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2.1.2.Upper-air land observations Anchor Section2.1.2 Section2.1.2
This module displays stations with the following criteria in OSCAR/Surface:
- The declared status of a program affiliated with the variable pressure profile is either operational or partly operational;
- Station class Upper-air Radiosonde or PILOT;
- “international exchange” field set to “yes” on the pressure profile variable;
- The reporting schedule of pressure profile indicates that the variable is reported during the period for which data is displayed.
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.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.
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