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Welcome to Equatorial-PRIMO
(Problems Related to Ionospheric Models and Observations)
• Original PRIMO dealt with mid-latitude
comparisons
• Most theoretical models underestimated the
noon-time, Nmax values by a factor of 2 at solar
maximum
• It’s appropriate to start a multi-year,
Equatorial-PRIMO with similar goals as the
original PRIMO workshops
Transport Processes in the Equatorial Ionosphere
Equatorial-PRIMO
(Problems Related to Ionospheric Models and Observations)
We do not fully understand all the relevant physics of the equatorial ionosphere, so
that current models do not completely agree with each other and are not able to
accurately reproduce observations.
To understand the strengths and the limitations of theoretical, time-dependent, lowlatitude ionospheric models in representing observed ionospheric structure and
variability under low to moderate solar activity and geomagnetic quiet conditions, in
order to better understand the underlying ionospheric physics and develop improved
models.
The vertical drift and global electric field at equatorial region are calculated through
the electrodynamics process which is strongly controlled by the neutral wind
velocity, ionospheric conductivity, and geomagnetic field. Comparing the
similarities and dissimilarities of inputs and outputs among different models as well
as the observations helps us to evaluate the reliability of existing physics.
A set of theoretical ionospheric models require neutral atmospheric densities and temperatures,
neutral winds, ExB drift velocities as inputs and calculate and Ion and electron densities as a
function of altitude, latitude and local time. Their calculations are not self-consistently.
– The Utah State University (USU) ”Ionospheric Forecast Model (IFM)”
– The Space Environment Corporation (SEC) “Low Latitude Ionospheric Specification Model
(LLIONS)”
– The AFRL “Physics Based Model (PBMOD)”
– The “Global Ionosphere and Plasmasphere (GIP)” model.
– The NRL “Still Another Model of the Ionosphere 2 (SAMI2)”
The other set of ionosphere-thermosphere models are time dependent, three dimensional, non-linear
models which solve the fully coupled, thermodynamic, and continuity equations of the neutral gas
self-consistently with the ion energy, ion momentum, and ion continuity equations.
– The NRL “Still Another Model of the Ionosphere 3 (SAMI3)”
– The Coupled Thermosphere Ionosphere Plasmasphere Electrodynamics (CTIPe) model
– The NCAR “Thermosphere-Ionosphere-Electrodynamics general circulation model (TIEGCM)” and “Thermosphere-Ionosphere-Mesosphere-Electrodynamics general circulation
model (TIME-GCM)”
– University of Michigan “Global Ionosphere-Thermosphere Model (GITM)”
– Integrated Dynamics through Earth’s Atmosphere (IDEA).
Equatorial-PRIMO
(Problems Related to Ionospheric Models and Observations)
13:30 – 13:35
Introduction of Equatorial-PRIMO Workshop
13:35 – 13:40
Jan Sojka – IFM
13:40 – 13:45
Vince Eccles – LLIONS
13:45 – 13:50
John Retterer – PBMOD
13:50 – 13:55
Tzu-Wei Fang – GIP
13:55 – 14:05
Joe Huba – SAMI2 and SAMI3
14:05 – 14:10
Art Richmond – TIE-GCM
14:10 – 14:15
Geoff Crowley – TIME-GCM
14:15 – 14:20
Aaron Ridley – GITM
14:20 – 14:30
Tim Fuller-Rowell – CTIPe and IDEA
14:30 – 15:30
Round-table Discussion
Burnside Factor (the collision frequency between O+-O) in the topside was multiplied
by 1.7. But today, the evidence suggests the factor is closer to 1.0.
Self consistent model – TIGCM and GTIM
[Anderson et al. JGR, 1998]
For self-consistent models, the
diurnal variation of vertical
drift at magnetic equator in
Jicamarca longitude and the
longitudinal variation of
equatorial vertical drift at
0UT. Height variation of drift
at daytime and nighttime.
model vertical drifts
50
30
10
-10
-30
-50
0
4
8
12
LT (hr)
16
20
[Scherliess and Fejer, 1999]
The zonal and meridional wind velocity (Lon vs. ±60° Lat at 0UT) at 120 km (or E
region) and 300 km (or F region) used as specified input or generated by the model.
For self-consistent models, the daytime and nighttime Pederson and Hall
conductivities (±30° Lat vs. height) in Jicamarca longitude.
http://wdc.kugi.kyoto-u.ac.jp/ionocond/sigcal/index.html
The daytime and nighttime electron density distribution (±30° Lat vs. height) at
Jicamarca longitude.
Equatorial-PRIMO
(Problems Related to Ionospheric Models and Observations)
(a) Chemical reaction rates, photoionization processes, diffusion coefficients,
nighttime ionization?
(b) Boundary conditions, numerical techniques, spatial resolution?
(1) The zonal and meridional wind velocity (Lon vs. ±60° Lat at 0UT) at 120 km (or
E region) and 300 km (or F region) used as specified input or generated by the
model.
(2) The daytime and nighttime electron density distribution (±30° Lat vs. height) in
Jicamarca longitude.
(3) For self-consistent models, the daytime and nighttime Pederson and Hall
conductivities (±30° Lat vs. height) in Jicamarca longitude.
(4) For self-consistent models, the diurnal variation of vertical drift at magnetic
equator in Jicamarca longitude and the longitudinal variation of equatorial
vertical drift at 0UT.
(5) For self-consistent models, the height variation of vertical drifts at magnetic
equator in Jicamarca longitude during the daytime and nighttime.