FAST auroral DC electric field studies using ion data and fields data to provide the full DC E vector

Details FAST auroral DC electric field studies using ion data and fields data to provide the full DC E vector FAST auroral DC electric field studies using ion data and fields data to provide the full DC E vector

Dec 2004

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004agufmsm51a0353h&link_type=abstract

American Geophysical Union, Fall Meeting 2004, abstract #SM51A-0353

Other

2407 Auroral Ionosphere (2704), 2411 Electric Fields (2712), 2704 Auroral Phenomena (2407), 2712 Electric Fields (2411)

Scientific paper

We present an analysis of auroral FAST perpendicular E data using ion distributions in return current regions to study the full DC E vector and potential structures. While the axial boom measurement is available, its interpretation requires careful use and some assumptions. Our new technique provides an independent measure of this axial component. Our new tool extracts two perpendicular components of electric field, using the electric field data from the field instrument for the spin-plane component of E, and the ion drift measurements for the axial DC E. This allows studies of the full perpendicular DC E vector for the first time with FAST data. In addition the new tool transforms from velocity-based coordinates to north-south, east-west coordinates for analyzing the morphology and structure of the auroral return current region more effectively. With more than fifteen return current region crossings collected at FAST altitudes above 3000 km in either the pre-noon dayside or near midnight sector, three quarters of our data show linearly polarized diverging electric field structures. A significant fraction (almost one quarter) show rotational polarity during large field events. For these rotational events, it is probable that the spacecraft was passing through the edge of elongated quasi-static potential structures. They can also be interpreted as a temporal variation. Generally in many orbits, linear and rotational polarity appear together, one followed by the other, which means the potential structure has a wiggled or droopy shape. Statistical comparison shows several differences between these two different polarizations. (1) When a rotational polarity appears, the correspondence between electron characteristic energy and the potential obtained by integrating E weakens. (2) For linear polarization the electric field vector is likely to be almost perpendicular to the magnetic disturbance, while for rotational polarization the E is not perpendicular to delta-B. (3) Both the absolute scale length of the current signature and its size relative to that of the electric field signature are smaller for the linearly polarized cases. With this full DC E vector, we can study various questions including the morphology of auroral return currents and inconsistencies with static return current models. Our tool for extracting this information will be part of the FAST software library.

Affiliated with

Also associated with

No associations

Rating

FAST auroral DC electric field studies using ion data and fields data to provide the full DC E vector 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 FAST auroral DC electric field studies using ion data and fields data to provide the full DC E vector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and FAST auroral DC electric field studies using ion data and fields data to provide the full DC E vector will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1469617