Category Archives: Climate
The Earth revolves around an imaginary line that passes through the North and South Poles, known as the spin axis. As it spins the Earth drifts and wobbles. And now scientists have identified three reasons.
The Earth wobbles on its axis once every 27,000 years, similar to a spinning top. This alters the relationship between the solstices and the distance from the Earth to the Sun. For example, 11,000 years ago the Northern Hemisphere summer solstice occurred at perihelion, when the Earth is closest to the Sun. That is almost the exact opposite of the case today, Continue reading
One of several diagnostic signals of a warming climate is the extent of sea ice in the Arctic, particularly its annual minimum extent which often arrives around the autumnal equinox.
The sea-ice extent is directly measured by satellite data and is available through the NASA-supported National Snow and Ice Data Center at the University of Colorado-Boulder. Continue reading
In southern Wisconsin, the average temperature for the summer months — defined as June, July and August — was near normal.
Rainfall was a different story. All of southern Wisconsin had summer accumulated precipitation of more than 16 inches, or 125 percent of normal. For much of the region, accumulated precipitation in August was more than 7 inches, which is more than 175 percent of normal. Continue reading
During the last week of July — the 25th through 31st — the temperatures across Wisconsin were 1 to 4 degrees below normal. In fact, much of the Midwest was cooler than normal.
The cooler temperatures resulted from a Canadian high-pressure system that settled over the central U.S. during that final week of July. Continue reading
The welcome respite we just enjoyed from the prolonged heat and humidity of late June and July may have inspired fond thoughts of autumn to many in southern Wisconsin.
Of course, there is still a lot of summer left, though we have just passed the climatologically warmest day of the year in Madison – July 14/15. This closely coincides with the date on which air with a temperature of 23 degrees at about 1 km above the surface shrinks to its annual minimum extent. Continue reading