you are working in, lnsp is then on the fly converted to the specified grid. Examples: "grid": "N256", "grid": "0.75/0.75". See also https://software.ecmwf.int/wiki/display/UDOC/Post-processing+keywords#Post-processingkeywords-grid
    "param": "lnsp",
    "step": "0",
    "stream": "oper",
    "time": "00:00:00/06:00:00/12:00:00/18:00:00",
    "type": "an",
    "target": "lnsp-an-2017-01.grb",
})

2. Calculate, using your preferred tools:

sp = e^lnsp