It's official. California is now 100% covered by “moderate to exceptional” drought, according to the National Oceanic and Atmospheric Administration (NOAA).
What is still unofficial, but suspected by a growing number of scientists, is that the drought is linked to global warming. Last week, the Associated Press reported that scientists at Utah State University are publishing a study that connects a complex series of cascading weather events that begin in cold China waters and end in California drought and the polar vortex blamed for the harsh winter elsewhere in the country.
“We found a good link and the link is becoming stronger and stronger,” researcher Simon Wang told AP reporter Seth Borenstein.
Months before other scientists recorded a warming of the mid-Pacific Ocean, a precursor to the El Nino phenomenon that changes rain and temperature patterns every few years, Wang was studying colder-than-usual water near China and establishing a connection between them. The assistant professor of climate at Utah State University and his colleagues then applied their observations of linkage to historical highs and lows in North America.
Wang ran computer simulations of his theory over a period of decades with and without carbon dioxide from burning fossil fuels and saw patterns that mirrored and predicted today's conditions. In the end, the study concluded that the weird combination of a high-pressure ridge in the West and a low-pressure trough emanating from the Great Lakes was responsible for weather extremes.
The report found the difference between the two extremes has been increasing for years.
Scientists are still struggling to find firm connections between real-time weather conditions and long-term atmospheric conditions that produce jet streams and other phenomena. Parts of the country, in the East and Midwest, suffered through one of the harshest winters on records while the Southwest experienced record heat and drought. What the country has in common are inexplicable extremes.
Wang told Utah Public Radio, “Global warming effect is modifying the weather pattern to become more and more extreme, meaning that when there is a drought case, it becomes a drought that causes cold air extremes like on the East Coast.”
–Ken Broder
To Learn More:
Study Links California Drought to Global Warming (by Seth Borenstein, Associated Press)
Climate Researchers Link Climate Change, California Drought and Polar Vortex (by Morgan Pratt, Utah Public Radio)
Drought Now Covers 100% of California (by Alexis C. Madrigal, The Atlantic)
Drought Now Covers Every Last Inch of California (by Jeff Spross, ThinkProgress)
Probable Causes of the Abnormal Ridge Accompanying the 2013-14 California Drought (by Simon Wang, Lawrence Hipps, Robert R. Gilles and Jin-Ho Yoon, Geophysical Research Letters)