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WDQMS - Assessing Quality of Upper Air Observations

WDQMS - Assessing Quality of Upper Air Observations

by Gregory Clarke -
Number of replies: 2

Greetings all,

I would like to inquire as to the mechanism and reference that is employed by the WDQMS for assessing the quality of the Upper air observations.

I am technically responsible for the upper air ascent for the UAE, and would like to know why the quality of measurements are calculated to be to be worse (higher RMSE) than ascents from a neighbouring country.

Sincerely,

Greg Clarke



In reply to Gregory Clarke

Re: WDQMS - Assessing Quality of Upper Air Observations

by Cristina Prates -

Dear Greg,

In WDQMS the quality check of observations is NWP based. In the case of upper-air observations, the NWP data assimilation systems provide the background fields (very short range forecasts) of temperature, humidity and wind that are used as independent estimates against which observations are compared, i.e. the so call O-B departures. The statistics based on O-B departures for each of the variables, in this case root mean square error (rmse), is then compared against observational requirements of global NWP defined in OSCAR/Requirements (https://www.wmo-sat.info/oscar/applicationareas/view/1). The atmospheric column is split into two layers and rmse computed for these two layers: “Trop”, is for the first level up to 100hPa inclusive, and “Stra”, is for the 100hPa level up to the top level reported. The 6-hourly and daily maps display the highest value of rmse of the two layers  “Trop” and “Stra”.

Kind regards,

Cristina Prates


In reply to Cristina Prates

Re: WDQMS - Assessing Quality of Upper Air Observations

by Gregory Clarke -

Dear Cristina,

Thank you for your response.

I am struggling to see how an actual measurement can be penalized because it does not live up to expectation (NWP BE). I would expect the BE to be updated to fit in measured values.

In this scenario, I now ask: How do I improve our reported performance?

Kind Regards,

Greg