These plots provide an overview of high resolution (2 spin or 12 s) upflowing ion (pitch angles less than 25 degrees) energy distributions and net ion outflow for perigee passes from launch until December 8, 1998.

First (top) color panel
• Energy distribution of H+ obtained by integrating over the pitch angle range 0 < pitch angle < 25 degrees
• Number flux in units of 1/(cm^2-s-sr-keV/e) is encoded using the color bar on the right
• All perigee data are from the southern hemisphere, so a pitch angles from 0 to 25 degrees corresponds to ions flowing up the field line from the ionosphere below.
• The energy range displayed is from 15 eV/e to 33 keV/e.
• Striped spectra indicate that the upflowing ion distribution changed significantly in the 2 spins required to sample both even and odd numbered energy steps. As noted in the instrument description, even and odd numbered energy steps are sampled on alternate spins.

Second color panel
• Energy distribution of O+ obtained by integrating over the pitch angle range 0 < pitch angle < 25 degrees
• Same format as first color panel.

Solid lines between second and third color panels
• Color of upper line indicates source of H+ and O+ data
• Color of lower line indicates source of He+ data shown in the third color panel.
• Green indicates data are from PAD data products and therefore have the highest angular resolution (~11 degrees) available from the TIMAS instrument.
  • PAD's (Pitch Angle Data product) are intended to provide the maximum angular resolution attainable from the TIMAS where it is reasonable to assume the distributions are gyrotropic in the measurement frame. PADs are again specified independently by detector half and M/Q; however, they are further specified by the number of pitch angle elements required and whether or not the data are summed over adjacent energy steps. The Data Processor uses the MAGAZ and MAGEL signals provided by the spacecraft to select the 9 detector sector elements that best characterize the pitch angle distribution for each detector half in either the first or both spin sectors that intercept the magnetic field vector within the TIMAS field of view. Each PAD consists of 63, 126, or 252 energy, pitch-angle elements. See This Page for more information about on board acquisition and processing of data.
• Orange indicates the data are from MRDF data products with medium angular resolution (~22 degrees).
  • As with the LRDF described below, the MRDF are defined independently by detector half and M/Q; however, MRDF are always for a single spin period. MRDF are generated from the spin buffer by summing over two adjacent detector sectors and summing over two adjacent spin sectors for the elements nearest the spin axis, thus producing an array of 104 solid angle elements per detector half. The MRDF may be specified to be further summed over adjacent energy steps (i.e. adjacent odd or adjacent even depending on spin). Thus each (of eight possible) MRDF is a 3-D distribution with either 728 or 1456 velocity space elements. See This Page for more information about on board acquisition and processing of data.
• RED indicates the data are from LRDF data products with low angular resolution (~45 degrees).
  • Data from each detector half and each M/Q are treated separately and can be integrated over 2^N spin periods (0 <= N <= 5), thus 8 separate LRDF are possible. LRDF are generated from the spin buffer data by summing over adjacent even and/or odd energy steps, summing over two adjacent spin sectors, and summing over four adjacent detector sectors except for those nearest to the spin axis which are summed over 2 sectors. Thus each LRDF represents a 3-D distribution with 224 velocity space elements (7 energy x 8 spin angles x 4 polar angles). This resolution is sufficient to characterize most magnetospheric ion distributions. See This Page for more information about on board acquisition and processing of data.

Third color panel
• Energy distribution of He+ obtained by integrating over the pitch angle range 0 < pitch angle < 25 degrees
• Same format as the first color panel

Line plots labeled Ion Fluence on the left.
• Upward directed ion fluence in units of cm^2/s for H+ (red), O+ (orange), He+ (green) and the sum of them all (blue) derived from full angular distributions. displayed in the color panels above.
• The data have NOT been normalized to a uniform altitude.
• Intervals with fluxes below 10^5 could be regions with a net downflowing fluence of ions.
• Statistical summaries of the net fluence of ions derived from data such as these can be found in the following papers:
  • The Seasonal Variation of Auroral Ion Beams, H.L. Collin, W.K. Peterson, O.W. Lennartsson, and J.F. Drake, Geophysical Research Letters, 25, 4071, 1998.

  • Polar/TIMAS Observations of Suprathermal Ion Outflow During Solar Minimum Conditions, W.K. Peterson, H.L. Collin, A.W. Yau, and O.W. Lennartsson, J. Geophys. Res., 106, 6059, 2001.

  • Solar wind control of Earth's H+ and O+ outflow rates in the 15-eV to 33-keV energy range, O.W Lennartsson, W.K. Peterson, and H.L. Collin, J. Geophys. Res., Vol. 109, No. A12, A12212 10.1029/2004JA010690, 15 December 2004.

  • Quiet time solar illumination effects on the fluxes and characteristic energies of ionospheric outflow, W.K. Peterson, H.L. Collin, O.W. Lennartsson and A.W. Yau, J. Geophys. Res., 111, A11S05, doi:10.1029/2005JA011596, 2006.

  • Solar-minimum quiet-time ion energization and outflow in dynamic boundary related coordinates, W.K. Peterson, L. Andersson, B.C. Callahan, H.L. Collin, J.D. Scudder, and A.W. Yau, To appear in J. Geophys. Res., 2008.

  • The line plot panel labeled N (density) on the left and V
    • Ion density in units of cm^-3 for H+ (red), O+ (orange), He+ (green) and the sum of them all (blue) derived from full angular distributions.
    • The dotted black line indicates the Space Craft desity derived from the spacecraft potential determined by the EFI instrument on Polar.

  • The line and number panel labeled BCR ICP and E Range on the left
    • The solid line gives the Background Counting Rate (BCR) in a log scale. No scale is indicated. Values near the top of the panel indicate regions where the signal (and therefore the information in the color panels above) is degraded because of high background counting rates.
    • The color of the BCR rate line indicates instrumental status. Green indicates OK. Orange indicates that caution should be used in applying the data. Red indicates that the data are not valid.
    • The TIMAS mode in use at the time is indicated by its ICP Table #. For a description of TIMAS modes by ICP table # see the TIMAS Mode description page
    • The color of the solid line above the UT information encodes the energy range sampled by the TIMAS instrument. Green indicates full ( 15 eV < E/q < 33 keV). Orange indicates the reduced energy range ( 15 eV < E/q < 25 keV ). Red indicates the low energy range ( 15 eV < E/q < 2 keV ).
  • Information about the orbit in tabular format
    • UT: Universal time in hours:minutes
    • R(Re): Geocentric distance of Polar in units of Earth radii
    • L(Re): McIlwain L parameter at the location of Polar
    • MLT(Hr): Magnetic Local Time at the location of Polar in decimal hour format
    • MagLAT: Geomagnetic Latitude at the location of Polar in degrees.
    • InvLat: Invariant Latitude at the location of Polar in degrees.

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  Prepared by WK (Bill) Peterson, May 2008

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