Solar and STP science Solar and STP science with AstroGrid with AstroGrid

Silvia Dalla

School of Physics & Astronomy, University of Manchester

A PPARC funded project

Science questions

• Solar: energy transfer from magnetic fields to the plasma in the corona (coronal heating)

• Transient energy release events: solar flares, coronal mass ejections (CMEs)

• STP (=Solar Terrestrial Physics): the Sun's influence on the Earth environment – geomagnetic storms, space weather

AstroGrid and solar/STP

• Apply processing tool over a large number of events – allows statistical studies, rather than based on a few events.

• Observe solar features in multiple wavelengths.

• Allow work involving solar (images), interplanetary, magnetospheric, ionospheric (time series) datasets.

• Link models with data.

Solar datasets and tools

• MSSL SURF archive: SOHO/CDS and TRACE

• Virtual Solar Observatory: SOHO/EIT

• EGSO: Solar Event Catalogue (SEC)

• Solar tools:

• Solar Movie Maker• Solar Overlay• Generic Movie Maker

Solar Movie Maker Service

New tool: Time Cross Matcher

• Modification of the 'standard' AstroGrid X-Matcher so that 2 catalogues can be matched on the basis of event time.

• Example: Catalogue of Soft-X-ray flares (GOES), characterised by start/end times and several other parameters.

• Time-X-match with catalogue of hard-X-ray flares observed by RHESSI spacecraft.

GOESGOES +RHESSI

STP study: Geoeffectiveness of CMEs

• Investigate the chain of events starting with a CME at the Sun, and leading to a geomagnetic storm and aurora at the Earth.

• Can we predict if a CME will hit Earth and cause a geomagnetic storm? Space weather.

• How is this process influenced by conditions in the interplanetary medium ?

with Mike Pinnock, Ian McCrea (RAL) et al

STP study – cont’d

• Query catalogue of halo CMEs

• Retrieval of interplanetary magnetic field and solar wind data (ACE spacecraft) [t-series]

• Retrieval of geomagnetic indeces

(RAL) [t-series]

• IDL tool extracting time series parameters (DST < 75? geoeffectiveness = 1) and making a summary plot

• Summary votable constructed including CME, interplanetary, geomagnetic parameters

Solar study 1: type III productive hard X-ray flares

• Aim: compare flare emission at radio and hard X-ray wavelength.

• Test the hypothesis that type III radio emission tends to be associated with hard X-ray flares of hard electron spectral index.

with Lyndsay Fletcher (Glasgow)

Type III burst

Solar study 1 - contd

• Access RHESSI fits data.

• IDL tool calculates spectral ratio for RHESSI flares.

• Time X-match radio type III and Hard-X-ray votables

B. Dennis GSFC

Solar study 2: Are Active Regions emerging near existing ARs more flare-productive?

• New active regions emerge on the solar disk every day

• Flare productivity increases with magnetic complexity in an AR.

• Is an AR emerging on disk near another one, more likely to produce flares than an isolated AR?

with Lyndsay Fletcher (Glasgow)

Solar study 2: contd

• Multiple queries to Active Region catalogue in a workflow loop, to establish ARs emerging on visible disk (rather than rotating into view)

• Define a region of given radius around newly emerged AR – any other ARs ?

• Time X-match votable of ARs with flare catalogue -> establish flare productivity

Conclusions and future work

• AstroGrid workflow environment is a powerful tool for developing solar and STP studies involving a large number of events, and requiring multiple catalogues and datasets.

• Time X matcher a very useful tool for Solar/STP.

• In the next few months, expand range of datasets available.

• First example of STP model running as CEA application: CTIP model developed at UCL.

• Standardise access to time-based datasets.

• Provide helper application for display of time series data.