Detecting moisture transport pathways to the subtropical North Atlantic free troposphere using paired H2O-δ D in situ measurements [Discussion paper]

We present two years of measurements of water vapour (H2O) and its isotopologue ratio (δD, the standardized ratio between H216O and HD16O) made at two remote mountain sites on Tenerife Island in the subtropical North Atlantic. We show that the data – if measured during nighttime – are well representative for the lower/middle free troposphere. We use the measured H2O-δD pairs, together with dust measurements and back-trajectory modelling for analysing the moisture pathways to this region. This study has been conducted in the framework of the project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water), funded by the European Research Council under the European Community’s Seventh Framework Programme (FP7/2007-2013/ ERC Grant agreement number 256961). Aerosol measurements are part of the project POLLINDUST (CGL2011-26259), funded by the Minister of Economy and Competitiveness of Spain. The AERONET sun photometer at Izana (PI: Emilio Cuevas) has been calibrated within AERONET EUROPE TNA supported by the European Community Research Infrastructure Action under the FP7 Capacities programme for Integrating Activities, ACTRIS grant agreement number 262254. Eliezer Sepúlveda is supported by the NOVIA project (Ministerio de Economía y Competitividad of Spain, CGL2012-37505).