To understand is to perceive patterns http sidc

"To understand is to perceive patterns" http: //sidc. be/nemo ROB NEMO ESSW 3 SIDC

Outline Introduction Ø NEMO in the context of Space Weather Services Ø Technological challenges Bare Bones of NEMO software Ø Architecture Ø Recognition & Diagnostic, Ø Catalogue in real time Discussion Ø Event classification, Ø hidden properties. Ø Perspectives NEMO ESSW 3 SIDC

Solar Eruptions in Real time Flares Ø SEC events at NOAA, SXI Ø Solar. Soft events Ø B 2 Xflare CMEs Ø “Gopalswamy” list Ø http: /sidc. be/cactus NEMO ESSW 3 SIDC

Importance of On-Disk Eruptions geoeffectivity SOHO profits continuous view of the Sun. SOHO is in the L 1 Lagrange point in the Solar-Terrestrial System, and goes around the Sun simultaneously with the Earth. NEMO ESSW 3 SIDC

How does Eruption look like in EUV? precursor “EIT wave” Original Image Discovery: Thompson et al, 1998; NEMO Image substructed from prevrious one On disk CME signatures: Biesecker & Thompson, 2002 ESSW 3 SIDC

To extract such a signal from noise Requires an advanced technological approach Ø Huge phenomenological diversity of events Ø Signal weakness on top of dynamical backgrounds Requires a new pattern recognition approach Ø methods for tracking solid objects do not apply, Ø regular properties of EIT waves classification -> to develop specifically tailored method. NEMO ESSW 3 SIDC

A. Detection LASCO CME 1. 1997/04/01 06: 22: 00 2. 1997/04/01 09: 24: 33 3. 1997/04/01 12: 05: 23 4. 1997/04/01 15: 18: 38 WHERE? 1. 2. 3. 4. ERUPTION MEASURE NEMO ESSW 3 SIDC

Higher-order Moments DETECTION: method Centered moment of order k: experimental: theoretical: PDF(xi) Measure of PDF asymmetry: flatness: - Skewness - Kurtosis g 1, g 2 >> 0 computed for pixels distribution of EUV image could be indicators of large scale coherent structures: for a Gaussian distribution g 1=g 2 = 0 g 1=0, g 2>0 Gaussian: g 1=g 2=0 g 1>0, g 2>0 NEMO ESSW 3 SIDC

2. Geometrical Extraction (1/3) CROSS-SECTION Eruption center EIT wave front dimmings NEMO 1. Solar demisphere projected on the plane 2. during an EIT wave event 2. 8 vertical cross-section from EC, radially 3. ESSW 3 SIDC

Geometrical Extraction (2/3) From Podladchikova & Berghmans, 2005 The integrated positive intensity of the front balances the integrated negative intensity of the dimmings. NEMO ESSW 3 SIDC

Geometrical Extraction (3/3) Dimmings evolution and ICME 1. Dimming is the coronal Magnetic filed probe 2. Webb & Hudson, 2000 3. NEMO Atrill et al, 2006 ESSW 3 SIDC

3. Validation (1/2) Density profile after cylindrical source explosion (Sedov) Spatial coordinate time Fast mode moving upwards and slow downwards NEMO ESSW 3 SIDC

3. Validation (2/2) NEMO ESSW 3 SIDC

Example of Daily List NEMO ESSW 3 SIDC

Architecture NEMO 5. 0 Matlab 7. 0 Detection Real Time Catalog Geometrical Extraction SOHO scan catalog Validation NEMO ESSW 3 SIDC

Conclusion (1/2) SIDC new product (sidc. be/nemo) ØReal-time catalog ØMonthly scan STEREO Waves NEMO ESSW 3 SIDC

STEREO Waves Under condition of free propagation rotation of EIT wave fronts observed regulary NEMO ESSW 3 SIDC

Conclusion (2/2) Ø detects only eruptions, not flares. Ø can build on-disk SP. W. event catalog with SWAP and SECCHI. Ø extraction technique brings new insight on events. Ø is able to sort out the SOL. O. or SDO dataflow ~TB/day. NEMO ESSW 3 SIDC

Thanks To Barbara Thompson for 1997 -1998 EIT wave catalog To SIDC preview web, Cactus, B 2 X team To BELSPO, ESA, NASA, SECCHI/STEREO Orleans, Meudon NEMO ESSW 3 SIDC

NEMO ESSW 3 SIDC