Early HMI Magnetic Field Observations Early Magnetic Field Observations From HMI J. Todd Hoeksema and the HMI Magnetic Field Team: Yang Liu, Keiji Hayashi,

Early HMI Magnetic Field Observations

Early Magnetic FieldObservations 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

HMI 2010.05.20_19:19:30Stanford, HAO, CORA, JPL, GSFC, MPS


HMI, the Helioseismic and Magnetic Imager on SDO is producing a synoptic series of full-disk arc-second magnetograms. Longitudinal field is 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.

Abstract


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 90s or 135 seconds.


HMI Magnetic Field Observables• 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]


Magnetic Processing Scheduling

There are four schedules for Magnetic Field data processing

• Quick Look/Near Real Time– Routine processing of some 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 MHD model

solutions, will be generated as resources allow. Completed when system resources allow


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


HMI 720s Magnetogram



Magnetic Field Blos Zero Level

• x

45s 720s


Magnetic Field Blos Mean FieldHMI – MDI – WSO


HMI Blos 45 vs HMI Blos Vector

HMI Blos 45 vs HMI Blos 720


HMI Blos Vector Method

HMI Blos 45 vs HMI Blos 720


HMI vs MDI Blos Comparison


HMI vs MDI Blos Comparison


MDI vs Solis MDI vs MtWSO

HMI vs MDIHMI = 1.03 SOLIS


AR 11066


AR 11069


HMI Vector Inversion and MDI FD LoS ComparisonR. Centeno Eliot, J. Borrero, S. Tomczyk, K. Hayashi, Y. Liu


Frame of Vector Field Movie from Mar 29 SunspotK. Hayashi, R. Centeno Eliot, et al.


Frame of Vector Field Movie from May 22 SunspotK. Hayashi, R. Centeno Eliot, et al.


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


CR2096 HMI LoS Synoptic Map – Y. Liu & X. Zhao


CR2096 HMI Synoptic Map Closeup – Y. Liu & X. Zhao


AR Patch IDMike Turmon & Xudong Sun

HMIMarch 29, 2010

MDIFeb 9, 2002


DAVE4VM Result Showing Horizontal Velocity Pete Schuck, Karin Muglach, Xudong Sun

Black - vertical magnetic field, Red - horizontal magnetic field,Blue, Horizontal plasma velocities.


Preliminary HMI Results

NLFFF Model Result, 2010.04.08

T. Wiegelmann & X. Sun

Disambiguated Vector Field March 29, 2010

K.D. Leka, G. Barnes, X. Sun

Disambiguated Bx



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.


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


Magnetic Field Modules

• Time Average_IQUV• Stokes Inversion• Field Disambiguation• Bx By Bz Coordinate

Transform• Br Bth Bph Transform• Btot Inc Az Transform• VectorB_Remap/Interpolate• VectorB Spatial Average• VectorB Temporal Average• Carrington Synoptic Chart• Synchronic Map & Frame• Polar Field Extrapolation• PFSS Model & Magnetic

Harmonic Coefficients

• Inferred Horizontal Flows• Non Linear Force Free Field

• MHD Model Active Regions• MHD Model Global Corona• Solar Wind Model• Model Heliospheric Conditions• Space Weather Products• HMI_Mean Field

Associated HMI Pipeline Modules

• AR Patch ID & Tracking• Feature Recognition • Spatial Averaging

Documents

Early HMI Magnetic Field Observations Early Magnetic Field Observations From HMI J. Todd Hoeksema and the HMI Magnetic Field Team: Yang Liu, Keiji Hayashi,