Northwest Research Associates, Inc.

Main Pages: [ NWRA SpaWx Services Home | SpaWx Indices Home | Scintillation Home | Scintillation Services Home | NWRA Tucson Home ]
Graphics: [ F10 | Ap | F10/Ap Forecasts | SSNe | SSN Comparison | 24hr SSNe | Auroral Boundary (TIROS) | Auroral Qe Index (DMSP) ]
Listings/Reports: [ Indices Table | Events | RSGA | SGAS | SRS ]

How Effective are Effective-SSN Values?

Plot of foF2 Obs/Model

This page links to plots comparing ionospheric parameters calculated from models using effective SSN values (the NWRA and the IPS T-index values) to foF2 observations and 7-day means for a variety of stations. Note that not all of the data shown in these plots went into the SSNe calculations. All stations above a geomagnetic latitude of 50deg were excluded, and some of the data were not received prior to the SSNe calculations.

The foF2 parameter shown in these plots, and used in generating the two effective SSN indices, is defined as the highest frequency which will reflect from the main (F2) layer of the ionosphere on a vertical propagation path. It is measured at a number of locations around the world using an instrument known as an ionosonde. The "o" in foF2 indicates that it is for the "ordinary" propagation mode (as opposed to the extraordinary, or "x", mode). More details on this measurement and on ionosondes can be found at the National Geophysical Data Center (NGDC) ionospheric WWW site.

All plots have the same format as the one shown above. The foF2 observations for the UT day from the station are plotted as + symbols, and the 7-day mean foF2 are plotted as * symbols. The lines are foF2 values calculated from the CCIR foF2 model (the URSI-88 coefficients) using the NWRA SSNe (solid line) and the IPS T (dashed line).

To hourly SSNe24 plot
To 24-day SSNe24 plot


Comparisons are available for the following stations:


Geographic Geomagnetic
Station Name IUWDS Latitude Longitude Latitude Longitude
*Qaanaaq 17801 77.5 -69.2 86.6 319.5
*Sondrestrom - 67.0 -51.0 74.0 41.0
*Dixon 38701 74.0 81.0 68.8 156.8
*Tromso - 69.7 18.9 67.0 104.2
*Narssarssuaq 14601 61.0 -45.0 67.0 43.7
*College 25602 64.0 -147.0 64.5 263.5
*Murmansk 03702 68.0 33.0 64.5 113.9
*Gakona - 62.0 215.0 63.1 266.8
*Goose Bay 16501 53.3 -60.4 62.6 22.3
*Lycksele - 64.6 18.7 61.9 100.2
*Salekhard 37701 66.0 66.0 61.7 141.2
*King Salmon - 59.0 -157.0 57.9 258.4
*Millstone Hill - 42.6 -71.5 54.0 5.2
*Magadan 45601 60.0 151.0 53.9 218.0
*Tomsk 08601 56.0 85.0 51.6 157.1
*Juliusruh 31506 54.0 13.0 50.8 90.7
*Bear Lake - 41.9 -111.4 50.4 310.9
Boulder 20401 40.0 -105.2 49.7 318.8
Fairford - 52.0 1.0 49.4 80.1
Chilton - 51.6 -1.3 49.1 78.1
Wallops Island 17402 37.0 -75.0 49.0 359.6
Warsaw 32507 52.0 21.0 48.3 96.8
Pruhonice - 50.0 15.0 46.3 91.1
Manzhouli 42503 49.0 117.0 43.5 189.1
Dyess AFB 19302 32.0 -99.0 42.5 327.5
Bermuda 16301 32.0 -64.0 42.5 13.9
Eglin AFB 19303 30.0 -86.0 42.1 344.0
Khabasrovsk 03501 48.0 135.0 41.6 206.1
Point Arguello 22306 34.0 -120.0 40.6 303.4
Wakkanai 44408 45.4 141.7 38.7 212.1
Rome - 41.8 12.6 36.8 87.4
Roquetes - 41.0 0.0 36.3 76.4
San Vito - 40.6 18.0 35.4 92.0
Beijing 42404 40.0 116.0 34.1 187.9
Athens - 38.1 23.9 32.6 97.1
Ashkhabad 36401 37.0 58.0 32.4 130.0
El Arenosillo - 37.0 353.0 32.0 69.8
Osan AFB 43404 37.0 127.0 30.5 198.5
Ramey 78514 18.5 -67.2 30.3 7.7
Kokubunji 44403 35.7 139.5 28.7 210.2
Chongqing 41305 29.0 106.0 22.6 177.5
Okinawa 43301 26.0 128.0 18.9 199.1
Guangzhou 41206 23.0 113.0 16.0 184.2
Kwajalein - 9.4 167.4 4.0 237.4
Jicamarca - -11.9 -76.0 0.9 355.1
Vanimo - -2.7 141.3 -11.8 212.6
*Ascension Island - -8.0 -14.6 -17.0 54.0
Port Moresby - -9.4 147.1 -18.6 219.2
Darwin 83101 -12.0 131.0 -22.3 202.5
Nuie - -19.0 170.0 -25.3 245.0
Townsville 85201 -19.0 147.0 -28.9 220.4
Madimbo - -22.0 31.0 -32.8 99.7
Learmonth 81202 -21.0 115.0 -32.9 185.7
Norfolk Island - -29.0 168.0 -36.5 245.4
Brisbane - -27.0 153.0 -36.9 228.4
Port Stanley - -51.7 -57.8 -38.3 10.4
Louisvale - -29.0 21.0 -38.6 86.6
Grahamstown - -33.0 27.0 -41.9 91.1
Camden 85305 -34.0 151.0 -44.7 227.7
Mundaring 82303 -32.0 116.0 -45.1 186.0
Canberra 85302 -35.0 149.0 -46.0 225.6
*Christchurch - -43.0 172.0 -50.5 255.1
*Hobart 85401 -42.0 147.0 -53.8 225.2
*MacQuarue Island 86501 -54.0 159.0 -64.4 246.9
*Mawson - -67.6 62.9 -71.0 91.4
*Scott Base - -77.0 166.0 -80.3 320.0
*Casey 81701 -66.3 110.5 -80.8 157.5

[NOTE: Stations marked with an * were not included in the SSNe calculation because they are above the high-latitude cutoff (poleward of 50deg geomagnetic latitude).


AKNOWLEDGEMENT:
The fof2 data used in these plots came from the NOAA Space Environment Center. The IPS T index came from the Australian IPS Radio and Space Services organization..

NWRA Tucson Links

[ NWRA Tucson Home Page | Space Weather Home Page | Scintillation Home Page ]

[ Home | Site Map | Company | Staff | Research Areas | Services | Products ]

How to contact NWRA

Copyright © 1996-2003 NorthWest Research Associates, Inc.  All rights reserved.