Micrometeorological data from an ice-floe site during the high-Arctic ASCOS expedition 2008

Thorsten Mauritsen

Micrometeorological observations were collected from two masts on an ice floe a few hundred meters from the Icebreaker Oden during ice drift of the ASCOS expedition; data are averaged over 10-minute periods. The main instrumentation in the masts consisted of sonic anemometers and two Licor open path gas analyzers at different heights up to 30 m. Additional observations include aspirated and radiation-shielded mean temperature and relative humidity at two levels, up- and downward long- and shortwave radiation at an undisturbed location some distance away, temperature observations at the surface and at a few levels into the snow and ice, and so-called surface heat-flux plates inserted at the interface between snow and ice.

References

Tjernström, M. et al. 2014. The Arctic Summer Cloud Ocean Study (ASCOS): overview and experimental design. Atmospheric Chemistry and Physics, 14, 2823–2869. DOI:10.5194/acp-14-2823-2014

Data description

Data from metalley averaged over 10 minute intervals. Two files are available, a matlab file with a data structure and a netcdf version. The netcdf version contains all relevant information. Thorsten.

Comments

Measurements of subtle meteorological variables, such as gradients of wind and temperature near the surface, turbulence and the corresponding turbulent fluxes of momentum and of sensible and latent heat requires a reasonably homogeneous fetch and are very complicated to perform on a ship due to the flow distortion. Hence a micrometeorological observatory was deployed on the during the ice drift ice, some distance away from the ship. This site was labeled “Met Alley”, since the deployment was along an “alley” approximately away from Oden, to minimize the ship’s blocking sector; the site was manned 24/7. The site consisted of two masts; one 15-m mast with instruments at five levels and one single level 30-m mast. The main instrumentation in the masts consisted of sonic anemometers and two Licor open path gas analyzers. Additional observations include aspirated and radiation-shielded mean temperature and relative humidity at two levels, up- and downward long- and shortwave radiation at an undisturbed location some distance away, surface temperature observations at the surface and a few levels into the snow and ice, and so-called surface heat-flux plates and a few levels from the surface and into the snow; the lowest of these at the interface between snow and ice. Primary problems with the mast observations were icing of the sensors; the lowest instruments in the 15-m mast, within reach from the surface were more easily maintained while the uppermost instrument in the 30-m mast was heated and has an almost unbroken record. Problems with the surface temperature observations is potential solar heating of uppermost levels, and melting and accumulation of new snow, making the exact positioning of the sensors uncertain; they were repeatedly repositioned. Also for radiation, the primary problem was icing on the upward-facing domes, that had to be cleaned manually. All the data is contained in one single file.

Original address: http://www.ascos.se/index.php?q=node/267

Files:
metalley_data-v1.mat (3.78 MB)
ascos_Metalley.nc (4.56 MB)