Frost flowers grow on newly-formed sea ice from a saturated water vapour layer. They provide a large effective surface area and a reservoir of sea salt ions in the liquid phase with triple the ion concentration of sea water.
Recently, frost flowers have been recognised as the dominant source of sea salt aerosol in the Antarctic, and it has been speculated that they could be involved in processes causing severe tropospheric ozone depletion events during the polar sunrise. These events can be explained by heterogeneous autocatalytic reactions taking place on salt-laden ice surfaces which exponentially increase the reactive gas phase bromine ("bromine explosion").
We analyzed
tropospheric bromine monoxide (BrO) and the sea ice coverage both measured from
satellite sensors. Our model based
interpretation shows that young ice regions potentially covered with
frost flowers seem to be the source of bromine found in
bromine explosion events and therefore have a large
influence on tropospheric chemistry.
The deposition of salts by frigid concentrations changes the ratios of major sea
water ions. The corresponding implications for the
interpretation of ice core records will be discussed.