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All the four WIGOS Monitoring Centres - ECMWF, DWD, JMA and NCEP- are providing quality monitoring reports for upper-air observations. Like the surface reports, these include qualitative as well as quantitative information. The quantitative information provided is obtained by aggregating the O-B departures into two main categories: layer between the first pressure level up to 100 hPa inclusive (Trop); and the layer from 100 hPa up to the last reported level (Stra). The quantitative information for the aforementioned layers consists of both the mean and standard deviation of O-B departures over the layer for the following observed physical quantities: upper-air temperature, upper-air humidity and upper-air wind. Provision of these data reports (four daily, centred at the main synoptic hours, 00, 06, 12 and 18UTC), typically happens 24 hours after the actual observation. The availability, quality and completeness of these conventional profiling observations can be easily assessed based on the information provided by the monitoring reports. It is worth mentioning that for the high-resolution BUFR reports, two messages are disseminated on the Global Telecommunication System (GTS): a preliminary message containing the measurements from the surface up to 100h Pa (TTAA=IUK header - I, Observational data Binary coded, U, upper-air message and K, radiosonde from fixed land station up to 100 hPa) and the final message containing the entire sounding from surface to balloon burst (TTAA=IUS, header - I, Observational data Binary coded, U, upper-air message and S, radiosonde from fixed land station up to balloon burst). ECMWF, JMA and DWD use the full BUFR message (i.e., IUS bulletin), and only if the full one is not available they use the IUK bulletin. Therefore, all NWP monitoring reports reflect this, i.e., the ascent report that contains the highest level will be used to calculate the statistics (i.e., IUS bulletin). This is a case of duplicates, however, if a radiosonde is launched 30 mins after the one that went wrong (i.e., burst at quite low altitudes), both will be used because they are not considered duplicates in those circumstances.
2.2.GBON monitoring
The GBON module monitors the compliance of all land-based surface and upper-air GBON-affiliated stations – as documented in OSCAR/Surface - with the GBON baseline requirements. Data availability at station level is calculated using the near-real-time monitoring data provided by the four NWP centres and stored in the WDQMS database at ECMWF.
2.2.1.Surface-land observations
This module displays stations with the following criteria in OSCAR/Surface:
- Station class GBON surface station;
- Station is not closed.
The 6-hourly monitoring reports provided by DWD, ECMWF, JMA and NCEP contain qualitative and quantitative (Observation-minus-Background, O-B, departures) information on the following observed variables: surface pressure (or geopotential height for some high-altitude stations), 2-metre temperature, 2-metre relative humidity and 10-metre wind (meridional and zonal components). This data is then aggregated and used to determine the station data availability per variable and time interval. It is based on the data availability that GBON station-level compliance is assessed. The station will only be compliant if it reports the required measurements at the required frequency, i.e., hourly for all the above-mentioned quantities.
2.2.2.Upper-air land observations
This module displays stations with the following criteria in OSCAR/Surface:
- Station class GBON upper-air station;
- Station is not closed.
The upper-air monitoring reports provided by the four NWP centers include qualitative as well as quantitative information for upper-air temperature, upper-air humidity, and upper-air wind aggregated into two main categories: the layer between the first pressure level and 100 hPa inclusive (Trop); and the layer from 100 hPa up to the last reported level (Stra). A radiosonde is deemed complete if an NWP centre obtains measurements for all the variables up to and above 100hPa, with the exception of humidity above 100hPa. Only complete soundings will be used to determine the station data availability. The assessment of GBON station-level compliance is done based on the data availability. The station will only be compliant if it reports the required measurements at the required frequency, i.e., complete soundings twice a day.
2.3.GCOS monitoring
The GCOS module of the WDQMS web tool monitors the performance of both surface and upper-air components of the climate observing system. The surface component is based on the routine monitoring of CLIMAT reports done by DWD and JMA in their capacities as GSN monitoring centres. The system collects a file provided monthly by DWD with information on availability and completeness of CLIMAT data for all the GSN stations recorded in OSCAR/Surface. The upper-air component is based on the routine monitoring of TEMP reports done by DWD and ECMWF in their capacities as GUAN monitoring centres. The system monitors the performance of all upper-air (radiosonde) land stations that are part of the GUAN as documented in WMO’s database OSCAR/Surface, based on monthly monitoring information provided by DWD. The system collects two files monthly containing the availability and quality monitoring information separately.
2.23.1.Surface-land observations
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DWD provides a monthly monitoring statistics report, which includes information on the availability and completeness of the CLIMAT reports sent by all the surface land stations that are part of GSN. The availability results are obtained by checking the collected monthly CLIMAT messages against the list of stations affiliated to the GSN and registered in OSCAR/Surface. For a station to be classified as reporting it needs to have sent a CLIMAT message that includes information of at least one of the following variables: monthly mean temperature, monthly precipitation amount, mean daily maximum temperature and mean daily minimum. The completeness is obtained from the information - not mandatory though - provided on the number of days of the month missing for some observed variables. The variables included in GSN completeness monitoring are: daily mean surface pressure, daily mean air temperature, daily maximum air temperature, daily minimum air temperature, daily mean water vapour, total daily precipitation and total daily sunshine duration. Provision of the data report (monthly), typically happens on the 22nd of the following month.
2.23.2.Upper-air land observations
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