Hungjui 2015: Evaluation of humidity correction methods for Vaisala RS92 tropical sounding data


This GRUAN relevant paper was published. Please have a look on the following abstract.

Hungjui 2015: Hungjui Yu, Paul E. Ciesielski, Junhong Wang, Hung-Chi Kuo, Holger Vömel, and Ruud Dirksen, 2015: Evaluation of humidity correction methods for Vaisala RS92 tropical sounding data, J. Atmos. Oceanic Technol.,doi: 10.1175/JTECH-D-14-00166.1

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A paper on correction of MEISEI radiosonde humidity data


We have recently published the following paper.

Sugidachi, T., and M. Fujiwara (2013), Correction of the stepwise change observed at 0C in Meisei RS2-91, RS-01G, and RS-06G radiosonde relative humidity profiles, Journal of the Meteorological Society of Japan, 91(3), 323-336, doi:10.2151/jmsj.2013-306.[link] Read the rest of this entry »

Pre-launch procedures for RS92 soundings


Attached is a document describing the requirements for GRUAN station regarding the pre-launch procedures for routine soundings with Vaisala RS92 radiosondes.  In order to obtain high data quality, ensure long term stability,  and to make sure that measurement uncertainties are within the ranges that are reported in the product files, it is important that some ground checks are made before launch in the way described in this document and that the meta-data are reported to the GRUAN lead centre.

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LAPBIAT2 campaign in Sodankylä/Finland


The GRUAN station FMI-ARC in Sodankylä Finland organized an atmospheric sounding campaign in early 2010, which included participants from several countries. The first phase of the campaign was focussing on radiosonde inter-comparisons that were carried out in January-February 2010. Different commercial and research grade in situ instruments were launched with a focus on the comparison of humidity and temperature measurements in the troposphere and stratosphere.

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FAQ-08: What is state-of-the-art in terms of upper-air RH measurements?


Currently the only balloon borne sounding instruments capable of measuring water vapour in the tropopause region and the stratosphere are the Cryogenic Frostpoint Hygrometer (CFH, and the closely related NOAA frostpoint hygrometer) and Fluorescent Advanced Stratospheric Hygrometer (FLASH). GRUAN encourages the development of new instruments and will allow the use of other sondes capable of measuring stratospheric water vapour as they come online. For middle and upper tropospheric water vapour a number of radiosonde sensors may be used, however, a careful analysis is required and will be done, to remove any systematic biases and to reduce random errors. Several assessments and comparisons are currently under way and will be available in the future.

GRUAN operations: Suggestion to do regular parallel ascents


Franz Immler wrote:

During the Lindenberg meeting it was agreed that among other things GRUAN station were required to conduct

1 x weekly production radiosonde with the best technology currently available (GCOS-121)

this suggestion has already often been argued about and is certainly one of the weaker points in the current concept of GRUAN. It obviously refers to an commercially available standard radiosonde which is currently launched at most sites 2 or even 4 times a day anyway. Even though some plans referring to extended ground check and alike are being discussed, it is currently not clear what should be the benefit of the additional launch of such an instrument.

What I suggest therefore, is to launch (at least) once a week two different high quality radiosondes on one balloon. Every GRUAN station can select one additional type of radiosonde to what they regularly start anyway and conduct a parallel launch of the two radiosondes once a week, better twice a week, one day and one night time. In principal every station can choose any radisonde they like but it is recommended to seek guidance from the lead centre.

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