Weather Station

Dry Times-It's a Drought

by Lindsey Michaels

Summers are always challenging when you call the desert home. Skies send relentless sun instead of rain. Sand gets baked until it sizzles. Hot breezes can singe the lungs clear through to your backbone.

In the desert, life and death exist in a delicate balance. During a drought, those scales tip decidedly more toward death. Early 1996 saw such a drought in Arizona and across the western United States.

"Things got so bad in some areas that we saw cattle with mouths full of cactus quills," says Robert Balling. "As painful as that was, the cattle simply had no choice. They had to chew cactus, which store water, to survive."

Balling studies droughts and other weather trends. He directs the Office of Climatology at ASU.

Meteorologists try to answer questions such as "Will it rain tomorrow?" Climatologists are different. They study weather's long-term trends. They ask questions such as "Will it rain next year or next decade?"

Balling spends lots of time studying rainfall and temperature patterns.

"Big rain and temperature fluctuations are part of desert living," he says. "In fact, our area follows a pretty regular 22-year rain/drought pattern. Many scientists believe that this 22-year cycle is linked to sunspot patterns"

Sunspots are big magnetic storms on the sun's surface. They have lifespans of only a few days. Yet, they somehow affect our weather here on Earth.

Some scientists believe that sunspots change pressure and temperature conditions at the equator. They know for sure that sunspot activity reaches a maximum every 11 years. That 11-year pattern somehow relates to the 22-year weather cycle we get on Earth.

Balling explains that our weather is tied to jet stream movement. The jet stream is a fast-moving column of hot air that runs from west to east. Its speed and warmth help stir up storms.

On average, Arizona gets just seven inches of rain per year. Balling says that about one-half of Arizona's yearly rainfall normally falls in winter. But during the winter of 1996, Salt River Project (SRP) collected less than one gallon of rain runoff for every four it normally receives.

SRP is Arizona's largest water supplier. The 1996 total was the smallest amount of rainfall they had collected since 1955.

But exactly what do those numbers mean to you and me? If you took all the water used by an average Phoenix family of four in a single year, it would cover one acre of land to a depth of one foot.

An acre is about the size of a football field minus the end zones. At that rate, the reduced runoff in winter 1996 would have left 520,000 Phoenix families without water for one full year.

SRP dipped into reserves stored behind dams in human-made lakes. They hoped for late summer rains to supply water to those families.

Unfortunately, most desert plants and creatures must rely solely on nature, not SRP, for their water.