| Clipped from: NASA Links Ancient Nile Records to Sun's Impact on Climate Change |
NASA Links Ancient Nile Records to Sun's Impact on Climate Change
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.
| Clipped from: NASA - NASA Finds Sun-Climate Connection in Old Nile Records |
"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," she said. "These
records are highly accurate and were obtained directly, making them a
rare and unique resource for climatologists to peer back in time."
...
The researchers found some clear links between the sun's activity
and climate variations. The Nile water levels and aurora records had
two somewhat regularly occurring variations in common - one with a
period of about 88 years and the second with a period of about 200
years.
...
So what causes these cyclical links between solar variability and the Nile? The authors suggest that variations in the sun's ultraviolet energy cause adjustments in a climate pattern called the Northern Annular Mode, which affects climate in the atmosphere of the Northern Hemisphere during the winter. At sea level, this mode becomes the North Atlantic Oscillation, a large-scale seesaw in atmospheric mass that affects how air circulates over the Atlantic Ocean. 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.
Related:
NASA Links Ancient Nile Records to Sun's Impact on Climate Change
NASA - NASA Finds Sun-Climate Connection in Old Nile Records
Altered climate reports spark stormy hearing - Los Angeles Times
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