Temperature and humidity profiles from a microwave profiler (RPG HATPRO-G3) in Innsbruck (2012-2025)

Abstract

This dataset provides quality-controlled passive microwave radiometer temperature and humidity measurements collected between August 2012 and June 2025. The instrument is installed on the roof of a nine-floor university building in Innsbruck as part of the i-Box project and provides temperature and humidity values at 39 height levels from the height of the instrument up to 10 km.

Dataset Description

1.    Spatial Coverage and Location

The RPG HATPRO-G3 Humidity And Temperature PROfiler (HATPRO), a passive microwave radiometer developed by Radiometer Physics (RPG 2011), is installed on the rooftop of a university building of height 38 m close to the centre of the city of Innsbruck, Austria (612 m above sea level; 47.2643°N, 11.3853°E) as part of the i-Box project (Rotach et al. 2017). The HATPRO measures temperature and humidity at 39 vertical levels, extending up to 10,000 m above the instrument.

2.    Temporal Coverage

The dataset contains HATPRO measurements at 10-minute intervals from 21 August 2012 to 5 June 2025 (ACINN 2025a). Due to frequent instrument breakdowns and maintenance periods, substantial gaps exist, and when all available measurements are summed at 10-minute resolution, the dataset comprises 6.39 years of actual data.

3.    Data Retrieval

Microwave radiometers detect thermal radiation mainly emitted by atmospheric oxygen, water vapour, and liquid water. The measured signal depends on the gases’ distribution and temperature. Because oxygen is uniformly mixed in the troposphere and emissions from water vapour and liquid water are also captured, retrieval algorithms can be used to derive tropospheric profiles (Decker et al. 1978). However, raindrops can distort the signal, making data collected during rainfall unusable (Sheppard 1996; Ware et al. 2004). For this dataset, the retrieval algorithm of Massaro et al. (2015) is applied, offering improvements over the original algorithm provided by the manufacturer.

4.    Quality Flags

An automated quality control procedure was developed for this long-term HATPRO dataset (Scheiber 2025b) to ensure the reliability of temperature and humidity measurements. The main objectives of this QC procedure are to remove unphysical data and filter out measurements affected by rainfall.

Some quality control tests are based on comparisons with a nearby weather station (TAWES Universität Innsbruck) operated by GeoSphere Austria (2025) in cooperation with the Department of Atmospheric and Cryospheric Sciences (ACINN 2025b) that provides a reference dataset close to the surface.

When proximity to the HATPRO instrument is crucial, measurements from the small weather station installed directly on the HATPRO unit are used instead.

Quality flags for temperature and humidity are recorded in binary format and are summarized in Table 1. Each flag applies to all height levels for a given timestep. Overall, 20.9% of temperature measurements and 23.5% of humidity measurements are flagged, with the majority of these cases flagged due to precipitation events. A detailed description of the quality control procedure is provided in Scheiber (2025a).

Table 1: HATPRO data quality flags description.

Flag

Variable

Meaning

0

Temperature and Humidity

Good quality data

1

Temperature and Humidity

Rain flag: data not reliable due to a precipitation event.

2

Temperature

Temperature range flag: retrieved HATPRO temperature outside physically plausible range.

2

Humidity

Humidity range flag: retrieved HATPRO humidity is negative.

4

Temperature

Zigzag flag: “zigzagging” of the HATPRO temperature without the same behaviour in weather station data.

4

Humidity

Pressure flag: HATPRO weather station pressure (used in the humidity retrieval algorithm) differs substantially from the reference weather station.

8

Temperature and Humidity

Level 1 flag: retrieved HATPRO temperature/humidity at Level 1 differs substantially from the reference weather station.

16

Temperature and Humidity

Spike flag: spikes in the HATPRO data.

32

Temperature and Humidity

Unphysical period flag: data shows physically not plausible behaviour over longer periods.

5.    Data File Structure

File format: netCDF.

Data: The netCDF file (HATPRO Innsbruck humidity temperature.nc) contains HATPRO temperature and humidity measurements at each height level with a 10-minute resolution (corresponding to the end of the averaging period) for the entire dataset period, along with the associated quality flags, temperature flag and humidity flag. Timestamps are not continuous; they are only recorded when data for at least one of the two variables is available. In cases where only one variable is measured, the other variable and its corresponding quality flag are set to NaN.

6.    Contact

For questions regarding the HATPRO dataset contact: manuela.lehner|AT|uibk.ac.at.

References

ACINN, 2025a: HATPRO UIBK Met. ACINN Weather Station Portal. https://acinn-data.uibk.ac.at/pages/hatpro-uibk-met.html. Accessed: 19.10.2025.

ACINN, 2025b: TAWES UIBK. ACINN Weather Station Portal. https://acinn-data.uibk.ac.at/pages/tawes-uibk.html. Accessed: 19.10.2025.

Decker, M., E.Westwater, and F. Guiraud, 1978: Experimental Evaluation of Ground-Based Microwave Radiometric Sensing of Atmospheric Temperature and Water Vapor Profiles. Journal of Applied Meteorology, 17 (12), 1788–1795, doi:10.1175/1520-0450(1978)017¡1788:EEOGBM¿2.0.CO;2.

GeoSphere Austria, 2025: GeoSphere Austria data hub. doi: https://doi.org/10.60669/8fya-7x87.

Massaro, G., I. Stiperski, B. Pospichal, and M. W. Rotach, 2015: Accuracy of retrieving temperature and humidity profiles by ground-based microwave radiometry in truly complex terrain. Atmospheric Measurement Techniques, 8 (8), 3355–3367, doi:10.5194/amt-8-3355-2015.

Rotach, M. W., et al., 2017: Investigating Exchange Processes over Complex Topography: The Innsbruck Box (i-Box). Bulletin of the American Meteorological Society, 98 (4), 787–805, doi:10.1175/BAMS-D-15-00246.1.

RPG, 2011: Instrument Operation and Software Guide. Principle or Operation and Software Description for RPG standard single-polarization radiometers. 129 pp.

Scheiber, H., 2025a: Boundary Layer Structures above Innsbruck. Measured by a Passive Microwave Radiometer. University of Innsbruck, Master’s thesis.

Scheiber, H., 2025b: HATPRO Quality Control Script. https://git.uibk.ac.at/c7071114/hatproqualitycontrol.

Sheppard, B. E., 1996: Effect of Rain on Ground-Based Microwave Radiometric Measurements in the 20-90-GHz Range. Journal of Atmospheric and Oceanic Technology, 13 (6), 1139–1151, doi:10.1175/1520-0426(1996)013<1139:EOROGB>2.0.CO;2.

Ware, R., Cimini, D. P. Herzegh, F. Marzano, J. Vivekanandan, and E. Westwater, 2004: Ground-based microwave radiometer measurements during precipitation. Presented at the 8th Specialist Meeting on Microwave Radiometry, 24-27 Feb 2004, Rome, Italy.