Over the past two years, we have conducted several experiments in which we grew frost flowers in a controlled laboratory environment.
In 1994 we demonstrated a technique to grow frost flowers in a small salt water tank in a cold room. Several important properties of the frost flowers and the ice surface were recorded, including the presence of a highly saline slush layer underlying the flowers. Our paper, A laboratory study of frost flower growth on the surface of young sea ice (Martin, Drucker and Fort, 1995), describing this experiment and its results was published in the Journal of Geophysical Research in April 1995.
In 1994-5 we repeated the frost flower experiments for a sequence of different temperatures, and demonstrated a number of temperature dependent properties of frost flowers. In particular, we showed that frost flowers grown at different temperatures exhibit a variety of crystal structures, and that the lateral growth rate is exponentially related to the temperature gradient. In addition, we measured the radiometric surface temperature of bare and flower-covered ice under several different conditions and showed that the surface appears much cooler to a radiometer when frost flowers are present. This work was done with the collaboration of Yanling Yu of the University of Washington's Applied Physics Laboratory (APL). Our paper entitled The temperature dependence of frost flower growth on laboratory sea ice and the effect of the flowers on infrared observations of the surface (Martin, Yu and Drucker, 1996) describes this experiment.
Also in 1995, we participated in a joint experiment at the US Army Corps of Engineers' Cold Regions Research and Engineering Laboratory (CRREL) with other researchers from CRREL and from NASA's Jet Propulsion Laboratory (JPL). In this experiment the radar backscatter of the ice surface was measured during the growth of the frost flowers in order to investigate the observed increase in radar brightness caused by the flowers. This work is described in A laboratory study of the effect of frost flowers on C band radar backscatter from sea ice (Nghiem et. al., 1997) This work is important in the use and analysis of Synthetic Aperature Radar (SAR) imagery.