Space Weather Effects of Solar Wind Transients in
the Sun - Earth Distance – IPS Studies

P.K. ManoharanRadio Astronomy Centre
National Centre for Radio Astrophysics
Tata Institute of Fundamental Research
Ooty 643001, India mano@ncra.tifr.res.in

AOSWA 3rd Workshop
Fukuoka, Japan
02 – 05 March 2015

National Centre for Radio Astrophysics
Tata Institute of Fundamental Research

Major Observing Facilities
Giant Metrewave Radio Telescope(multi-frequency synthesis imaging system)

Ooty Radio Telescope(solar spectrograph)Ooty Radio Telescope (ORT)•530m (N-S) x 30m (E-W) – east-west tracking of ~9.5 hours•

North-South beam steering (± 65 deg. declination)•High sensitivity, S/N ~ 25 (1s integration, BW 4 MHz)••

Observes ~1000 radio sources per day

Ooty Radio Telescope is upgraded (BW ~40 MHz, 27 deg coverage)

http://rac.ncra.tifr.res.inOoty Callisto – Part of Worldwide Radio Network

Space Weather Forecasts: Required Solar, IPM Measurements and Models

Magnetic Field Imprint & Spatial Geometry
Photospheric & H-alpha Measurements

Source Region Identification
Full Disk EUV Observations

CME Spatial Structure, Propagation & Interaction with Ambient Corona
Coronagraph and IPS (essential) Observations
Elliptical Cone Model & Expansion/Propagation Models

Space Weather Consequences
Models for Interplanetary Evolution (Expansion and Interaction)

Interplanetary scintillation

Ooty IPS Observations• Measurements on a large number of radio sources in a day(different line-of-sight cuts in 3D heliosphere) – allow speed andΔne estimates – provide couple of snap shot images of the innerheliosphere per day.
• At Ooty more than 1000 radio sources are observed per day– Computer assisted tomography (CAT) developed by Bernie Jackson andhis group at UCSD can provide line of sight integral corrected solar wind
– The time-dependent CAT (e.g., Jackson et al. 2009) can been employed toreconstruct the solar wind density and velocity structures.

2003

Solar Wind Density Turbulence and Speed (3 days)

Manoharan et al. 2006, Solar Physics

Ooty IPS Synoptic Maps – Density Turbulence and Speed

ascending phasemaximum

descending phase

Representative synoptic images of solar wind normalized density turbulence (G-map,left) and speed (v-map, middle) from Ooty IPS measurements for Carrington Rotations
1936, 1964, and 2043, respectively for ascending, maximum, and minimum phases ofthe solar cycle #23. At the right, extrapolated magnetic field images are shown.

Evolution of Coronal Mass Ejections(Sun to 1 AU distance)

CME Propagation Speed (from Sun to Earth)
Height – Time plot

Radial Evolution of Speed

K.E. lost/dissipated within <100Rsun~1032 erg

VCME ~ R-0.08 at R < 100 Rsun
VCME ~ R-0.72 at R > 100 Rsun

Speed Profiles: VCME(R)deceleration

constant speedacceleration

Which CMEs can cause most intense geo-magnetic storms?

70 Events
CME Initial Speed

CME at 100 R
(Ooty IPS)(LASCO field of view)

Shock Speed

ICME Speed(at 1 AU)(at 1 AU)

Dst = -75.4 –74.7BZV100R +4.8(BZV100R)2

Three-dimensional density (left panels) and velocity (right panel) images of the solar windreconstructed from Ooty IPS observations, showing the merged structure of two CMEs (showninside the ellipse) hitting the Earth on 20 November 2003, at around 6 UT.

Two merged magnetic clouds in the interplanetary medium with the solar sources.

Near-Earth Observations

Merged CMEs cause intense storm
Shock travel time T=47.5 hours
Solar wind speed~430 to 750 km/s
Bz ~-45.58 nTDuration southward Bz ~13.5 hrs
Dst index~-472 nTInterplanetary medium plasma parameters at 1 AU during 19-23 November 2003

Tomography reconstruction of Ooty IPS Data

Solar rotation and radial outward flow of the solar wind provide the 3-d structure of thesolar wind at different view angles

Computer Assisted Tomography analysis
can remove the line-of-sight integration imposed on the solar wind parameters
also provides high spatial resolution

3D Ooty Density and Speed Reconstructions

Ecliptic cuts through the 3D Ooty IPS reconstruction(density and speed )3-D reconstruction of heliosphere
Solar Events during September 4 – 13, 2005

Corresponding ARs #803 and #808 - These events were responsible
for spectacular and orderly flux-rope type of ejections, as illustrated
following by the Ooty IPS analyses.

LASCO C2images

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abcdefabcdefabcdefCo-rotating Interaction Regions (CIRs)

Negative CHon SunPositive CH

0.5 AU

Positive CH

Geo-Storms:• coronal hole (~100olongitude) does notproduce significantstorms

Negative CH• where as CH at ~330o1 AU
causes moderate storms
at the Earth (AE & Dst).

at Earth
IMF geometry and CH
Magnetic field play key role

why weak Bz?
Moderate Bz

But, nearly equal |B|

CR2013

CR2014

Interested in IPS data, welcome to collaborate

Thank You