Paper#: 77
Poster #:
Session Name: Workshop 1A: High Latitude Processing
Room: West Ballroom
Day: Monday
Time: 10:55-11:20 a.m.
Abstract Title: What Is the Interrelation Between Polar Cap and Substorm Processes?
PresentSurname: Kauristie, K.
All Authors: K. Kauristie, O. Amm, A. Viljanen, K. Liou, P.T. Newell, L. Lazutin, J. Weygand
Abstract : The oval boundaries can be monitored locally using ground-based and low-altitude satellite observations, while UV-imagers onboard high-altitude satellites yield an instantaneous global view on the oval. Statistical fits combining low-altitude particle precipitation data (DMSP satellites) from different MLT-sectors show the well known substorm behavior: polar cap (PC) expansion during the growth phase and its contraction during the expansion phase. These models show also a widening of the morning sector auroral oval during the recovery phase. Comparison studies of DMSP and Viking data have shown that the expansion phase PC contraction in the particle data is not directly related with the auroral bulge poleward expansion in the global UV-images. The particle PC boundary is often more than 2 degrees poleward of the most intense UV luminosity, especially in the midnight and morning sectors of the oval. In the presentation we study the latitudinal distribution and dynamics of UV and visible auroras and electrojet currents during the different substorm phases. These observations are compared with simultaneous DMSP PC boundary observations and with the previously developed statistical oval models. We discuss especially the cases where the behavior of the PC boundary did not follow the dynamics of the other observations.