Statistical Averages of F-Layer Electron Density, Electron Temperature
and Ion Temperature over Millstone Hill
 
Shun-Rong Zhang, John M. Holt, and Larisa Goncharenko
MIT Haystack Observatory, Route 40, Westford, MA 01886
 
 Abstract
 
All Millstone Hill incoherent scatter radar data collected since 1978 are
available through the Madrigal Database at MIT Haystack Observatory.  A
set of empirical models for basic and derived incoherent scatter
parameters, including electron density Ne, electron and ion temperatures
Te and Ti, electric field and parallel ion drift is being developed from
this extensive dataset. Such models of the average behavior of key
ionosphere-thermosphere (IT) parameters, based on long term accumulated
data, are important for space weather studies not only in terms of
quantitative descriptions of the IT system but also in terms of clarifying
several outstanding scientific problems.
 
This paper reports Ne, Te and Ti averages in the ionospheric F-layer from
which local empirical models can be generated. We sort every parameter
measured locally into bins. The binning parameters are local time
(0000-2400 LT), the day of year (season), and altitude (150-1000 km).  
Each data point belongs to a certain bin and has corresponding solar flux
index F107 and geomagnetic index Ap. For each bin, a multiple regression
is performed for a function including (1) the constant term, (2) linear
effect terms of F107 and (3) Ap, and (4) the F107 and Ap cross effect
term, to give a set of fitting coefficients, such that our model of bin
averages is keyed to F107 and Ap. The deviations of actual data from the
model represent the remaining day-to-day variability. We will present the
data distribution of each bin and discuss the main features of our
averages and models.