Effect of irregular fluctuations in Antarctic precipitation on global sea level

Abstract

One of the reasons for the continuing interest in the global sea level is that secular variations may be caused. by climatic changes. Such a change could, :for example, be an atmospheric warming due to CO, accumulation., Changes in the amount of ice in the major ice sheets. will be reflected in secular variations of sea level; it has, for example, been suggested that ice-shelf, thinning may change the drainage of parts of the Antarctic Ice Sheet Attempts to. monitor climatic change- by measuring global sea level will, however, be complicated by random, fluctuations of the ice volume in the major ice sheets, themselves the consequence of random variations in the ice accumulation rate. Precipitation rates are highly variable, and this also applies to Antarctica', which stores most of the continental ice mass. By means of a simple model for ice flow in the Antarctic, together with proxy data on precipitation variability derived from ice cores, I show that long-term lea-level variations with a standard deviation of roughly 5 cm are to be expected an this account. This `climatic noise' is comparable in magnitude with many of the secular effects now being sought.