RS92 GRUAN Data Product Version 2
DOI for scientific and technical data
Sommer, Michael; Dirksen, Ruud; Immler, Franz. (2012): RS92 GRUAN Data Product Version 2 (RS92-GDP.2). GRUAN Lead Centre. DOI:10.5676/GRUAN/RS92-GDP.2
GRUAN Lead Centre (at Deutscher Wetterdienst)
Creators / Authors
Sommer, Michael; Dirksen, Ruud; Immler, Franz
Description / Summary
This dataset comprises reference radiosoundings performed with the Vaisala RS92. Reference in this case means that:
- all known biases are corrected for
- best possible vertically resolved uncertainty estimates
- well-documented correction algorithms
- extensive meta data collection
The GCOS (Global Climate Observing System) Reference Upper-Air Network (GRUAN) data processing for the Vaisala RS92 radiosonde was developed to meet the criteria for reference measurements. These criteria stipulate the collection of metadata, the use of well-documented correction algorithms, and estimates of the measurement uncertainty. An important and novel aspect of the GRUAN processing is that the uncertainty estimates are vertically resolved. The algorithms that are applied in version 2 of the GRUAN processing to correct for systematic errors in radiosonde measurements of pressure, temperature, humidity, and wind, as well as how the uncertainties related to these error sources are derived. Currently, the RS92 is launched on a regular basis at 13 out of 15 GRUAN sites.
An additional GRUAN requirement for performing reference measurements with the RS92 is that the manufacturer-prescribed procedure for the radiosonde's preparation, i.e. heated reconditioning of the sensors and recalibration during ground check, is followed. In the GRUAN processing however, the recalibration of the humidity sensors that is applied during ground check is removed. For the dominant error source, solar radiation, laboratory experiments were performed to investigate and model its effect on the RS92's temperature and humidity measurements.
GRUAN uncertainty estimates are 0.15 K for night-time temperature measurements and approximately 0.6 K at 25 km during daytime. The other uncertainty estimates are up to 6 %RH for humidity, 10–50 m for geopotential height, 0.6 hPa for pressure, 0.4–1 m/s for wind speed, and 1° for wind direction. Daytime temperature profiles for GRUAN and Vaisala processing are comparable and consistent within the estimated uncertainty. GRUAN daytime humidity profiles are up to 15 % moister than Vaisala processed profiles, of which two-thirds is due to the radiation dry bias correction and one-third is due to an additional calibration correction.
Redundant measurements with frost point hygrometers (CFH and NOAA FPH) show that GRUAN-processed RS92 humidity profiles and frost point data agree within 15% in the troposphere. No systematic biases occur, apart from a 5 % dry bias for GRUAN data around -40 °C at night.
14.2 GiB (2015-02-01)
Dirksen, R. J., Sommer, M., Immler, F. J., Hurst, D. F., Kivi, R., and Vömel, H. (2014): Reference quality upper-air measurements: GRUAN data processing for the Vaisala RS92 radiosonde, Atmos. Meas. Tech., 7, 4463-4490, doi:10.5194/amt-7-4463-2014.
GRUAN-TD-4: Brief Description of the RS92 GRUAN Data Product (RS92-GDP), Michael Sommer, Ruud Dirksen and Christoph von Rohden, v2.0 (2016-02-11).
Spatial and Temporal Coverage (Availability)
- Availability of GRUAN data product RS92-GDP.2 at GRUAN sites
Dataset includedes Vaisala RS92 soundings of following GRUAN sites:
- BAR - Barrow (US), 2009-01-01 to present
- BEL - Beltsville (US), 2012-10-16 to present
- BOU - Boulder (US), 2011-06-15 to present
- CAB - Cabauw (NL), 2011-01-01 to present
- LAU - Lauder (NZ), 2012-12-11 to present
- LIN - Lindenberg (DE), 2008-12-01 to present
- MAN - Manus (PG), 2011-01-01 to 2014-07-06
- NAU - Nauru (NR), 2011-01-01 to 2013-08-26
- NYA - Ny-Alesund (NO), 2006-05-20 to present
- PAY - Payerne (CH), 2012-09-23 to present
- POT - Potenza (IT), 2011-02-23 to present
- SGP - Lamont (US), 2009-01-01 to present
- SOD - Sodankylä (FI), 2010-09-10 to present
- TAT - Tateno (JP), 2009-12-14 to present
Dataset details and ordering
- Before accessing the data please register yourself on our website or our newsletter.
- Immler, F. J.; Dykema, J.; Gardiner, T.; Whiteman, D. N.; Thorne, P. W. and Vömel, H., Reference Quality Upper-Air Measurements: guidance for developing GRUAN data products. Atmospheric Measurement Techniques, 2010, 3, 1217–1231, doi:10.5194/amt-3-1217-2010; pdf (PDF)
- Reference measurement specifications - A guideline for upper-air reference measurements, Presentation Payerne 2010 (ICM-2), Franz Immler, John Dykema, Tom Gardiner, David Whiteman, Peter Thorne, Holger Vömel; Presentation (PDF)