Scientifically interesting events (newest first)

Magnetic cloud-like structure and stream interface on Feb 4 - 9, 2025.

ICME and stream interface on Feb 4 - 9
Figure 1. Magnetic cloud-like structure followed by a stream interface .

Shock on Feb 1, 2025.

Shock on Feb 1
Figure 2. An interplanetary shock captured with PAS 1s mode.

High-speed stream, shock, ICME on Jan 28 - Feb 8, 2025.

several structures on Jan 28 - Feb 8
Figure 3. High-speed stream, shock, ICME on Jan 28 - Feb 8, 2025.

ICME on 31 Dec 2024 – 3 Jan 2025

ICME on Dec 31 - Jan 3
Figure 4. Earth-directed ICME, aurorae seen with Kp 4 – 8, clear magnetic cloud with cold protons and alphas and with heavier ions. High-speed hot wind after the magnetic cloud.

A few stream interfaces on Dec 7 - 14, 2024

stream interfaces on 7 - 14 Dec 2024
Figure 5. Interface between slow and fast streams on Dec 7th, and perhaps also on Dec 3rd and14th.

Interval with clear presence of alphas on Nov 25, 2024

clear alpha interval 25 november 2024
Figure 6. Interval with clear presence of alphas.

Stream interaction region on Nov 16, 2024

stream interface 16 Nov 2024
Figure 7. A familiar structure looking like either a stream interface or an ICME in the slow/intermediate-speed wind.

Stream interaction region on Nov 12, 2024

stream interface 11 Nov 2024
Figure 8. Stream interaction region with non-thermal protons and alpha particles especially in the fast wind. Significant data correction for the slow wind that preceded the stream interface.

IP Shock in slow wind on Nov 6, 2024

IP shock in slow wind 6 Nov 2024
Figure 9. Interplanetary shock with V jump of 60 km.s^-1 (Ratio Nd to Nu is about 2). Clear alpha particles. Non-thermal proton intervals.

High-speed stream on October 27, 2024

PAS missed data 27 Oct 2024 during WOL
Figure 10. Interesting interval with high-speed stream on October 27, 2024. Missed data context during WOL at the beginning of STP 332. Clear non-thermal ion intervals. Data quality is mostly good.

Slow ICME-like structure on October 13, 2024

ICME in slow wind 12 Oct 2024
Figure 11. ICME in slow wind. Max proton speed ~ 420 km/s. Clear alpha particle flux. High correction factor due to low proton speed surrounding the structure.

Overview of October 2024 perihelion

October perihelion 2024 data
Figure 12. PAS 1s mode except for Sep 23 – 25 in STP 328, where PAS was on 2s mode (see operation table). High correction factor (lower data quality) for slow wind streams. High solar activities with several ICMEs detected. PSP was also in the vicinity of SO during this perihelion.

Shock, ICME on 9 - 10 October 2024

ICME on 9 - 14 October 2024
Figure 13. An ICME-like structure. PAS 1s data. Good data quality throughout apart from the slow wind. Velocity jump > 400 km/s. Hot and dense ion stream (sheath) behind the velocity jump. The jump contains two-step-like shocks. Interesting non-thermal proton and alpha interval.

Shock 4 October 2024

Shock on 4 October 2024
Figure 14. A shock at the perihelion (0.3 AU). PAS 1s data. Good data quality throughout apart from the slow wind. A shock with \Delta 𝑉 400 km/s with a very dense interval behind the shock (sheath?).

Interesting structure at the perihelion on Sep 29 – Oct 2, 2024

Interesting structure on 2 October 2024
Figure 15. Interesting structure at the perihelion (0.3 AU). PAS 1s data. Good data quality throughout apart from the slow wind. Either a stream interface (transition from slow- to high-speed stream) or an ICME with cold materials containing clear alpha particles. Featured by spiky structures (time scale of hours).

Data near Oct 2024 perihelion (0.3 AU)

Spiky structures near Oct perihelion 2024
Figure 16. Slow, dense, and hot solar wind featured by spiky features (~ timescale of hours) in energy, velocity, temperature. A transition to intermediate/high-speed stream after Sep 30th.

Intermediate-speed wind with spiky features near Oct perihelion (0.3 AU)

Intermediate-speed wind with spiky features perihelion 2024
Figure 17. Slow/intermediate fast wind intervals. Clear small-scale (hours) spiky features. Very dense SW interval after Sep 24.

Slow, steady wind near Oct 2024 perihelion (0.3 AU)

slow steady wind Oct 2024
Figure 18. Slow, dense, and hot solar wind featured by spiky features (~ timescale of hours) in energy, velocity, temperature. A transition to intermediate/high-speed stream after Sep 30th.

ICMEs on Sep 9 – 14, 2024

icmes on sep 9 2024
Figure 19. ICME with max H+ speed~ 700 km/s. Clear presence of non-thermal H+/He2+ populations (complex distribution functions).

ICMEs on Sep 4 – 9, 2024

icme on Sep 4
Figure 20. Clear shock and sheath on Sep 4 followed by cold, tenuous H+ and He2+ streams on Sep 5. Another ICME with two-step shocks on Sep 6 followed by alternating cold and hot intervals. Data contamination by photoelectrons on September 4 - 6 visible as uniform energy flux across all energies in green.

Shock, ICME on 24 - 31 July, 2024 (PAS 1s cadence)

icme on july 24 2024
Figure 21. Shock-ICME sampled with PAS 1s cadence.

Shock, ICME on 24 - 28 July 2024

ICME on 24 - 28 July 2024
Figure 22. Detected with PAS 1s data. Shock with V jump of 400 km/s. Clear sheath behind the shock. Proton speed in ICME ~ 1000 km/s. Secondary electron contamination on 23rd and 27th July.

Fast, hot stream on 10 July 2024

Fast-hot stream on 10 July 2024
Figure 23. Fast and hot stream (correlated velocity and temperature).

ICME on 19 - 22 June 2024

ICME on 19 - 22 June 2024
Figure 24. ICME detected at 0.94 AU with clear alpha particles and some additional ion species. Cold materials.

Two shocks on 13 - 14 June 2024

Shocks on 12 - 16 June 2024
Figure 25. Two-step shocks on 13 - 14 June 2024.

ICME on May 21st

ICME on 21st May 2024
Figure 26. An ICME preceded by a shock. Velocity jump > 200 km/s. Photoelectron contamination visible as uniform energy flux at all energies.

ICME on May 9th (0.68 AU)

ICME on 9th May 2024
Figure 27. An ICME preceded by a shock. Velocity jump ~ 200 km/s. Plausibly clear flux rope structure. Clear alpha energy flux throughout.

ICME at 0.45 AU with some heavy ions

ICME on 20th April 2024
Figure 28. An ICME at 0.45 AU with a shock and plausibly a flux rope with cold prominence materials. An additional species above He2+ omnidirectional energy flux.

Dense wind and a shock in slow wind

Slow wind interval near perihelion April 2024 with multiple populations
Figure 29. Slow (V~ 350 km/s) and dense (200 /cc) wind with multiple populations and additional species.

Fast wind near the perihelion with jets

Fast wind interval near perihelion April 2024 with jets
Figure 30. Fast-/intermediate-speed wind on April 8th – 12th at 0.35 AU with a presence of jets throughout.

Dense wind near the perihelion (0.32 AU)

Dense wind interval near perihelion April 2024
Figure 31. Dense wind interval preceding a high-speed stream. Presence of jets and sub-populations.

Perihelion Mar - Apr 2024

Perihelion Mar - Apr 2024
Figure 32. March – April 2024 Perihelion data (0.29 AU).

Stream in the vicinity of the perihelion

stream-perihelion-30mar2024
Figure 33. Slow and high-speed streams with broad energy flux. Presence of strong non-thermal H+ population.

Shock, ICME on 23rd March 2024 (0.39 AU)

Shock
Figure 34. Overview.
Shock
Figure 35. Zoom-in.

Overview on Dec 2023 – March 2024

overview-dec2023-mar2024
Figure 36. Note: the new PAS high cadence tests (1s or 2s) were running from Nov 2023 – 10 March 2024. There are several intervals with partial VDFs. PAS is on 2s cadence from March 11, 2024.

Shock, ICME on 29th - 30th Nov 2023

Shock
Figure 37. PAS was in 1s cadence, some partial VDF with 5 elevations. Nice wave activities upstream of the shocks seen by MAG.

Shock, ICME on 11th Nov 2023 (0.68 AU)

Shock
Figure 38. IP shock or shock/ICME in moderate speed wind, calm upstream conditions.

Shock, ICME on 17th Oct 2023 (0.3 AU)

Shock
Figure 39. Shock/ICME in slow wind with high alpha density in the trailing edge.

Shock, ICME on 11th Oct 2023 (0.3 AU)

Shock
Figure 40. Dense ICME. Only partial VDF at the beginning of the interval.

Shock, ICME on 4th Oct 2023 (0.3 AU)

Shock
Figure 41. Hot, slow streams at 0.3 AU. Some visible reflected ions upstream of the shock.

Perihelion Sep - Oct 2023

Perihelion Sep - Oct 2023
Figure 42. Mostly slow-intermediate speed wind with a few ICMEs. PAS static mode (window changes every 6h, 4s cadence). Distance 0.29 AU.

ICMEs on the 4th of Sep 2023

ICMEs on the 4th of Sep 2023
Figure 43. Possibly two ICMEs. 1st shock with \Delta V = 500 km/s, 2nd shock with \Delta V = 300 km/s. The ion energy flux of the 1st shock overshoots the PAS field of view. Alternate intervals of hot and cold materials.

A high density interval with clear He2+ on the 21st August 2023

High-density interval with clear He2+ on the 21st of August 2023
Figure 44. A high density interval with clear He2+ (and possibly another ionized species above He2+?).

Alternating hot/cold intervals with clear He2+ on the 18th of Aug 2023

Hot/cold intervals with clear He2+ and possibly an IP shock on the 18th of August 2023
Figure 45. Alternating hot/cold intervals with clear He2+. There is possibly an IP shock on 20th of August at 4:00.

An IP shock on the 10th of Aug 2023

IP on the 10th of August 2023
Figure 46. An IP shock, with some possible partial IP crossings.

An enhanced density interval on the 8th of Aug 2023

Density enhancement on the 8th of August 2023
Figure 47. An interval with the ion density enhancement.

An IP shock on the 3rd of Aug 2023

IP on the 3rd of August 2023
Figure 48. An interplanetary (IP) shock in the slow wind.

An ICME on the 26th of July 2023

ICME on the 26th of July
Figure 49. An ICME on the 26th of July with maximum proton speed of 1130 km/s. There are two intervals of fast and dense protons. A cold trailing interval after the 2nd speed bump. There are some contaminations possibly due to photoelectrons across all the energies before the shock.

An ICME on the 18th of July 2023

ICME on the 18th of July
Figure 50. ICME with maximum proton speed of 800 km/s and intervals of cold H+ and He2+ (and some hot H+). A few hours interval with a very low density (0.02 cm-3).

An ICME on the 14th of July 2023

ICME on the 14th of July
Figure 51. ICME with maximum proton speed of 600 km/s and cold trailing interval (with a second proton peak, possibly a very fast beam, above the first peak).

Cold then hot wind strems on the 26th of June 2023

cold then hot wind on 26th June 2023
Figure 52. A hot ion stream with intermediate/high speed wind, preceded by an intermediate/slow wind interval with clear He2+.

Slow, hot wind on the 20th of June 2023

Slow
Figure 53. Slow, hot solar wind with some clear (dense) He2+.

Stream Interface on the 10th of June 2023

SI on 10th June 2023
Figure 54. Stream interaction region with clear H+ and He2+ in the trailing part (slow wind).

Stream Interface on the 29th of May 2023

SI on 29th May 2023
Figure 55. Cold stream of H+ and He2+ preceding hot stream (with a stream interface – like structure), followed by an ICME-like structure in intermediate – fast wind.

ICMEs on the 1st of May 2023

ICMEs at 0.5 AU
Figure 56. ICMEs in intermediate/slow wind with hot sheath and cold plasmas (0.5 AU).

A stream interface during the April 23 perihelion

Stream interface at the perihelion
Figure 57. A stream interface observed at 0.29 AU during the perihelion. The fast stream has a very high number density, reaching 1500 /cc. There is an intense He2+ energy flux with a clear separation from the cold protons in the fast stream.

An ICME on the 20th of March 2023

An ICME
Figure 58. An ICME with shock on the 20th and a cold/dense plasma with clear proton-alpha separation in the trailing part. This event was observed to have a strong Bz and it arrives at Earth.

A shock on the 14th of March 2023

A shock
Figure 59. A shock arrival.

A shock and/or stream interface on the 19th Feb 2023

A stream interface
Figure 60. A shock and/or stream interface with preceded cold plasma.

An interplanetary shock on the 17th Jan 2023

An interplanetary shock
Figure 61. An interplanetary shock.

Possible ICME on 11th Jan 2023

A coronal mass ejection
Figure 62. A potential Coronal Mass Ejection with a broaden shock region and a flux-rope structure at the trailing edge.

Ion density dropout (also observed by MMS on 25/12/2022)

A drop in ion energy flux on the 24th of December 2022. Also observed by MMS.
Figure 63. A drop of ion omnidirectional energy flux on the 24th December 2022, characterised by a 12-hr interval of a very low ion Eflux with n ~ 0.01 - 0.1 cm-3. Likely high uncertainties for moment calculations, seen as strong fluctuations of temperature and ion number density. SolO was located before Earth/MMS. Stereo-A was between SolO and Earth.
slow wind and high-speed streams during the perihelion in October 2022
Figure 64. Slow and dense solar wind at 0.33 AU and high-speed streams plausibly containing switchback patches at 0.3 AU.

Shock/ICME on 6th September 2022

CME 6th September 2022
Figure 65. A shock/ICME arrival on the 6th of September 2022. High-speed protons up to 1100 km/s and high-temperature protons up to a few hundred eV in the shock. Cold protons in the magnetic cloud.

SIR/HSS or ICME on 3rd September 2022

SIR/HSS or ICME 3rd September 2022
Figure 66. A stream interaction region / high-speed stream or an ICME arrival on the 3rd of September, 2022.

Shock/ICME on 1st September 2022

ICME 1st September 2022
Figure 67. An ICME detected on the 1st of September 2022. Proton speed up to 1200 km/s in the shock. Cold plasma in the magnetic cloud. Data gap at the beginning STP 220, starting from 12:35 due to WOL and TCM.

Interplanetary shock on 17/06/2022

Interplanetary shock
Figure 68. Interplanetary shock. Warning - data quality factor exceeding the lower threshold before IP shock.

Shock/ICME on 25/07/2022

Shock/ICME arrival
Figure 69. Shock/ICME arrival on 25/07/2022 with the proton bulk reaching ~1000 km/s.