A professor from the University of Delaware spoke to students at Cal Poly about climate mapping and estimation last Friday, addressing some statistical problems encountered in his research that effect the accuracy of weather maps and weather prediction.
Cort Willmott, a professor of geography and land surface climatologist, was invited by the geography department while Willmott and his wife stayed at their vacation home in Cambria. His appearance was a special event for the room packed with social science majors, said Greg Bohr, an attending geography professor.
“The whole idea of someone who is critical about maps is something we don’t get to talk about in intro courses, so it was nice to see that applied,” Bohr said.
In his presentation titled “Some statistical issues in estimating and mapping climate and climatic change from weather-station records,” Willmott gave a brief introduction to his ongoing research. He and his assisting graduate students have identified problems with commonly used methods of climate estimation from observational records. They have also developed better methods of spatial interpolation of climate maps — a process that helps create climate maps from past temperature and rainfall records.
His research reveals many existing methods to be slightly inaccurate, producing climate maps and other related information that can be as much as two degrees Celsius off.
“We should be aware of some of the problems that exist in this information and how to critically interpret what’s being recorded,” Willmott said. “When someone reports an average temperature, for example, you really need to know how they got it, because it could make a big difference in terms of what the temperature is.”
With his speech, Willmott wants to bring to light the implications of accepting statistical information without question.
“What I’m hoping is some of the students will stop, will look at a (weather) map with a more critical eye and start asking questions,” Willmott said. “‘What data did they use? Where are those data points located? How did they estimate the average?'”
Social science junior Audrey Porcella, who attended the lecture, says though his presentation was heavy in statistics terminology, she was able to follow it because of a class she took on Graphic Information Systems. Part of this class focuses on the differences of various weather predictions, she said.
“It was interesting to see how these variations played a role in assessing climate maps, and to find out that many of the errors in maps are because the climatologist did not take into account elevation,” Porcella said. “In general, becoming aware of all the potential areas for error was quite enlightening.”