25:["$","title",null,{"children":"Space Weather Scenario Tool: December 2006 Solar Storms | Jenny Knuth | Observable"}] 49:T1c0f,CreateTree = { const root = d3.hierarchy(treeData); const selectionRoot = root.copy(); root.x0 = dy / 2; root.y0 = 0; // initialize root root.descendants().forEach((d, i) => { d.id = i; d._children = d.children; if ( d.depth > 1 && selectedCategory !== 'All' ) { d.children = null; } }); // initialize alternative root based on filter selection selectionRoot.descendants().forEach((d, i) => { d.id = i; d._children = d.children; }); // find all nodes that match filter selection const filteredNodes = selectionRoot.descendants().filter( child => child.data.colorCode === selectedCategory); // collect all the node ids along the paths to the selected nodes const nodesToDisplay = new Set(); // find path from root to all selected nodes filteredNodes.forEach( node => { // push ids of all nodes in path to set of nodes to display selectionRoot.path( node ).forEach( nodeInPath => nodesToDisplay.add(nodeInPath?.id) ); }); // update alternative root with nodes to display selectionRoot.descendants().forEach( d => { if ( nodesToDisplay.has(d.id) ) { const childrenInPath = d.children?.filter( child => nodesToDisplay.has(child.id)); d.children = childrenInPath?.length ? childrenInPath : null; } else { d.children = null; } }); // choose root by selected category const rootToUse = selectedCategory === 'All' || selectedCategory === 'Origin' ? root : selectionRoot; const svg = d3.create('svg') .attr('viewBox', [-margin.left, -margin.top, width, dx]) .style('font', '16px sans-serif') .style('user-select', 'none'); const gLink = svg.append('g') .attr('fill', 'none') .attr('stroke', 'grey') .attr('stroke-opacity', 0.4) .attr('stroke-width', 5); const gNode = svg.append('g') .attr('cursor', 'pointer') .attr('pointer-events', 'all'); function update(source) { const duration = d3.event && d3.event.altKey ? 2500 : 250; const nodes = rootToUse.descendants().reverse(); const links = rootToUse.links(); // Compute the new tree layout. tree(rootToUse); let left = rootToUse; let right = rootToUse; rootToUse.eachBefore(node => { if (node.x < left.x) left = node; if (node.x > right.x) right = node; }); const height = right.x - left.x + margin.top + margin.bottom; const transition = svg.transition() .duration(duration) .attr('viewBox', [-margin.left, left.x - margin.top, width, height]) .tween('resize', window.ResizeObserver ? null : () => () => svg.dispatch('toggle')); // Update the nodes… const node = gNode.selectAll('g') .data(nodes, d => d.id); // Enter any new nodes at the parent's previous position. const nodeEnter = node.enter().append('g') .attr('transform', d => `translate(${source.y0},${source.x0})`) .attr('fill-opacity', 0.5) .attr('stroke-opacity', 0) .on('click', (event, d) => { d.children = d.children ? null : d._children update(d); }); const circles = nodeEnter.append('circle') .attr('r', 12) .attr('fill', colorNode) .attr('stroke', colorNode) .attr('fill-opacity', d => d.height ? 1 : 0) .attr('stroke-width', 6) .attr('cursor', d => d._children ? 'pointer' : 'default') .attr('title', d => d.data.tooltipTitle); const tooltips = tippy(circles.nodes(), { allowHTML: true, interactive: true, placement: 'auto-start' }); nodeEnter.append('text') .attr('dy', d => { if ( d.id === 0 ) { return -20; } else { return 5 } }) .attr('dx', d => { if ( d._children ) { return -20; } else { return 25; } }) .attr('text-anchor', d => { if ( d.id === 0 ) { return 'start'; } else if ( d._children ) { return 'end'; } else { return 'start'; } }) .text( d => d.data.name ) .clone(true).lower() .attr('stroke-linejoin', 'round') .attr('stroke-width', 3) .attr('stroke', 'white'); // date above nodeEnter.append('text') .attr('dy', -14) .attr('dx', d => { if ( d.id === 0 ) { return 10; } if ( d._children ) { return -20; } else { return 25; } }) .attr('text-anchor', d => { if ( d.id === 0 ) { return 'middle'; } else if ( d._children ) { return 'end'; } else { return 'start'; } }) .text( d => d.data.date ) .clone(true).lower() .attr('stroke-linejoin', 'round') .attr('stroke-width', 3) .attr('stroke', 'white'); // line below nodeEnter.append('text') .attr('dy', 25) .attr('dx', d => { if ( d.id === 0 ) { return 10; } if ( d._children ) { return -20; } else { return 25; } }) .attr('text-anchor', d => { if ( d.id === 0 ) { return 'middle'; } else if ( d._children ) { return 'end'; } else { return 'start'; } }) .text( d => d.data.substring ) .clone(true).lower() .attr('stroke-linejoin', 'round') .attr('stroke-width', 3) .attr('stroke', 'white'); // Transition nodes to their new position. const nodeUpdate = node.merge(nodeEnter).transition(transition) .attr('transform', d => `translate(${d.y},${d.x})`) .attr('fill-opacity', 1) .attr('stroke-opacity', 1); // Transition exiting nodes to the parent's new position. const nodeExit = node.exit().transition(transition).remove() .attr('transform', d => `translate(${source.y},${source.x})`) .attr('fill-opacity', 0) .attr('stroke-opacity', 0); // Update the links… const link = gLink.selectAll('path') .data(links, d => d.target.id); // Enter any new links at the parent's previous position. const linkEnter = link.enter().append('path') .attr('d', d => { if ( nodesToDisplay.has(d.id) ) { const o = {x: source.x0, y: source.y0 }; return diagonal({source: o, target: o}); } else { return null; } }); // Transition links to their new position. link.merge(linkEnter).transition(transition) .attr('d', diagonal); // Transition exiting nodes to the parent's new position. link.exit().transition(transition).remove() .attr('d', d => { const o = {x: source.x, y: source.y }; return diagonal({source: o, target: o}); }); // Stash the old positions for transition. rootToUse.eachBefore(d => { d.x0 = d.x; d.y0 = d.y; }); } update(rootToUse); return svg.node(); }4a:Te29a,treeData = ({ "colorCode" : "Origin", "name": "Active Region 13664", "tooltipTitle": 'Active Region 10930
Active Region (AR) 10930 appeared on the Earth-facing Solar Disk. The first view was on the east limb of the sun on late Dec. 4, 2006 at ~E80. The AR developed with virtually no warning. At the same time, a coronal hole facilitating high speed solar wind streams was already in place near the western limb.
'+`

Image: MDI Magnetograms spanning Dec. 5 - 17 courtesy of SolarMonitor.org, modified by D. Knipp

`+ 'More information on active regions

More information on coronal holes

Journal article on AR 10930
', "children": [ { "colorCode" : "Origin", "name": "East Hemisphere Eruptions", "tooltipTitle": 'East Hemisphere Eruptions
Sequence of events from AR 10930 on the east limb of the sun coincident with the arrival at Earth of high speed streams from the coronal hole on the west limb.
'+`

`+'Journal article with more information
', "children": [ {"colorCode" : "Origin", "name": "Transient Events", "date": "Dec. 5", "tooltipTitle": 'Dec. 5: Transient Events
First sequence of transient events from AR 10930 on the east limb, beginning on Dec. 5.
', "children":[ { "colorCode" : "Signal", "name": "M-Class Flare", "tooltipTitle": 'M-Class Flare
Characteristics: An M-class (M1.8) solar flare occurred early on Dec. 5, flaring from 07:45UT - 08:06UT with a peak time of 08:03UT.
'+`

`+ ' More information from SpaceWeatherLive.com', "children": [ {"colorCode" : "Communication", "name": "VLF Phase", "substring": "Amplitude Variations", "tooltipTitle": 'VLF Phase Amplitude Variations
Characteristics: Very Low Frequency (VLF) phase amplitude variations due to changes in dayside D region of the ionosphere observed in Australia, East Asia, Indian Ocean and North America. Variations observed on Dec. 5 at ~08:0UT following the M1.8 solar flare.
'+`

`+ ' Journal article with more information'}]}, { "colorCode" : "Signal", "name": "X-Class Flare", "tooltipTitle": 'X-Class Flare
Characteristics: X9.0 observed on Dec. 5 at E79. X9 corresponds to a radio storm at Earth at NOAA level 4 (R4). Start time: 10:18UT; peak time: 10:35UT; end time: 10:45UT. It was a level 2 ‘normal’ flare in the hydrogen alpha measure (optical wavelength). Usually such large X-ray flares are level 3 brilliant, however the East limb location may have obscured some of the optical brilliance.
'+`

`+ ' More information', "children": [ {"colorCode" : "Communication", "name": "HF Radio Blackout", "tooltipTitle": 'HF Radio Blackout
Characteristics: High-frequency radio blackouts occurred on the sunlit side of Earth following the X-class and M-class series of flares due to excess ionization. The blackout period followed the X9.0 flare on Dec. 5 and lasted from 10:35-12:05UT.
'+`

`+ ' Journal article with more information'}, {"colorCode" : "Communication", "name": "VLF Phase", "substring": "Amplitude Variations", "tooltipTitle": 'VLF Phase Amplitude Variations
Characteristics: Very Low Frequency (VLF) phase amplitude variations due to changes in dayside D region of the ionosphere observed in Australia, East Asia, Indian Ocean and North America. Variations observed on Dec. 5 at ~10:30UT following the X9.0 solar flare.
'+`

`+ ' Journal article with more information'}, { "colorCode" : "Hardware", "name": "X-ray Imager Damaged", "tooltipTitle": 'X-ray Imager Damaged
Characteristics: GOES-13 X-ray imager damaged on Dec. 5. First image to indicate sign of anomaly was taken at 10:40:15UT. Imager was on for 3 seconds and the Charge Couple Device (CCD) was affected. These impacts develop at speed of light, so no advanced warning.
'+`

`+ 'More information'} ]}, { "colorCode" : "Eruptive", "name": "Inferred CME", "tooltipTitle": 'Inferred CME
Characteristics: Inferred CME on Dec. 5 associated with the X9 flare. The CME did not hit Earth, but various geophysical impacts suggest the eruption of a CME. Observed development of shock in solar wind.

More information on CMEs
', "children": [ { "colorCode" : "Eruptive", "name": "SEP Event", "tooltipTitle": 'SEP Event
Characteristics: A solar energetic particle (SEP) event follows the inferred CME on Dec. 5. >10 MeV enhancements and minor >100 MeV enhancements.

' + `Click here to download a PDF with archived GOES SEP data` + '

', "children": [ { "colorCode" : "Eruptive", "name": "Earth SEP Onset", "tooltipTitle": 'Earth SEP Onset
Characteristics: Energetic particles were produced, but they were constrained to travel along magnetic field lines that were not well connected to Earth. Hence the arrival of the SEPs was delayed for several hours and the intensity was muted. SEPs arrived at ~17:00UT on Dec. 5 coincident with high speed flow arrival for western low-latitude coronal hole.
'+`

`+ 'Journal article with more information'}, { "colorCode" : "Geo", "name": "Ion Outflows", "tooltipTitle": 'Ion Outflows
Characteristics: Ion outflows observed at Mars and Venus. SEPs arrived almost immediately at Mars and caused an ion outflow event.
'+`

`+ ' Journal article with more information'}, { "colorCode" : "Human", "name": "ISS Safe Haven", "tooltipTitle": 'ISS Safe Haven
Characteristics: International Space Station (ISS) astronauts were instructed to seek safe haven because the SEP intensity was difficult to forecast.
'+`

`+ ' More information'}, ]}, { "colorCode" : "Signal", "name": "Type II Radio Burst", "tooltipTitle": 'Type II Radio Burst
Characteristics: There was a radio signal observed at Earth that indicated mass was moving outward through the solar atmosphere. This was observed by the solar monitoring station in Australia as a Type II burst, which is almost always a signal that a CME has erupted.

More information

'}, { "colorCode" : "Geo", "name": "IP Shock and", "substring": "Enhanced E-Field", "tooltipTitle": 'Interplanetary Shock and Enhanced Interplanetary Electric Field
Characteristics: Development of a shock in the solar wind from the inferred CME is observed.
'+`

`+ 'More information on IP Shocks', "children": [ { "colorCode" : "Geo", "name": "Coronal Wave", "tooltipTitle": 'Coronal Wave
Characteristics: Coronal wave transits the solar disk. The Soft X-ray Imager (SXI) on GOES 12 recorded an X-ray wave which traveled from the E79 flare site at 10:34UT on Dec. 5 to W90 by 12:00UT - thus it transited the solar disk in 90 minutes. This wave may represent the low coronal extension of the interplanetary shock.

Journal article with more information
'} ] }]} ]}, {"colorCode" : "Origin", "name": "Transient Events", "date": "Dec. 6", "tooltipTitle": 'Dec. 6: Transient Events
Second sequence of transient events from AR 10930 on the east limb, beginning on Dec. 6.
', "children":[ { "colorCode" : "Signal", "name": "M-Class Flares", "tooltipTitle": 'M-Class Flares
A series of 4 M-class solar flares occurred on Dec. 6 and 7. M1.1 on Dec. 6 start time: 01:30UT, peak time: 02:20UT, end time: 02:54UT. M6 on Dec. 6 start time: 08:02UT, peak time: 08:23UT, end time: 09:03UT. M3.5 on Dec. 6 start time: 20:14UT, peak time: 20:19UT, end time: 20:22. M2 on Dec. 7 start time: 18:20UT, peak time: 19:13UT, end time: 19:33UT.
'+`

`+ 'More information'}, { "colorCode" : "Signal", "name": "X-Class Flare", "tooltipTitle": 'X-Class Flare
Characteristics: X6.5 flare observed on Dec. 6 at E63. Began at 18:29UT, peaked at 18:47UT, and ended at 19:00UT. H-alpha flare level 3 Brilliant Flare, observed by ISOON network.
'+`

`+ 'More information', "children": [ {"colorCode" : "Communication", "name": "HF Radio Blackout", "tooltipTitle": 'HF Radio Blackouts
Characteristics: High-frequency radio blackout occurred on the sunlit side of Earth following the X-class and M-class series of flares due to excess ionization. The blackout period occurred on Dec. 6 and lasted from 08:23-09:53UT. Starts just after the M6 flare and intensifies with the arrival of the X6.5 flare.
'+`

`+ 'Journal article with more information'} ]}, { "colorCode" : "Eruptive", "name": "Halo CME", "tooltipTitle": 'Halo CME
Characteristics: Halo-shape CME on Dec. 6. First appeared in SOHO Lasco C2 at 20:12:05UT.
'+`

`+ 'More information on CMEs', "children": [ { "colorCode" : "Eruptive", "name": "SEP Event", "tooltipTitle": 'SEP Event
Characteristics: Long lasting Solar Energetic Particle (SEP) Event. >100 MeV SEP event observed by the GOES satellite late on Dec. 6. 10 MeV SEPs exceed event threshold (S1) on Dec. 6, remain greater than S1 until Dec. 12.

' + `Click here to download a PDF with archived GOES SEP data`, "children": [ { "colorCode" : "Communication", "name": "PCA", "tooltipTitle": 'PCA
Characteristics: Polar cap absorption (PCA) event began early on Dec. 7 and continued intermittently until Dec. 16. Delayed because SEPs have to travel to Earth, which can take about 0.5 hr or longer. PCA is a common feature of SEP events.
'+`

Image: Fig. 19 of Elliptical Model of Cutoff Boundaries for the Solar Energetic Particles Measured by POES Satellites in December 2006 (Dmitriev et al., 2010)

`+ 'Journal article with more information'}, { "colorCode" : "Human", "name": "ISS Safe Haven", "tooltipTitle": 'ISS Safe Haven
Characteristics: International Space Station (ISS) astronauts were advised to seek safe haven from SEP event.
'+`

`+ 'More information'}, { "colorCode" : "Hardware", "name": "ACE Contamination", "tooltipTitle": 'ACE Contamination
Characteristics: SEP contamination of ACE satellite measurements. Some ACE solar wind monitor observations are overwhelmed by SEPs from Dec. 7 07:00UT - Dec. 8 16:00UT.
'+`

`+ 'Journal article with more information'}, { "colorCode" : "Hardware", "name": "CALIPSO Operations", "substring": "Shut Down", "tooltipTitle": 'CALIPSO Operations Shut Down
Characteristics: CALIPSO Satellite Payload Controller shut down for radiation safety reasons on Dec. 7 after notification of enhanced 100 MeV protons at 7:11UT on Dec. 6. Operations remained shut down until Dec. 12, when the Payload Controller was turned on at 12:14UT. However, full operations were not able to resume before the Dec. 13 SEP event arrived!
'+`

` + `Click here to download a PDF with more information` + ''} ] }, { "colorCode" : "Geo", "name": "IP Shock and", "substring": "Enhanced E-Field", "tooltipTitle": 'Interplanetary Shock and Enhanced Interplanetary Electric Field
Characteristics: Interplanetary shock arrives at Earth.
'+`

Image: IP shock impacting the Earth's magnetosphere, courtesy of the European Space Agency (ESA)

`+ '', "children": [ { "colorCode" : "Geo", "name": "Geomagnetic", "substring": "Storm", "tooltipTitle": 'Geomagnetic Storm
Characteristics: CME did not hit earth, but shock from the Dec. 6 CME and shock from previous inferred CME on Dec. 5 merged and arrived at Earth early on Dec. 8. The shock arrival produces minor geomagnetic storm conditions: Kp = 5. This contributes to gradual heating of the thermosphere.
', "children": [ { "colorCode": "Geo", "name": "Substorms", "tooltipTitle": 'Substorms
Characteristics: The geomagnetic storm produced three days of moderate substorms. These are oscillations of plasma caused by the amplification of southward interplanetary magnetic field perturbations.

Conference Proceedings paper with more information' } ] } ]}, { "colorCode" : "Signal", "name": "Type II Radio Burst", "tooltipTitle": 'Type II Radio Burst
Characteristics: Interplanetary (IP) Type II radio burst. This is a short burst (10’s of minutes) that sweeps through several orders of frequencies. It starts when the CME is low in the solar corona and its motion starts disturbing electrons in the solar atmosphere. As the CME rises the density of electrons decreases (exponentially with height), thus the radio noise decreases in frequency. An IP Type II radio burst indicates that a CME is moving from the corona into the interplanetary medium. The change of frequency with time is related to the speed of a CME, so early speed estimates of fast CMEs come from the burst of noise that becomes a signal.
'}, { "colorCode" : "Signal", "name": "Solar Moreton Wave", "tooltipTitle": 'Solar Moreton Wave
Characteristics: H-alpha Chromospheric Moreton wave causes an eruption of solar magnetic arcade structure, begining at 18:43UT from AR 10930 with ~270° azimuthal span and propagating outward at a speed of 500-1000 km/s. This is a ‘fast mode MHD wave’ characteristic of a CME-driven shock in the chromosphere/lower corona which causes the wave to propagate. These are coincident with Type II radio bursts.
'+`

`+ 'Journal article with more information' } ]}, { "colorCode" : "Eruptive", "name": "Radio Burst", "tooltipTitle": 'Radio Burst
Characteristics: Great solar radio (decimetric) burst occurred after the CME in the “post-eruption loops” in arcade. Radio disturbances begin as flare begins at ~18:40UT, then a sharp rise at 18:55UT at 1.4 GHz, with a peak time of 19:36UT (note delay from flare); microwave radio burst. Burst intensity >1e5 sfu measured by RSTN; ~1e6 sfu measured by Owens Valley Solar Array (OVSA). Enhanced emissions at 1.4 GHz, 2.7 GHz, 5.0 GHz, 8.8 GHz, and 15.4 GHz monitored by the Radio Solar Telescope Network (RSTN) of the US Air Force.
'+`

`+ 'Journal article with more information', "children": [{ "colorCode" : "Communication", "name": "GPS Receiver Saturation", "tooltipTitle": 'GPS Receiver Saturation
Characteristics: GPS ground-based receivers, including the ZHU1 Federal Aviation Administration (FAA) Wide Area Augmentation System (WAAS), experienced significant saturation on De. 6 from 18:55UT through ~19:45UT. Signal-to-noise ratio experiences rapid decreases associated with increases in solar radio burst power at the L1 and L2 frequencies (near 1.6 GHz and 1.3 GHz, respectively).
'+`

`+ 'Journal article with more information'}, { "colorCode" : "Communication", "name": "GPS Loss of Tracking", "tooltipTitle": 'GPS Loss of Tracking
Characteristics: On Dec. 6 from 19:15UT through 19:48UT, for many dayside GPS receivers the number of satellites tracked decreases significantly from the nominal ~8 satellites tracked. Many receivers were not meeting operational requirements, i.e. were tracking fewer than 4 satellites.
'+`

`+ 'Journal article with more information'}, { "colorCode" : "Communication", "name": "Detection by WAAS", "tooltipTitle": 'Detection by WAAS
Characteristics: This was the first time a solar radio burst was detected on the civil air navigation system, Wide Area Augmentation System, or WAAS.

More information'} ] } ]}, {"colorCode" : "Origin", "name": "Coronal Hole", "tooltipTitle": 'Coronal Hole
The coronal hole preconditions the system by unleashing steady high speed streams. These streams couple with the shorter-duration transient events to yield longer lasting geo-effects.
'+`

`+ '', "children": [ {"colorCode": "Geo", "name": "Neutral Density Increase", "tooltipTitle": 'Neutral Density Increase
High speed streams lead to gradual but sustained neutral density increases in the thermosphere.'+`

Image: Neutral density along the CHAMP orbit (~400km). Image courtesy of the Space Weather TREC Data Portal

`+ ''} ] }] }, { "colorCode" : "Origin", "name": "West Hemisphere Eruptions", "tooltipTitle": 'West Hemisphere Eruptions
Sequence of events from AR 10930 once it reaches the west limb. After remaining relatively quiet for a few days, AR 10930 began to reconfigure between Dec. 9 and Dec. 11. New magnetic flux began to emerge, and the shear in the magnetic field grew as a small spot in the southern portion of the region began to rotate. Status as a type 2 δ-spot, which are produced by the emergence of satellite spots near large older spots, became evident.
'+`

Image: Fig. 13 of Flare-productive Active Regions (Toriumi & Wang, 2019)

`+ 'Journal article with more information', "children": [ {"colorCode" : "Origin", "name": "Transient Events", "date": "Dec. 13", "tooltipTitle": 'Dec. 13: Transient Events
First sequence of transient events from AR 10930 on the west limb.', "children": [ { "colorCode" : "Signal", "name": "X-Class Flare", "tooltipTitle": 'X-Class Flare
Characteristics: X3.4 from S06W23 observed on Dec. 13. X3 corresponds to a radio storm at Earth at NOAA level 3 (R3). Start time: 02:14UT; peak time: 02:40UT; end time: 02:52UT. H-alpha flare level 4B.
'+`

`+ 'More information', "children": [ {"colorCode" : "Communication", "name": "HF Radio Blackout", "tooltipTitle": 'HF Radio Blackout
Characteristics: The Australian Government reported a 2-hour high-frequency radio blackout following the X-class flare due to excess ionization. X-ray radiation released by the Dec. 13 flare caused long range HF radio communications such as those used by Defence Forces, emergency services and airlines to be completely blacked out for two hours.
'+`

` + `Click here to download an Australian press release PDF` + '
'}, { "colorCode" : "Signal", "name": "Type III Radio Burst", "tooltipTitle": 'Type III Radio Burst
Characteristics: Intense type III radio burst at ~02:25UT on Dec. 13, coincident with the peak of X-ray flux. Type III bursts are produced by near-relativistic electrons escaping from the flaring site so they drift very rapidly in frequency and appear as almost vertical features in the dynamic spectrum.', "children": [ { "colorCode" : "Communication", "name": "GPS Receiver Saturation", "tooltipTitle": 'GPS Receiver Saturation
Characteristics: GPS ground-based receivers experienced significant saturation on Dec. 13 from 02:24UT through ~02:30UT. Signal-to-noise ratio dropped at the L1 and L2 frequencies (near 1.6 GHz and 1.3 GHz, respectively) for an FAA WAAS receiver located in Honolulu, HI. ~30% of GPS receivers in Australia became saturated.
'+`

Image: Fig. 4 of Effect of Intense December 2006 Solar Radio Bursts on GPS Receivers (Cerruti et al., 2008)

` +'Journal article with more information'} ] }, { "colorCode" : "Geo", "name": "EUV Brightening", "tooltipTitle": 'EUV Brightening
Characteristics: Extreme Ultraviolet (EUV) brightening followed by dimming on the solar disk.'}, { "colorCode" : "Geo", "name": "Coronal Wave", "tooltipTitle": 'Coronal Wave
Characteristics: Coronal waves observed on the solar disk.'}, {"colorCode" : "Communication", "name": "VLF Phase", "substring": "Amplitude Variations", "tooltipTitle": 'VLF Phase Amplitude Variations
Characteristics: Very Low Frequencye (VLF) phase amplitude variations due to changes in dayside D region of the ionosphere. Variations observed on Dec. 13 at ~02:20UT following the X3.4 solar flare.
'+`

`+ 'Journal article with more information'} ]}, { "colorCode" : "Eruptive", "name": "Halo CME", "tooltipTitle": 'Halo CME
Characteristics: CME evident in LASCO imagery at 02:30UT in southwest quadrant of LASCO C2. Designated as a Halo CME at ~02:55UT. EUV brightness decreases as coronal plasma is removed due to the lift-off of the CME. Speed projected on the sky was ~1774 km/s. Largest since October 2003.
'+`

`+ 'Journal article with more information', "children": [ { "colorCode" : "Signal", "name": "Type II Radio Burst", "tooltipTitle": 'Type II Radio Burst
Characteristics: A long-duration metric type II burst was observed through most of Dec. 13, starting at 02:27 UT, indicating a CME-driven shock wave.
'+`

`+ 'Journal article with more information'}, { "colorCode" : "Eruptive", "name": "SEP Event", "tooltipTitle": 'SEP Event
Characteristics: The CME-driven shock produces energetic particles throughout the interplanetary transit. The shock accelerates the particles faster than it can move. Several individual particle enhancements occurred during this period of activity. The first particle enhancement is associated with the injection from the flare and CME on Dec. 13 at ~02:30UT. The second major particle enhancement is with the ICME forward shock (14:38UT on Dec. 14). There is an additional minor particle enhancement following the departure of the ICME.

' + `Click here to download a PDF with archived GOES SEP data` + '
', "children": [{ "colorCode" : "Geo", "name": "GLE", "tooltipTitle": 'GLE
Characteristics: This SEP event was very strong and produced a Ground Level Event (GLE) at Neutron Monitors. This was the 70th GLE recorded (GLE-70). Timing: Dec. 13 at 03:05UT at the Oulu ground station.
'+`

Image: GLE-70, courtesy of the University of Delaware Bartol Research Institute Neutron Monitor Program

`+ 'Journal article with more information

' + `Click here to download a PDF with NM station data for GLE 70 data` + '
'}, { "colorCode" : "Hardware", "name": "Coronograph 'Snowstorm'", "tooltipTitle": 'Coronograph "Snowstorm"
Characteristics: "Snowstorm" effect observed on the LASCO C3 coronagraph on Dec. 13, 03:42:04UT. The C3 imager was tracking the oncoming CME and became blinded by this SEP event.
'+`

Image: Fig. 2 of Three-dimensional MHD Modeling of the Solar Wind Structures Associated with 13 December 2006 Coronal Mass Ejection (Kataoka et al., 2009)

`+ 'Journal article with more information'}, { "colorCode" : "Hardware", "name": "CALIPSO Operations", "substring": "Shut Down", "tooltipTitle": 'CALIPSO Operations Shut Down
Characteristics: CALIPSO Satellite Payload Controller shut down again for radiation safety reasons on Dec. 13 at 08:06UT on Dec. 13 after notification of enhanced 10 MeV and 100 MeV protons. Operations remained shut down until Dec. 19, when the Payload Controller resumed nominal data acquisition at 13:56 UTC.

'+`

` + `Click here to download a PDF with more information` + ''}, { "colorCode" : "Hardware", "name": "ACE Contamination", "tooltipTitle": 'ACE Contamination
Characteristics: SEP contamination of ACE satellite measurements. Some ACE solar wind monitor observations are overwhelmed by SEPs on Dec. 13 from 13:40UT - 18:00UT following the SEP onset associated with the X-class flare.
'+`

Image: Fig. 3 of Predicting Interplanetary Shock Arrivals at Earth, Mars, and Venus: A Real-time Modeling Experiment Following the Solar Flares of 5–14 December 2006 (McKenna-Lawlor et al., 2008)

`+ 'Journal article with more information'}, { "colorCode" : "Hardware", "name": "Cluster Spacecraft Anomalies", "tooltipTitle": 'Cluster Spacecraft Anomalies
Characteristics: Three out of the four spacecraft in the Cluster II mission experienced anomalies likely due to the increased energetic particle flux on Dec. 13. Cluster 1 had a minor instrument anomaly, Cluster 2 lost power to its Attitude and Orbit Control unit, and the High-Power Amplifier on Cluster 4 shut down.
'+`

`+ 'ESA Press Release with more information'}, { "colorCode" : "Hardware", "name": "Envisat Spacecraft Anomaly", "tooltipTitle": 'Envisat Spacecraft Anomaly
Characteristics: On Dec. 13 at 17:00 UTC, The Envisat Payload Module Computer shut down, causing all payload instruments to be switched off.
'+`

`+ 'ESA Press Release with more information'}, { "colorCode" : "Hardware", "name": "Integral Spacecraft", "substring": "Operations Suspended", "tooltipTitle": 'Integral Spacecraft Operations Suspended
Characteristics: The JEM-X instrument onboard Integral, which was sensitive to X-rays, automatically switched into safe model twice. Operators manually shut down the IBIS instrument to avoid over-exposure from charged particles.
'+`

`+ 'ESA Press Release with more information'} ]}, { "colorCode" : "Geo", "name": "IP Shock and", "substring": "Enhanced E-Field", "tooltipTitle": 'Interplanetary Shock and Enhanced Interplanetary Electric Field
Characteristics: The interplanetary shock initiates at ~02:30UT and develops with the CME. The interplanetary shock arrives at L1 at ~14:00UT on Dec. 14. Shock speed was 1030 km/s (so decelerating in the preceding solar wind). Shock normal makes an angle of ~56 deg with the upstream magnetic field, so the shock may be quasi-perpendicular making it very geoeffective. Sheath region behind shock has high density and multiple current sheets. 36 hr transit time for CME to arrive at L1 with average speed of 1160 km/s. Arrived at Earth as a Magnetic Cloud and remained magnetically connected to the Sun through the end of the UT day on Dec. 14 (and probably longer).
'+`

`+ 'Journal article with more information', "children": [ { "colorCode": "Geo", "name": "Geomagnetic", "substring": "Storm", "tooltipTitle": 'Geomagnetic Storm
Characteristics: Sustained energization of plasma in the magnetotail.
', "children": [{ "colorCode" : "Geo", "name": "TEC Enhancement", "tooltipTitle": 'TEC Enhancement
Total Electron Content (TEC) enhancements, derived from GPS observations at the PKU0 station. Derived GPS instrumental bias fluctuates in response to storm. TEC enhancement period: Dec. 15, 01:00UT - 13:00UT. TEC was enhanced by more than 100% from 01:45UT - 04:00UT.
'+`

`+ 'Journal article with more information'}, { "colorCode" : "Geo", "name": "F-Region Uplifting", "tooltipTitle": 'F-Region Uplifting
Sudden uplifting of the ionospheric F-region and equatorial plasma bubbles observed.
'}, { "colorCode" : "Geo", "name": "GIC", "tooltipTitle": 'GIC
Geomagnetically Induced Current (GIC) event, defined as an hour-long interval during which the GIC intensity exceeds 1 A, in Japan associated with the Dec. 13 - Dec. 14 geomagnetic storm. The GIC event started at Dec. 14 ~23:30 UT and ended Dec. 15 ~01:00 UT.
'+`

`+ 'Journal article with more information'}, { "colorCode" : "Hardware", "name": "ISS Attitude Control", "tooltipTitle": 'ISS Attitude Control
Dec. 15 problems with attitude control for the International Space Station. The density at ISS likely started changing within a few hours of shock arrival and significantly responded to the southward IMF of the body of the main CME, which arrived at ~23:30 UT on Dec. 14. The ISS needed to burn an extra 39 kg of propellant over 8 hours to maintain attitude control. This occurred when the ISS had docked the STS-116 Space Shuttle. Nominal burn rate for ISS is ~1 kg/hr.
'+`

`+ 'More information'}, { "colorCode" : "Hardware", "name": "Spacecraft Charging", "tooltipTitle": 'Spacecraft Charging
Giove-A spacecraft charging at MEO. Charging was due to enhanced electrons in the radiation belt that started to rise after 16:00UT on Dec. 15. This is a long lasting radiation belt enhancement that was associated with geomagnetic storm from the shock and subseqent CME, with long interval southward IMF. This Dec. 13 CME takes ~2 days to arrive at Earth and accelerate the outer-belt electrons.
'+`

`+ 'Conference Proceedings paper with more information'}] } ]} ] } ] }, {"colorCode" : "Origin", "name": "Transient Events", "date": "Dec. 14", "tooltipTitle": 'Dec. 14: Transient Events
Second sequence of transient events from AR 10930 on the west limb.', "children": [ { "colorCode" : "Signal", "name": "X-Class Flare", "tooltipTitle": 'X-Class Flare
Characteristics: X1.5 flare (22:14UT on Dec. 14) from same active region at S06W46.
'+`

`+ ' More information', "children": [ {"colorCode" : "Communication", "name": "VLF Phase", "substring": "Amplitude Variations", "tooltipTitle": 'VLF Phase Amplitude Variations
Characteristics: Very Low Frequency (VLF) phase amplitude variations due to changes in dayside D region of the ionosphere. Variations observed on Dec. 14 at ~22:10UT following the X1.5 solar flare.
'+`

`+ 'Journal article with more information'}] }, { "colorCode" : "Eruptive", "name": "Halo CME", "tooltipTitle": 'Halo CME
Characteristics: Halo CME produced, first observed by C2 on Dec. 14 at 22:30:04.
'+`

`+ 'More information from the SOHO LASCO CME catalog', "children": [ { "colorCode" : "Eruptive", "name": "SEP Event", "tooltipTitle": 'SEP Event
Characteristics: Produces new SEP enhancement which superposes on existing SEP event.

' + `Click here to download a PDF with archived GOES SEP data` + '
'}, { "colorCode" : "Geo", "name": "IP Shock and", "substring": "Enhanced E-Field", "tooltipTitle": 'Interplanetary Shock and Enhanced Interplanetary Electric Field
Characteristics: The interplanetary shock initiates and develops with the Dec. 14 22:30UT CME. This ICME is a magnetic cloud, which is characterized by the IMF Bz or By component displaying a 180 degree rotation. The magnetic cloud is preceded by an interplanetary fast shock but only the magnetic cloud field causes the storm. This type of structure is a magnetic cloud with a shock.

Journal article with more information
', "children": [ { "colorCode" : "Geo", "name": "GIC", "tooltipTitle": 'GIC
Geomagnetically Induced Current (GIC) event, defined as an hour-long interval during which the GIC intensity exceeds 1 A, in China associated with the Dec. 15 geomagnetic storm. GIC intensity was recorded as 14.52 A and lasted from ~06:30UT - 09:30UT, peaking at 08:00UT.
'+`

`+ 'Journal article with more information'} ] } ] }] } ] } ] } ) 4b:T698,//import {legend, swatches} from '@d3/color-legend' function swatches({ color, columns = null, format = x => x, swatchSize = 15, swatchWidth = swatchSize, swatchHeight = swatchSize, marginLeft = 0 }) { const id = DOM.uid().id; if (columns !== null) return html`

${color.domain().map(value => { const label = format(value); return html`

${document.createTextNode(label)}

`; })}

`; return html`

${color.domain().map(value => html`${document.createTextNode(format(value))}`)}

${swpLinks.map((link, i) => ``)}

`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":1784,"value":"swpLinks = [\n {\n text: 'Solar Data',\n url: 'https://lasp.link/OWEp4'\n },\n {\n text: 'Heliospheric Data',\n url: 'https://lasp.link/3BVs4' \n }, \n {\n text: 'Magnetospheric Data',\n url: 'https://lasp.link/hD1DG' \n }, \n {\n text: 'Thermospheric Data',\n url: 'https://lasp.link/ewr2s' \n }, \n {\n text: 'Ground-Based Data',\n url: 'https://lasp.link/Y03gf' \n }\n];","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":1866,"value":"buttonColors = d3.schemeSpectral[10];","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":1733,"value":"categories = ['Origin', 'Signal', 'Eruptive', 'Geo', 'Hardware', 'Communication', 'Human'];","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":1752,"value":"nodeCategoryColors = d3.schemeTableau10;\n// nodeCategoryColors = d3.schemeSpectral[7];\n// nodeCategoryColors = d3.schemeCategory10;\n// nodeCategoryColors = d3.schemeSet1;","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":2191,"value":"categoryLabels = ['Origin', 'Space Weather Event Signal', 'Space Weather Eruptive Event', 'Geophysical Imact', 'Hardware Impact', 'Communication Impact', 'Human Impact'];","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":407,"value":"function colorNode(d){\n const colorIndex = categories.indexOf( d.data.colorCode );\n return nodeCategoryColors[ colorIndex ] || 'gray';\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":158,"value":"d3 = require('d3@6')\n//d3 = require('d3@5')","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":155,"value":"$4a","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":167,"value":"dx = 80","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":433,"value":"width = 1200","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":164,"value":"//dy = width /4.5\ndy = width/7.5 //for video presentation","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":172,"value":"tree = d3.tree().nodeSize([dx,dy])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":175,"value":"diagonal = d3.linkHorizontal().x(d=> d.y - 9).y(d => d.x)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":161,"value":"margin = ({top: 60, right:60,bottom :60, left: 60})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":472,"value":"$4b","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":546,"value":"function entity(character) {\n return `&#${character.charCodeAt(0).toString()};`;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":684,"value":"styles = html``\n","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":807,"value":"//code references\n//Collapsible Tree by Mike Bostock, \n//Electoral College Decision Tree by Kerry Rodden","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":890,"value":"// A tooltip library written in vanilla JS\ntippy = require('https://unpkg.com/tippy.js@2.5.4/dist/tippy.all.min.js')\n// tippy = require('https://unpkg.com/tippy.js@3/dist/tippy.all.min.js')\n// tippy = require(\"tippy.js@6\")","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W4c","stdlib":"1"}} 24:null