Around the Pier: Inaugural Roger Revelle Chair En Route to Scripps

Without oceans, the effects of the sun’s heat on the planet would be much simpler to predict. Instead, the wild cards of ocean temperature and heat-carrying currents drive climate in complicated ways.

Climate scientist Shang-Ping Xie describes himself as being lucky to have been a graduate student during the late 1980s, a “golden age” of studies into ocean-atmosphere interactions.  Now Xie will join Scripps Institution of Oceanography, UC San Diego, to continue work in a field that has matured considerably since then.  Xie will be the first Roger Revelle Chair in Environmental Science when he joins the Scripps faculty in November. His hire is the culmination of a process that began in 2007 when Ellen Revelle, widow of the famous oceanographer and former Scripps director, presented the institution with a $2.5 million gift to establish the chair, the largest single donation for an endowed chair in Scripps history.

“Roger Revelle was instrumental in setting up the long-term CO₂ measurements on Mauna Loa. The result is the Keeling Curve, an icon of global warming,” said Xie. “Prediction should be based on physical understanding of the past and present. Scripps has a world-class program in oceanography, providing a solid grounding for studying climate change under global warming. Scripps researchers are also connecting the science and applications of climate change. This is a big advantage because the needs from the applied community often drive science forward.”

Xie is interested in air-sea interactions that create important climate phenomena such as Pacific Ocean-scale El Niño/Southern Oscillation cycles. That strong interaction drives tropical climate to deviate from what is expected from solar radiation. For example, Xie points out, on the Galapagos Islands on the equator, solar radiation hardly varies year round but ocean temperature shows a large annual cycle with an annual minimum as low as 18degrees C (64.4 degrees F) in September. Charles Darwin visited the Galapagos in the cold season of 1835, and noted an arid climate.

Xie’s work has contributed to understanding the annual cycle on the equator and year-to-year climate variability.  He discovered an ocean-atmosphere interaction mechanism that explains why the earth’s climate develops latitudinal asymmetry across the equator. Such asymmetry is obvious from satellite images: tropical rain bands are displaced north of the equator across much of the Pacific and Atlantic Oceans. As a result, lush rain forests cover Central America while the Pacific coast of Peru is desert.

“It is a great pleasure to welcome such a serious and productive scholar to the Scripps community,” said Scripps Director Tony Haymet. “I am sure he and his students will thrive.”

Xie is currently a professor of meteorology at the University of Hawaii. Born in Quzhou, China in 1963, he received a bachelor of science degree in 1984 from the Ocean University of China in Qingdao. He received his master’s degree and doctorate in physical oceanography from Tohoku University in Sendai, Japan.

“I hope to develop new science filling the gap between global-mean temperature rise and regional rainfall change, say in California. Our recent work shows that atmospheric convection change is sensitive to the spatial unevenness in ocean warming,” said Xie. “To the extent that tropical convection drives important changes in climate around the globe, this result puts the ocean and its interaction with the atmosphere on the center stage of regional climate change research. Dynamics of regional climate change is a new line of research. Like any new developing science, there is a lot we need to figure out.”

– Robert Monroe