HR: 0800h
AN: SA31A-0350    [Abstracts]
TI: Statistical High-Latitude Convection Patterns from ISRs Observations at Millstone Hill and Sondrestrom
AU: * Zhang, S
EM: shunrong@haystack.mit.edu
AF: MIT Haystack Observatory, Off Route 40, Westford, MA 01720 United States
AU: Holt, J
EM: jmh@haystack.mit.edu
AF: MIT Haystack Observatory, Off Route 40, Westford, MA 01720 United States
AU: Foster, J
EM: jcf@haystack.mit.edu
AF: MIT Haystack Observatory, Off Route 40, Westford, MA 01720 United States
AU: McCready, M
EM: mary.mccready@sri.com
AF: SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025 United States
AB: A combined database from long-term incoherent scatter radar line-of-sight observations at Millstone Hill and Sondrestrom has been used to construct statistical patterns/models of high-latitude convections between 55 and 78 invariant latitudes in Northern America. This paper presents variations of the convection as a function of IMF By and Bz conditions and season. It is shown that the cross polar cap potential is on average higher in equinox than in solstice. As the season turns from winter to summer, the convection pattern appears to move anti-sunward and the axis across the two cells rotates toward earlier local times, meanwhile, the cross polar potential weakens for By - and vice verse for By +. The dusk-dawn cell similarity in summer is found to be high for By - and low for By +, supportive of the theory of lobe cell generation in summer. It is therefore noted that the procedure to simply switch the By sign in order to obtain the convection for the conjugate hemisphere may be not alway appropriate, because of the asymmetry of the convection response to By + and -, and of seasonal differences in the convection.
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2437 Ionospheric dynamics
DE: 2447 Modeling and forecasting
DE: 2712 Electric fields (2411)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005