Observations and mapping by seismologists at the University of California Davis in the hours and days after the August 24 earthquake in northern California are helping scientists understand why the earthquake caused so much damage in the region, according to a post in The Trembling Earth blog, hosted by the American Geophysical Union.
Selecting where the next Mars rovers will land involves a series of open-invitation workshops that solicit input from the scientific community. Think of the selection process as the science fair to end all science fairs, where the scientists who volunteer their time are rewarded with new data on their favored locales on Mars.
Ozone (O3), an important component of the Earth's atmosphere that is created by both natural and man-made processes, is a greenhouse gas, contributing to climate warming. Modeling the changes in concentrations of greenhouse gases, including O3, helps scientists project the effects of these gases in the future. However, some scientists have raised questions about the accuracy of long-term trends of ground-level O3 calculated by models, prompting Parrish et al. to take a closer look.
The authors looked at three model calculations of O3 concentrations, focusing on their changes over the last several decades. They then compared these model calculations with actual measurements taken by ground- and air-based instruments over the same time period.
The authors find that the models significantly underestimated the change in lower troposphere O3 at northern midlatitudes over the last five to six decades, implying that its contribution to radiative forcing may currently be higher than previously thought. These disagreements, the authors note, indicate that "limited confidence" can be placed on current estimates of radiative forcing by O3 and that resolving the discrepancies will improve scientists' ability to predict O3 concentrations in the future.
|Contact: Alexandra Branscombe|
American Geophysical Union