Research Stories

by Diane Boudreau

Want to know the biggest hailstone ever to strike the Earth? Or the coldest outdoor temperature ever recorded? Perhaps you want to find out what place on Earth has gone the longest without a drop of rain.*

All of this information is easy to find, thanks to a new, interactive map of weather extremes created by graduate students in the new School of Geographical Sciences and Urban Planning at Arizona State University. You can access the map at: http://wmo.asu.edu/maps/map.html

The map is part of the World Meteorological Organization’s “World Weather/Climate Extremes Archive.” The archive is housed at ASU and maintained by Randy Cerveny, an ASU professor of climatology and the Rapporteur of Extreme Climate with the WMO.

The archive is the first database of its kind for recording global climate extremes, and it serves a greater purpose than just satisfying curiosity.

“In order to know if our climate is changing, we need to know the extremes,” says Cerveny. “The best way to know is by what happened in the past. For example, I heard a lot of reports on the news that Katrina was the worst hurricane of all time. That’s not true. We have to have a climate history to judge whether what happens in the future is significant or not.”

The interactive map makes the archive data easily accessible. It was created by geographical sciences graduate students in an advanced Geographical Information Systems (GIS) course taught by Elizabeth Wentz. The students designed and constructed an xml database, designed and developed icons for each weather type, and carried out javascript programming. Wentz brought Cerveny into the class as a “client” for whom the students created a product.

“One of the problems we had was creating international symbols,” says Cerveny. “They have to be universal. It’s very difficult to come up with weather symbols recognizable to someone from Bangladesh or from China or from the USA. The only English we have on the map is the ‘H’ and ‘L’ for high and low pressure.”

He adds, “I’ve heard nothing but praise from around the world on this.”

Read more about how weather extremes are recorded.

* The world’s heaviest hailstone weighed 2.25 pounds and hit the Earth in Bangladesh in 1986. The lowest outdoor temperature ever recorded was -128.5 degrees F at Vostok Station in Antarctica. And Arica, Chile, saw no rainfall for more than 14 years from October 1903 to January 1918.

Students who helped develop the interactive map were: Ashish Kumar Agrawal, Elyssa Gutbrod, Min Jo Kang, Scott Kelley, Won Kyung Kim, Myunghwa Hwang, Shea Lemar and Terry Song.

For more information, contact Randy Cerveny, President’s Professor, School of Geographical Sciences and Urban Planning, College of Liberal Arts and Sciences, 480.965.7533, cerveny@asu.edu

Read more about how weather extremes are recorded.