CO 2 and water vapour exchange between an alpine ecosystem and the atmosphere

Abstract

First results of the European project “ECOMONT” are presented. In a field campaign on Monte Bondone near Trento, Italy, fluxes of H 2O and CO 2 over a composite ecosystem area were measured with scintillation anemometers and an instrumented aircraft. The turbulent fluxes from the aircraft data are discussed. The budget of the fluxes from the aircraft data is evaluated and compared to the scintillation mass fluxes. The budget is formulated for an air volume above a horizontal triangle over a heterogeneous ecosystem of a few square kilometers in the Alps. The budget is based on data obtained from aircraft measurements on different heights. The H 2O-budget consists of four terms: a divergence of the vertical turbulent flux of −1.08 g m −3 h −1, an increase of water vapour with time of +0.25 g m −3 h −1, an advection of dry air of +2.80 g m −3 h −1 and a subsidence of wet air of −1.97 g m −3 h −1. Additionally, exchange rates for H 2O and CO 2 with the vegetation are estimated.