| Autor: |
Galley, R.J., Else, B.G.T., Geilfus, Nicolas-Xavier, Hare, A.A., Babb, D., Papakyriakou, T.N., Barber, D.G., Rysgaard, Søren |
| Jazyk: |
angličtina |
| Rok vydání: |
2015 |
| Zdroj: |
Galley, R J, Else, B G T, Geilfus, N-X, Hare, A A, Babb, D, Papakyriakou, T N, Barber, D G & Rysgaard, S 2015, ' Micrometeorological and thermal control of frost flower growth on young sea ice ', Arctic Institute of North America. Research Paper, vol. 68, no. 1, pp. 79-92 . https://doi.org/10.14430/arctic4457 |
| DOI: |
10.14430/arctic4457 |
| Popis: |
Frost flowers are transient crystal structures that form on new and young sea icesurfaces. They have been implicated in a variety of biological, chemical and physicalprocesses and interactions with the atmosphere at the sea ice surface. We describethe atmospheric and radiative conditions and the physical and thermal properties ofthe sea ice and atmosphere that form, decay and destroy frost flowers on young seaice. Frost flower formation occurred during a high-pressure system that caused airtemperatures to drop to -30°C, with relative humidity of 70% (an under saturatedatmosphere), and very calm wind conditions. The sea ice surface temperature at thetime of frost flower initiation was 10-13°C warmer than the air temperature. Frostflowers grew on nodules raised above the mean surface height by 5 mm, which were 4-6°C colder than the bare, brine-wetted, highly saline sea ice surface that provided the necessary moisture. The cold nodules created potential water vapour super saturation zones above them with respect to air over the brine skim. Frost flowers formed and grew overnight in the absence of shortwave radiation, while the net long wave radiation was negative and dominated the net all-wave radiation balance at the surface. The observed crystal habits of the frost flowers were long needles, betraying their origin from the vapour phase at temperatures between -20°C and -30°C. After a night of growth, frost flowers decayed associated with increased solar radiation, a net surface radiation balance of 0 W m-2, increased air and surfacetemperatures, increased wind speed, and decreased relative humidity. We hypothesize that these conditions increased vertical mixing, which eroded near-surface water vapour saturation and initiated sublimation. The frost flowers were finally rapidly destroyed by snowfall. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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