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Ξ January 25th, 2009 | → 1 Comments | ∇ Uncategorized |
NASA Links Ancient Nile Records to Sun’s Impact on Climate Change
levitra bestellen While Congress was setting the climate-change record straight, challenging the Bush Adminstration’s deliberate distortion of the facts about global warming, NASA announced that a group of NASA and university scientists has found a convincing link between long-term solar and climate variability in a unique and unexpected source: directly measured ancient water level records of the Nile, Earth’s longest river, which runs south to north through Egypt.
Scientists have traditionally relied upon indirect data gathering methods to study climate in the Earth’s past, such as drilling ice cores in Greenland and Antarctica. Such samples of accumulated snow and ice drilled from deep within ice sheets or glaciers contain trapped air bubbles whose composition can provide a picture of past climate conditions.
The NASA team analyzed Egyptian records of annual Nile water levels collected between 622 and 1470 A.D. These records were then compared to another well-documented human record from the same time period: observations of the number of auroras reported per decade in the Northern Hemisphere. Auroras are bright glows in the night sky that happen when mass is rapidly ejected from the sun’s corona, or following solar flares.
Since the time of the pharaohs, the water levels of the Nile were accurately measured, since they were critically important for agriculture and the preservation of temples in Egypt. These records are highly accurate making them a rare and unique resource for climatologists to peer back in time.
A similarly accurate record exists for auroral activity during the same time period in northern Europe and the Far East. People there routinely and carefully observed and recorded auroral activity, because auroras were believed to portend future disasters, such as droughts and the deaths of kings.
The researchers found some clear links between the sun’s activity and climate variations. During periods of high solar activity, the North Atlantic Oscillation’s influence extends to the Indian Ocean. These adjustments may affect the distribution of air temperatures, which subsequently influence air circulation and rainfall at the Nile River’s sources in eastern equatorial Africa. When solar activity is high, conditions are drier, and when it is low, conditions are wetter.
NASA Link
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Congress Global Warming
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