Katabatic winds at Hells Gate

Measurements performed at Hells Gate in the austral summers 1993-1994, 1994-1995, 1995-1996, 1996-1997, 1997-1998, 2001-2002 with three three-axial fast response Sonic Anemometers GILL RESEARCH, one three-axial fast response Sonic Anemometer KAJIO DENKI, one three-axial Sonic Anemometer METEK, three slow response impact Anemometers SITEP, three fast response Kripton Lamp Igrometers CAMPBELL KH20, three fast response Thermometers and Igrometers SITEP, one global Solarimeter Sitep, three Ice Thermometers, two Barometers SETRA, a Barometer SITEP, two Microbarometers SETRA (signal filtered before acquisition with low-pass Bessel 50 sec filter - during austral summers 2001-2002).

The scanning time interval is of about 1/20 sec for the three-axial Sonic Anemometers; 1/10 sec for the Kripton Lamp Igrometers CAMPBELL KH20; 1/4sec for the SITEP Anemometers; 60sec for slow response instruments (Thermometers, Igrometers, Solarimeter and Barometers); 1/10 sec for the Microbarometer SETRA without low-pass Bessel 50 sec filter and 10 sec with low-pass Bessel 50 sec filter. Turbulent fluxes of mechanical momentum, sensible and latent heat into the first 10 meters, were evaluated by means of the eddy correlation methodology.