Broom's Barn Meteorological Station

  • Description:

    Meteorological data was first collected in Brooms Barn in 1963, though only data from 1982 is currently available in e-RA. Fewer variables are measured than at Rothamsted and Woburn. Most manual observations ceased in 1996, and meteorological records are now measured by a range of sensors attached to an automatic data logger. Between August 2009 and May 2012 the weather station was not fully functional, and raw data supplied by the Brooms Barn Met Office weather station was used for some variables. Hourly data from 2016 (radiation from 2003) are available from the e-RA Curators.

    The Brooms Barn meteorological station is approx. 30m from the main buildings, which are approx. 10m high. This may cause some interference with the measurement of wind speed and wind direction, as ideally a mast with wind sensors should be a minimum of 10 times the height of the nearest building away from the nearest building (ie at least 100m apart). This gives enough fetch for the wind to settle down. The met station and main building have always been in these positions.

    Mean annual temperature 1964-2008 was 9.9 °C. Rainfall averages 612mm (1963-2008).

    Real-time hourly, daily and yearly weather charts for Brooms Barn are available on-line over 28 days or 365 days (rolling) via the Rothamsted Environmental Change Network (ECN) pages

  • Date Start: 1982.
  • Date End: Ongoing.
  • Recording: Daily at 0900GMT.
  • Automatic data recording began: 1996.
  • Manual recording finished: 1996 (except sunshine).
  • Address: Higham, Bury St. Edmunds, Suffolk, IP28 6NP, United Kingdom.
  • OS Grid Ref: TL 75195 65582.
  • Latitude/Longitude: 52.2605 N 0.5656 E.
  • Altitude: 70 m asl.

Key Contacts

  • Andy Macdonald

  • Role: Principal Investigator
  • Organisation: Rothamsted Research
  • Address: West Common, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom.
  • Tony Scott

  • Role: Data Manager
  • Organisation: Rothamsted Research
  • Address: West Common, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom.
  • Sarah Perryman

  • Role: Data Manager
  • ORCID: https://orcid.org/0000-0002-0056-2754
  • Organisation: Rothamsted Research
  • Address: West Common, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom.
  • Margaret Glendining

  • Role: Data Manager
  • ORCID: https://orcid.org/0000-0002-6466-4629
  • Organisation: Rothamsted Research
  • Address: West Common, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom.

Funding

Meteorological data available in BROOMET

Daily meteorological data recorded at Brooms Barn, Higham, Bury St Edmunds, Suffolk, available since 1982. Manual observations ceased in 1996 (apart from sunshine) and meteorological records are now measured by a range of sensors attached to an automatic data logger. The dataloggers were upgraded from CR21X to CR1000 on 12 December 2012.

Between August 2009 and May 2012 the weather station was not fully functional, and raw data supplied by the Brooms Barn Met. Office weather station at the same site was used for some variables. This is indicated in the descriptions below. Please ensure you cite this. The faulty sensors were replaced on 23 May 2012.

Hourly data from 2016 (radiation from 2003) is available from the e-RA Curators.

Variable Units Description When recorded Methods of measurement

Air temperature

TMAX degrees C Maximum temperature 1982-current date Recorded over the 24 hour period up to 0900GMT, for the previous day's maximum temperature.

Since April 25th 2018, measured by an automatic EE181 E+E Relative Humidity and Temperature probe (E+E Elektronic Corporation, supplied by Campbell Scientific). Prior to this measured with an automatic HMP45C Relative Humidity and Temperature sensor. New temperature sensors were installed on 8th November 2012.

Before November 1996, manually recorded with a mecury-in-glass sheathed maximum thermometer, housed in a naturally aspirating temperature screen.

Data from August 2009-May 2012; 16-17/08/2016; 30/10/2016-3/11/2016 and 18/4/2018-25/4/2018 provided by the Met. Office. © Crown Copyright 2009-2012, 2016, 2018, published by the Met. Office.

TMIN degrees C Minimum temperature 1982-current date

Recorded over the 24 hour period up to 0900GMT, for the current day's minimum temperature.

Since April 25th 2018, measured by an automatic EE181 E+E Relative Humidity and Temperature probe (E+E Elektronic Corporation, supplied by Campbell Scientific). Prior to this measured with an automatic HMP45C Relative Humidity and Temperature sensor. New temperature sensors were installed on 8th November 2012.

Before November 1996, manually recorded with a spirit-in-glass with indicator bar minimum thermometer, housed in a naturally aspirating temperature screen.

Data from August 2009-May 2012, 16-17/08/2016; 30/10/2016-3/11/2016 and 18/4/2018-25/4/2018 provided by the Met. Office. © Crown Copyright 2009-2012, 2016, 2018, published by the Met. Office.

WETB degrees C Wet bulb temperature, measuring temperature of evaporation 1982 - 2009

Recorded at 0900GMT. Until 2009 used with DRYB to calculate RELH, VAP and DEWP.

Since November 1996, calculated from an automatic Relative Humidity and Temperature sensor. Prior to this measured with a mercury-in-glass sheathed thermometer housed in a naturally aspirating temperature screen, the bulb covered by a cotton wick kept moist from a water reservoir. Discontinued September 2009 and replaced by a HMP45C Relative Humidity and Temperature sensor, to measure relative humidity (RELH), from which VAP and DEWP are now calculated after the method of Buck (1981).

DRYB degrees C Dry bulb Temperature 1982-current date

Recorded at 0900GMT.

Since April 25th 2018, measured by an EE181 E+E Relative Humidity and Temperature probe (E+E Elektronic Corporation, supplied by Campbell Scientific). Prior to this it was measured with an automatic HMP45C Relative Humidity and Temperature sensor. New temperature sensors were installed November 2012.

Before November 1996, recorded with a mecury-in-glass sheathed thermometer housed in a naturally aspirating temperature screen.

Data from August 2009-May 2012; 16-17/08/2016; 30/10/2016-3/11/2016 and 18/4/2018-25/4/2018 provided by the Met. Office. © Crown Copyright 2009-2012, 2016, 2018, published by the Met. Office.

DEWP degrees C Dew point (derived) 1982-2009

Recorded at 0900GMT.

Until August 2009, derived from DRYB and WETB, calculated by the datalogger (see derived variables). Before November 1996 calculated from hygrometric tables.

Since September 2009, available as a derived variable within e-RA, derived from DRYB and RELH calculated after the method of Buck (1981).

GRSMIN degrees C Grass minimum temperature 1982-current date

Recorded at 0900GMT, for the minimum temperature on grass over the previous 24 hours.

Recorded by a thermistor (electronic temperature probe, Campbell Scientific, type 107). Before Nov 1996, recorded manually with a spirit-in-glass with indicator bar minimum thermometer, with cotton sleeve and anti-condensation shield on upper part of the instrument.

Data from 16-17/08/2016 provided by the Met. Office. © Crown Copyright 2016, published by the Met. Office.

Soil temperature under grass

G30T degrees C Soil temperature under grass at 30cm 2012-current date

Recorded at 0900GMT.

Measured by thermistors (electronic temperature probes, Campbell Scientific, type 107), buried in the soil at the appropriate depth.

G30T data from 16-17/08/2016 and 18/4/2018-25/4/2018 provided by the Met. Office. © Crown Copyright 2016, 2018, published by the Met. Office.

G50T degrees C Soil temperature under grass at 50cm 2012-current date
G100T degrees C Soil temperature under grass at 100cm 2012-current date

Soil temperature under bare soil

S10T degrees C Bare soil temperature at 10cm 2012-current date

Recorded at 0900GMT.

Measured by thermistors (electronic temperature probes, Campbell Scientific, type 107), buried in the soil at the appropriate depth.

S10T data from 16-17/08/2016 and 18/4/2018-25/4/2018 provided by the Met. Office. © Crown Copyright 2016, 2018, published by the Met. Office.

S20T degrees C Bare soil temperature at 20cm 1982-current date

Rainfall

RAIN mm Rainfall 1982-current date

Recorded at 0900GMT for the total rainfall over the previous 24 hours.

Since Sept 8th 2020 recorded with an SBS500 tipping bucket rain gauge, funnel diameter 25.2cm and calibrated to tip at 0.2mm, manufactured by Environmental Measurements Ltd (EML), supplied and calibrated by Campbell Scientific. From 1996 until Sept 2020, recorded with electronic tipping bucket rain gauge of 25.4cm diameter, calibrated to tip at 0.2mm, ARG100 manufactured by EML, supplied and calibrated by Campbell Scientific. Before November 1996 recorded manually using a 5" (12.7cm) copper cylindrical rain gauge.

EML state that the "ARG100 rain gauge typically captures over 5% more rainfall than most traditionally-shaped cylindrical gauges due to its unique aerodynamic shape and reduced evaporation-loss properties". This has been found to be the case at Rothamsted, where rainfall in the 5" rain gauge continued to be measured on a twice weekly basis. The 5" gauge at Brooms Barn ceased to be used at the time of automation, so it is not possible to make a comparison.

Data from August 2009-May 2012; 01/10/2014-03/11/2014; 30/10/2016-3/11/2016; 9/11/2016; 18/4/2018-25/4/2018 provided by the Met. Office. © Crown Copyright 2009-2012, 2014, 2016, 2018 published by the Met. Office.

Sunshine

SUN hr Hours of sunshine 1982-current date

Hours of bright sunshine recorded over the previous 24 hours, 0000 to 2400GMT.

Since Jan 15 1998 recorded automatically, calculated using the Campbell-Stokes equation from total radiation measurements using a Kipp and Zonen CM3 thermopile pyranometer. From 2012 calculated using Campbell Scientific's algorithms (Tech Note 18).

Previously measured manually with a Campbell-Stokes sunshine recorder, at 2m above the ground. The sun's rays are focused onto a card (treated to prevent it from catching fire) and the brown scorch mark on the card is then measured. The cards are of varying lengths applicable to the time of year (winter, equinox, and summer).

Radiation

RAD MJ/m2 Total radiation 1982-current date

Total radiation recorded in the previous 24 hours, 0000 to 2400GMT

Total (or global) radiation is total incoming radiation. Recorded automatically using a Kipp and Zonen CM3 thermopile pyranometer. Before November 1996, it was recorded manually.

NETRAD MJ/m2 Net radiation 1998-current date

Net radiation in previous 24 hours, 0000 to 2400GMT.

Net radiation is the balance between incoming and outgoing radiation under outdoor conditions. Since September 2002 it has been measured by a Kipp & Zonen NR-LITE net-radiometer. An automatic Q7 net radiometer was installed in January 1998.

Wind

The weather station is situated approx 30m from the main buildings, which are approx 10m high. This may cause some interference with wind direction and wind speed measurements.
WDIR degrees Wind direction (at 2m) 2012-current date

Recorded at 0900GMT.

Wind direction is shown as an angle (0-360 degrees), going clockwise from North. 360 = North, 90 = East, 180 = South, 270 = West. The reading 0 indicates that there is no wind, ie the windspeed is 0 m/s. A WDIR reading of 0 with a windspeed greater than 0 implies that the WDIR is 360 degrees (North).

Measured by an electronic wind vane (Vector Instruments, W200P) at 2m height.

WINDSP m/s Wind speed (at 10m) 2012-current date

Recorded at 0900GMT.

Windspeed is measured by automatic cup anemometer Vector Insturment type A100R at 2m and adjusted to the standard height of 10m by multiplying by 1.28. Between 24th May 2012 and 11th December 2012, windspeed was a 10 minute average, recorded between 0850 and 0900GMT. Since 2013 it has been a point value recorded at 0900GMT.

Average daily (24 hour) windspeed can be calculated from total daily WINDRUN, correcting for height (see Conversion factors).

WINDRUN km Run of Wind (at 2m) 1982-current date

Recorded at 0900GMT, the run of wind in the previous 24 hours.

Windrun is currently measured by automatic cup anemometer Vector Insturment type A100R at standard height of 2m. Before November 1996 it was manually measured with a cup anemometer at 2m high, with a calibrated counter.

Other

GROUND code State of ground 1982-96 Recorded at 0900GMT. Visual assessment of the state of the ground's surface, using numerical codes based on the Met Office Standard weather codes.
RELH % Relative humidity 2009-current date

Recorded at 0900GMT.

Since April 25th 2018, measured by an EE181 E+E Relative Humidity and Temperature probe (E+E Elektronic Corporation, supplied by Campbell Scientific). Prior to this it was measured with a HMP45C Relative Humidity and Temperature sensor.

Data from September 2009-May 2012; 16-17/08/2016; 30/10/2016-3/11/2016 and 18/4/2018-25/4/2018 provided by the Met. Office. © Crown Copyright 2009-2012, 2016, 2018 published by the Met. Office.

Before September 2009 available as a derived variable within e-RA, derived from WETB and DRYB (see derived variables)

VAP mb Vapour pressure (derived) 1982-2009

Recorded at 0900GMT.

Derived from DRYB and WETB until 2009 (see derived variables). From 2009 available as a dervied variable within e-RA, calculated from RELH and DRYB after the method of Buck (1981).

Key References

1998

  • Jaggard, K. W. , Dewar, A. M. and Pidgeon, J. D. (1998) "The relative effects of drought stress and virus yellows on the yield of sugarbeet in the UK, 1980-95", Journal of Agricultural Science, 130, 337-343
    DOI: 10.1017/s0021859698005371

1991

  • Asher, M. J. C. and Williams, G. E. (1991) "FORECASTING THE NATIONAL INCIDENCE OF SUGAR-BEET POWDERY MILDEW FROM WEATHER DATA IN BRITAIN", Plant Pathology, 40, 100-107
    DOI: 10.1111/j.1365-3059.1991.tb02298.x

For further information and assistance, please contact the e-RA curators, Sarah Perryman and Margaret Glendining using the e-RA email address: era@rothamsted.ac.uk