Results from the MERKUR experiment: Mass budget and vertical motions in a large valley during mountain and valley wind

Summary Based on measurements made in March 1982 in the Inn valley during the MERKUR experiment, an attempt was made to compute the mass budget of a large alpine valley during periods of mountain and valley wind.The computations come from measurements of the alongvalley mass flux and assumptions on the fluxes in the slope layer and tributaries.Vertical motions in the valley's atmosphere have been evaluated from the mass budget computations. These motions, including the subsidence which compensates for daytime upslope winds and the subsidence which compensates for the valley wind flowing into tributaries during the day, are of great importance for the understanding of the thermal circulation.The results allow better estimation of vertical advection, which contributes to the budgets of momentum and energy.With 8 Figures