CCMC Support of Active Missions:STEREO, THEMIS

Adam SzaboNASA Goddard Space Flight Center

Heliospheric Physics LaboratoryGreenbelt, Maryland

CCMC WorkshopNovember 5-8, 2007Arecibo, Puerto Rico

Outline

STEREO Support

• Model – data comparison for quiet solar wind

• Magnetic foot point tracing

• Dynamic solar wind – CMEs

THEMIS Support

• Model – data comparison - substorms

STEREO Support

Impressions:

• Dedicated page• Clean interface

Recommendations:

• Clickable imagesleading to modeldescriptions.

STEREO Support

Impressions:

• Clean interface• Example thumbs

Recommendations:

• Again, definitionswould be helpful.

Aug 19 Aug 23

STEREO Data

• Relatively quiet solarwind conditions.

• Noticeably differentdata between STEREO A and B.

|B| (

nT)

Bn

(nT)

Bt (

nT)

Br (

nT)

STEREO A

STEREO B

STEREO Spacecraft Location

The longitudinal separationof the STEREO spacecraft is beginning to be significant.

Orbit information from:

STEREO – Science Centerhttp://stereo-ssc.nascom.nasa.gov

11.3°14.9°

August 21, 2007

STEREO Data

|B| (

nT)

Bn

(nT)

Bt (

nT)

Br (

nT)

STEREO A

STEREO B

Aug 19 Aug 23

To compare the data,STEREO B data istime shifted by 1.75 days.

Significant differencesexist.

Data – Model Comparison

Impressions:

• Finding daily run was easy• Default settings good

Recommendations:

• Had to ask aboutcoordinate system used.

• An option to over plot Earth,and STEREO locationswould be useful.

Data – Model Comparison

Impressions:

• Intuitive plot options

Recommendations:

• Options for normalizedfield parameters(e.g., Br * R2) would behelpful.

Data – Model Comparison

Numerical values of theline plots can be listed toa downloadable file.

|B| (

nT)

Bn

(nT)

Bt (

nT)

Br (

nT)

Aug 19 Aug 23

STEREO A

STEREO B

STA Model

STB Model

Data – ModelComparison

Model line cuts scaled(|B| with Parker formula,Br with R2) and themodel V is used toconvert space into time.

Reasonable agreementfor |B|.

Detailed sector structuremissing from Br model

Tracing Foot Points

Tracing Foot Points

Starting Point:R = 0.96 1.09 AULon = 15 349 degLat = 7.3 6.0 deg

Traced to:R = 0.102 0.102 AULon = 49 28 degLat = 6.4 4.5 deg

Tracing Foot Points

STEREO A

STEREO B

• Could locate foot points offield lines on a 21.5 Rs sourcesurface.

• But could not connect field linesto photospheric map. PFSSdoes not come out to 0.1 AUand MAS is not yet available.

• Description of picture notationsand how the synoptic map isgenerated would be helpful.

Tracing Foot Points

• Mapping points from the21.5 Rs source surface tothe photosphere can bedone and will be availableshortly.

• Precise foot point mappingis difficult. Regularlycomputing it for the STEREOlocations might be a solution.

Dynamic Heliosphere

Cone model of CMEs availableOn request.

Also planned to beexecuted automaticallyfor large events.

Need the Sun’scooperation tocompare toSTEREO data.

THEMIS

POLAR

http://sscweb.gsfc.nasa.gov/tipsod

SUNSUN

X

Y

Z

X

Y Z

DETAILED VIEW

THC

THE

THDTHB

THA SUNSUNTH-CTH-D

TH-BTH-A

TH-E

First light: Nature’s welcome.Two substorms seen on March 23

C (fgm)

C (sst)

D (fgm)

D (sst)

B (fgm)

B (sst)

A (fgm)

A (sst)

E (fgm)

E (sst)

Clear dipolarization with a propagation or expanding speed of 200~300 km/s along GSM y direction.

Injection occurs ~10-30s earlier than dipolarization

Data

Open GGCM Model - J. Raeder

Model

CONCLUSIONS

STEREO Support:• Well developed dedicated CCMC support with daily runsfor the heliosphere.

• Was able to compare model predictions to spacecraft observationsand trace magnetic field lines back to 0.1 AU.

• Need more work to trace field lines to the photosphere / coronal holesand to model realistic ICMEs.

THEMIS Support:• No dedicated page, but model runs on request should beable to satisfy most requirements.

• It appears that the THEMIS community is not yet availing themselvesto the capabilities of CCMC.