U.S. Water News Online
AMES, Iowa -- Louis Thompson says he's learned to keep
quiet when Iowa's crops begin to wither.
For decades, the retired soil scientist had been forming his moon
theory to explain widespread drought every couple of decades, but he
says critics prefer to use other explanations.
"People thought I was a nut, so I quit talking about it," says
That doesn't mean he abandoned his theory. The statistics, after
all, are eerily accurate.
Thompson has studied weather and crop records for almost 50 years
and his research at Iowa State University pointed him to an 18.6-year
cycle of drought and rainy weather that coincides with the moon's
path around the Earth. When the moon's orbit is at its northernmost
track above the equator -- as it is now -- the Corn Belt is due for a
drought, Thompson says.
1988 was the last year when severe drought hit, which means the
probabilities are mounting that dry weather could hit this year or
next. With many areas of Iowa receiving less precipitation this year,
Thompson is quietly pointing to his theory.
S. Elwynn Taylor, an Iowa State University Extension
climatologist, says Thompson is known around the world for his 18- to
19-year crop cycle.
He says the correlation of the moon's orbit and rainfall lacks
scientific proof but at least has historical support. Tree ring
records going back 800 years in parts of the United States show the
cycle has been amazingly consistent, Taylor says.
Thompson's resume indicates he knows what he's talking about. He
was educated as a soil scientist at Texas A & M and Iowa State
University, where he received a doctorate in 1950 in soil fertility.
Thompson taught agronomy at Iowa State, was the professor in charge
of farm operations for seven years and served as an associate dean in
the agriculture college. He retired in 1983.
In 1960, Thompson developed an interest in climatology while he
served in the U.S. Army Reserve.
"I proposed that I could develop a method to predict crop yields
from weather data," Thompson says. "I was told it couldn't be done,
but I did it in a year."
Digging into records going back to 1810, he found there was an 18-
to 19-year cycle between drought years. That lined up with the moon's
orbit cycle, Thompson says.
Decades of the 1930s, 1950s and 1970s were mostly dry, Thompson
says. The 1920s, 1940s and 1960s were generally wetter.
Thompson has spoken about other weather phenomena over the years,
including the impact of the warming or cooling of the eastern Pacific
Ocean known as El Nino-La Nina.
Those forces trump the moon's impact on climate and drought,
Thompson says, and that's why a drought may not happen this year.
Taylor says that after months of neutral signals, the scale is
tipping toward El Nino conditions, which generally produce better
crops in the Corn Belt.
"That's nothing but good news for us," Taylor says. "It means it
won't be oppressively hot."
If this El Nino develops and trumps the moon cycle, as Thompson
says it might, there's always next year.
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