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Ice albedo and sea ice classification

 


The total albedo is defined as the ratio of the integrated outgoing short wave (250 - 2500 nm) radiation and the intergrated incoming short wave radiation.
The albedo of polar regions varies from that of open water (0.05) to that of new snow (0.90), and encompasses the entire range of albedos found on the surface of the planet. This is illustrated in a picture taken by Hajo Eicken at SHEBA. Albedo is variable on many spatial scales. It is well possible that the variability on a small scale (less than a square kilometer) is larger than that between the large scale albedo of the Arctic versus the Antarctic.
Albedo is a very crucial parameter in the study of global climate because of its potential positive feed back effect (warmer climate > more open water > lower albedo > further warming).

First, a classification of the different sea ice types - using the albedo as a parameter - is attempted. The existing ice nomenclature is already largely based on albedo. This is natural because the albedo is what determines what an observer sees and is therefore the most straight forward classifier.

A second section contains a list of albedos as a function of various climatic parameters (ice thickness, roughness, snow cover). The goal is to provide a rough idea of ice albedo values, given a knowledge of parameters like ice thickness, precipitation, wind speed and fetch. Such a classification could eventually be useful for large scale climate models.