HMI Magnetic Field Products

Four basic types of magnetic field products are described below.

Some data products suitable for space weather applications are available in near real time (nrt). Such data products always have nrt in the series name.

More details are provided at LineofsightMagneticField, VectorMagneticField, SynopticMaps, HARPDataSeries, SHARPs, and SpaceWeatherProducts.

Quick access to HMI magnetic field catalogs and data products can be found at

Notes for users of HMI Magnetic field pipeline data can be found at PipelineCode

Available vector field papers for reference: Vector Field Pipeline Overview VFISV ME inversion SHARP

Line-of-sight Magnetograms

Vector Magnetic Field Image Data

Synoptic Maps

HARPs - HMI Active Region Patches (HARPs)

SHARPs - HMI Active Region Patches (HARPs) with Computed Space Weather Quantities

HMI Active Region Patches

A HARP (short for HMI Active Region Patch) is an enduring, coherent magnetic structure at the size scale of a solar active region. The primary purpose of the HARP data series is to provide the practical geometric information needed to follow an evolving region as it crosses the solar disk. A HARP is initially identified automatically in a sequence of HMI line-of-sight magnetograms. HARPs are typically observed over several days (possibly as long as a disk passage) and tracked from one image to the next. At each time step, the rectangular HARP bounding box is provided and a BITMAP that characterizes the pixels of the HARP is recorded. The bounding box encloses the maximum heliographic extent of the region during its life time. The BITMAP indicates which pixels in the box are part of the HMI active region patch and can be applied to an HMI image. Keywords provide summary information about the patch (e.g. the total line-of-sight magnetic flux) as well as geometric and heliographic specifics.

The HARP information is being used to determine regions of interest for vector field inversion processing, both for past data (hmi.ME_720s_fd10) and for near real time processing (hmi.ME_720s_fd10_nrt). Near real time HARPs (hmi.Mharp_720s_nrt) are a little different than definitive HARPs because the entire history or each region is not known; NRT and definitive HARP numbers differ.

See HARPDataSeries for details.

JsocWiki: MagneticField (last edited 2014-11-18 05:17:51 by ToddHoeksema)