Cloud radiative forcing in arctic polynyas: parameterization and modelling
Abstract
The number of sites within the Arctic equipped to measure the multitude of variables necessary to force a radiative transfer model is limited to one: the ARM site at Barrow, Alaska. Beyond this, only a handful of Arctic weather stations and a very few shipboard studies have collected data that would satisfy most of the model requirements, and those are either topographically or temporally constrained. Data collection of this order within in polynyas is far rarer, owing to their inaccessibility and variable ice cover. Clearly, in order to accurately parameterize and model surface cloud radiative forcing in Arctic polynyas, additional elements must be assimilated. Combining in situ data collected from several polynyas across the North American Arctic with remotely-sensed measurements, this study evaluates several parameterizations of downwelling short- and longwave radiation used in radiative transfer models. Shipboard and station measurements provide information about cloud type and cover, radiometrically-derived skin temperatures, ozone and radiosonde profiles, aerosol optical depths, and a suite of meteorological variables. Ice cover and type, surface albedo, and cloud top temperatures are supplied by RadarSat, AVHRR, and TOVS data collected in each of the four polynya regions. The union of this data provides a singular look at the evolution of the cloudy boundary layer over a polynya and to what degree clouds force the surface in maritime Arctic environments.
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA.....7240K