Volume 1 - The Atmospheric Studies Group at TRC

Table 4-8 lists meteorological data used in the SEA.DAT file after the adjustments
are made. The lateral turbulence intensity (I y ) is used in the CALPUFF turbulence
profile file.
The UP.DAT (upper-air) input file is designed to provide CALMET with vertical
profiles of wind and temperature representative of the onshore flow at 00Z (mid to
late afternoon) during the tracer sampling. Both 00Z and 12Z vertical profiles of
wind and temperature are developed for four levels: surface, 10m, overwater mixing
height, and model-top (3000m). The 00Z wind speed at 7m is extended to levels up
to the mixing height using a stability-class-dependent power-law profile (A,B=0.07;
C=0.10; D,E,F=0.15) and the speed at the model-top is set to that at the mixing
height. The surface wind speed is set to that at 10m, which has been adjusted from
the anemometer height to 10m. Wind direction at all levels equals the release wind
direction. Temperature at the surface equals the air temperature in the SEA.DAT
file, and temperature aloft is computed from this using the temperature gradient
dT/dz (in the SEA.DAT file) up to the overwater mixing height. The default
CALMET temperature gradient -0.0045 ºK/m is used above the mixing height.
Pressure is assumed to be 1013 mb at the surface, and decreases with height at 0.1
mb/m.
Oresund, Denmark/Sweden
Description
The tracer dispersion study over the strait of Oresund was conducted between the
coasts of Denmark and Sweden during nine test days between May 15 and June 14,
1984 (Mortensen and Gryning, 1989). SF 6 was released as a nonbuoyant tracer from
a tower at either 95m above the ground on the east side of the strait of Oresund
(Barseback, Sweden) or 115m above the ground on the west side of the strait of
Oresund (Gladsaxe, Denmark), and was sampled at arcs set up along the opposite
shore and at distances 2-8 km inland. The strait is about 20km wide, and the flow
was not always perpendicular to its axis, so transport distances vary between 22 and
42 km. Air-sea temperature differences were as large as 6˚C to 8˚C in five of the
experiment-days with warm air being advected over colder water, and 2˚C to –2˚C in
the other four experiment-days. On each experiment-day, the tracer release started
about three hours before the samplers were turned on, and the sampling lasted for one
hour. Sampling usually occurred between 1100 and 1200 CET, but was as late as
1330 to 1430 CET.
Meteorological data included in the study were obtained from synoptic stations, a
lighthouse in the strait, meteorological towers and masts, SODARS, three-hourly
radiosondes, and occasional minisondes released from a boat in the strait. These data
and the tracer release and sampling data are distributed on CD in a general magnetic
Final Report Vol.1 48