naa a22 4500 528794485 20180925065149.0 cr unu---uuuuu 180925s2018 xx s 000 0 eng 1867-8610 10.5194/amt-2018-69 doi (BORIS)oai:boris.unibe.ch:120069 620 ddc WIRA-C: A compact 142-GHz-radiometer for continuous middle-atmospheric wind measurements [Elektronische Daten] [Jonas Hagen, Axel Murk, Rolf Rüfenacht, Sergey Khaykin, Alain Hauchecorne, Niklaus Kämpfer] publishedVersion openAccess eu-repo Ground-based microwave wind radiometry provides a method to measure horizontal wind speeds at altitudes between 35 and 75 km as it has been shown by various previous studies. No other method is capable of continuously delivering wind measurements in this altitude region. In this paper, we present the WIRA-C (WInd Radiometer for Campaigns) instrument that observes the 142.17504 GHz rotational transition line of ozone with a high spectral resolution using a low noise single side band heterodyne receiver. Because the emitting molecules are drifting with the wind, the line is Doppler shifted. Together with the pressure broadening effect, this allows the retrieval of altitude resolved wind profiles. The novel WIRA-C instrument represents the newest development in microwave wind radiometry. The main improvements include the compact structure, lower noise and an advanced retrieval setup. This paper describes the instrument and the data processing with a focus on the retrieval that takes into account a three-dimensional atmosphere and has never been used in ground-based radiometry before. The retrieval yields profiles of horizontal wind speeds with a 12 hour time resolution and a vertical resolution of 10 km for zonal and 10 to 15 km for meridional wind speeds. We give an error estimate that accounts for the thermal noise on the measured spectra and additionally estimate systematic errors using Monte Carlo methods. WIRA-C has been continuously measuring horizontal wind speeds since one year at the Maïdo observatory on La Réunion Island (21.4°S, 55.9°E). We present the time series of this campaign and compare our measurements to model data from the European Centre for Medium-range Weather Forecasts (ECMWF) and coincident measurements of the co-located Rayleigh-Mie Doppler wind lidar. We find a good agreement between our measurements and the ECMWF operational analysis for the time series, where many features are present in both datasets. The wind profiles of the coincident WIRA-C and lidar observations are consistent and agree within their respective uncertainties for the lidar measurements with long integration times. Hagen Jonas joint author Murk Axel joint author Rüfenacht Rolf joint author Khaykin Sergey joint author Hauchecorne Alain joint author Kämpfer Niklaus joint author Atmospheric Measurement Techniques. Discussions pp. 1-30 1867-8610 https://boris.unibe.ch/120069/1/4795.pdf text/html WWW-Backlink auf das Repository 1 info:eu-repo/semantics/article boris PeerReviewed boris peerstatus BORIS 856 40 https://boris.unibe.ch/120069/1/4795.pdf text/html WWW-Backlink auf das Repository BORIS 700 1- Hagen Jonas joint author BORIS 700 1- Murk Axel joint author BORIS 700 1- Rüfenacht Rolf joint author BORIS 700 1- Khaykin Sergey joint author BORIS 700 1- Hauchecorne Alain joint author BORIS 700 1- Kämpfer Niklaus joint author BORIS 773 0- Atmospheric Measurement Techniques. Discussions pp. 1-30 1867-8610 BK010053 XK010053 XK010000 BORIS BORIS BORIS info:eu-repo/semantics/article openAccess