Weather Station

Weather Detectives at Devil’s Hole

by Lindsey Michaels

Randy Cerveny is a weather detective. Instead of solving crimes, the ASU scientist looks at the mysteries of temperature, wind, and rain. To do this, Cerveny and his team members keep one eye on the sky and the other on computers.

Cerveny's work has little to do with tomorrow's weather forecast. Instead, his work focuses on long-term weather changes— everything from predicting global warming to establishing safety guidelines for a planned nuclear waste site.

"Predicting weather 10,000 years from now is actually a lot easier than predicting if it will rain tomorrow," Cerveny says. "With tomorrow's weather, we're looking at one small slice in time. We're looking at heat, wind, and moisture conditions that may or may not materialize."

However, with long-term predictions, scientists look for overall patterns. For instance, Cerveny spends much of his time studying whether the Earth is warming up or cooling off. And, if so, how those changes might affect our lives.

The Earth's temperature is in a constant state of change. It warms up for some time, then it cools off. That pattern started millions of years before the time dinosaurs roamed the planet. In fact, some scientists believe that one long, cold streak might have killed off the giant reptiles.

Luckily for humans, however, the Earth's temperature shifts very, very slowly. In fact, it shifts so slowly that Earth was probably only one degree cooler way back in 1492, when Christopher Columbus first reached America.

If temperatures shift that slowly, why should we worry about Cerveny's work? Because even the slightest temperature change can dramatically shift the balance of climate and affect weather patterns.

The Earth's average temperature was only five degrees cooler during the last Ice Age than it is today. The last Ice Age ended about 10,000 years ago. It was a time when much of North America was frozen solid. And, much, much earlier, when dinosaurs ruled the planet, the Earth was only five or six degrees warmer than it is today.

Five degrees may not seem like much. But it can mean the difference between Ice Ages or dinosaurs. In the meantime, even the slightest shifts in temperature can affect how much it rains. That's why the government asked Cerveny and his ASU graduate student, John Shaffer, to predict rain and temperature patterns near Yucca Mountain, Nevada.

The government wants to use Yucca Mountain to store dangerous nuclear waste. If exposed to the air, this waste could kill or injure people. In fact, the nuclear waste will be hazardous for thousands of years to come. That's why the government wants to seal it tightly inside special metal containers and bury them deep inside Yucca Mountain.

Today, the area around Yucca Mountain is very dry and unpopulated. If it stays that way, there's little chance of those containers rusting open. But, if rainfall patterns change, the amount of ground water in the area could also change.

Think of ground water as a giant underground lake. If lake water ever rose high enough to reach the Yucca Mountain storage site, it could rust open the waste containers. The chemicals inside would leak and be carried away by the water. The waste could poison people drinking that water.

Cerveny and Shaffer's job is to predict rainfall at Yucca Mountain for the next 10,000 years. Doing so will help ensure that any nuclear waste stored there never poisons people.

Cerveny and Shaffer began their quest by studying weather records that have existed for hundreds of years. The records were for rainfall in many places around the world.

The ASU scientists tried to gather the most reliable long-term, scientific weather information available. However, most places that have recorded weather for a really long time are far away from Yucca Mountain.

That fact posed a problem. Could weather information from far away places be used to reliably predict weather at Nevada's Yucca Mountain site?

Given the dangers of nuclear materials, neither Cerveny nor the government was willing to accept a "best guess" answer to that question.

Luckily, long-term weather information—called climate data—is also available for a site in New Mexico. That site, called Devil's Hole, is much closer to Yucca Mountain than sites in Canada or Europe.

Devil's Hole also exhibits weather patterns that are similar to those found near Yucca Mountain. Cerveny and his team could figure out how much rain fell at Devil's Hole by studying the layers of calcite deposits there. Using this data, they could better predict weather at the nuclear waste storage site. (How they did it: Determining rainfall at Devil's Hole)

Using the Devil's Hole data, a good computer, and the worldwide rainfall data, Cerveny and Shaffer were ready to do some great detective work.

Their findings were interesting. Using the information, Cerveny and Shaffer can predict that both the Devil's Hole and Yucca Mountain sites will cool slightly during the next 10,000 years or so—by about a degree or two. Even so, the findings show that cooling won't significantly affect rainfall at Yucca Mountain. (How they did it: Diagramming information)

The ASU weather detectives believe they've solved their case. Based on all known scientific data, rainfall patterns at the Yucca Mountain site won't change dangerously during the next 10,000 years. That means people won't have to worry about rain-related ground water poisoning when the government starts using Yucca Mountain as its nuclear waste storage site.