Early Magnetic Field Observations From HMI J. Todd Hoeksema and the HMI Magnetic Field Team: Yang Liu, Keiji Hayashi, Xudong Sun, Jesper Schou, Sebastien Couvidat, Xuepu Zhao, Rick Bogart, Priya Desai Steve Tomczyk, Juan Borrero, Rebecca Centeno Elliot K.D. Leka, Graham Barnes, Ashley Crouch M Turmon, P Schuck, T. Wiegelmann The rest of the HMI Team Stanford, HAO, CORA, JPL, GSFC, MPS HMI 2010.05.20_19:19:30 Early HMI Magnetic Field Observations
Abstract HMI, the Helioseismic and Magnetic Imager on SDO is producing a synoptic series of full-disk arc-second magnetograms. Longitudinal field will be determined every 45s and vector inversions computed every 12 minutes in patches. Higher level products will be produced including tracked AR patches, synchronic frames, NLFFF and MHD coronal field models, and photospheric flow maps Some quick-look products are available in minutes for space weather purposes. Early HMI Magnetic Field Observations
HMI Magnetic Field Observables • Line-of-sight magnetic field is computed from Doppler velocity in two polarizations, as for MDI. • Vector Field is computed from Stokes parameters derived from an independent set of polarized filtergrams. • The possibility of combining the two cameras is being explored to improve sensitivity. • The nominal line-of-sight cadence is 45 seconds. The basic vector field cadence is 90 or 135 seconds. • Vector field data products are the following quantities, uncertainties on each, and some covariances: – |B| - total flux – Filling factor (where possible) – Inclination (gamma) to the line of sight – Azimuth (phi) CCW relative to ‘up’ on the CCD camera – Magnetic line-of sight velocity • Data will be exported in a variety of coordinate systems: [ Bx,By,Bz ], [ B_total,gamma,phi ], and [ Br,Btheta,Bphi ] Early HMI Magnetic Field Observations
Magnetic Processing Scheduling There are four schedules for Magnetic Field data processing • Quick Look/Near Real Time – Routine processing on data available within minutes of observation • Standard – Routinely completed for all data on regular cadence (e.g. Vector B) after about 25 hours. • On Demand – Completed for small fraction of data when interesting things happen or whenever requested by a qualified user (HiRes MHD time series for a big flare & CME campaign • On Request – Products, such as high-resolution time series of MDH model solutions, will be generated as resources allow. Completed when system resources allow Early HMI Magnetic Field Observations
Definitive Science Observables – HMI Magnetic Field Images • Standard Pipeline Observables – 45-second • Magnetic line-of-sight field on full disk • Continuum intensity and line depth on full disk • Doppler velocity on full disk – 12-minute • Inverted vector B on full disk • Disambiguated B on selected patches • IQUV – 12-hour • Disambiguated vector field on full disk • On Demand – 180-second spatially binned disambiguated vector field in patches – 360-second disambiguated patches – 12-minute full disk disambiguated vector field • On Request – 90-second disambiguated patches – 90-second or other cadence IQUV – Anything else Early HMI Magnetic Field Observations
Additional Magnetic Field Model Products Produced as Standard ,On-demand, or On-request • Synoptic synchronic maps and frames • Automated Identification and Tracking of AR Patches and other features – 12 minutes • PFSS Model – Various resolutions and Cadences • Open Field Foot Point Maps • NLFFF Model – AR patches, daily and on request • MHD Models – Daily low-resolution – Monthly and major events in hi-res • Surface Flow Maps – ILCT, FLCT DAVE4VM Early HMI Magnetic Field Observations
HMI Space Weather and Quick-Look Browsing Products • HMI space weather and browse products can be computed in near real time from quick look data. They may be used for space weather forecasting or real time monitoring and display. They should not be used for scientific analysis, except perhaps to compare the quality of preliminary and definitive products. • HMI space weather and quick-look products will be coordinated with the Heliophysics Events Knowledge Base. These data products will complement the AIA Quick Look Browse Products • Proposed Space Weather Product LIST – Comments welcome! This list is preliminary and is not a commitment. Each product must have a prospective user. • Full Disk – Line-of-sight magnetograms (Blos) - 90-sec; 1K*1K resolution – Vector magnetogram, inverted & disambiguated - 12 hour – Movie of Blos - 12-day history, frames updated each 90 seconds • Active Region Patches (ARPs) – Identification of active region patches - 12 minute (hourly?) – Vector magnetic field in major ARPs, disambiguated - 12 minute – Time series of major ARP indices (since appearance, updated every 12 min • Location, orientation, separation, total flux, net flux, delta-B,helicity, non-potentiality, complexity, field gradient, other – Alerts based on indices • Increased time resolution during alerts – Blos at full spatial resolution in ARPs - updated each 90 seconds Early HMI Magnetic Field Observations
HMI Space Weather and Quick-Look Browsing Products II – Synoptic Maps • Synchronic Frame - radial field estimate - 96-minute, reduced resolution • Evolved Carrington/Synchronic map - 6 hour – Far side active region map - daily – Movie of global sun activity - 54-day, updated daily – Full-disk Velocity – averaged snapshot every 12 minutes – Full-disk Intensity - 12 minute average – Full-disk Line Depth - 12 minute average – Full-disk and ARP Overlays of AIA and HMI Blos - 90-sec update, movie – Alerts & Indices - 12 minute • Irradiance, mean field, ARP intensity/flare detection – Movies of ARPs in Intensity (updated hourly) – Horizontal Flow from LCT in ARPs (daily) – Coronal Field Models (daily, weekly) • Global - PFSS, Hybrid - HCCSSS, MHD • ARPs/Local - PF, NLFFF, MHD • Field line maps, source surface maps, AIA overlays, MHD quantities – Magnetic field global harmonic coefficients - daily – 1 AU Predictions - WSA velocity, polarity, field strength, etc (daily) – Coronal Holes - open foot points (daily) – Polar Field Estimate (monthly) Note: Not all products are produced by HMI. Early HMI Magnetic Field Observations
Magnetic Field Modules • Inferred Horizontal Flows • Time Average_IQUV • Non Linear Force Free Field • Stokes Inversion • Field Disambiguation • MHD Model Active Regions • Bx By Bz Coordinate • MHD Model Global Corona Transform • Solar Wind Model • Br Bth Bph Transform • Model Heliospheric Conditions • Btot Inc Az Transform • Space Weather Products • VectorB_Remap/Interpolate • HMI_Mean Field • VectorB Spatial Average • VectorB Temporal Average Associated HMI Pipeline Modules • Carrington Synoptic Chart • Synchronic Map & Frame • AR Patch ID & Tracking • Polar Field Extrapolation • Feature Recognition • PFSS Model & Magnetic • Spatial Averaging Harmonic Coefficients Early HMI Magnetic Field Observations
CR2096 HMI LoS Synoptic Map – Y. Liu & X. Zhao Early HMI Magnetic Field Observations
CR2096 HMI Synoptic Map Closeup – Y. Liu & X. Zhao Early HMI Magnetic Field Observations
HMI Vector Inversion and MDI FD LoS Comparison R. Centeno Eliot, J. Borrero, S. Tomczyk, K. Hayashi, Y. Liu Early HMI Magnetic Field Observations
Preliminary HMI Results NLFFF Model Result, 2010.04.08 T. Wiegelmann & X. Sun Disambiguated Vector Field April 8, 2010 K.D. Leka, G. Barnes, X. Sun Disambiguated Bx Early HMI Magnetic Field Observations
Frame of Vector Field Movie from Mar 29 Sunspot K. Hayashi, R. Centeno Eliot, et al. Early HMI Magnetic Field Observations
DAVE4VM Result Showing Horizontal Velocity Pete Schuck, Karin Muglach, Xudong Sun Black - vertical magnetic field, Red - horizontal magnetic field, Blue, Horizontal plasma velocities. Early HMI Magnetic Field Observations
MDI Feb 9, 2002 AR Patch ID Mike Turmon & Xudong Sun HMI March 29, 2010 Early HMI Magnetic Field Observations
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