wmo_gross_errors: WMO Gross Errors Tests for Pressure, Temperature, Dew Point,...

In C3S-Data-Rescue-Lot1-WP3/C3S-QC: C3S quality control tools for historical climate data

Description

Applicable to a series (daily or sub-daily) of air pressure, air temperature (ta), dew point temperature (td), wind speed (w). The pressure series can be at mean sea level (mslp) or at station level (p). Flags the records where the observations values exceed the limit values given by WMO (1993).

Usage

wmo_gross_errors(series, meta = NULL, outpath = getwd())

Arguments

series	A character string giving the path of the SEF file, or a five or seven-column (daily or subdaily) data frame with the series.
meta	A character vector with 6 elements: station ID, latitude, longitude, altitude, variable code, units. If series is a path, meta is ignored.
outpath	Character string giving the path for the QC results. By default this is the working directory.

Details

Input:

• A SEF file or a data frame and metadata. The observations data frame must have five or seven columns: variable code, year (YYYY), month (MM), day (DD), (hour (HH), minute (MM)), observation. The required metadata are the station identifier, the station latitude and variable units.

The WMO gross error limits for air pressure, air temperature, dew point temperature, and wind speed:

• For station level pressure the gross error limits are latitude and meteorological season independent (WMO, 1993: VI.7). According to the same reference, for mean sea level pressure, temperature, dew point, and wind speed, the WMO establishes the gross error limits as function of the station latitude and the meteorological season in which the observations were collected.

• The tests divide the meteorological seasons in Winter and Summer. So, based on the meteorological calendar for the Northern Hemisphere, which defines seasons as Spring (March, April, May), Summer (June, July, August), Autumn (September, October, November) and Winter (December, January, February), it was here considered:

  • Northern Hemisphere Winter / Southern Hemisphere Summer - January, February, March, October, November, December;

  • Northern Hemisphere Summer / Southern Hemisphere Winter - April, May, June, July, August, September.

• The gross error limits for each variable divide the flagged values in suspect and erroneous (WMO, 1993: VI.6 - VI.8).

• Latitude independent

  • Meteorological season independent

    • Station Level Pressure (p):

      • Suspect: 300 <= p < 400 hPa or 1080 < p <= 1100 hPa

      • Erroneous: p < 300 or p > 1100 hPa

• Latitudes belonging to the interval [-45, +45]

  • Winter

    • Mean Sea Level Pressure (mslp)

      • Suspect: 870 <= mslp < 910 hPa or 1080 < mslp <= 1100 hPa

      • Erroneous: mslp < 870 hPa or mslp > 1100 hPa

    • Air Temperature (ta)

      • Suspect: -40 <= ta < -30 ºC or 50 < ta <= 55 ºC

      • Erroneous: ta < -40 ºC or ta > 55 ºC

    • Dew Point Temperature (td)

      • Suspect: -45 <= td < -35 ºC or 35 < td <= 40 ºC

      • Erroneous: td < -45 ºC or td > 40 ºC

    • Wind Speed (w)

      • Suspect: w > 60 m/s and w <= 125 m/s

      • Erroneous: w > 125 m/s

  • Summer

    • Mean Sea Level Pressure (mslp)

      • Suspect: 850 <= mslp < 900 hPa or 1080 < mslp <= 1100 hPa

      • Erroneous: mslp < 850 hPa or mslp > 1100 hPa

    • Air Temperature (ta)

      • Suspect: -30 <= ta < -20 ºC or 50 < ta <= 60 ºC

      • Erroneous: ta < -30 ºC or ta > 60 ºC

    • Dew Point Temperature (td)

      • Suspect: -35 <= td < -25 ºC or 35 < td <= 40 ºC

      • Erroneous: td < -35 ºC or td > 40 ºC

    • Wind Speed (w)

      • Suspect: w > 90 m/s and w <= 150 m/s

      • Erroneous: w > 150 m/s

• Latitudes belonging to the interval [-90, -45[ U ]+45, +90]

  • Winter

    • Mean Sea Level Pressure (mslp)

      • Suspect: 910 <= mslp < 940 hPa or 1080 < mslp <= 1100 hPa

      • Erroneous: mslp < 910 hPa or mslp > 1100 hPa

    • Air Temperature (ta)

      • Suspect: -90 <= ta < -80 ºC or 35 < ta <= 40 ºC

      • Erroneous: ta < -90 ºC or ta > 40 ºC

    • Dew Point Temperature (td)

      • Suspect: -99 <= td < -85 ºC or 30 < td <= 35 ºC

      • Erroneous: td < -99 ºC or td > 35 ºC

    • Wind Speed (w)

      • Suspect: w > 50 m/s and w <= 100 m/s

      • Erroneous: w > 100 m/s

  • Summer

    • Mean Sea Level Pressure (mslp)

      • Suspect: 920 <= mslp < 950 hPa or 1080 < mslp <= 1100 hPa

      • Erroneous: mslp < 920 hPa or mslp > 1100 hPa

    • Air Temperature (ta)

      • Suspect: -40 <= ta < -30 ºC or 40 < ta <= 50 ºC

      • Erroneous: ta < -40 ºC or ta > 50 ºC

    • Dew Point Temperature (td)

      • Suspect: -45 <= td < -35 ºC or 35 < td <= 40 ºC

      • Erroneous: td < -45 ºC or td > 40 ºC

    • Wind Speed (w)

      • Suspect values: w > 40 m/s and w <= 75 m/s

      • Erroneous values: w > 75 m/s

Output:

• A text file of flagged observations with six or eight columns: variable code, year (YYYY), month (MM), day (DD), (hour (HH), minute (MM)), observation, test. The test column has the description "gross_errors".

Author(s)

Clara Ventura, Yuri Brugnara

References

WMO, 1993: Chapter 6 - Quality Control Procedures. Guide on the Global Data-processing System, World Meteorological Organization, Geneva, No. 305, VI.1-VI.27, ISBN 92-63-13305-0.

Examples

wmo_gross_errors(series = Rosario$p, meta = Meta$p[which(Meta$p$id=="Rosario"),])
wmo_gross_errors(series = Rosario$ta, meta = Meta$ta[which(Meta$p$id=="Rosario"),])
wmo_gross_errors(series = Rosario$td, meta = Meta$td)

C3S-Data-Rescue-Lot1-WP3/C3S-QC documentation built on Jan. 15, 2020, 10:36 p.m.