Advancing the field.A SOHO Solar MaximumScienceprogramwillenable afuller understanding of the complex changesin

the solar interior and outer atmosphere during the rise to solar maximum than currently exists. Such a program will also allow

usto amassa sufficientsample ofearthward-directed coronalmassejectionsto allow a principal-componentanalysisof the

SOHO observablesto determine which of those observables(presenceof a flare,location on the disk oferuptive filamentor

flare,pre-existing coronalstructures,following high-speed streams,and so on) are reliable predictorsof geoeffectiveness.It

cannotbe sufficiently stressed thata SOHO Solar MaximumScience program,in conjunction with other ISTP missions, will

allow usto make dramaticimprovementsin the quality ofgeomagneticstormforecasts--applied science-- over whatis

currently available.No other partof the Space Science endeavoroffersthe promise of advancesin forecasting effectson the

complex electronic communications environment upon which our civilization is ever more dependent.

The Science Return from SOHO alone.By "alone," we mean without the enormous benefit to be realized by operating SOHO

in conjunction with other Sun-Earth Connections (SEC) missions, but with the full resources of ground-based solar observato-

ries.We stressthatwe assessthis scenario only becauseitwascalled forin the solicitation for thisproposal: we believe that

NASA should seize the unique opportunity offered by the existing ISTP missions and Yohkoh so that we can examine the entire

range of Sun-Earth phenomena.We would be able to observe solar irradiance, eigenmode frequency, interior rotation rate as a

function of latitude and depth, subsurface convective energy transport, surface magnetic field, solar wind acceleration, plasma

parametersofsolar wind sourceregions,solar wind anisotropy,coronalhole areaand location,large-scalecoronalstructure,

coronalmassejection frequency and distribution, and smaller-scale solar atmospheric phenomenachangeswith the changein

phase of the solar cycle. We would be able to relate those changes to changesin effects atthe earth through proxies or through

other missions not considered under this review.

The Science ReturnfromSOHO inConjunctionwith OtherSECMissions.WithUlysses,we could observecycle-related

changesin the high-latitude solar wind and relatethemto possible changesin polar plumesand transients.WithYohkoh,we

could determine whether the rise in > 2.5x10⁶K plasma in active regions is spatially correlated with changes in lower-tempera-

ture (1 - 2.5 x 10 ⁶K )emission observedin the EUVand electron-scattering coronalstructures,and determine wheremore

coronalheating really occurs:in the limited volumesof hotter (SXR) plasma or the larger areasof lower (EUV) temperature

plasma, and in what sorts of structures. Collaboration withYohkohwould also allow us to address the solar cycle variation of a

whole range of solar phenomena: jets, X-ray/EUV bright points, CME's, &c. With GGS, we could achieve much better linkage

between CME's,flares,filamenteruptions,and other eruptive phenomenain the solaratmosphereand magnetic cloudsand

other geomagnetic events.(We assume thatTRACE, ACE,and Cluster willalloperateduring the proposed Solar Maximum

Scienceprogram,and each ofthese missionsprovidessome,butby no meansall,of thecapabilitiesof themissionsunder

review.)

SOHO and the Outside Community.SOHO is already strongly engaging the worldwide solar physics community; this will only

increase with the increase in solar activity and the improved, rapid access to SOHO data we propose here. If a Guest Investigator

program of the size we propose is approved, support will be available for new researchers, including young Ph.D.'s, to analyze

SOHO data for thefirsttime.If,asweurge,theSOHOand GGSGuestInvestigatorprogramsaremergedandemphasize

interdisciplinary proposals,NASA willfinally be able to leverage itsinvestmentin the ISTP. We have already discussed (cf.

Data Access,above) proposed improvementsin the timelinessand usefulnessof data releases,including making the MDI and

EIT data setscompletely open to the public . We believe that this exceeds the open data compliance of any other PI-class mission

in SpaceScience.

6. Implementation of the SOHO Solar Maximum Science program

Asnoted in theProgrammaticssection ofthisproposal,wearealreadyoperating atthe"minimumviable" levelofscience

operations. The only cost savings that we can achieve without sacrificing core science for a Solar Maximum Science program is

to disenfranchisenearly allCo-Investigatorswho arenotdirectly involved in scienceoperationsandinstead allow themto

compete with the other membersof the SEC community for funds to do SOHO-related research. Thiswe propose to do.

Implementation of the SOHO Solar Maximum Science program therefore entails no changes toscienceoperations at the EOF or

data archiving, and no changes in pipeline data processing, calibration, and validation. It is the considered opinion of the US PI's

and lead Co-I's,aswellasthe ProjectScientists, thatany significantreduction in scienceoperationsresourceswillmake the

scientific operation moot.

A major re-engineering effort atNASA Goddard will effect enormous savings inmissionoperations, but with minimal impact

Proposal forSOHO SolarMaximum Science Program-

23