John Prytherch, Michael Tjernström
Measurements of near-surface wind speed and direction, temperature, relative humidity, air pressure, shortwave and longwave downwelling radiation, and surface temperature (determined from infrared measurement) from the Eastern Arctic Ocean in July to October 2014.
The dataset provides rare high quality meteorological observations from sea-ice regions of the Arctic Ocean. They enable analysis of meteorological conditions and provide context for other measurements and analysis associated with the expedition.
Measurements are from the MISU weather station installed on icebreaker Oden’s 7th deck at 25 m above sea level during the SWERUS-C3 expedition to the Arctic Ocean. Additional measurements of temperature and humidity were also made on Oden’s foremast at 20 m above sea level. These data were processed as part of the Arctic Clouds in Summer Experiment (ACSE).
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Citation
John Prytherch, Michael Tjernström (2020) Weather data from the MISU weather station during the SWERUS-C3 Arctic Ocean expedition in 2014. Dataset version 3. Bolin Centre Database. https://doi.org/10.17043/oden-swerus-2014-misu-weather-3
References
Tjernström, M., Achtert, P., Shupe, M. D., Prytherch, J., Sedlar, J., Brooks, B. J., Brooks, I. M., Persson, P. O. G., Sotiropoulou, G., Salisbury, D. J. (2019). Arctic summer air-mass transformation, surface inversions and the surface energy budget. Journal of Climate: 32, 769–789. https://doi.org/10.1175/JCLI-D-18-0216.1
Sotiropoulou, G., Tjernström, M., Savre, J., Ekman, A. M. L., Hartung, K., and Sedlar, J. (2018). Warm-air advection and air-mass transformation over melting sea ice in the summer Arctic. Quarterly Journal of the Royal Meteorological Society: 144, 2449–2462. https://doi.org/10.1002/qj.3316
Prytherch, J., Brooks, I. M., Crill, P. M., Thornton, B. F., Salisbury, D. J., Tjernström, M., Anderson, L. G., Geibel, M. C., Humborg, C. (2017): Direct determination of the air-sea CO2 gas transfer velocity in Arctic sea-ice regions. Geophys. Res. Lett., 44. https://doi.org/10.1002/2017GL073593
Sotiropoulou, G., Tjernström, M., Sedlar, J., Achtert, P., Brooks, B. J., Brooks, I. M., Persson, P. O. G., Prytherch, J., Salisbury, D. J., Shupe, M. D., Johnston, P. E., Wolfe, D. (2016): Atmospheric conditions during the Arctic Clouds in Summer Experiment (ACSE): Contrasting open-water and sea-ice surfaces during melt and freeze-up seasons. J. Clim., 29, 8721– 8744. https://doi.org/10.1175/JCLI-D-16-0211.1
Achtert, P., Brooks, I. M., Brooks, B. J., Prytherch, J., Persson, P. O. G., Tjernström, M. (2015): Measurement of wind profiles over the Arctic Ocean from ship-borne Doppler lidar. Atmos. Meas. Tech. 8, 4993-5007. https://doi.org/10.5194/amt-8-4993-2015
Tjernström, M., Shupe, M. D., Brooks, I. M., Persson, P. O. G., Prytherch, J., Salisbury, D. J., Sedlar, J., Achtert, P., Brooks, B. J., Johnston, P. E, Sotiropoulou, G., Wolfe, D. (2015): Warm-air advection, air mass transformation and fog causes rapid ice melt. Geophys. Res. Lett., 42. https://doi.org/10.1002/2015GL064373
Data description
Data from the MISU weather station, averaged over either 1 or 30-minute intervals. Three data formats are available: Matlab (.mat), NetCDF (.nc) and comma separated value (.csv) text, with an accompanying readme (.rtf) file.
Comments
The main components of the MISU weather station (Gill 2D sonic anemometer, Vaisala PTU TRH and pressure sensor, Eppley PIR and PSP downwelling radiation sensors) were mounted mid-ship on the 7th deck forward railing. Two Heitronics KT15.IIp infrared sensors for measurement of surface temperature (managed by University of Leeds) were mounted separately on the 7th deck, to enable measurement of the sea/ice surface to beam of the ship. An additional aspirated Rotronic TRH sensor was mounted at the top of Oden’s foremast.
Winds are measured relative to the ship. The ship acts to distort the wind speed and direction, increasingly so for winds away from bow-on. A computational fluid dynamics (CFD) model of airflow over Oden is used to correct the measured winds for wind directions within 110° of bow on. Due to the significant distortion at the site of the weather station, weather station winds should be treated with caution for wind directions more than 60° from bow on. The ship-relative winds and navigation data are also used to derive ‘true’ wind speed and direction.
Downwelling radiation sensors were subject to icing during the expedition. Ice was removed with regular cleaning. Clear-sky radiation determined from radiosonde measurements and RRTM simulations was used to provide further quality control. A flag is provided to indicate when solar radiation may be affected by shading from the ship superstructure.
Data from the system are combined into a cruise-length file. The data are time-averaged to both 1-minute and 30-minute intervals, to correspond with the micrometeorological averaging periods used for the mast sensors.
These data were processed by Joe Sedlar (CIRES, University of Colorado, Boulder).
The Arctic Clouds in Summer Experiment (ACSE) was a component in the Swedish–Russian–US SWERUS-C3 expedition. The main scientific questions of SWERUS-C3 concerned the linkages between climate, cryosphere, and carbon. ACSE was focused on exploring the role of clouds in shaping the new Arctic climate. Clouds remain a large uncertainty in our understanding of the climate system, in particular in the Arctic. The understanding of the processes involved is poor in part because of a lack of direct observations. The icebreaker Oden was equipped with a suite of in-situ and remote sensing instruments to study these processes in detail, with field work along the Russian Arctic coast on the icebreaker Oden during three months from early summer to early autumn (July 6 to October 14, 2014).
More information about the SWERUS-C3 expedition is available from the Swedish Polar Research Secretariat. See also SWERUS-C3 program website, managed by the Department of Geological Sciences, Stockholm University.
Version history
Version 3
Incorporates updated clear sky radiative fluxes determined from RRTM simulations. Now the clear sky shortwave radiative fluxes are from RRTM_SW using the nearest 5-day mean surface albedo.
Version 2
Initial release. Also known as version 2.1.
Version 1
Not published.