The 6th IAGA/ICMA/CAWSES workshop on "Long-Term Changes and Trends in the Atmosphere" was held at the National Center for Atmospheric Research (NCAR) Center Green Conference Center, Boulder, Colorado, USA, June15–18, 2010, the week before the 2010 CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions) workshop, which was also held in Boulder.

Attendees Photograph

Trend 2010 attendees. High resolution.

This workshop coincided with the 40th year of uninterrupted work of Ray Roble, who made substantial contributions in the topic which became a major theme of the workshop. It had been 20 years since Roble and Dickinson [1989] first concluded that global change will occur in the upper atmosphere as well as in the lower atmosphere as a result of increased greenhouse gas concentrations. Since this workshop was held at NCAR where Ray worked for nearly 40 years, a symposium in honor of Ray Roble was held on 18 June, 2010 in conjunction with the workshop to celebrate Dr. Roble's pioneering contributions to solar-terrestrial research. See Ray Roble Symposium.

Long-term changes to Earth's atmosphere are becoming more and more relevant to the future of our world and it is paramount that we quantify and understand changes occurring at all levels within the coupled atmospheric system. The increasing concentration of greenhouse gases, stratospheric ozone depletion, varying solar and geomagnetic activity, secular change of Earth's magnetic field, and changing dynamics propagating up from the troposphere are some of the possible causes of long-term changes in the stratosphere, mesosphere, thermosphere and ionosphere. The goals of this workshop were to review the current state of knowledge about trends in these atmospheric regions, and to discuss what research is necessary for resolving inconsistencies, reducing uncertainties, and achieving a deeper understanding of middle and upper atmospheric climate change—especially the relative influences of anthropogenic and solar effects.

We welcomed papers using all types of observational techniques to determine the long-term changes and trends that have occurred in the past and also to determine the processes behind those changes. We also welcomed contributions considing the availability, quality and acquisition of various data sets which were exploited for trend studies, and statistical methods for deriving and validating those trends. Interpretation and attribution of observational results depends heavily on theoretical models and numerical simulations of the trends, and presentations dealing with these topics were particularly welcomed. While the troposphere is not the main focus of the workshop, it is clear that it has a major role to play in middle and upper atmosphere trends; papers that demonstrated this relevance were also welcome.