Gravity-Driven Dynamo in the Electrodynamics of the Low-Latitude Ionosphere

Details Gravity-Driven Dynamo in the Electrodynamics of the Low-Latitude Ionosphere Gravity-Driven Dynamo in the Electrodynamics of the Low-Latitude Ionosphere

Dec 2002

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002agufmsa72b0539e&link_type=abstract

American Geophysical Union, Fall Meeting 2002, abstract #SA72B-0539

Mathematics

Logic

2409 Current Systems (2708), 2411 Electric Fields (2712), 2415 Equatorial Ionosphere, 2447 Modeling And Forecasting

Scientific paper

Plasma drifts in the low latitude ionosphere are climatologically well defined and generally understood given the success of physics-based dynamo models. The neutral wind current dynamo during magnetically quiet periods dominates the determination of the low-latitude electric fields. However, a second dynamo is also involved in low latitude electric fields. A gravity driven current generated by GxB drift of O+ is essential to the Rayleigh-Taylor instability and equatorial spread F (ESF) phenomena. The gravity term is generally ignored in global dynamo electric field models, but is included in the low-latitude electrodynamics of Haerendel et al. [JGR, 1992]. This paper examines the effect of the gravity dynamo on the low-latitude background plasma drifts. The gravity dynamo only slightly effects the vertical plasma drifts at most local times. The largest effect occurs right before sunrise. The predawn vertical plasma drift becomes more positive under the influence of the gravity dynamo by about 8 m/s during solar maximum and about 2 m/s for solar minimum. Examination of h'F vertical lifts in the NGDC Ionospheric Digital Database shows a consistent vertical lift predawn in ionosondes within a couple of degrees of the magnetic dip equator. The Coupled Ionosphere thermosphere Electrodynamics Forecast Model (CItEFM) [Eccles, JGR, 1998] also shows a similar predawn upward lift when the gravity dynamo term is included. The magnitude of the predawn lift depends on the nighttime decay of the O+ density. If the nighttime decay of O+ is not correctly modeled then the vertical lift before sunset will be not correct. The model also shows that the gravity dynamo strongly dependent on Apex altitude.

Affiliated with

Also associated with

No associations

Rating

Gravity-Driven Dynamo in the Electrodynamics of the Low-Latitude Ionosphere 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 Gravity-Driven Dynamo in the Electrodynamics of the Low-Latitude Ionosphere, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gravity-Driven Dynamo in the Electrodynamics of the Low-Latitude Ionosphere will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1434592