ESRL Quarterly Newsletter - Summer 2010

Balloon Science

ESRL celebrates 30 years of water vapor data

A six-foot diameter weather balloon soared into low clouds over Boulder, CO, April 21, its historic payload dangling from a string below. For 30 years now, NOAA researchers have sent balloon-borne instruments nearly 100,000 feet into the air twice a month, to collect data about the atmosphere, from the ground up to the darkness of near space. Among the measurements the balloon would take on its journey was water vapor concentration, which is critical for understanding climate change.

A few dozen scientists, journalists, and members of the general public watched the NOAA-instrumented balloon disappear into the clouds, during a celebration of the unique, 30-year “Boulder Record” of water vapor measurements. 

“Today, we sing a little bit about something that often goes unsung: long-term monitoring,” said Jim Butler, Director of the NOAA Earth System Research Laboratory’s (ESRL) Global Monitoring Division (GMD). Butler and several colleagues recognized the scientific foresight of ESRL’s Sam Oltmans, who began the water vapor measurements in 1980. Scientists are increasingly interested to know if the amount and distribution of water vapor in the upper atmosphere are changing, said Dale Hurst, who runs the Boulder water vapor program today. Water vapor is a greenhouse gas that plays critical roles in climate change.

When Oltmans began the measurement program, the balloons had to be even bigger to carry water vapor instruments, called frost-point hygrometers, that weighed three times as much as today’s miniaturized versions. Over the years, Oltmans and his colleagues have worked to ensure that the water vapor data are precise, accurate, and comparable with those from previous years. Along the way, these data have helped solve some significant scientific disputes about the amounts of water vapor in various parts of the atmosphere, Oltmans said, and they’ve uncovered patterns that remain puzzling today.

ESRL’s Susan Solomon, who helped lead the Intergovernmental Panel on Climate Change effort that earned the 2007 Nobel Peace Prize, spoke at the ceremony. She thanked Oltmans and his colleagues for their dedication, and described how she used the Boulder water vapor record—and satellite data—in a recent paper linking changes in upper atmospheric water vapor levels to temperatures here at Earth’s surface.

“You can be assured that the world scientific community recognizes the incredible value of this dataset,” Solomon said.

Top photo courtesy of Barb DeLuisi, NOAA; bottom photo courtesy of Will von Dauster, NOAA