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Spectral Analysis of wind time-series data obtained with the
Boundary Layer Instrument Package (BLIP) during the Barbados
Oceanographic and Meteorological Experiment (BOMEX) in 1969
shows the spectra to be contaminated by ship and balloon motion
only at the very high frequencies (0.11 to 0.07 Hz). Spectra
for undisturbed weather show the existence of weak eddies with
wavelengths centered near 300 m, while those for disturbed
conditions indicate energetic two-dimensional eddies with
wavelengths of up to several hundred meters. One of the
objectives of the Barbados Oceanographic and Meteorological
Experiment (BOMEX), held in the summer of 1969, was to gather
information about the marine tropical planetary boundary
layer. Since the experiment was to take place on the open sea,
standard instrumentation and techniques could not be used, The
need for specially designed instrumentation gave birth to the
Boundary Layer Instrument Package (BLIP), which was developed
for BOMEX by the U niversity of Wisconsin. The BLIP is a
modified radiosonde that was launched by a tethered balloon
during the first three BOMEX observation periods from the four
corner ships and from the Oceanographer and Mt. Mitchell during
the fourth observation period. It consist of a three cup
anemometer mounted on an A-frame that acts as a wind vane, with
temperature, humidity, and pressure sensors contained in a
package attached to the bottom of the frame. A detailed
description of the instrumentation has been given by Almazan
(1972). The data obtained by the BLIP are likely to be
contaminated by ship movement, balloon motion, and the
interaction between the balloon and the tether line. The
purpose of this study is to separate the effects of such motion
from meteorological scales of motion using spectral analysis of
BLIP data for both undisturbed and disturbed weather
conditions.
[Source: Canadian Geospatial Data Infrastructure]
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