Incoherent Scatter Radar Model (ISRIM) is a series of ionospheric empirical models developed at MIT Haystack Observatory from long-term incoherent scatter radar (ISR) observations around the world. These models give climatological means of ionospheric parameters, including basic ISR ones of electron density, ion and electron temperatures, and in some cases ion drift / electric field. Three types of models have been created to represent (1) local and (2) regional ionospheric features and (3) high latitude electric convection patterns.

The following models are now available for public access:

1)  Arecibo Radar Ionosphere Model (local model)
2)  Millstone Hill Ionosphere Model  (local model)
3)  Sondrestrom Radar Ionosphere Model (local model)
4)  EISCAT Svalbard Radar (ESR) Ionosphere Model (local model)
5)  EISCAT Tromsø Radar Ionosphere Model (local model)
6)  St. Santin Ionosphere Model (local model)
7)  Shigaraki (MU) Radar Ionosphere Model (local model)
8)  Millstone Hill Regional Ionosphere Model  
9)  Eastern American Regional Model
10) Western European Regional Model
11) Millstone Hill / Sondrestrom Radar Ionospheric Convection Model


These local climatological models of the ionosphere included seasonal, local time, and height variations, as well as dependence on solar activity and magnetic activity.


The Eastern American ionospheric model combines local models for Sondrestrom, Millstone Hill (local and regional), and Arecibo to form a regional model including latitudinal changes over geodetic latitude 18-70 degrees in the Eastern American longtitude. The Western European ionospheric model combines local models for St. Santin, Tromso, and Svalbard and covers a geodetic latitude range of 45-78 degrees in the Western European longitude.


The new convection model uses up-to-date line-of-sight measurements from Millstone Hill and Sondrestrom radars, and provides high latitude electrostatic potential patterns as well as the convection velocity and its variability.


We have developed integrated software, named ISRIM (FORTRAN), to provide calculations of all the local and regional ionospheric models. We have also created a web site and developed several ways for users to easily access our model products:


1) User-friendly Web interfaces allows a user to select a site or region and key in inputs with great flexibility; based on user's inputs, a variety of possible plotting options is provided to display results. Results can also be forwarded automatically to user's email address.


2) Virtual Incoherent Scatter Radar provides, over each of the ISR sites, model profiles for the current time and model diurnal contours for the current day; the high latitude convection seen as an steady and averaged pattern are also given. These model values are obtained by using latest geophysical indices and updated routinely (30 min).


3) FTP site to provide model software (ISRIM).


The web site contains also relevant papers, presentations, posters, animated pictures. The URL is