5. Upper atmosphere influences weather near Earth's surface
To what extent does what's happening in the stratosphere, tens of kilometers above Earth, influence the weather in the troposphere, the layer of atmosphere that touches Earth? Gerber et al. perform a series of forecast experiments using a general circulation model to study the role of the stratosphere in influencing tropospheric weather following sudden stratospheric warming events. It is known that the troposphere influences the stratosphere in driving these events, but scientists were unsure of whether the stratosphere actively influenced the troposphere. The authors find that the stratosphere does indeed influence the troposphere, although this influence is weak and easily masked by tropospheric variability. The results indicate that improved resolution in stratospheric simulations would probably lead to better weather forecasts.
Title: Stratospheric influence on the tropospheric circulation revealed by idealized ensemble forecasts
Authors: E. P. Gerber: Center for Atmosphere Ocean Science, Courant Institute, New York University, New York, New York, USA; C. Orbe and L. M. Polvani: Department of Applied Physics and Applied Mathematics and Department of Earth and Environmental Science, Columbia University, New York, New York, USA.
Source: Geophysical Research Letters (GRL) paper 10.1029/2009GL040913, 2009 http://dx.doi.org/10.1029/2009GL040913
6. New finding on key element of Earth's lower mantle
The electronic spin state of iron in perovskite, a major component of Earth's lower mantle, can influence the physical and chemical properties of the mantle. However, previous studies have presented an unclear picture of the spin state of iron in perovskite, with some experiments contradicting computational results. In a new experiment designed to bett
|Contact: Maria-Jose Vinas|
American Geophysical Union