8 30 9 10 AM Philip Scherrer What

8: 30 -9: 10 AM: Philip Scherrer, What Can We Hope to Learn from SDO Overview of SDO HMI Investigation HMI Instrument

MDI Status Excellent Condition Half Way

Solar-Heliospheric Activity Research and Prediction Program

SDO-EVE MEGS - Multiple Euv Grating Spectrograph ESP - Euv Spectrophotometer OFS - Optics Free Spectrometer

The primary goal of the Helioseismic and Magnetic Imager (HMI) investigation is to study the origin of solar variability and to characterize and understand the Sun’s interior and the various components of magnetic activity. The HMI investigation is based on measurements obtained with the HMI instrument as part of the Solar Dynamics Observatory (SDO) mission. HMI makes measurements of the motion of the solar photosphere to study solar oscillations and measurements of the polarization in a spectral line to study all three components of the photospheric magnetic field.

HMI produces data to determine the interior sources and mechanisms of solar variability and how the physical processes inside the Sun are related to surface magnetic field and activity. It also produces data to enable estimates of the coronal magnetic field for studies of variability in the extended solar atmosphere. HMI observations will enable establishing the relationships between the internal dynamics and magnetic activity in order to understand solar variability and its effects, leading to reliable predictive capability, one of the key elements of the Living With a Star (LWS) program.

The broad goals described above will be addressed in a coordinated investigation in a number of parallel studies. These segments of the HMI investigation are to observe and understand these interlinked processes: Convection-zone dynamics and the solar dynamo; Origin and evolution of sunspots, active regions and complexes of activity; Sources and drivers of solar activity and disturbances; Links between the internal processes and dynamics of the corona and heliosphere; Precursors of solar disturbances for space-weather forecasts. These goals address long-standing problems that can be studied by a number of immediate tasks. The description of these tasks reflects our current level of understanding and will obviously evolve in the course of the investigation.

HMI Major Science Objectives J – Sunspot Dynamics I – Magnetic Connectivity B – Solar Dynamo C – Global Circulation A – Interior Structure D – Irradiance Sources H – Far-side Imaging E – Coronal Magnetic Field NOAA 9393 Far-side G – Magnetic Stresses F – Solar Subsurface Weather

The HMI instrument will produce filtergrams in a set of polarizations and spectral line positions at a regular cadence for the duration of the mission. These are combined on the ground to produce: 1 -arc-second resolution full-disk Doppler velocity and line-of-sight magnetic flux images at least every 50 seconds 1 -arc-second resolution full-disk vector-magnetic images of the longitudinal solar magnetic field at least every 90 seconds

Fe. I 6173Å instead of Ni. I 6768Å

HMI Filter Profiles

HMI Observing Sequence

Sample MDI Filtergrams

Sample MDI Observables

The HMI investigation will provide sufficient computing capability to convert these raw filtergram measurements into a set of observables and derived data products that satisfy the HMI science objectives The primary observables (Dopplergrams, longitudinal and vector magnetograms, and continuum intensity images) will be available at full resolution and cadence. Other derived products such as subsurface flow maps, far side activity maps, and coronal and solar wind models that require longer sequences of observations will be produced. Open data policy: ALL data products will be freely available as soon as they are created.

Lev. Description Examples Rate [GB/day] Rate [TB/yr] Cache [day] Archived [%] Raw Telemetry - 600 200 30 100 0 Filtergrams - 1000 400 100 400 160 600 30 10 3 3000 100 <1 <1 2000 1 2 3 Observables Reorganized data Inferences VLOS, BLOS, Ic, Vector Field Parameters Spatial/temporal Samples, Averages; Synoptic Maps Global Modes, Analysis Maps, Farside Images, Coronal Fields HMI Data Archive

HMI 0. 02 Ops 600 SDO Telemetry HMI Dataflow Concept (Gigabytes/day) 1000 400 Data Capture Lev 1 30 d Cache Online Data Telem Archive Analysis Archive 10 Re. Org Data Inferences <1 30 d cache Net Access

HMI Education/Public Outreach Partnerships Institution Student K-14 Teacher Assess Multi- Distance Distri- Access Public/ Involve Curric- Workment media Learning bution of to Under infomal ment ulum shops Support Develop Support Materials -served education Develop ment Stanford X X LMSAL X X Stanford-Haas X The Tech Museum X X Chabot SSC X Morrison Planetarium /CA Academy of Sciences X X X IIISE X X X X X Lawrence Hall of Science NASA-CORE X X X X X

First HMI Science Team meeting in spring 2003

For continuing HMI information see: http: //hmi. stanford. edu