SOT Preliminary Science Plan Tom Berger LMSAL SOT 17 Meeting NOAJ April 17-20, 2006

Solar-B Top Level Science Goals A.Understand the origin and dynamics of the Solar magnetic Field 1.Large-scale structure and dynamics of active regions. 2.The mechanisms of sunspot formation, dynamics, and decay. 3.Small-scale magnetic fields: global vs. local or “fast” dynamo action. B.Understand the modulation of Solar irradiance and luminosity by the magnetic field 1.Active region irradiance contributions: sunspot& facular contrast as f(  ). 2.Photospheric network irradiance contributions. 3.Physics of small-scale magnetic element irradiance. 4.Chromospheric irradiance variations over the solar cycle. C.Discover the source of heating of the upper atmosphere 1.Coronal heating mechanisms: photospheric/chromospheric drivers. 2.Spicules, jets, microflares. 3.MHD waves and atmospheric seismology. 4.Connectivity of photospheric magnetic structures to coronal loops. D.Identify the physical mechanisms behind flares and coronal mass ejections. 1.Photospheric magnetic field evolution during flares. 2.Prominence/filament formation. 3.CME initiation and evolution. 4.Photospheric and chromospheric response to transients (particles and waves).

SOT/FPP Science Programs A.1. Large-scale active region structure and dynamics A.1.1. Active region evolution: the “flux history” of active regionsAR_FLUX A.1.2. Active region surface flowfieldsAR_FLOW A.1.3. Active region sub-surface flowfieldsAR_SUBF A.1.4. Active region decay mechanismsAR_DCAY A.1.5. Active region helicity, currents, non-potential fieldsAR_HELI A.2. Sunspot formation, dynamics, and decay A.2.1. Sunspot formation mechanismsSS_FORM A.2.2. Sunspot decay mechanismsSS_DCAY A.2.3. Sunspot penumbral structure, flowsSS_PNUM A.2.4. Sunspot light-bridge and internal convective structuresSS_CONV A.2.5. Sunspot wave frequencies and phasesSS_WAVE A.2.6. Sunspot moving magnetic featuresSS_MMFS A.3. Small-scale magnetic field structures A.3.1. Small-scale field generation mechanismsSF_GENR A.3.2. Small-scale field interactions with convectionSF_CONV A.3.3. Small-scale field thermodynamicsSF_THRM A.3.4. Internetwork and weak fieldsSF_WEAK A.3.5. Ephemeral region origins and flowfield interactionsSF_EPHM

SOT/FPP Science Programs B. Solar Irradiance B.1 Active region irradiance budgetSI_ACTV B.2. Photospheric network irradiance SI_PNET B.3. Physics of small-scale magnetic structure irradianceSI_PHYS B.4. Chromospheric irradiance variabilitySI_CHRM C. Coronal Heating C.1. Photospheric and chromospheric mechanismsCH_MECH C.2. Spicules, jets, and microflaresCH_SPIC C.3. MHD waves and atmospheric acousticsCH_MHDW C.4. Connectivity of the corona to the photosphere & chromosp.CH_PCON D. Flares and Transient Events D.1. Photospheric magnetic field changes during flaresFT_PHOT D.2. Prominence & Filament activationFT_PROM D.3. CME initiationFT_CMES D.4. Photospheric & chromospheric impacts (particles & waves)FT_PART

A.1.1. Active Region Evolution: the “flux history” of active regions Scientific Objective To measure the distribution of magnetic flux over time for an ensemble of active regions. To determine the magnetic topologies that manifest themselves in the surface evolution; can we distinguish  -loops, U-loops, and horizontal flux tubes in the emergence process? Are there regular patterns to helicity, e.g. does it show hemispheric or solar cycle variation? Requirements Synoptic observation of several active regions per year over the course of the solar cycle. Requires at least some active regions to be observed during their initial emergence. Active regions must be tracked for as long as possible as they traverse the disk.Vector magnetic field maps as well as surface flow and Doppler velocity maps must be made with high spatial resolution with cadence varying from rapid (1 minute or less) during the initial emergence to moderate (2—5 minutes) during the mature and decaying phases. Observing Program Target: Multiple active regions including some emerging regions. FOV: Minimum 2K x 2K (164” x 164” in NFI), 4K x 2K for larger ARs to capture surrounding plage. Duration: 7—14 days continuous tracking of AR. Cadence: Emergence phase: high: 1 minute Mature/decay phase: moderate 2—5 minutes. FPP observables: NFI –Fe I nm Stokes shuttered IQUV, 1x1 binning –Fe I nm Dopplergram, 2x2 binning –H  nm line scam: -700 mÅ, LC, +700 mÅ, 2x2 binning BFI –Gband nm, 1x1 binning SP –Normal map mode, full spatial resolution, 160 x 160 arcsecond scan widths depending on active region size. Mosaic maps if needed. –Repeat scans every 4—6 hours. Sample SOT/FPP Science Program XRT: AR DEM Program DEM6 filter set Full resolution 60 sec cadence EIS: He II 256 for H  align TR lines Raster over SOT field

Sample SOT/FPP Science Program A.1.3. Active Region Subsurface Flows Scientific Objective To measure the horizontal flows at a range of depths beneath active regions. Can we detect the 50 m/sec inflow around active regions recently measured with MDI local helioseismology and ring-diagram analysis? Do sunspots have systematic and scale varying downflows below the photosphere? Do moving magnetic features show a correlated velocity signature as a function of depth? Requirements Extended “staring” at an active region near disk center. Duration is 4 days minimum. Cadence can be moderate (2—3 minutes) but must be extremely regular for the duration of the observations. Uninterrupted pointing and smooth solar rotation compensation are required for the duration. Observing Program Target: Multiple active regions as close to disk center as possible. FOV: 2K x 2K (164” x 164” in NFI). Duration: 0.5 days continuous tracking of AR. Cadence: 1 minute. FPP observables: NFI –Fe I nm Dopplergram, 2x2 binning –Fe I nm Stokes V magnetogram, 2x2 binning BFI –Blue continuum nm, 1x1 binning SP –None.

Sample SOT/FPP Science Program A.3.4. Internetwork (IN) and weak magnetic fields Scientific Objective To measure the distribution of magnetic field, both in terms of flux density and field strength, outside of active regions with a resolution of 0.3”. Can we detect a latitudinal or solar cycle variation in this distribution? What is the distribution of size scales in the IN? What is the evolutionary history of IN flux? Can we detect the operation of a local/fast dynamo in the upper convection zone? Requirements Quiet Sun tracking with initial position at disk center. Spatial resolution as high as possible, highest possible polarimetric S/N in order to detect and measure magnetic elements with B < 100 G. FOV must encompass a supergranule area, at least partially. Duration of tracking on the order of 10 hours. Observing Program Target: Disk center Quiet Sun. FOV: 1K x 1K (80” x 80” in NFI). Duration: 10—15 hours. Cadence: moderate 2—5 minutes. FPP observables: NFI –Fe I nm Stokes-V Magnetogram, 1x 1 binning –16” mask shutterless Stokes IQUV –Fe I nm Dopplergram, 1 x 1 binning BFI –Gband nm, 1x1 binning –Ca II H-line nm, 1x 1 binning SP –Deep magnetogram mode, window to 512 pixels along slit, 16” scan width, lossless compression.

Sample SOT/FPP Science Program B.1. Active Region Irradiance Budget Scientific Objective To measure the continuum and spectral line contrast of active region sunspots, pores, micropores, and magnetic elements as a function of magnetic field strength at a range of disk positions, from extreme limb to disk center. To determine the horizontal and vertical flow patterns associated with AR faculae. To measure the brightness temperatures of AR components and compare them to quiet Sun values. Requirements Observation of a number of active regions at as many locations on the disk as possible with high spatial but moderate to low temporal resolution. Cotemporal observations of quiet Sun regions at the same line-of-sight angle as any active region observations (for QS reference contrast measurements). High photometric precision is required in the continuum filtergrams. Observing Program Target: Multiple active regions at various disk positions. FOV: 2K x 2K (164” x 164” in NFI). Duration: 4 hours. Cadence: 2—5 minutes. FPP observables: NFI –Fe I nm Dopplergram, 2x2 binning –Fe I nm shuttered Stokes IQUV, 2x2 binning –Fe I 630 nm continuum filtergram, 1 x 1 binning –H  nm line scam: -700 mÅ, LC, +700 mÅ, 2x2 binning BFI –Blue continuum nm, 1x1 binning –Green continuum nm, 1x1 binning –Red continuum nm, 1x1 binning SP –Normal map mode, 164” scan width.

Sample SOT/FPP Science Program C.2. Coronal Heating: spicules, jets Scientific Objective To measure horizontal and vertical velocity and magnetic field patterns in both the photosphere and chromosphere of spicules, larger jets, and microflares. Can we detect opposite polarity cancellation at the location of spicules? How are spicules related to the surface flowfield? Can we detect the existence of acoustic shocks in spicules? Are spicules found primarily along non-vertical magnetic flux tubes? Requirements Observations of spicules both at the limb and on the disk (where they are referred to as “mottles”). Both quiet network spicules and AR spicules (sometimes referred to as “fibrils”) are required in order to explore the full range of magnetic flux density values. Observing Program Target: Multiple active regions as close to disk center as possible. FOV: 1K x 1K (80” x 80” in NFI). Duration: 4—6 hours. Cadence: high 30—40 seconds. FPP observables: NFI –Mg Ib nm Magnetogram, 2 x 2 binning –Fe I nm Dopplergram, 1x 1 binning –Fe I nm Magnetogram, 1x 1 binning –H  nm line scan: -700 mÅ, -350 mÅ, +350 mÅ, 1x 1 binning BFI –Gband nm, 1x1 binning –Ca II H-line nm, 1x 1 binning SP –Normal map mode, 80” scan width.

Program vs. Observables Matrix Program BFINFISP NMFMDMDP AR_FLUXFDVLCX AR_FLOWFDIQUVX AR_SUBFFDVX AR_DCAY AR_HELI SS_FORM SS_DCAY SS_PNUM SS_CONV SS_WAVE SS_MMFS SF_GENR SF_CONVFFFVX SF_THRM SF_WEAKFFFDVLCX SF_EPHM SI_ACTVFFFFVLSX SI_PNET SI_PHYSFFFFFFDIQUVLSX SI_CHRMFFVF

Program vs. Observables Matrix (cont.) KEY: F: Filtergram D: Dopplergram V: Stokes V magnetogram IQUV: Stokes vector magnetogram LC: Line center LS: Line scan NM: Normal map FM: Fast map DM: Dynamics Mode DP: Deep magnetogram Program BFINFISP NMFMDMDP CH_MECH CH_SPICFFDVLSX CH_MHDWFFVDDVLSX CH_PCONFFFVVIQUVLSX FL_PHOT FL_PROMFDIQUVLSX FL_CMES FL_PART

Period of 4 months following Performance Verification (PV) phase 2006/Early 2007: close to solar minimum Targeting priorities 1.Track any active region on the disk 2.When no AR on disk Disk center QS studies Irradiance scans Prominence limb scans 3.Targets of Opportunity Flaring regions Active filaments Priority “minimum success” data –Vector magnetic map of AR –G-band movie of AR + granulation –H  movies of AR –Ca II H-line movie of AR –Flare capture Initial Science Operations Outline AR on Sun? Yes No Disk Center QS Programs Irradiance Scans AR Tracking Programs Prominence/Polar Scans Enough AR Data? No Yes

AR Tracking Programs 1.Emerging Active Region –Target: center on emerging flux region –Duration: 2 days Ca II H (1x1) G-band (1 x 1) Blue Cont (1 x 1) Fe I Shutterless Stokes IQUV (1 x 1) Fe I Dopplergram (2 x 2) H  Line Scan (2 x 2) (-350, LC, +350) FG 1K x 1K FOV SP Fast Map Mode 3.2 sec/slit 0.32” step 80” x 80” map 15 min/map 3 min/cycle? NFI 80” x 80”

AR Tracking Programs 2. Mature/Decaying AR –Target: center on AR centroid –Duration: 7-14 days Ca II H (1x1) G-band (1 x 1) Blue Cont (1 x 1) Fe I Stokes V Magnetogram (2 x 2) Fe I Dopplergram (2 x 2) H  Line Scan (1 x 1) (-350, LC, +350) FG 4K x 2K FOV SP Normal Map Mode 4.8 sec/slit 0.16” step 164” x 164” map 83 min/map 10 min/cycle? Green Cont (1 x 1) Red Cont (1 x 1) Na D Dopplergram (2 x 2) Mg Ib Stokes V Magnetogram (2 x 2) NFI 320” x 160”

AR Tracking Programs 3. Flaring Active Region –Target: center on  -spot or emerging flux region –Duration: triggered or ~1 day Ca II H (1x1) G-band (1 x 1) Blue Cont (1 x 1) Fe I Stokes V Magnetogram (1x1) Fe I Dopplergram (2 x 2) H  Line Center (1 x 1) FG 512 x 512 FOV SP Dynamics Mode 1.6 sec/slit 0.16” step 16” x 32” map 3 min/map 30 sec/cycle? NFI 40” x 40”

AR Tracking Programs 4. Active Region subsurface flows –Target: center on AR centroid near disk center –Duration: 1 day Fe I Dopplergram (1 x 1) FG 2K x 2K FOV SP Normal Map Mode 4.8 sec/slit 0.16” step 164” x 164” map 83 min/map 1 min/cycle Fixed cadence NFI 160” x 160” Fe I Continuum (1 x 1)

AR Tracking Programs 5. MHD Waves –Target: center on spot –Duration: 1 day Ca II H (1x1) Red Cont (1 x 1) Fe I Stokes V Magnetogram (1x1) H  Line Scan (1 x 1) (-350, LC, +350) FG 512 x 512 FOV SP Dynamics Mode 1.6 sec/slit 0.16” step 8” x 32” map 1.5 min/map 20 sec/cycle? NFI 40” x 40”

Quiet Sun Observing Programs 1. Quiet Network Flux Dynamics –Target: center on supergranular network –Duration: 2 days G-band (1 x 1) Blue Cont (1 x 1) Fe I Shutterless IQUV (1 x 1) Fe I Dopplergram (1 x 1) FG 512K x 1K FOV SP Normal Map Mode 4.8 sec/slit 0.16” step 16” x 60” map 8 min/map 1 min/cycle? H  Line Center (1 x 1) NFI 40” x 80” Ca II H (1x1)

Quiet Sun Observing Programs 2. Internetwork Flux –Target: center of supergranule –Duration: 1 day G-band (1 x 1) Blue Cont (1 x 1) Fe I Stokes V Magnetogram (1 x 1) Fe I Dopplergram (1 x 1) FG 1K x 1K FOV SP Deep Magnetogram Mode 12.8 sec/slit 0.16” step 16” x 80” map 15 min/map 1 min/cycle? H  Line Center (1 x 1) NFI 80” x 80” Ca II H (1x1)

Quiet Sun Observing Programs 3. Convective Flow Structure –Target: center on supergranular network –Duration: 8 hours Blue Cont (1 x 1) Fe I Stokes V Magnetogram (1 x 1) Fe I Dopplergram (1 x 1) FG 4K x 2K FOV SP Normal Map Mode 4.8 sec/slit 0.16” step 164” x 164” map 83 min/map 2 min/cycle? Green Cont (1 x 1) Red Cont (1 x 1) NFI 320” x 160”

Irradiance Scan Programs 1. Activity Belt Irradiance –Target: Activity belts (40°N – 40°S) from East limb to West limb SC pointing mosaic –Duration: 2 hours (depends on SC pointing/stabilization rate) Blue Cont (1 x 1) Fe I Stokes V Magnetogram (2 x 2) FG 4K x 2K FOV SP Normal Map Mode 4.8 sec/slit 0.16” step 164” x 164” map 83 min/map 7 min/cycle? Green Cont (1 x 1) Red Cont (1 x 1) H  Line Scan (2 x 2) (-350, LC, +350) Ca II H (1x1) NFI 320” x 160”

Irradiance Scan Programs 1. Polar Region Scans –Target: Polar regions (60—90°N & 60—90°S) from East limb to West limb SC pointing mosaic –Duration: 2 hours (depends on SC pointing/stabilization rate) Blue Cont (1 x 1) Fe I Stokes V Magnetogram (2 x 2) FG 4K x 2K FOV SP Normal Map Mode 4.8 sec/slit 0.16” step 164” x 164” map 83 min/map 3 min/cycle? Green Cont (1 x 1) Red Cont (1 x 1) H  Line Scan (2 x 2) (-350, LC, +350) Ca II H (1x1) NFI 320” x 160”

Prominence Observing Programs 1. Prominence at the limb –Target: see title… –Duration: 4 hours Blue Cont (1 x 1) Fe I Shuttered Stokes IQUV (1x1) H  Line Scan (1 x 1) (-700, -350, LC, +350, +700) FG 1K x 1K FOV SP Fast Map Mode 3.2 sec/slit 0.32” step 164” x 164” map 30 min/map 40 sec/cycle? NFI 80” x 80”

Minimally Successful Mission Criteria FPP 2B00955_B Solar-B Level 1 Requirements, Appendix A BFI –The SOT BFI will record sequences of diffraction-limited images at a wavelength of nm over a period of 1 week showing the evolution of the photospheric granulation and the motion of the magnetic field elements in the quiet sun and near sunspots. A typical sequence will last for 10 minutes and have a cadence of 10 images per minute NFI/SP –The SOT “Vector Magnetograph” will record maps of the transverse and longitudinal magnetic fields surrounding sunspots and other concentrations of magnetic field with a polarimetric accuracy of and a spatial resolution of 500 km (0.7 arcsec). A typical observation will cover a field-of-view of 160 arcsec X 160 arcsec and be repeated every 10 minutes for 10 orbits.

Fully Successful Mission Criteria FPP 2B00955_B Solar-B Level 1 Requirements, Appendix A Vector fields –Detailed studies of vector magnetic field structure, evolution, and discontinuous change on all spatial scales ranging from micro-flares through sub-flares to the very largest explosive events to determine whether these events are different manifestations of the same or similar processes Coronal heating –A determination of whether the quasi-steady state magnetic field plays an active or passive role in coronal heating Irradiance –A determination of whether the solar cycle spectral irradiance variation has a magnetic origin will be made and the nature of the controlling mechanism identified Transients & Magnetic reconnection –Using both observations and analytical extrapolation of the data, studies of how the field is restructured in transient events will be performed. One goal is to provide unambiguous evidence, simultaneously in all three instruments, for magnetic reconnection Magnetic elements –The dependence of network and intranetwork magnetic structure and activity on latitude and proximity of sunspot groups will be determined.