Dartmouth Events

Physics and Astronomy Colloquium - Dr. Maura E. Hagan, NCAR, Boulder, CO.

Title: "Dynamical Connections between Meteorological and Space Weather"

Friday, March 6, 2015
3:30pm – 4:30pm
Wilder 104
Intended Audience(s): Public
Categories: Lectures & Seminars

Abstract: Recent investigations reveal an important and previously inconspicuous set of drivers of quiescent variability in the region of near geospace known as the thermosphere-ionosphere. These results confirm that the Earth’s atmosphere is a complex and coupled system, rather than a series of independent layers.

Diurnal heating in the Earth’s lower and middle atmosphere through the absorption of solar infrared and ultraviolet radiation, as well as latent heating of evaporation associated with raindrop formation in deep convective tropical clouds, excite a spectrum of global-scale waves known as thermal atmospheric tides.  Some of these tides propagate upward, grow exponentially in the increasingly rarified atmosphere, and penetrate the ionosphere-thermosphere. Therein, they impact the electro-dynamo process at lower thermospheric altitudes and/or directly modulate the diurnal variations generated by in-situ absorption of extreme ultraviolet radiation aloft.

After some introductory remarks about the relevant properties and underlying processes in the Earth’s atmosphere, this presentation will overview the important role that thermal atmospheric tides play in coupling meteorological weather to space weather.

For more information, contact:
Tressena Manning
603-646-2854

Events are free and open to the public unless otherwise noted.