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By Bob Valen 

The Climate Divide is changing


In 1878, John Wesley Powell, solider, geologist, explore and professor, placed an imaginary longitudinal line on a map based on his exploration observations. That line, he explained, represented the separation of the dry and arid west and the humid east of the United States. That line goes through all of North America and is the 100th Meridian.

Powell was best known for his exploration of the Grand Canyon as well as other parts of the great west. Powell, who explored many areas of the west, held deep concerns about long-term future development in the arid western environment and the sustainability of that development. Later, Powell attempted to work with and convince Congress to create water and land management districts that would cross state lines and would address large-scale environmental constraints. Though, like many of the attempts to work with Congress, it simply never transpired, especially the idea of cross-state border cooperation.

We come to present day and the issues and potential issues we face with climate change. It’s been 140 years since Powell drew his line. Today, scientists are revisiting the Powell line. Two recent studies confirm the line is real and is reflected in the population and farming practices of both the west and east and is well expressed in terms of vegetation, land hydrology, crops, and the farm economy.

The 100-degree longitudinal line stays as a cartographic feature, but it’s that Powell divider line between the dry west and humid east that is moving eastward. The studies state the Powell line is moving eastward due to climate change.

“The main contributor to the changes is rising potential evapotranspiration, while changes in precipitation working alone increase aridity across the southern and decrease across the northern United States,” the studies read.

The studies can be found on the American Meteorological Society website.

Let’s review April’s weather data. April proved to be well above our mean precipitation of 0.86 inches. Here at the home weather station we measured 1.93 inches while the “official weather station” measured 1.40” (another great example of micro climates. These stations are only 3.62 miles apart). The all-time high precipitation for April was in 1948 at 2.31 inches. Our mean temperature was 49.5˚F for April. The all-time mean is 49.9˚F. We experienced a high of 84.9˚F on the 27th at the home weather station as compared to our official all-time high of 92˚F in 1936. The low temperature was 30.6˚F on the 17th compared to our official all-time low of 20˚F, again in 1936.

Our friends at EarthSky website share this for all you night sky observers. “Circle May 16-18 on your calendar. That’s when the young moon will be sweeping past Venus in the evening sky. The pairing will be especially striking in the western twilight on May 17. Visible in May are five planets - Jupiter, Venus, Mars and Saturn, Mercury. Venus will be the brightest planet in the night sky. It will be very noticeable in May in the west after sunset. Throughout May, Venus will be the impressive evening “star.” Venus will still be climbing upward from the sunset point through the month. Each evening in May, it stays out longer after the sun sets. Enjoy.

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