Early climate research at the Preserve:
• Wind Research at Tent Colony
• Energy Budget Research at the Marsh Farm
• Heat Budget Research of Lake Mendota
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By John Kutzbach, published in 2016
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Energy Budget Research at the Marsh Farm
In the early days of the UW-Madison Dept. of Meteorology, now the Dept. of Atmospheric and Oceanic Science, Profs. Suomi, Bryson, Ragotzkie, and Lettau looked no further than campus environs to find launch pads for research. One Launchpad was the Marsh Farms of the College of Agriculture, around and over the now-restored Class of 1918 Marsh and recreation fields, the other was the Tent Colony facilities that provided easy access to Lake Mendota.
In the summer of 1948, the year the department was founded, Profs Suomi and Bryson looked at the lush cornfields of the Marsh Farm and saw the opportunity to calculate the contributions of sunlight and water to the energy and moisture budgets of the growing corn. They installed six rain gauges, air and soil thermometers, anemometers. Perhaps most importantly, they quickly recognized the unique advantage of these fields for monitoring crop moisture requirements. The ‘reclaimed’ land of the Marsh Farm was several feet below the level of Lake Mendota, and because subsurface water continually seeped into the field, a pumping station (still operating along Willow Drive) returns this excess water to the lake.
The “Flowerpot” project
Suomi and Bryson soon referred to the huge 120 acre cornfield as a big ‘flower pot’ in an article published in the Wisconsin State Journal in 1948. They could measure the input of water (rain) and the net outflow (the pumped discharge). The difference was the amount of water returned to the atmosphere by the cornfield through evaporation and transpiration from the leaves. By recording the pump’s output, they quickly confirmed that the pump worked harder at night than during the day, when sunlight fueled the corn’s photosynthesis and water was ‘pumped’ up through the plants and out the stomates.
In the early days of the UW-Madison Dept. of Meteorology, now the Dept. of Atmospheric and Oceanic Science, Profs. Suomi, Bryson, Ragotzkie, and Lettau looked no further than campus environs to find launch pads for research. One Launchpad was the Marsh Farms of the College of Agriculture, around and over the now-restored Class of 1918 Marsh and recreation fields, the other was the Tent Colony facilities that provided easy access to Lake Mendota.
In the summer of 1948, the year the department was founded, Profs Suomi and Bryson looked at the lush cornfields of the Marsh Farm and saw the opportunity to calculate the contributions of sunlight and water to the energy and moisture budgets of the growing corn. They installed six rain gauges, air and soil thermometers, anemometers. Perhaps most importantly, they quickly recognized the unique advantage of these fields for monitoring crop moisture requirements. The ‘reclaimed’ land of the Marsh Farm was several feet below the level of Lake Mendota, and because subsurface water continually seeped into the field, a pumping station (still operating along Willow Drive) returns this excess water to the lake.
The “Flowerpot” project
Suomi and Bryson soon referred to the huge 120 acre cornfield as a big ‘flower pot’ in an article published in the Wisconsin State Journal in 1948. They could measure the input of water (rain) and the net outflow (the pumped discharge). The difference was the amount of water returned to the atmosphere by the cornfield through evaporation and transpiration from the leaves. By recording the pump’s output, they quickly confirmed that the pump worked harder at night than during the day, when sunlight fueled the corn’s photosynthesis and water was ‘pumped’ up through the plants and out the stomates.
Left: Verner Suomi looking at the radiometer in the corn field. Right, the instrument is installed in Explorer 7 launched in 1959. Its shape is a bit like a flowerpot. Photos Credit NASA.
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The project quickly expanded with collaborating faculty from the College of Agriculture and the College of Engineering, and Suomi designed additional instruments. A ‘radiometer’ measured the net effects of incoming and reflected sunlight, and downward and upward ‘heat’ radiation (infrared) at the height of the corn – the difference between the downward and upward energy streams (positive during daylight) is the net energy available to the cornfield to heat its surface, evaporate/transpire water, and power photosynthesis. Other instruments monitored air temperature, air moisture content, wind, and evaporation from a small water container. Taken together, this instrumented cornfield (a large ‘flower pot’ brimming with numerous electronic gadgets) allowed Suomi to make quantitative estimates of how the corn used solar energy and water. Results were published in Suomi’s PhD thesis (U. Chicago) in 1953.
By this time Suomi had turned his attention from the cornfield to measuring the energy budget of planet Earth. He designed a miniaturized, space-toughened radiometer, but one based directly on the ideas of his cornfield radiometer. It was placed on the Explorer 7 satellite, which was only 30” in diameter, and launched from Cape Canaveral 13 October 1959. The banner headline of the Wisconsin State Journal of 14 October shouts “WISCONSIN PAYLOAD IN ORBIT.” Explorer 7 was the first satellite to measure the energy budget of Earth, the balance between incoming sunlight, light reflected by clouds and ice, and the infrared energy emitted by the warmth of the earth and its atmosphere. Its modern-day successors are helping scientists understand the physics of climate and climate change. Explorer 7 stopped transmitting in 1961 but it is still in orbit, 57 years after launch! Visitors to the Preserve can perhaps visualize the long-gone corn field, south of the Class of 1918 Marsh and a bit west of the Pumping Station on Willow Drive, and then marvel at the scientific ideas and gadgets that connect the energy budget of a cornfield, or marsh, to the energy budget of the Earth and to the Wisconsin-made instrument still aboard Explorer 7 that made it happen. |
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