LTCS stands for "Lower Thermosphere Coupling Study".
It entails coordinated investigation of the mesosphere/thermosphere
region using a combination of observations and modeling efforts with the goal of better understanding the dynamic and electrodynamic processes coupling the mesosphere to the lower and upper thermosphere.
A cornerstone of LTCS is the conduct of campaigns involving
simultaneous observations by a variety of instruments distributed
globally over periods of several consecutive days.
LTCS is an NSF-sponsored effort operating within the CEDAR
program in the Division of Atmospheric Sciences.
It is the U.S. component of an international effort,
MLTCS, which is an official working group in the
STEP program with Alan Manson, U. Sasketchewan, as coordinator.
Campaigns/Observations: Past, Present, Future
Summary of 1998 CEDAR/LTCS Workshop
Science Motivation/Foci
The purpose of LTCS is to perform coordinated investigations of the mesosphere/lower thermosphere combining both experimental and theoretical modeling efforts. The experimental techniques include incoherent scatter radars in America and Europe, MF, MST, meteor, and partial reflection drift radars, optical instruments, and satellite measurements when available. Lidar observations are beginning to be incorporated into the program.
Emphasis is on the measurement of neutral temperatures, winds, and densities and ionospheric electric fields in the region 80-150 km. Specific scientific objectives are investigations of:
- global scale circulation in the lower thermosphere: winds at various altitudes and latitudes;
- electrodynamic coupling: E- and F-region dynamos and coupling; conductivities; penetration of magnetospheric convection electric fields
- upward propagating tides: upper thermosphere penetration, ion transport, heat and momentum deposition.
- waves: oscillations of lower atmospheric and auroral origin, if observed during campaigns;
- turbulence: turbopause/composition questions, downward heat transport.
- geomagnetic storm effects: time delay and latitudinal extent of such effects in lower thermosphere, if campaign occurs during geomagnetic disturbance.