SOTERIA abstract
Pert diagram

SOTERIA WP2


Description of work
and role of participants

The SOTERIA WP2 focuses on a significant advancement in the photospheric data service. The targeted photospheric phenomena are the sunspots, sunspot groups and photospheric faculae. These are the most important manifestations of the solar activity on the solar surface, so the availability of their detailed data with high temporal and spatial resolution is of basic importance. The main source of observations will be the SOHO/MDI instrument, but a network of ground-based observatories also contributes to the completeness of the material, data validation and the security of data flow, in some cases also to the higher temporal and spatial resolution. Thus the primary task of the WP is data production but the scientific merit of these pioneering data will be also demonstrated with the partners of the present project. Relevant space weather studies are flare forecast, solar cycle analysis, and solar global scale distributions related to heliospheric distributions. The data will be also important for a broader solar community not involved in this project dealing with different aspects of the solar activity.

Task 2.1. SDD Sunspot data (KO)

- The SDD catalogue work will be continued and published on-line until full coverage of the SOHO era.

Task 2.2. Facular data (KO, UNIGRAZ, ROB)

-Modification of the sunspot-processing procedure for measuring photospheric faculae derived from SOHO/MDI images

-Comparison of continuum and CaK faculae

Task 2.3. White-light measurements (KO, UNIGRAZ, ROB, HVAR)

-Software and hardware development to handle the white-light observations of all other involved participants.

-Comparison of data derived with different methods, data validation.

-Inserting sunspot data of KO into the sunspot index of ROB.

-Digitalisation of the observations available in non-digitised form

Task 2.4. Magnetic observations (KO, OBSPARIS)

-Testing magnetograms obtained by the ground-based GONG experiment about suitability for substitution of MDI magnetograms during gaps.

-Providing high cadence NaD1 magnetograms with 4' x 4' field of view, pixel 0.5", within an exceptional temporal resolution of 1 mn, allowing to investigate fast changes of the magnetic field.

Task 2.5. Standardisation of database formats (KO, ROB, UNIGRAZ)

- Transformation of all existing photospheric databases to easily accessible and exploitable formats in cooperation with WP6 and according to the EC guiding principles.

Task 2.6. Utilization of photospheric data in solar and space weather analyses (KO, UOulu, ROB, HVAR, UNIGRAZ)

- Study of the possibility of flare forecast based on the unprecedented time-resolution of the photospheric data and also on the complexity data of sunspot groups.

- Study of the so-called active longitudes based on the new sunspot data and their relationships with the heliospheric anisotropy along with their temporal variations (in cooperation with WP4).

- Investigation of the solar rotation and related phenomena by comparing the sunspot rotation with the rotation of coronal bright points traced in SOHO-EIT 28.4 nm images measured by automatic and an interactive method.

- Study of magnetic flux emergence by detailed monitoring of individual active regions and their temporal evolution: area, morphology, internal motions and rotation rate, etc.

- Derivation of extended global indices (sunspot hemispheric index, sunspot classification per cycle to which they belong, facular index), the study and selection of the most appropriate observables (counts, area, contrast, etc.) or combinations thereof. This task is essential to provide the necessary contraints to the last generation of solar dynamo models, which can reproduce the chaotic variations of the solar cycle (amplitude, duration, meridional drifts of "dynamo wave"). It also provides more elaborate proxies to help in the reconstruction of the total solar irradiance or spectral irradiances in specific wavelength ranges.

- Extension of standard photospheric indicators backwards in time, recovery from images/photographic archives of unexploited information leading to present an future standard indices (e.g. hemispheric sunspot numbers, facular index). This work can be only extended by the combination of multiple ground-based data collections. This project offers a perfect international context to initiate this long-term effort.


Deliverables (brief description and month of delivery)

- SOHO/MDI Continuum faculae- on-line publication of the database of SOHO/MDI continuum faculae. Public, 30 m: Deliverable D2.1

- SOHO/MDI Sunspot data (SDD)- derived from SOHO/MDI images for the whole SOHO era, Public, Delivery date: 36 m: Deliverable D2.2

- NaD1 magnetograms, Public, Delivery date: 36 m: this deliverable has been exchanged to another one, the D3.8, the relevant report is presented there.

- 4 papers – peer-reviewed publications of research results based on the new data, Delivery date: 36 m: Deliverable D2.4