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Dataset

 

The Disdrometer Verification Network (DiVeN): particle diameter and fall velocity measurements from a network of Thies Laser Precipitation Monitors around the UK (2017-2019)

Update Frequency: Not Planned
Status: Final
Online Status: ONLINE
Publication State: Citable
Publication Date: 2019-10-29
DOI Publication Date: 2019-10-31
Download Stats: last 12 months

Abstract

Starting in February 2017, a network of 14 Thies™ manufactured Laser Precipitation Monitors (LPMs) were installed at various locations around the United Kingdom to create the Disdrometer Verification Network (DiVeN). The instruments were installed for verification of radar hydrometeor classification algorithms but are valuable for much wider use in the scientific and operational meteorological community.

Every Thies LPM is able to designate each observed hydrometeor into one of 20 diameter bins from >= 0.125 mm to > 8 mm, and one of 22 speed bins from > 0.0 m s-1 to > 20.0 m s-1. A laser and diode receiver operate in tandem; a falling particle will occlude the beam. The duration of the occlusion and the maximum extent (measured by diode voltage) determines the fall velocity and diameter respectively. Using empirically-derived relationships, the instrument classifies precipitation into one of 11 possible hydrometeor classes in the form of a 'present weather code', with an associated indicator of uncertainty. To provide immediate feedback to data users, the observations are plotted in near real time (NRT) and made publicly available on a website within 7 minutes (see linked documentation section). A 'present weather code' is a World Meteorological Organisation (WMO) code used to define the present observatory weather (see linked documentation for the WMO present weather code list).

The instruments belonged to the Met Office but were loaned to the National Centre for Atmospheric Science (NCAS) for the duration of the project. NCAS handle the receiving server for real-time DiVeN data, which is the only route to this dataset. On-site collection of data are not guaranteed in all circumstances. Some of the sites rely on unreliable O2 3G dongles; whilst the Feshie instrument was solar and wind powered and the Coverhead instrument suffered from power / connectivity issues. Any missing data can be explained by these reasons, and are handled appropriately in the files. The data were collated into daily files of 1440 minutes. More information can be found in Pickering et al., 2018, see related documentation.

Citable as:  Natural Environment Research Council; Met Office; Pickering, B.S.; Neely III, R.R.; Harrison, D. (2019): The Disdrometer Verification Network (DiVeN): particle diameter and fall velocity measurements from a network of Thies Laser Precipitation Monitors around the UK (2017-2019). Centre for Environmental Data Analysis, 31 October 2019. doi:10.5285/602f11d9a2034dae9d0a7356f9aeaf45. http://dx.doi.org/10.5285/602f11d9a2034dae9d0a7356f9aeaf45
Abbreviation: Not defined
Keywords: disdrometer, rainfall, precipitation, verification, hydrometeors

Details

Previous Info:
No news update for this record
Previously used record identifiers:
No related previous identifiers.
Access rules:
Access to these data is available to any registered CEDA user. Please Login or Register for an account to gain access.
Use of these data is covered by the following licence: http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/. When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record.
Data lineage:

The resource came into existence to fulfil a need for more reliable hydrometeor type data in the UK (compared with automated stations using a visiometer) in order to verify radar hydrometeor classification algorithms for the UK C-band dual-polarisation radar network, which was upgraded to dual-polarisation 2013-2018.

The recorded disdrometer precipitation data are uploaded in real time to an NCAS server, where it has been converted to a netCDF format. The instrument itself does all the internal processing to generate the extra variables before outputting the data to a user, but the raw particle counts are retained. Raw diode voltages are not an available product.

Data Quality:
No quality control information has been provided for these data by the data provider, nor has any been undertaken by the data centre.
File Format:
Data are NetCDF formatted.

Process overview

This dataset was generated by instruments deployed on platforms as listed below.

Instrument/Platform pairings

NCAS Thies Laser Precipitation Monitor (LPM) number 14 Deployed on: Coverhead Estate
NCAS Thies Laser Precipitation Monitor (LPM) number 1 Deployed on: Chilbolton Atmospheric Observatory (CAO)
NCAS Thies Laser Precipitation Monitor (LPM) number 2 Deployed on: Chilbolton Atmospheric Observatory (CAO)
NCAS Thies Laser Precipitation Monitor (LPM) number 3 Deployed on: University of Reading Atmospheric Observatory
NCAS Thies Laser Precipitation Monitor (LPM) number 4 Deployed on: Cranfield University FAAM Building
NCAS Thies Laser Precipitation Monitor (LPM) number 5 Deployed on: Weybourne Atmospheric Observatory
NCAS Thies Laser Precipitation Monitor (LPM) number 6 Deployed on: Capel Dewi Atmospheric Observatory (CDAO)
NCAS Thies Laser Precipitation Monitor (LPM) number 7 Deployed on: University of Lancaster Hazelrigg Weather Station
NCAS Thies Laser Precipitation Monitor (LPM) number 8 Deployed on: University of Edinburgh GeoSciences Weather Station
NCAS Thies Laser Precipitation Monitor (LPM) number 9 Deployed on: Mountain Weather Information Service Laurieston meteorological site
NCAS Thies Laser Precipitation Monitor (LPM) number 10 Deployed on: Holme Moss meteorological site
NCAS Thies Laser Precipitation Monitor (LPM) number 11 Deployed on: Cairngorm Raingauge and Snow Scale meteorological site
NCAS Thies Laser Precipitation Monitor (LPM) number 12 Deployed on: University of Dundee Druim nam Bo weather station
NCAS Thies Laser Precipitation Monitor (LPM) number 13 Deployed on: Dunkeswell Aerodrome, UK
Output Description None
  • units: min-1
  • long_name: 2D binned grid of particle diameter vs. particle fallspeed, per minute.
  • var_id: size_velocity_distribution
  • names: 2D binned grid of particle diameter vs. particle fallspeed, per minute.
  • units: 1
  • long_name: 5 Minute Averaged Hydrometeor type, defined by Pickering et al. 2019. (+2)
  • var_id: hydrometeor_type_5m
  • names: 5 Minute Averaged Hydrometeor type, defined by Pickering et al. 2019. (+2)
  • units: 1
  • long_name: 5 Minute WMO Tab.4680 Present Weather Code
  • var_id: present_weather_5m
  • names: 5 Minute WMO Tab.4680 Present Weather Code
  • units: %
  • long_name: An index of quality of the measurement, specificaly regarding the Present Weather Code algorithm.
  • var_id: measurement_quality
  • names: An index of quality of the measurement, specificaly regarding the Present Weather Code algorithm.
  • var_id: qc_flag
  • long_name: Data Quality Flag
  • names: Data Quality Flag
  • units: 1
  • long_name: Day
  • var_id: day
  • names: Day
  • units: 1
  • long_name: Day of Year
  • var_id: day_of_year
  • names: Day of Year
  • units: mm
  • long_name: Diameter
  • var_id: diameter
  • names: Diameter
  • units: dBZ
  • long_name: Equivalent radar reflectivity factor for 1 minute.
  • var_id: reflectivity
  • names: Equivalent radar reflectivity factor for 1 minute.
  • units: m s-1
  • long_name: Fallspeed
  • var_id: fallspeed
  • names: Fallspeed
  • units: min-1
  • long_name: Histogram of particle diameter, a.k.a. DSD, per minute.
  • var_id: drop_size_distribution
  • names: Histogram of particle diameter, a.k.a. DSD, per minute.
  • units: min-1
  • long_name: Histogram of particle fallspeed, a.k.a. DVD, per minute.
  • var_id: drop_velocity_distribution
  • names: Histogram of particle fallspeed, a.k.a. DVD, per minute.
  • units: 1
  • long_name: Hour
  • var_id: hour
  • names: Hour
  • units: 1
  • long_name: Hydrometeor type, defined by Pickering et al. 2019. (+2)
  • var_id: hydrometeor_type_1m
  • names: Hydrometeor type, defined by Pickering et al. 2019. (+2)
  • units: mm
  • long_name: Maximum observed diameter of any hail detected for 1 minute.
  • var_id: max_hail_diameter
  • names: Maximum observed diameter of any hail detected for 1 minute.
  • units: 1
  • long_name: Minute
  • var_id: minute
  • names: Minute
  • units: 1
  • long_name: Month
  • var_id: month
  • names: Month
  • units: kg m-2 s-1
  • long_name: Precipitation rate (only for the observed solid hydrometeors) for 1 minute in mm hr-1 (liquid equivalent)
  • var_id: solid_precipitation_flux
  • names: Precipitation rate (only for the observed solid hydrometeors) for 1 minute in mm hr-1 (liquid equivalent)
  • units: kg m-2 s-1
  • var_id: precipitation_flux
  • long_name: Precipitation rate for 1 minute in mm hr-1 (liquid equivalent for solid precipitation)
  • names: Precipitation rate for 1 minute in mm hr-1 (liquid equivalent for solid precipitation)
  • units: 1
  • long_name: Second
  • var_id: second
  • names: Second
  • units: 1
  • long_name: Total number of particles detected in 1 minute
  • var_id: particle_count
  • names: Total number of particles detected in 1 minute
  • units: m
  • long_name: Visibility reduction caused by precipitation at 1 minute intervals. Invalid when not precipitating.
  • var_id: precipitation_visibility
  • names: Visibility reduction caused by precipitation at 1 minute intervals. Invalid when not precipitating.
  • units: 1
  • long_name: WMO Tab.4680 Present Weather Code
  • var_id: present_weather_1m
  • names: WMO Tab.4680 Present Weather Code
  • units: 1
  • long_name: Year
  • var_id: year
  • names: Year

Co-ordinate Variables

  • units: degrees_north
  • standard_name: latitude
  • var_id: latitude
  • long_name: Latitude
  • names: latitude, Latitude
  • units: degrees_east
  • standard_name: longitude
  • var_id: longitude
  • long_name: Longitude
  • names: longitude, Longitude
  • standard_name: time
  • var_id: time
  • names: time
Coverage
Temporal Range
Start time:
2017-02-10T00:00:00
End time:
2019-09-30T22:59:59
Geographic Extent

 
59.2500°
 
-10.7500°
 
2.2500°
 
48.7500°