Last Updated: 02/26/2024


Version: 2018

The Probability Distribution Function (PDF) model is a project of the Department of Climate and Space Sciences and Engineering from the College of Engineering at the University of Michigan.

The Probability Distribution Function(PDF) model (Bussy‐Virat & Ridley, 20146) forecasts the wind speed at L1 up to 5 days in advance using probability distributions, which have been constructed by analyzing solar wind observations between 1995 and 2011. These PDFs specify the likelihood that a particular wind speed will occur, given the current speed and the current slope of the wind speed curve. The model also takes account of rotational periodicities at quiet times and was updated (Bussy‐Virat & Ridley, 2016) to improve its ability to identify stream interaction regions (SIRs).


OMNI solar wind data from NASA/GSFC Space Physics Data Facility


Forecast of solar wind speed at L1

Model is time-dependent.


  • Heliosphere / Inner Heliosphere
  • Heliosphere / Outer Heliosphere



Code Languages: IDL


Publication Policy

In addition to any model-specific policy, please refer to the General Publication Policy.