Vi forecasting solar euv uv radiation euv spectral synthesis
This presentation is the property of its rightful owner.
Sponsored Links
1 / 20

VI. Forecasting Solar EUV/UV Radiation – EUV spectral synthesis PowerPoint PPT Presentation


  • 235 Views
  • Uploaded on
  • Presentation posted in: General

VI. Forecasting Solar EUV/UV Radiation – EUV spectral synthesis. Margit Haberreiter Juan Fontenla LASP, University of Colorado Boulder, USA. Motivation. EUV/UV influences the neutral density in the thermosphere/ionosphere Influence on satallite drag

Download Presentation

VI. Forecasting Solar EUV/UV Radiation – EUV spectral synthesis

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Vi forecasting solar euv uv radiation euv spectral synthesis

VI.Forecasting Solar EUV/UV Radiation – EUV spectral synthesis

Margit Haberreiter

Juan Fontenla

LASP, University of Colorado

Boulder, USA


Motivation

Motivation

  • EUV/UV influences the neutral density in the thermosphere/ionosphere

  • Influence on satallite drag

  • Aim: forecast the EUV radiation based on physical principles over a solar rotation

  • Focus: physics-based EUV spectral synthesis


Euv spectrum

EUV spectrum

  • Contribution from

    • chromophere

    • transition region

    • corona

  • Input to our model:

    • temperature and density structures of each of these regimes for various regions on the solar disk


Atmosphere structures chromosphere

Atmosphere structures – chromosphere

Upper chromosphere

Lower chromosphere

Quiet Sun

Quiet Netw.

Active Netw.

Plage

Faculae

Semi-empirical NLTE structures reproduce radiance observations at 1-2‘‘(Fontenla et al 2008, in prep.) The models describes the distribution of heated areas on solar disk


Coronal models

Coronal models


Vi forecasting solar euv

SRPM

  • Multi level atoms

    • 373 ions,from neutral H to Ni with ioncharge 25

    • ~14’000 atomic levels

    • ~170’000spectral lines

  • Chromosphere and transition region:

    • for ioncharge up to 2:

    • full NLTE (Fontenla et al., 1999; 2006; 2007)

    • plus optically thin transition region lines

  • Corona

    • ioncharge >2: optically thin, i.e. collisions and spontaneous emission


Extension of corona

Extension of Corona


Spherical symmetry

Spherical Symmetry

Spherical symmetrie: Calculation of intensities at and beyond the limb

In total:

2 x area of solar disk

Plane parallel:

Only disk rays

are calculated


Fe ix 17 1 nm disk integrated plane parallel vs spherical

Fe IX 17.1 nm - disk integrated Plane parallel vs. spherical


Eve rocket flight

EVE rocket flight

  • Calibration flight on April 10, 2008 at “Solar minimum“ conditions (EVE rocket team at LASP: Tom Woods, Frank Evapier, Phil Chamberlin, Rahel Hock, a.o., Chamberlin et al., in preparation)


Vi forecasting solar euv

EUV irradiance spectra


Euv irradiance spectra

EUV irradiance spectra

  • 0.75 Quiet Sun (B) +0.22 (Quiet Network) +0.03 Active Network (F)

  • Lyman continuum matches well with EVE rocket spectrum from April 10, 2008


Euv irradiance spectra at instrument resolution

EUV irradiance spectra at instrument resolution


Vi forecasting solar euv

Shorter than 50 nm coronal/upper TR lines form a pseudo continuum


Euv irradiance qs 10 40 nm

EUV Irradiance QS 10-40 nm


Euv radiance spectra of quiet sun

EUV radiance spectra of quiet Sun

  • 0.75 Quiet Sun (B) +0.22 (Quiet Network) +0.03 Active Network (F)

  • Good agreement with average QS (SUMER Atlas, Curdt et al.)


Masks of active regions

Masks of active regions

Solar maximum: September 22, 2001

Solar minimum: April 10, 2008


Euv spectrum active sun

EUV spectrum Active Sun


Conclusions

Conclusions

  • The vast number of spectral lines have to be included

  • Due to the extension of the corona spherical symmetry is essential for coronal lines

  • SRPM EUV spectra agree well with EVE rocket irradiance spectrum and SUMER radiance spectra


Future plans

Future plans

  • Validation against more EUV observations

  • include coronal holes and active region loops in the calculation of the spectrum

  • Produce daily EUV/UV spectra

    • changing distribution of coronal features, e.g. coronal holes, active region loops

    • Apply the forcasting scheme as shown before


  • Login