[Baps] MIT Talk: Transient Luminous Events, Luque and Gordillo-Vázquez, Tuesday Nov. 13, 11:30 am in 33-116

[Kerri Cahoy]

Transient Luminous Events in the Earth’s upper atmosphere:
electrodynamics, plasma kinetics and spectroscopy.

A. Luque and F. J. Gordillo-Vázquez
IAA – CSIC, Granada, Spain

Tuesday November 13th
11:30 am
MIT Building 33, Room 116

Transient Luminous Events (TLEs) is a generic name covering a variety
of electrical phenomena discovered in 1989 that occur in the upper
atmosphere (20–90 km) of the Earth as a consequence of the electrical
activity (lightning) in the troposphere. Blue jets and giant blue jets
start just above the cloud tops (15–20 km) while other TLEs, such as
sprites and halos, take place within the mesosphere (45–90 km). Since
the beginning of TLE research, investigations by different groups have
tried to answer key questions related with the electrical and chemical
impact of TLEs in the Earth atmosphere. By opening a window into
regimes not easily accesible in the laboratory, upper-atmospheric
electricity is also a valuable tool for the investigation of
fundamental processes in electric discharges.

This talk will be divided in two parts: first A. Luque will briefly
overview the physics of TLEs and then focus on the electrodynamic
modelling of sprite streamer formation and propagation. Then the talk
will address recent results by our group about the ignition mechanisms
underlying prompt (few ms after parent lightning) and long-delayed
(tens of ms) sprites.

In the second part, F. J. Gordillo–Vázquez will comment on a few
results of our kinetic modelling of TLEs. Nonequilibrium
state-to-state kinetic models are useful to understand the complex
chemical and electrical impact of TLEs in the atmosphere. Some recent
kinetic results will be presented
on the calculation of air electrical conductivity enhancement due to
TLE activity as well as computations of non-equilibrium vibrational
distribution functions (VDF) of the main N2 emitting electronic states
responsible for the optical emissions of TLEs in the visible range.
Calculations of TLE spectra in the ultraviolet (UV)-visible-near
infrared (NIR) will also be shown and compared with recorded spectra
to date. Finally, we will present a short
description of the prototype instrument GRAnada Sprite Spectrograph
and Polarimeter (GRASSP) recently (Oct 24) fielded that will be used
to carry out systematic TLE spectrocopic campaigns in Europe using
medium (0.4 nm) spectral resolution.

To meet with the speakers, who are visiting MIT all week, please
contact cguerrag at mit.edu and mmart at mit.edu

Please distribute! Thank you.

-- 
Kerri Cahoy
Assistant Professor of Aeronautics and Astronautics
Massachusetts Institute of Technology, 37-367
77 Massachusetts Ave.
Cambridge, MA 02139, USA
Cell phone: 650 814-8148
Office phone: 617 324-6005
E-mail: kcahoy at mit.edu, kerri.cahoy at gmail.com