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The Solar Eclipse: 11 August 1999 Research performed for Cluj
/ Romania by BITNET - Research Centre on Sensors & Systems Ltd. |
ABSTRACT
1. Optical Effects
Instrumental observations of the brightness of the sky at different wave
lengths of the optical spectrum form one of the most interesting and
appropriate experiments to be carried out during a solar eclipse. It allows one
to quantify the degree of darkness attained for the sky while the eclipse
observation place is located within the Moons shadow.
Reported observations of previous eclipses have indicated that the abrupt drop
of the solar light, produced during the few minutes of the total or near total
phase, produces a sudden darkness enough as to generate appreciable changes
which are characteristics of this kind of phenomena. - confirmed
by our observations.
RESULTS: see local meteo parameters.
2. Thermal, Relative Humidity, and Pressure Effects
Atmospheric temperature, relative humidity and pressure observations made in other total solar eclipses have shown a rapid change of these parameters which produce meteorological anomalies typical in this kind of phenomena:
- the appearance of winds - confirmed by our observations.
- the appearance of pressure waves with characteristic periods of minutes to hours - confirmed by our observations
- rapid change of temperature - only a slow change has been observed, possibly due to the clouds covering the Sun during the eclipse
- rapid change of relative humidity - the measurements during the eclipse has been aborted due to short rainfalls.
RESULTS: see local meteo parameters.
3. Environmental / Physiological Effects
The object of our investigations was a nyctinastic plant, Mimosa pudica, i.e.., a plant whose leaflets assume a vertical orientation (closed) in darkness and a horizontal orientation (open) under illumination. The leaf's components and the leaf itself oscillate with a circadian period under normal environmental illumination and respond to changes in light intensity. The purpose of the experiment was to monitor leave movements during the eclipse.
RESULTS: see leaf movement induced by eclipse.
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