Summary of MDI progress in 2003 to 2005
with examples of work planned for the coming few years. This page created
Notes from MDI for use in preparing senior review of SOHO
operations, data processing, data analysis, and science investigations for
II. Previous Senior Reviews
The SOHO Prime Mission was from April 1996 through April 1998. The SOHO
program was reviewed along with other operating missions in the NASA SEC Theme
in June 1997. The result of that review was approval to continue SOHO
operations and science analysis for what was called the SOHO Solar Maximum
Science Program. This was followed by Senior Reviews in 2001 and 2003. The MDI
submission for the proposal development, the SOHO
proposal, and the final reports of the panels are linked on the following
III. MDI Science Contributions
MDI successfully provided
observations leading to discoveries and progress in understanding of a number
of topics during the SOHO prime mission and extended phases. MDI data
has contributed to at least 21 PhD dissertations, made significant contribution
to many symposia and workshops with refereed proceedings, and provided data for
c. 1352 papers as of August 2005. Of the papers, there were 17, 45, 164, 117,
121, 139, 253, 210, 217, 69 for the years 1996 to 2005
respectively. (Note: Some of these may inadvertently be press stories,
abstracts, etc. although I have tried to eliminate these from this count).
Some highlights of Helioseismology
research based on MDI observations. (.pdf)
highlights of magnetic field research based on MDI observations – links
to two papers. (.pdf)
IV. Proposed Investigations
There are many science investigation topics presently proceeding with the
support of MDI observations. The range of topics presently under investigation
is similar to the topics in the hundreds of papers published to date. Some
sample studies that require continued MDI observations in the declining and
near minimum phases of the present cycle are described here.
V. MDI Instrument Status
After nine and a half years of operation, MDI is basically working very
- MDI has made about ninety million
images. After on-board computations, it has delivered about fifteen
million raw data images to the ground.
- There is an expected
degradation in total light throughput likely due to changes in the front
window. The reduction in transmission to June 2005 was about 33% which corresponds to about 4% per year. The throughput is plotted at http://soi.stanford.edu/results/2005_MDI_sr_review/fd_transmission_mean.gif.
The jumps in early 2001, 2003 and 2004 correspond to changes in the full
disk exposure time from 150ms to 165ms to 180ms and presently to
195ms. The small jumps in 2004
and 2005 show the combined effect of operating SOHO
upside down, the Doppler gradient from solar rotation, and the
non-uniformity of the MDI filters.
- In March 2000 the MDI
shutter began to show a drop in exposure uniformity. The uniformity went
from a part in 12000 to a part in 4000. For the 165 ms this corresponded
to a jitter from one frame to the next of about 40 microseconds. The
pre-launch specification was 40 microseconds. The shutter has not degraded
further. In fact its performance continues to improve since we reduced the
optics package temperature in February 2002. The plots at http://mdisas.nascom.nasa.gov/shutter
show the trends. In particular the shutter_quality.gif plot shows the uniformity. The
shutter noise affects the helioseismology ONLY for degree l < 4 and adds noise to the
zero level of the magnetic field. The magnetic field zero is corrected by
analysis of the data (see Liu et al, 2002). If further degradation were to
begin we can reduce the shutter usage with some loss of science
opportunity. Since the shutter has not degraded below a part in 4000 we do
not presently plan to change the observing sequence.
- There is no detected change
in the CCD flat field except for variations with focus change.
- The drift in central
wavelength of the Michelson's has nearly stopped.
- The drift in best focus
position has moved the nominal focus setting back almost to the design
point. Shortly after launch it was at the limit of the adjustment range. This
drift has also apparently slowed.
In summary, there is no known limit to MDI's
useful life within the SOHO expected fuel life.
VI. MDI Data Processing
For the 2 year period ending 2005.06.30, the MDI data
processing system had archived 404 thousand datasets containing 19.4 Terabytes
of raw and processed data. Of this 81 thousand datasets containing 3.9
Terabytes contain the calibrated level 1.5 science data and 44 thousand
datasets totaling 6.8 Terabytes contain higher level science products. This
data resides on 86 high-density tape cartridges. Additional copies of the
level-0 data are maintained off-site.
The MDI data center has responded to 25 thousand individual online requests for
data amounting to about 25 Terabytes. Data exports in the two years ending
2005.06.30 included 9600 requests totaling 6.2 Terabytes. Most requests are for
multiple datasets. Requests for MDI data processed through the SOHO
archives at GSFC and the remote SOHO archives in Europe
are not shown here. Data export requests plots are shown at http://soi.stanford.edu/production/cumulative.html
VII. MDI Publication Record
For the list of 21 known Dissertations see: Dissertation List (Wachter
JOSO - Joint Organization for Solar Observations – Prize: Laurent Gizon was awarded the first JOSO
Roth Saubermacher Prize for an
outstanding paper by a young scientist. Dr. Gizon’s
work is in local helioseismology with MDI data. His dissertation is in the list above.
For list of Proceedings see: Conference Proceedings List
For list of Papers see: Paper
VIII. MDI Education and Public Outreach
Education and Public Outreach are important adjunct activities of the MDI
team. These activities include:
Release – MDI Co-Is at LMSAL presented a press release concerning the
coupling of evolving magnetic fields in the corona. Both TRACE and MDI data are used in this
study. This report extends prior understanding of the connection between field
changes in the photosphere and the types of dynamics in the corona. This understanding will help the
development of flare prediction techniques.
National Geographic – MDI images and consultation were used in the
July 2004 story on “Hot News From
Our Stormy Star”
of MDI images - The press used MDI images and interviews with MDI
scientists on a number of occasions including the 2003 transit of Mercury and
the October-November 2003 active regions and flares. The daily farside
images are often highlighted in stories in spaceweather.com.
- Space Weather Monitors -- In conjunction with NSF, the Stanford
has developed low-cost (~$150) space weather instruments that monitor and
track changes to the Earth’s ionosphere caused by solar
activity. The monitors were
designed and developed by teacher interns over a 2-year period and have
been beta-tested in local minority-serving high schools. 100 monitors,
funded by MDI, are currently in production, to be distributed to high
school and community colleges throughout the nation. The hope is to provide experience
with hands-on science and generate enthusiasm for science and technology
amongst young people, with a key target being students from
The International Heliophysical Year (IHY), 2007, Organizing
Committee and the United Nations have designated our Space Weather Monitors as
supported projects of the IHY. The
hope is to place 5 of these low-cost monitors in each of the 191 nations of the
(UN-designated) world. Funding is
being sought from private foundations.
- Our poster-spectroscopes, previously developed with MDI funding,
continue to be extremely popular.
During the last 2 years we have redesigned and reprinted the
instrument to be distributed in a flat format (instead of rolled up
poster), 11”x17” size, and perforated for punch-out. This saves about 20 minutes
of cutting and the instrument can now be assembled by a student in less
than 15 minutes. Class-size
packets of spectroscopes are provided to teachers through the nation. To date, we have distributed
roughly 40,000 spectroscopes.
- Teacher Workshops -- One of our scientists, John Beck, has
been working very closely with Lawrence Livermore Laboratory’s
Fusion-Astro Research Academy and the Edward Teller Education
Center to develop and present workshops for teachers throughout the
state. Spectroscopy is a key
topic for these workshops, and John has taught middle and high school
science teachers how to make and use our foldable spectroscopes.
- Participation in Earth& Sky SECEF workshop – MDI
team members participated in a workshop hosted by the SECEF and designed
for National Park Rangers. We
provided information and activities relating to the Sun and how
information on the Sun could be provided to the public through the
national parks. One of our
activities, a model of the Sun’s path during the solstices and
equinoxes, was particularly well-received and ended up being used in the
field and highly praised by one of the ranges.
- Student Workshops – MDI team members continue to give a
collection of workshops to local elementary, middle, and high school
students. New additions in the
last 2 years include Science Nights for elementary schools, Take Your Sons
& Daughters to Work spectroscope workshops, SUCCESS Summer Camp
workshops for under-served middle school girls, Reach for Tomorrow
workshops for underserved students nationwide, short activity workshops
for Community Day at Stanford, as well as the occasional teacher-requested
spectroscope workshop for local schools. During the last year we expanded
our repertoire by adding planetarium programs using a portable StarLab
planetarium. In conjunction with
the Lawrence Hall of Science, we are currently developing a solar-science
based program designed for use in small, interactive planetaria.
- Solar Center Website – We have continued development and
maintenance of our public information web site at http://solar-center.stanford.edu. To coordinate with NASA’s
educational theme of “Ancient Observatories – Timeless
Knowledge,” we developed a section on Native American Medicine
Wheels, which was highlighted and linked into NASA’s primary AO
website. The Solar Center
website now also includes an extensive section on the Space Weather
Monitor project mentioned above. We also had a new logo designed and
upgraded the “look” of the website.
- Distribution of informative and educational posters -- We
continue to distribute a collection of Sun-related posters and
informational material, as well as the spectroscopes. Most of the requests
are generated by our website, but we also distribute the materials at
public events such as "Sun-Earth Day" museum exhibits. During the last 2 years we estimate
to have distributed about 10,000 posters, 75% of which were spectroscopes.