DenisStuber
commented
3 years ago In July 2018, the World Meteorological Organization, launched a one-year trial phase for the monthly reporting of daily climate data as per BUFR template 3 07 074 (WMO 20180730), named DAYCLI message. This message includes 6 variables: maximum temperature, minimum temperature, mean temperature, precipitation, depth of new snowfall and depth of total snow on the ground (See File WMO 20180730). WMO 20180730.pdf
An assessment report of the trial phase was published in May 2020 (See File WMO 20200918 ). It recommends enhancing the DAILY message, both in term of climatological practices (metadata) and BUFR structure. It suggest also a way forward on monitoring the exchange of DAYCLI messages, and the promotion of WMO Member participation on this project. Assessment_DAYCLI_2020.pdf
EXTENSION OF THE TRIAL PHASE OF THE INTERNATIONAL EXCHANGE OF DAILY CLIMATE DATA WITH THE AIM OF RECOMMENDING ITS OPERATIONAL IMPLEMENTATION IN 2021 EC72_Doc4_2_1_DAYCLI.pdf
The Expert Team on Data Requirements for Climate Services (ET-DRC) from the WMO Services Commission has been proposed to specify all information needed for the complete data understanding, which means the necessary metadata.
At first analysis the BUFR template should precise:
- the definitions of the parameters especially for the snow (are they daily averages or instantaneous measurements);
- the definitions of the climatological day for each of the value that represents an average, a cumulative or an extreme value;
- the time of the extremes and of the instantaneous measurements;
- the quality of the values based on a new WMO quality system (system that ET-DRC should design in a short time);
- If "TRACE" of precipitations and other rain metadata (e.g. cumulative over more than 24 h) should be added.
A start on the DAYCLI requirement is available here: 20201005_DAYCLI_Requirements.pdf
tomkralidis
sergioh-pessoal
jlawrimo
jitsukoh
lemkhenter
sebbari
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Summary and purpose
Background, history and reasoning for the reporting of daily climate observations The development of the principal measure of the state of the climate - the global temperature record - has extensively depended on monthly CLIMAT data provided by National Meteorological and Hydrological Services (NMHSs). Over the last 20 years, there has been a growing demand for indices and measures of the climate that also consider extremes (Jones et al., 2012). For many extreme measures, monthly data are insufficient and there is a need for operationally exchanged daily climate data. This need is not just for timeliness, but principally for data that is compatible with long historical daily series developed and made available by NMHSs. Attempts have been made to use SYNOP data for this purpose (e.g. by the European Climate Assessment and Dataset but there are serious issues of incompatibility of SYNOP data with traditional methods of climate measurement within NMHSs (see van den Besselaar et al., 2012). Daily summaries in SYNOP messages are based on measurements that occur between synoptic reporting times and often over a period of less than 24 hours. For instance, in Europe, minimum temperatures are recorded usually over the 18 to 06 UTC 12-hour period and maximum temperatures during the 06 to 18 UTC 12-hour period. Measured in this way, the true daily minimum and maximum temperatures may not be reported because they may have occurred outside those particular 12-hour periods. As a result, SYNOP reports have been shown to significantly underestimate extremes: minimum temperatures measured in this way may be higher than the true daily minimum temperature, and maximum temperatures reported may be lower than the true daily maximum temperature reported as 24-hour climate observation. Similar problems occur for precipitation. In other regions of the world, SYNOP reporting practices can differ but problems remain. The Commission for Basic Systems (CBS) Open Programme Area Group on Integrated Observing Systems (OPAG-IOS), Implementation/Coordination Team on Integrated Observing Systems (ICT-IOS), recommended in 2012 that daily climate observations be included in monthly CLIMAT reports as a means of addressing the gap in the quality of daily climate observations. The U.S. National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information (NCEI), in cooperation with WMO Inter-programme Expert Team on Data Representation Maintenance and Monitoring (IPET-DRMM) and NOAA National Centers for Environmental Prediction (NCEP), developed a BUFR template for transmission of daily climate observations in BUFR format. This template was approved by CBS for implementation in May 2015. It was subsequently tested in the United States, with the cooperation of the UK Met Office. A one-year trial phase for the monthly reporting of daily climate observations was accepted by delegates to the seventeenth session of the Commission for Climatology in April 2018 (see Recommendation 5 (CCl-17)).
Reporting daily climate observations: Technical solution NOAA/NCEI, in cooperation with IPET-DRMM (taken over by the Inter-programme Expert Team on Codes Maintenance (IPET-CM) in 2016) and NOAA/NCEP, developed a BUFR template, 3 07 074 - Supplemental daily temperature and precipitation values, for daily climate observations in BUFR format, for monthly reporting. Please note that this does not replace the existing CLIMAT BUFR templates but offers complementary reporting of daily observations once per month. BUFR template 3 07 074 enables NMHSs to provide 31 daily observations consistent with national climate databases for the following elements: • Time of observation for temperature • Daily maximum temperature • Daily minimum temperature • Daily mean temperature (if it differs from (Tmax+Tmin)/2) • Time of observation for precipitation • Total daily precipitation • Depth of new snowfall • Depth of total snow on the ground Each of these observations should be recorded at the observing time consistent with the climate reporting practices of the NMHS and should reflect conditions over the previous 24-hour period. The climate convention varies from country to country; each country should retain its traditional observing practice in reporting daily climate summaries. For example, while in the U.S. the reporting time is local midnight, in Australia it is 9 a.m. local, and in Canada it is 06 UTC. These observations can be efficiently provided via daily CLIMAT reports or other methods specifically designed for climate purposes.
Consultations and Reviewers
References Jones, P.D., Lister, D.H., Osborn, T.J., Harpham, C., Salmon, M., Morice, C.P., 2012: Hemispheric and large-scale land-surface air temperature variations: An extensive revision and an update to 2010. Journal of Geophysical Research, 117, D05127, doi:10.1029/2011JD017139.
Van den Besselaar, E.J.M., Klein Tank, A.M.G, van der Schrier, G. and Jones, P.D., 2012: Synoptic messages to extend climate data records. Journal of Geophysical Research, 117, D07101, doi:10.1029/2011JD1688.
Detailed proposal
(Final proposal, updated by @jitsukoh December 20.) 1. Add a new entry in the significance qualifier class of table B (0-08-094) and a new code table to describe the method used to calculate the daily average temperature.
CODE TABLE 0-08-094 0-08-094 Method used to calculate the average daily temperature
Note (1) : The letters "a", "b", "c", "d" and "e" generically represent the weight associated with the respective temperature T. The sub-index of T: "1", "2", "3", "x" and "n" represent the values measured at different times or maximum (x) or minimum (n) values.
2. Quality flag for each climatological value (Temperatures, Precipitation and Snow). Add a new entry (5) of 8-bit indicator of quality control in the Associated field significance (0 31 021).
3. Siting classification and Measurement Quality Classification
Discussion: It is necessary to add the Siting Classification (SC) and also Measurement Quality Classification (MQC). However, the MQC must be accompanied by the siting classification.
Proposal:
Add 2 entries in table B: One for Temperature and another for Precipitation. Both with 8-bit code tables, where, the first character represents the Siting Classification from "1" to "5", as defined by defined ISO/WMO standard 119289:2014(E) (see the Guide to Instruments and Methods of Observation (WMO-No. 8) edition 2014 Part I, Chapter I, Annex 1B for details), and the second character represent the Measurement Quality Classification from “A” to “D” defined by the Guide to Instruments and Methods of Observation (WMO-No. 8) edition 2020.
4. Element names for 0 13 012 (depth of fresh snow) and 0 13 013 (total snow depth) This change will not be implemented. ~~Update the element name for 0 13 012 (depth of fresh snow) and 0 13 013 (total snow depth) to add terminology used in WIGOS Metadata.~~
* CSV file: BUFRCREX_TableB_en_13.csv0 13 012Depth of fresh snowDepth of fresh snow (Depth of snowfall)0 13 013Total snow depthTotal snow depth (Snow depth) (see Note 2)5. The new DAYCLI BUFR message Create a new descriptor 3-07-075 in the next version of BUFR table D.
(Depth of snowfall)(Snow depth)