The Solar Eclipse: 11 August 1999

Research performed for Cluj / Romania by BITNET - Research Centre on Sensors & Systems Ltd.
this work was made possible by support from the National Agency for Science, Technology and Innovation
and by the Romanian Space Agency


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:

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.