Correlation of7BE concentrations in surface air and precipitation with the solar cycle

As a natural tracer the cosmic-rayproduced 7Be has proven to be useful for studying atmospheric transport mechanisms. It is well known that the concentration of 7Be in ground level air and precipitation shows seasonal variations. Feely et. al. [1] reported that the variations in the concentration of 7Be are due to at least four factors: the rate of exchange between the stratosphere and the troposphere, the rate of vertical mixing within the troposphere, the transport of air masses from middle to higher latitudes, and variations in the rainfall rate. We have determined at Munich-Neuherberg the seasonal variations of the 7Be concentrations [2, 8] and the long-term variations of the an