Clouds and beryllium-7

Abstract

We present a 10-year record of 10 different cloud cover types at three different locations in Scandinavia together with Be-7 surface concentration data. The aim is to estimate the degree of correlation, if any, between various cloud types at different latitudes and measured Be-7 concentrations. The study matches weekly Be-7 data to cloud raster data from high resolution multispectral satellite sensors recorded on a monthly basis between 1991 and 2001. The results are presented as a Be-7 correlation coefficient and show a consistent pattern with small variations across the latitudes and rather large variations between the different cloud classes. The strongest coherence is inverse and associated with Be-7 and high-level clouds (cumulonimbus and nimbostratus), generally, at low latitudes while mid-level clouds (altocumulus, altostratus and cumulus congestus) show little (insignificant) correlation. Despite variable correlation trends, merging of the two data sets has proven valuable in order to understand aerosols-Be-7 (and likely Be-10) correlation to different cloud types.