Integrated column water vapor and liquid water paths from expedition SAS, Arctic Ocean, 2021

Michael Tjernström, John Prytherch, Sonja Murto

Estimates of vertically integrated water-vapor and liquid-water paths are obtained from measurements with a HATPRO5 passive microwave radiometer deployed on the Swedish icebreaker Oden during the Synoptic Arctic Survey (SAS) expedition in the central Arctic Ocean, 31 August to 19 September, 2021.

The radiometer was installed on the roof of a 4th deck container, at about 20 m above sea level, located on the forward starboard side of Oden's superstructure.

Measurements ran continuously during the whole expedition but with a brief period of malfunction.

AtmosphereWeather observationsCloudsWater vaporPrecipitable waterCloud liquid waterArcticArctic OceanMeteorologyAtmosphereWeather observationsSynoptic Arctic SurveySAS 2021 expeditionIcebreaker Oden

Name

Version

Citation

Data description

This dataset includes one matlab (.mat) file with the time series of vertically integrated water-vapor path, sometimes also known as precipitable water, and vertically integrated liquid-water path, derived from the passive microwave radiometer irradiances. The data is provided in a matlab struct and the file size is ~35 MB. A list of variable names, with short explanations and units is provided below.

Variables

Primary variables are the water-vapor and liquid-water paths.

• Primary variables
  • day_of_year Decimal day of year (in UTC) [time]
  • year Year - constant [time]
  • month Month of the year [time]
  • day Day of the month [time]
  • hour Hour of the day (in UTC) [time]
  • minute Minutes of the hour [time]
  • second Seconds of the minute [time]
  • integrated_water_vapor Integrated water vapor (kg m⁻²)
  • liquid_water_path Liquid water path (g m⁻²)
  • flag_for_rain Data flag for rain; related to liquid water path. 0 = no rain, 1 = raining

Comments

Measurement system

The data was obtained from a Radiometer Physics microwave radiometer (HATPRO5) that passively measures the atmospheric irradiance at a number of microwave frequencies.

Quality control

Only a cursory quality control was applied, except for removing data (replacing with NaN) from around 15 UTC on 9 September to around 14 UTC on 10 September due to a faulty calibration profile. While Oden left the ice on 12 September and the expedition ended on 15 September, the data extends through the transit until 19 September.

The water vapor measurements are insensitive to the presence clouds, however, the liquid water path measurement is sensitive to water droplets or snow that may reside on the on the surface of the instrument. A fan blows heated air across its surface to remove droplets or snow; a rain sensor indicates if rain was present.

Data creators' roles

The instrument system was continuously logging and was monitored by the Stockholm University Meteorology team onboard Oden:

• John Prytherch (Work package leader on board)
• Sonja Murto (operator)

Michael Tjernström (also Stockholm University) was Work package leader on shore and is data creator.

The expedition

The data were collected in summer 2021 from Swedish icebreaker Oden during the Synoptic Arctic Survey (SAS) 2021 expedition organized by the Swedish Polar Research Secretariat.

Project

Synoptic Arctic Survey (SAS) 2021 expedition.

Publisher

Bolin Centre Database

License

First name

Michael

Last name or organisation

Tjernström

Email address

michaelt@misu.su.se

Address

Department of Meteorology; Stockholm University

Postal code

SE-106 91

City

Stockholm

Country

Sweden

GCMD science keyword

Earth science > Atmosphere

GCMD location

Ocean > Arctic Ocean

Dataset language

English

Begin date

2021-07-31

End date

2021-09-19

DOI

Time