
NOAA > NESDIS > NGDC > stp > solar	comments \| privacy policy

COSMIC RAY NEUTRON MONITOR DATA

1.) Cosmic Ray Neutron Monitor data daily and monthly averages from a worldwide network 1953-present

2.) Cosmic Ray Forbush Decreases (FDs) from Mt. Washington Observatory 1955-1995

3.) Cosmic Ray Ground Level Enhancements (GLEs) 1942-2001 -- M.A. Shea and D.F. Smart

4.) Annals of the International Geophysical Year bihourly Neutron Monitor, Cubical Telescope, Vertical Telescope, Ion Chamber, Underground Telescope and Shower Apparatus data monitored during the July 1957-December 1959 IGY and International Geophysical Cooperation (IGC) time period.

Cosmic Ray Neutron Monitors Daily and Monthly Data (All ftp)

See the descriptive text about cosmic rays. Cosmic rays affect satellite electronics and ground-based computer systems at high altitudes -- see Terrestrial Cosmic Rays and Soft Errors, IBM experiments in soft fails in computer electronics, IBM Journal, Vol. 40, 1996. Engineers can find useful information about soft errors in electronics from cosmic rays on the Particle Interactions with Matter website. The high energy particles affect airplane passengers -- the FAA has an online cosmic ray airline flight profile calculation available. These effects are especially augmented during large solar particle events. During these times, polar flights are generally diverted to lower latitude flight paths.

Cosmic Ray Tabulated Observations -- The tables present the daily (UT) average counting rates per hour (scaled) for about seven high counting rate neutron monitors: Thule, Deep River, Kiel, Climax, Beijing, Tokyo, and Haleakala. The characteristics of the stations are given below; the data are corrected applying the barometric coefficients to the listed standard station pressure.

Cosmic Ray Neutron Monitors

Geographic
Station	Lat. North	Long. East	Cutoff GV*	Alt. m	Scaling Type	Scaling Factor	Baro. coeff. %/mm Hg	Standard press. mm Hg
Thule	76.50	291.30	0.00	44	NM 64	100	0.99	754
Deep River	46.10	282.50	1.07	145	NM 64	300	0.987	747
Calgary	51.08	245.87	1.09	1128	NM 64	300	1.0155	671.1
Kiel	54.34	10.12	2.32	54	NM 64	100	0.961	755
Climax	39.37	253.82	2.97	3400	IGY	100	0.962	504
Beijing	40.08	116.26	9.56	47	NM 64	256	0.75%/mb	624.8
Tokyo	35.75	139.72	11.50	20	NM 64	256	0.888	760.5
Haleakala	20.71	203.07	13.30	3052	NM 64	1000	0.962	518

Calculated by DGRF75 (COSMIC RAY TABLE No.1, ed. WDC-C2 Japan, March 1983).

Hourly data for many stations are available in the Space Physics Interactive Data Resource (SPIDR) database management system -- an inventory of the data is available.

1. Cosmic ray neutron monitor data -- daily and monthly averages from a worldwide network 1953-present

Description of the data (text)
- Daily values in annual tables
  - Beijing -- Monthly values 1993-present
    - 1993 1994 1995 1996 1997 1998 1999
    - 2000 2001 2002 2003 2004 2005 2006 2007 2008
  - Calgary Monthly values 1964-present
    - 1994 1995 1996 1997 1998 1999
    - 2000 2001 2002 2003 2004 2005 2006 2007 2008
  - Climax -- Monthly values 1953-present
    - 1989
    - 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
    - 2000 2001 2002 2003 2004 2005 2006
  - Deep River -- Monthly values 1958-present
    - 1989
    - 1990 1991 1992 1993 1994 1995
  - Goose Bay
    - 1996 1997 1998 1999
    - 2000
  - Haleakala -- Monthly values 1953-present
    - 1994 1995 1996 1997 1998 1999
    - 2000 2001 2002 2003 2004 2005 2006
  - Huancayo -- Monthly values 1953-present
    - 1989
    - 1990 1991 1992 1993
  - Kiel -- Monthly values 1958-present
    - 1989
    - 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
    - 2000 2001 2002 2003 2004 2005 2006 2007 2008
  - Moscow -- Monthly values 1958-present
    - 1994 1995 1996 1997 1998 1999
    - 2000 2001 2002 2003 2004 2005 2006 2007 2008
  - Thule
    - 1989
    - 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
    - 2000 2001 2002 2003 2004 2005 2006 2007 2008
  - Tokyo
    - 1989
    - 1990 1991 1992 1993 1994 1995

2. Cosmic Ray Forbush Decreases (FDs) from Mt. Washington Observatory 1955-1995 data -- (N44.30 E288.70; Cut-off Rigidity = 1.24 GV; Altitude 1900 m) -- Forbush decreases are abrupt decreases of the background galactic cosmic ray intensity as observed by neutron monitors. They are associated with major plasma and magnetic field enhancements in the solar wind at or beyond the earth. These magnetic field enhancements deflect the background cosmic ray particles. The phenomenon is named after Scott Forbush who studied them extensively.

Table of YYMMDD and percent decrease of daily averages (text) -- dn/n% less than 3% are not included
- Plottable x-y file of YYMMDD and percent decrease (text)
- Supplemental List -- Mt. Washington Forbush decreases -- Remarks are included.

3. Cosmic Ray Ground Level Enhancements (GLEs) 1942-2001 -- M.A. Shea and D.F. Smart -- GLEs are sharp increases in the gound-level cosmic ray count to at least 10 percent above background, associated with solar protons of energies greater than 500 MeV. GLEs are relatively rare, occurring only a few times each solar cycle. When they occur, GLEs begin a few minutes after flare maximum and last for a few tens of minutes to hours. Intense particle fluxes at lower energies can be expected to follow this initial burst of relativistic particles. GLEs are detected by neutron monitors, e.g., the monitor at Thule, Greenland.

List of GLEs -- includes the event number (1 to 65), event date, and some information about the baseline data used to determine the magnitude of the event. The Australian Antarctic Division maintains a listing of GLEs 1942 to the present.

4. Annals of the IGY Data -- ANNALS OF THE INTERNATIONAL GEOPHYSICAL YEAR (IGY) Volumes XXVI, XXVII and XXVIII (26, 27, and 28), Editor J.A. Simpson, CSAGI Reporter for Cosmic Rays

Explanation of the IGY Data Tables

TABLES OF IGY COSMIC RAY DATA Part I
TABLES OF IGY COSMIC RAY DATA Part II
TABLES OF IGC COSMIC RAY DATA Part III

NOTE: These cosmic ray data are published in three volumes of the Annals of the IGY. Data were stored on 5 1/4 inch floppy diskettes and converted in 2005 to more recent storage media. Originally they were stored on punched cards. Not all station data published in the Annals have been found.

These bihourly cosmic ray databases include Neutron Monitor (46 stations), Cubical Telescope (38 stations), Vertical Telescope (2 stations), Ion Chamber (16 stations), Underground Telescope and Shower Apparatus (1 station) data monitored during the July 1957-December 1959 IGY and International Geophysical Cooperation (IGC) time period.

Go to top of this page.

go to Solar Data Services Home

NGDC home | disclaimers | questions

Website of the US Dept of Commerce/NOAA/NESDIS/NGDC, last update July 11, 2005