Thank you for your interest in SOHO EIT data analysis.

Proposal ID Neupert_9

Date of Proposal

Werner M. Neupert

Hughes STX Corp. (NASA/Goddard)

Code R/E/SE /NOAA 325 Broadway, Boulder CO




Short Title: A comparison of Coronal Limb Observations and the
Development of Coronal EUV Proxies

Keywords: EUV proxies; coronal indices

Proposal: We propose to study the correlations in limb
observations of the solar corona as observed by EIT, by the
LASCO C1 coronagraph and by ground-based coronagraphs. The
comparisons will be made principally in the ions of Fe,
comparing EIT's Fe IX/Fe X channel with the "red line" of Fe
X, the FE XII channel with the "green line" of Fe XIV and
the Fe XV channel with the "yellow line" of Ca XV. Coronal
indices will be calculated from the limb observations and
compared with full-disk EUV fluxes from EIT images. The
objective is to evaluate the use of limb observations in
deriving solar coronal EUV proxies. In addition, the
comparison of EUV and visible data may lead to a study of
the relative importance of collisional excitiation and
radiative excitation in the low corona.

Specific tasks will be to:

Compare EIT emission above the solar limb and LASCO C1 data
with ground-based data as a function of position angle and
height above the limb;

Compare coronal indices derived from LASCO and ground-based
observations with actual total disk fluxes derived from EIT
images by summation over all pixels.

Compare the coronal indices so derived, as a function of
time, with other indices of solar variability such as the 10
cm microwave flux, and with total solar EUV output as
measured by the SEM on SOHO to evaluate the suitability of
using a coronal index based on limb observations in place of
the currently used microwave (F10) index as a measure of
coronal EUV variability.

Examine any deviations between EUV and visible emission in
terms of the relative importance of electron collisional
vs. radiative excitation of the ions.

Routine synoptic images recorded by EIT on a daily basis as
the primary data input. However, to evaluate a potential
source of error due to non-simultaneity of space and ground-
based measurements, we will also request SOHO observations
by EIT (possibly only an annulus around the solar limb) at
times when observations are routinely made at ground-based
coronal observing stations.

EIT Consortium Collaborators: D. Michels

LASCO Collaborators: R. Schwenn and others TBD.

External collaborators: R. Altrock, Sac Peak Observatory,
NSO, and others TBD



A comparison of Coronal Limb Observations and the
Development of Coronal EUV Proxies

Please describe additions or updates to your proposal.

You must click the "submit" button in order to enter your proposal update. Thank you.

Return to the EIT home page.