Presentation is loading. Please wait.

Presentation is loading. Please wait.

Driving 3D-MHD codes Using the UCSD Tomography

Similar presentations


Presentation on theme: "Driving 3D-MHD codes Using the UCSD Tomography"— Presentation transcript:

1 Driving 3D-MHD codes Using the UCSD Tomography
H.-S. Yu1, B.V. Jackson1, A. Buffington1, P.P. Hick1, M. Tokumaru2, D. Odstrcil3, C.-C. Wu4 1CASS, UCSD, USA ; 2STELab, Nagoya, Japan; 3George Mason University & NASA/GSFC, United States 4NRL, United States

2 Introduction Data Sets - Interplanetary scintillation (IPS)
IPS data are mainly from ISEE, Japan; MEXART and data from other sites (WIPSS) can fill in Analysis - 3D Heliospheric Tomography Fitting a kinematic model to the IPS observations (a time-dependent heliospheric model assuming conservation of mass and mass flux from a single observer’s location) Speeds and densities from the IPS, vector fields from solar surface magnetograms Current Applications: A global solar wind boundary for driving 3D-MHD models (UAH/MS-FLUKSS; NRL/H3D-MHD; ENLIL in real time)

3 Interplanetary Scintillation (IPS) data - ISEE
IPS is caused by the presence of density inhomogeneities in the solar wind that disturb the signal from point-like radio sources. These produce intensity variations that, when projected onto Earth’s surface, make a pattern that travels away from the Sun with the solar wind speed. The correlation of this pattern between different radio sites allows a determination of the solar wind outflow speed. The “normalized scintillation level” (g-level) of an IPS radio source signal relative to a nominal average value allows a determination of the solar wind density.

4 3D Heliospheric Tomography
The 3D tomographic reconstruction basically proceeds by least-squares fitting a purely kinematic heliospheric solar wind model to the IPS LOS signal assuming radial outflow and enforcing conservation of mass and mass flux (Jackson et al., 1998). The UCSD 3D-reconstructed heliospheric density, velocity, and vector magnetic fields are available, as standard, from 15 Rs out to 3.0 AU and can be extracted at any distance in between to provide inner boundary inputs to drive 3D-MHD forward modeling.

5 ftp://cass185.ucsd.edu/data/IPSBD_Real_Time/ENLIL/

6 A Global Solar Wind Boundary for 3D-MHD models – H3D-MHD

7 3D Heliospheric Tomography- 2011/09/24 CME Sequence
A pair of closely-spaced CMEs erupted from NOAA AR1302 in conjunction with an M7 strength solar flare.

8 3D Heliospheric Tomography- 2011/09/24 CME Sequence

9 9/26th Geomagnetic Storm Bz became sharply south at times
solar wind increase from 350km/s to over 700 km/s

10 UCSD IPS Analysis (Yu et al., 2015)

11 UCSD IPS Analysis (1-day average) 0.93 0.93 date UT shock CME1 CME2

12 IPS driven 3D-MHD: H3D-MHD (40 Rs, 5ox5o) (Yu et al., 2015)

13 IPS driven 3D-MHD: H3D-MHD (1-day average)
shock CME1 CME2 0.58 shock CME1 CME2 0.73 date UT

14 A Global Solar Wind Boundary for 3D-MHD models – ENLIL

15 IPS driven 3D-MHD: ENLIL (0.1 AU, 4ox4o)
(Yu et al., 2015)

16 IPS driven 3D-MHD: ENLIL (1-day average)
shock CME1 CME2 0.45 shock CME1 CME2 0.90 date UT

17 CMEs in HI-1 images

18 CMEs in HI-1 images

19 H3D-MHD & ENLIL (6-hr average)
IPS driven 3D-MHD: H3D-MHD & ENLIL (6-hr average) H3D-MHD Good fit in magnitude WIND Model Density ENLIL Model Velocity Good fit in timing

20 IPS driven ENLIL: Space Weather at Rosetta Spacecraft

21 2014-09-19 Rosetta plasma energy (IES data)
IPS driven ENLIL: Space Weather at Rosetta Spacecraft Rosetta plasma energy (IES data)

22 IPS driven ENLIL: Space Weather at Rosetta Spacecraft
SOHO/LASCO HALO CME Sep.09, 2014 C2 Start Time:   00:06 UT C3 Start Time: 00:31-06:28 UT Type of CME: Asymmetric HALO CME — FRONTSIDE pa1:  064   pa2:  063       Total Width:  360 degrees Velocity Measurements: C2: 5 points PA 064 C3: 12 points PA 064 Average through both fields:  km/sec @ PA 064 Acceleration: m/sec^2 GOES reports a LDE M4.5 class X-ray flare at 23:12/00:29/01:31 UT from AR 12158

23 IPS driven ENLIL: Space Weather at Rosetta Spacecraft
SOHO/LASCO HALO CME Sep.10, 2014 C2 Start Time:   18:00 UT C3 Start Time: 18:06-22:30 UT Type of CME: Asymmetric HALO CME — FRONTSIDE pa1:  335   pa2:  334       Total Width:  360 degrees Velocity Measurements: C2 2 points PA 335 C3 12 points PA 335 Average through both fields:  km/sec @ PA 0335 Acceleration: m/sec^2 GOES reports a LDE X1.6 class X-ray flare at 17:21/17:45/18:20 UT from AR 12158

24 IPS driven ENLIL: Space Weather at Rosetta Spacecraft

25 IPS driven ENLIL: Space Weather at Rosetta Spacecraft

26 IPS driven ENLIL: Space Weather at Rosetta Spacecraft

27 IPS driven ENLIL: Space Weather at Rosetta Spacecraft

28 Summary The analysis of IPS data provides low-resolution global measurements of density and velocity with a time cadence of about one day for both density and velocity, and slightly longer cadences for some magnetic field components. Evaluating the 3D reconstruction at a given spherical radius provides a “global solar wind lower boundary” which can then be extrapolated outward by 3D-MHD models. The 3D-MHD simulation results using IPS boundaries as input compare fairly well with in situ measurements. Real-time IPS boundary data for driving MHD model (ENLIL) are now available. A current development in the IPS analysis is that we now provide three-component magnetic fields in GSM coordinates Bx, By, and Bz.

29 UCSD Prediction Analyses (See: http://ips.ucsd.edu/ips_workshop_2016)
Analyses from ISEE (See: Bz A Hammer-Aitoff display showing the STELab source locations. The source value is indicated relative to the model background value.


Download ppt "Driving 3D-MHD codes Using the UCSD Tomography"

Similar presentations


Ads by Google