Physics Department Seminar | University of Alaska Fairbanks |
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J O U R N A L C L U B |
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Uncertainty
quantification of the ionosphere-thermosphere conditions
associated with the solar wind |
by |
Weijia Zhan |
University of Colorado Boulder |
ABSTRACT Information
of the uncertainty in the ionosphere-thermosphere (IT)
system is important to make probabilistic predictions of space
weather events (i.e., equatorial ionospheric irregularities),
satellite or debris obits (i.e, neutral density and atmospheric
drag), and impacts on HF communications (i.e., HmF2). In this
study, we apply uncertainty quantification (UQ) methods to
quantify the variability of the IT conditions associated with the
uncertainty of the solar wind by using the whole atmosphere model
with ionosphere-plasmasphere dynamics (WAM-IPE) model. To apply
the UQ method and conduct sensitivity analysis, historical
measurements of solar wind velocity, density, and interplanetary
magnetic field (IMF) Bz are fed into a neutral network
(variational autoencoder, VAE) to reduce the dimensions of input
parameters and generate new solar wind samples to drive WAM-IPE.
Polynomial chaos expansion (PCE) is then applied to quantify the
uncertainty of the quantities of interest (QoIs) from the outputs
of WAM-IPE. Electron densities, plasma drifts, and neutral winds
from 6 magnetic equatorial and low latitude locations are selected
as QoIs. The uncertainties of these QoIs will be compared with
previous observations and numerical simulations. Sensitivity
analysis will be conducted to identify the drivers that contribute
the most to the uncertainty of the QoIs. |
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Friday, 18 November 2022 |
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Only on Zoom : https://alaska.zoom.us/j/88028763203?pwd=cmxjNVA0aGFmdTBONUJyUERDOXF2Zz09 | |||
3:45PM |