Clouds and beryllium-7

We present a 10-year record of 10 different cloud cover types at three different locations in Scandinavia together with 7Be surface concentration data. The aim is to estimate the degree of correlation, if any, between various cloud types at different latitudes and measured 7Be concentrations. The study matches weekly 7Be 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 7Be 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 7Be 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-7Be (and likely 10Be) correlation to different cloud types.