Response of the Middle Atmosphere to a Total Solar Eclipse Using a Prototype High-Altitude Global Numerical Weather Prediction Model

Details Response of the Middle Atmosphere to a Total Solar Eclipse Using a Prototype High-Altitude Global Numerical Weather Prediction Model Response of the Middle Atmosphere to a Total Solar Eclipse Using a Prototype High-Altitude Global Numerical Weather Prediction Model

May 2006

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006agusmsa23a..09e&link_type=abstract

American Geophysical Union, Fall Meeting 2007, abstract #SA23A-09

Physics

3384 Acoustic-Gravity Waves, 0342 Middle Atmosphere: Energy Deposition (3334), 3332 Mesospheric Dynamics, 3334 Middle Atmosphere Dynamics (0341, 0342), 3359 Radiative Processes

Scientific paper

Solar eclipses provide a natural reproducible perturbation experiment for studying the atmosphere's reponse to changes in solar forcing. Theory suggests a large-scale gravity wave response in the middle and upper atmosphere, yet nearly 4 decades of observations aimed at testing these predictions have been largely inconclusive. To investigate in more detail the atmosphere's response to the total solar eclipse that occurred in the Southern Hemisphere on 4~December 2002, we use an advanced-level physics and high-altitude (ALPHA) prototype version of the spectral forecast model of the Navy Operational Global Atmospheric Prediction System (NOGAPS), the Department of Defense's global weather prediction model. The NOGAPS-ALPHA runs reported here extend from the surface to ~100~km. Our control simulations are standard "cold-start" hindcasts initialized at 0000~UTC on 4~December 2002 which have no eclipse effects included. In these runs we update the radiative heating and cooling rates at every model time step, rather than the more typical 1--2~hours. Our eclipse simulations rerun these same hindcasts, but insert a moving eclipse shadow at the appropriate times based on 60~s time series of the leading and lagging limbs of the lunar shadow on the Earth's surface, issued by the U.S. Naval Observatory. For implementation in NOGAPS-ALPHA, we convert eclipse magnitudes within these shadow regions into local reductions in solar UV intensity using geometry and consenus estimates of limb darkening across the solar disk at 200-300~nm. We study evolving atmospheric responses to this moving UV eclipse shadow using global atmospheric difference fields between the two simulations. In particular, we compare the observed response to the theoretical predictions of Chimonas and Fritts--Luo. Finally, we present preliminary results from similar runs for the most recent total solar eclipse that occurred on 29 March 2006.
www.nrl.navy.mil/dynamics/html/nogaps.html

Affiliated with

Also associated with

No associations

Rating

Response of the Middle Atmosphere to a Total Solar Eclipse Using a Prototype High-Altitude Global Numerical Weather Prediction Model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Response of the Middle Atmosphere to a Total Solar Eclipse Using a Prototype High-Altitude Global Numerical Weather Prediction Model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Response of the Middle Atmosphere to a Total Solar Eclipse Using a Prototype High-Altitude Global Numerical Weather Prediction Model will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1025731