Michael Tjernström, Sonja Murto, Michail Karalis, John Prytherch
Profiles of temperature and humidity are obtained from an RPG HATPRO5 microwave radiometer deployed on the roof of a container on the 4th deck of Oden during the expedition ARTofMELT (Atmospheric Rivers and the Onset of Arctic Melt) in the Fram Strait, operating continuously from 7 May, 2023, until 14 June, 2023.
This data is the direct profile output from the instrument and provides different data in different files.
Corresponding complete, quality controlled and user friendly datasets with corrected data are available separately.
Download data
Citation
Michael Tjernström, Sonja Murto, Michail Karalis, John Prytherch (2024) Temperature and humidity profiles from microwave radiometer during expedition ARTofMELT, Arctic Ocean, 2023 — raw data. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/oden-artofmelt-2023-microwave-profiles-raw-1
References
Tjernström M, Murto S, Karalis M, Prytherch J (2024) Temperature and humidity profiles from microwave radiometer during expedition ARTofMELT, Arctic Ocean, 2023. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/oden-artofmelt-2023-microwave-profiles-1
Tjernström M, Murto S (2024) Scripts for concatenating, processing NetCDF native output files and creating final netCDF files from HATPRO microwave-profiler observations, from the expedition ARTofMELT, Arctic Ocean, 2023. Software version 1.0.0. Bolin Centre Code Repository. https://doi.org/10.57669/oden-artofmelt-2023-microwave-profiles-1.0.0
Data description
This dataset is provided zipped into one zip-file with four folders, each including a set of daily NetCDF (.nc) files. Total file size is about ~400 MB (compressed 53 MB).
The observations stem from microwave irradiances but is converted to temperature and humidity profiles in different observation modes. The instrument has two modes of observing:
- vertical stare, with higher temporal resolution but less vertical accuracy,
- scanning in the vertical, with less temporal resolution and better vertical resolution.
The latter is sometimes referred to as a "boundary-layer mode". In this dataset, these are defined into three types: TPC, TPB and TMP. TPC are pure vertical-stare mode observations while the TPB-results comes from vertical scanning and TMP is an optimized combination of both. Both relative and absolute humidity are contained in the same files.
A list of all variable names, with short explanations and units is provided below.
Temperature variables
Files are named as YYMMDD.CMP.TPC.NC in folder rawTMP, or YYMMDD.TPC.NC in folder rawTPC, or YYMMDD.TPB.NC in folder rawTPB.
- Primary variables Temp
time Instrument time (s) [time] altitude Altitude of observations (m) [height] RF Rain flag, o = no rain, 1 = rain [time]T_prof Temperature from instrument (K) [time/height]
Humidity variables
Files are named as YYMMDD.HPC.NC in folder rawRH.
- Primary variables Hum
time Instrument time (s) [time] altitude Altitude of observations (m) [height] RF Rain flag, o = no rain, 1 = rain [time]AH_prof Absolute humidity from instrument (g m⁻³) [time/height]RH_prof Realtive humidity from instrument (%) [time/height]
Dimensions
Dimensions for the fields are time and height.
Comments
Measurement system
The data is obtained from an RPG HATPRO5 microwave radiometer. This is a passive instrument detecting microwave radiation emitted by the atmosphere in a number of wavelengths. Profiles of temperature and humidity are retrieved from the microwave irradiances using a proprietary neural network, trained on reanalysis of Arctic profiles (ERA5).
The instrument has two modes of observing: vertical stare and scanning in the vertical. For the vertical-stare mode, well-defined weighting functions are utilized by scanning over several nearby frequencies. When the instrument is scanning in the vertical, the atmospheric path is progressively increased as the zenith angle increases and the maxima of the weighting functions are thereby shifted lower, hence increasing the resolution in the lower parts of the atmosphere. The latter is sometimes referred to as a "boundary-layer mode". The normal continuous mode for the instrument is the vertical stare. Every 15 minutes, this is briefly interrupted by the vertical-scan mode; however, this is only relevant for temperature profiles.
Quality control
This is the raw data directly from the instrument and no additional quality control is applied.
Associated processed data and code
A concatenated, packed and corrected dataset derived from these data is available Tjernström et al. (2024). Computer codes, in Matlab and Python that were used to derive the dataset in NetCDF format using these raw data is also available Tjernström and Murto (2024).
Data creators' roles
The instrument system was continuously logging and was monitored by the Stockholm University Meteorology team onboard Oden:
- Michael Tjernström (chief scientist and dataset creator)
- Sonja Murto (operator)
- Michail Karalis (operator)
John Prytherch (also Stockholm University) is responsible for the instrument system.
The expedition
Data were collected during the ARTofMELT 2023 expedition on board the Swedish icebreaker Oden, which was organized by the Swedish Polar Research Secretariat from 8 May through 14 June, 2023.