Heliospheric Computations

Dusan Odstrcil

University of Colorado/CIRES and NOAA/Space Environment Center

Solar MURI Team Meeting, Berkeley CA, December 5, 2002

Outline

• Programming Activities

• Merging of Coronal and Heliospheric Models

- requirements for coupled simulations

- first 3-D coupled simulations

• Incorporation of More Realistic Ambient Solar Wind

- validation and calibration studies

• Interfacing with Other Models

- driving magnetospheric LFM model (Mike Wiltberger)

- providing results for SEP computations (Ilan Roth)

- acceleration of electrons (Marek Vandas)

Programming Activities

• (A) Graphical User Interface

- Model specification and compilation

- Initial and boundary conditions

- Remote computations, pre-views, data transfers

• (B) Code modernization

- New FORTAN standard

- HDF-5 data format

- CVS for source code

Coronal & Heliospheric Computations

SDSC, San Diego, CA NCAR/SCD, Boulder, CO

Requirements for Coupled Simulations

• Input Data

- 8 variables (2x120x180 cells) = 2.7 MBytes

- 400 time levels (1h interval) = 1 GByte

• Output Data

- 8 variables (256x120x180 cells) = 340 Mbytes

- 50 time levels (2h interval) = 17 GByte

- visualization = + 10-30 GByte

Interplanetary Transient Disturbance

Magnetic Field Disturbance

Solar eruption evolves into a traveling disturbance of interplanetary magnetic field that significantly exceeds its original angular size

Interplanetary Magnetic Flux Rope

Disturbed Magnetic Field

Interplanetary Magnetic Flux Rope

Flux rope (white lines) is initially connected to the Sun, but magnetic field lines reconfigure during its propagation. Color shows density in the equatorial plane. Black circle is boundary between the coronal and heliospheric regions (30 Rs).

Flux Rope Connected to Sun

N, T, and Bphi in the equatorial plane and model interface seen from below. (Computations are not performed for +-30 deg from the poles). Magnetic field is traced back to Sun.

Flux Rope Disconnects

The same but 20 hours later. Magnetic field lines (tracing starts from the heliosphere) does not reach the Sun; they reconfigure in the coronal region.

Connectivity of Magnetic Field Lines

Ambient Solar Wind

Ambient Solar Wind

Ambient Solar Wind

Shock-Cloud Interaction