| NSF Org: |
AGS Division of Atmospheric and Geospace Sciences |
| Recipient: |
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| Initial Amendment Date: | July 14, 2014 |
| Latest Amendment Date: | July 14, 2014 |
| Award Number: | 1444560 |
| Award Instrument: | Standard Grant |
| Program Manager: |
Ilia Roussev
AGS Division of Atmospheric and Geospace Sciences GEO Directorate for Geosciences |
| Start Date: | October 1, 2014 |
| End Date: | September 30, 2016 (Estimated) |
| Total Intended Award Amount: | $30,899.00 |
| Total Awarded Amount to Date: | $30,899.00 |
| Funds Obligated to Date: |
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| History of Investigator: |
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| Recipient Sponsored Research Office: |
1100 NE 45TH ST, STE 500 SEATTLE WA US 98105-4696 (206)556-8151 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
3380 Mitchell Ln. Boulder CO US 80301-2245 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): | SOLAR-TERRESTRIAL |
| Primary Program Source: |
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| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.050 |
ABSTRACT
The main thrust of this 1-year project is to debug and optimize the existent codes that are used to process data from the Imaging Vector Magnetograph (IVM) gathered during 1992-2006 (1.5 solar cycles). Historic data from the IVM have contributed to major advances in understanding the photospheric vector magnetic fields of active regions on the Sun. The main goal is to advance those data-processing codes of IVM data, so that the released archive of IVM data is of as high quality as possible for use by the broad solar community. Upon completion of this project, the available IVM data archive will be treated consistently, and it will ready for scientific analysis. This research project will contribute to improved community knowledge on handling imaging spectro-polarimetric data, which will have an impact on analyzing data from the future DKIST (formerly known as the ATST). The project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research.
A consistently produced archive of IVM data presents a unique data source for studying the long-term behavior of the Sun, since it allows for inversion-independent determination of magnetic field strengths in sunspots over 1.5 solar cycles. The IVM data have featured prominently in novel investigations of solar flares and their prediction --- a topic with societal impacts that range from communications disruptions to power-grid outages. The IVM data would contribute to the large statistical samples needed for further progress, complementing present data from SDO/HMI. Predicting solar flares, and quantitatively understanding the inter-cycle behavior of our Sun, are questions with potentially major impacts on today's society.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
The Imaging Vector Magnetograph (IVM) was a unique instrument run for over a decade at the U. Hawai`i for observing the solar magnetic fields. The PI has been involved in a small but long-running project to rescue the IVM data from decaying magnetic tapes, process the data to a scientifically useful product, and provide the data to the research community. This small NSF grant helped investigate problems with, and improve, the data reduction algorithms.
The results have been mixed. A few elements of the data reduction pipeline (which brings the raw data to a form ready for inversion) have been improved, such as the improved removal of some known artifacts. Other aspects, such as further improving the instrumental variations in time-series data, were not improved primarily due to lack of time. Regarding the inversion algorithm (which takes the calibrated spectra and produces solar magnetic field maps), the PI revisited previously identified options and confirmed that they were unsatisfactory (while identifying additional problems in the data reduction to address). The PI also attempted to mitigate problems in a probably more promising algorithm, but was unable to fully resolve the unsatisfactory performance. The continuing issues are likely in part due to subtle problems, still, in the data reduction.
Overall, this is a very complex instrument, data set, and set of codes with many inter-dependent issues. The PI was hopeful that the issues would be more straightforward, and that by following some of the approaches used, for example, for the Helioseismic and Magnetic Imager data inversion, the lingering problems would abate. But they did not, and there were insufficient resources to investigate even further. An older inversion method based on a hybrid used for initial guess plus full Milne-Eddington inversion, when used on spatially-binned data, is likely the best present option.
In the context of intellectual merit: the scope required to really get the data to be what the PI still believes they could be, is larger than was estimated originally, and any further efforts would benefit from other sources of expertise. In the context of broader impacts, the PI will undertake routine inversion and disambiguation of the data for distribution to the community, with a large "caveat emptor" on the distribution webpage.
Last Modified: 12/29/2016
Modified by: K.D. Leka
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