Global Solar Magnetic Field Maps Action Team (S2-03)�

Key Question:

How best to address the challenges and limitations of creating global solar magnetic field maps, which serve as the primary input for coronal and solar wind models.

Key Science Gaps

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1. The primary challenge of global magnetic map making is how best to account for the two thirds of the solar surface unobserved at any given time.

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• A major drawback with standard Carrington (time history of central meridian) synoptic maps is that space and time are mixed. The community needs to move toward synchronic (instantaneous), rather than traditional diachronic, maps using flux transport models (or direct measurements (e.g., GONG/HMI+ PHI).

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• How best to data assimilate multiple sources to update maps?

Goal of session is to discuss possible methods for quantitatively validating and comparing photosphere magnetic field maps (directly or indirectly).

Session Goal

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Direct (Simple) Methods

• Advantages – allows simple comparisons of different types of maps (diachronic, synchronic) to be easily compared

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Mean

Polar Fields

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Examples:

1. Mean
2. Polar Fields
3. Spherical harmonics (1^st few)
4. Total flux?
5. Weak fields
6. Others?

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Key Question: How best to develop an ensemble set of photospheric field input maps that truly represents the uncertainty in the state of the global magnetic field distribution.

Reviewed and discussed 2 flux transport models.

• PSI’s Open Flux Transport (OFT) Model
• Air Force Data Assimilative Flux Transport (ADAPT) model

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Potential metrics

• Briefly discussed metrics to compare maps
• Plan to meet in Boulder to discuss methods for comparing multiple flux transport models