Space Weather Prediction with Cosmic Rays

Clicking any plot below will produce an enlargement.
Scroll down for information about this site, and links to additional online plots.

Spaceship Earth Loss Cone Display and Bidirectional Streaming Display
Spaceship Earth GLE Monitor (Minute Resolution)
Cosmic Ray Flow Direction
Individual Station Count Rates
(6-panel display; only one shown here)

Introduction

This Website is a gateway for space weather displays based upon cosmic ray data returned by the Spaceship Earth network of neutron monitors. In the future it will also include space weather displays based upon data from the worldwide network of muon detectors.

The top of the site contains reduced versions of the plots that we consider most relevant for space weather prediction. Click any plot to obtain an enlarged version. As our space weather products are improved and optimized, these plots will change from time to time.

Below is a brief description of the multi-national team providing data for this site. Following that is a listing of available realtime space weather displays based upon cosmic ray data, including a link to the display, a brief discussion of its use for space weather forecasting or specification.

Disclaimer

This is a prototype, experimental site. Use of material on this site for any purpose is at your own risk. We do not guarantee that the realtime displays will be available or up-to-date at all times. Realtime data have not been subjected to rigorous quality control; it may contain "glitches" that produce false alarms or fail to detect true space weather disturbances. Even when the data are good, there may be physical factors that produce false alarms or fail to detect true space weather disturbances.


Participating Institutions

Spaceship Earth

Spaceship Earth is an 11-station network of neutron monitors strategically located to provide precise, real-time, 3-dimensional measurements of the cosmic ray angular distribution. Participating institutions include the University of Delaware, IZMIRAN, Polar Geophysical Institute (Apatity), Institute of Solar-Terrestrial Physics (Norilsk), Institute of Cosmophysical Research and Aeronomy (Tixie Bay). Institute of Cosmophysical Research and Radio Wave Propagation (Cape Schmidt), Australian Antarctic Division (Mawson), and the University of Tasmania.

For additional information on Spaceship Earth, neutron monitors, and space weather, please visit the home page of the University of Delaware Bartol Research Institute neutron monitor program

The Muon Team

In the future this site will include space weather products from a growing muon detector network. Participating institutions include the University of Delaware, Shinshu University (Japan), Nagoya University (Japan), Southern Space Observatory of INPE (Brazil), University of Santa Maria (Brazil), Australian Antarctic Division, and the University of Tasmania.


Links to Space Weather Displays (with Brief Explanations)

Spaceship Earth Loss Cone Display and Bidirectional Streaming Display

Important Note: This plot is an experimental prototype. The display format may change as a result of ongoing research to optimize space weather prediction with cosmic rays. Refer here for a brief explanation of the current display format.

DISPLAY FORMAT
Top Panel: ACE magnetic field magnitude |B| (green), north-south component Bz (pink-red) in GSE coordinates, and 1-hour estimated Kp index (blue).
Second Panel:Cosmic ray density determined by fitting a first-order anisotropy to available Spaceship Earth stations.
Third Panel (Loss Cone Display): Each circle represents an hourly average of the cosmic ray intensity measured by a single Spaceship Earth station relative to the cosmic ray density. Red circles indicate deficit intensity, blue circles indicate excess intensity, and the size of the circle scales with the magnitude of the deficit or excess; see right side of plot for scale. Horizontal axis is time (3 days total displayed), and vertical axis is station pitch angle. Station pitch angle is the angle between the station viewing direction (median rigidity particle) and the Sunward magnetic field direction (ACE 1-h average). Here "Sunward" is defined relative to a nominal 45 degree sprial field; a station with zero degree pitch angle views particles coming from the Sun along the magnetic field. Stations were inter-normalized by means of a 24-h trailing moving average.
Fourth Panel (Bidirectional Streaming Display):Residual deviation after subtracting the fitted first-order anisotropy from each station. Red and blue now represent deficit and excess relative to a first-order anisotropy. This plot is thus a display of higher order anisotropies in the cosmic ray pitch angle distribution.

USE OF THIS PLOT
Loss Cone Display (third panel): This plot will sometimes display a cosmic ray loss cone precursor ahead of an approaching CME shock. The defining characteristic of a loss cone precursor is a strong suppression of cosmic ray intensity for particles arriving from the Sunward magnetic field direction. Thus, look for large red circles concentrated near small pitch angles. The physical mechanism behind loss cones is that these particles trace to the region downstream of the shock, where cosmic ray intensity is generally suppressed (Forbush decrease). In major storms, loss cones are often observed about 4 h in advance of shock arrival, and may be observed 24 h in advance in rare cases. Depending upon shock-field geometry, however, loss cones can be difficult to detect, or absent entirely.
Bidirectional Streaming Display (fourth panel):This plot can be used to indicate when Earth is within a large interplanetary CME. Cosmic rays within a large CME often exhibit bidirectional streaming, in a manner similar to the bidirectional electrons observed at much lower energy. Intensity is suppressed near 90 degree pitch angles, and elevated near 0 and 180 degrees. Thus, look for red circles concentrated near 90 degrees, with blue circles on both sides.

Spaceship Earth GLE Monitor (Minute Resolution)

Important Note: This is a plot of nearly raw realtime data, recommended for use only by those familiar with interpretation of neutron monitor data. A display format more useful for nonspecialists is under development.

DISPLAY FORMAT
Pressure corrected 1-minute data from several Spaceship Earth stations and a few other high-latitude stations are displayed.

USE OF THIS PLOT
This plot can be used as an early warning of a large solar energetic particle event. Look for a smooth rise at one or more stations (preferably more) occuring over a period of 15 minutes or more, followed by a (usually) slower decay. Generally these displays will be of interest only during cosmic ray ground level enhancements (GLE) or major Forbush decreases. Most of the time the displayed variations are simply statistical noise. Isolated spikes are probably data glitches and should be ignored if unconfirmed by other stations.

Cosmic Ray Flow Direction

Important Note: This plot is an experimental prototype. The display format may change at any time. Refer here for a brief explanation of the current display format.

DISPLAY FORMAT
Top Panel: ACE magnetic field magnitude |B| (green), north-south component Bz (pink-red) in GSE coordinates, and 1-hour estimated Kp index (blue).
Second Panel:Cosmic ray density determined by fitting a first-order anisotropy to available Spaceship Earth stations.
Third Panel:Cosmic ray flow direction projected into ecliptic plane, as determined by fitting a first-order anisotropy to Spaceship Earth data. The GSE X-axis points toward the Sun (upward in the plot), and the Y-axis points opposite the direction of Earth's revolution about the Sun (leftward in the plot). Each red line segment represents an hourly measurement of the anisotropy, with the base plotted at the time of measurement, and the head oriented according to the direction and magnitude of the anisotropy. We follow the meteorological convention, i.e., arrows point in the direction that the flow is coming from.
Fourth Panel:Cosmic ray flow direction projected into a plane oriented normal to the Earth-Sun line, as determined by fitting a first-order anisotropy to Spaceship Earth data. The GSE Z-axis points northward of the ecliptic plane (upward in the plot), and the Y-axis points opposite the direction of Earth's revolution about the Sun (leftward in the plot). Each red line segment represents an hourly measurement of the anisotropy, with the base plotted at the time of measurement, and the head oriented according to the direction and magnitude of the anisotropy. We follow the meteorological convention, i.e., arrows point in the direction that the flow is coming from.

USE OF THIS PLOT

This plot specifies current conditions in the nearby interplanetary medium. It simply tells which way the (cosmic ray) wind blows and how strongly.

Individual Station Count Rates

This plot displays neutron rates at individual stations. It should be self-explanatory. Only McMurdo is displayed above, but clicking the link will transfer to a page where six stations (South Pole, McMurdo, Thule, Inuvik, Fort Smith, and Newark) are displayed in a similar format.

Other Cosmic Ray Displays (not realtime)

  • Solar Modulation Plot. Pressure-corrected McMurdo neutron rate (27-day means) along with monthly sunspot number from 1960 to the present. Typically updated monthly.
  • Six-Month Plot. Pressure-corrected count rates for the past 6 months at multiple (~15) stations, along with Kp and Dst. Typically updated daily. (Note: SPoleN is a standard 3NM64 at South Pole, while SPoleB is our "Polar Bare," a 3NM64 without the usual lead shielding.) It responds to a slightly lower energy primary cosmic ray than the standard monitor.
  • Multi-Year Plot. Pressure-corrected count rates from 2000 September 8 to the present for multiple (~8) stations, along with Kp and Dst. Depending upon your browser settings, you may need to expand the image and scroll to view the entire plot. (Note: SPoleN is a standard 3NM64 at South Pole, while SPoleB is our "Polar Bare," a 3NM64 without the usual lead shielding. It responds to a slightly lower energy primary cosmic ray than the standard monitor.)
  • Longer Multi-Year Plot. Similar to previous, but goes back to 1998 for some stations.

This space weather site is operated with support of the U.S. National Space Weather Program under NSF grant ATM-0207196.

Spaceship Earth is supported by the U.S. National Science Foundation under grant ATM-0000315, with participation by IZMIRAN, Polar Geophysical Institute (Apatity), Australian Antarctic Division, and University of Tasmania.

The muon detector network is a joint project of the University of Delaware (NSF support from grant ATM-0207196), Shinshu University, Nagoya University, Southern Space Observatory of INPE, University of Santa Maria, Australian Antarctic Division, and University of Tasmania.

Any opinions, findings and conclusions or recomendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation (NSF).

Send feedback to John W Bieber