Data Assimilation

From Soteria

Jump to: navigation, search

Contents

Current initiatives

NOVELTIS is in charge of supporting data assimilation initiatives in the frame of SOTERIA in order to demonstrate data assimilation capability for space weather forecasting.

Several collaborations are initiated.

KU Leuven

KU Leuven is working on data assimilation in order to improve space weather models (heliosphere and/or magnetosphere model).

Several ideas were at first suggested:

  1. To improve magnetosphere model using magnetometers (Cluster mission, etc.). Data assimilation in magnetosphere model is also interesting DTU in order to get the region 2 currents right which remains a problem in global magnetosphere model.
  2. To improve heliosphere model (like ENLIL) using magnetometers and ACE satellites.
  3. To achieve a toy problem that is manageable (quick runs) and having same features in order to assess methods with paradigmatic examples.

Three specific possibilities were discussed at a meeting in Leuven between Noveltis and KU Leuven, on July 3:

Possibility 1

Data assimilation for setting up self-similar flux rope expansion models for CMEs. The basis can be the paper:

  • J.M. Finn, G. Lapenta, H. Li, Similarity Solutions for Magnetic Bubble Expansion, Physics of Plasmas, 11, 2082-2096, 2004.

There is a rich literature on the topic of self-similar expansion and also on using those in connection with observations. For example:

  • MS Nakwacki, S Dasso, CH Mandrini, P Demoulin, Journal of Atmospheric and Solar-Terrestrial Physics 70 (2008) 1318– 1326.

As well as several papers by BC Low in Boulder.

Possibility 2

Assimilation of satellite crossings into models of current sheets. Two recent papers can be used as starting points

The information can then be used in models of stability such as:

Possibility 3

Driving simulations with observational data. A possibility is to set up a simulation based on photospheric information and collecting its output at ACE. Data assimilation can be used to refine the accuracy of the simulation. References:

  1. G. Lapenta, D.A. Knoll, Effect of a Converging Flow at the Streamer Cusp on the Genesis of the Slow Solar Wind, Astrophysical Journal, 624, 1049, 2005.
  2. G. Lapenta, A.L. Restante, Blob formation in the solar wind: role of converging flows and viscosity, Annales Geophysicae, 26, 3049–3060, 2008.


At the end possibility 3 has been selected and the work is under way: Solar Data Assimilation

DTU

DTU is also interested by data assimilation to improve space weather models. Unfortunately, DTU has not modeling capability. Currently, DTU work with models has been based on a close collaboration with CCMC (Coordinated Community Modeling Center). Collaboration with CCMC to prototyping data assimilation seems not acheivable in the frame of SOTERIA project. Finally, DTU and NOVELTIS engaged works on Field Aligned Currents (FACs) estimation which are of great interest for ionosphere dynamics at high latitudes.

LPC2E (CNRS)

LPC2E is interested by data assimilation methods in order to reconstruct solar spectral irradiance using LYRA and SWAP data. LPC2E opened a post-doctoral position which a part of time will be devoted to the development of an online nowcast of the solar UV spectrum using real-time data from the LYRA radiometer onboard PROBA2. Such reconstruction refers to data inversion issue which is based on mathematical theories similar to data assimilation ones. Modality of support has to be discuss.


Collaboration opportunities

This table resume potential collaboration on data assimilation

Partners Main topics Contact Are you developing model ? Are you interested by data assimilation ? If you are interested, what is your objective ?
KU Leuven Plasma simulations G. Lapenta YES YES To improve Heliosphere/Magnetosphere modeling
UNIGRAZ Solar monitoring, dynamics of photosphere and chromosphere W. Otruba NO NO  ?Offer observational data on a regular basis?
PMOD-WRC Solar radiation and influence on climat E. Rozanov NO NO
KO Solar monitoring, statistics of sunspot, irradiance variations modeling A. Ludmany NO YES To reconstruct total solar irradiance by using sunspot and facular data
CNRS Solar-terrestrial physics T. Dudok De Wit YES YES To reconstruct solar spectral irradiance using LYRA data
ROB Space weather forecasting, solar monitoring D. Berghmans, F. Clette NO YES Sunspot number forecasting
OBSPARIS Plasma physics, solar physics J.-M. Malherbe NO NO
SRC-PAS Solar X-ray flux monitoring and analysis J. Sylwester NO YES Solar flare investigation
MTA-KFKI-RMKI Solar energetic particles, solar wind interaction with magnetosphere K. Kecskemety NO YES WP4: To study the effect of solar disturbances on magnetospheric boundaries and on solar energetic particle fluxes
DTU Earth magnetic field, terrestrial effects of space storms S. Vennerstom YES YES To improve Field Aligned Currents estimation
UOulu Solar wind, heliospheric magnetic field, magnetospheric physics, solar-terrestrial physics K. Mursula NO YES To provide expertise on potential field modelling of solar magnetic field
UGOE CMEs and their effects on geospace, stellar surface structure V. Bothmer YES YES Quantitative CME/flare Forecast
HVAR Solar monitoring (WP2), flares/CMEs (WP3), ICMEs/solar wind (WP4) WP2: Roman Brajsa, WP3&4: Bojan Vrsnak YES YES WP2: solar-cycle predictions (amplitude, epochs, duration) and reconstruction in the past ; WP4: validation of the coronal-hole/high-speed-stream empirical forecasting, validation of the drag-based model for prediction of the ICME arrival
LPI Solar radiation, CME and active regions precursors, solar monitoring V. Slemzin NO NO
IEEA Ionospheric scintillation and ionosphere propagation Y. Béniguel YES YES To assimilate GPS data (and more) in a scintillation model.
Retrieved from "http://soteria-space.eu/wiki/index.php/Data_Assimilation"
Personal tools