= PAS Scientifically Interesting Events logs (July 2022 - present)
Rungployphan Kieokaew (rkieokaew@irap.omp.eu)
Last update 17/02/2025
== Scientifically interesting events (newest first)
=== Magnetic cloud-like structure and stream interface on Feb 4 - 9, 2025.
[#img-pas-icme-stream-feb2025]
.Magnetic cloud-like structure followed by a stream interface .
image::images/Interesting-event_4-9Feb_2025.png[ICME and stream interface on Feb 4 - 9, 2025]
=== Shock on Feb 1, 2025.
[#img-pas-icme-newyear2025]
.An interplanetary shock captured with PAS 1s mode.
image::images/shock_1Feb2025.png[Shock on Feb 1, 2025]
=== High-speed stream, shock, ICME on Jan 28 - Feb 8, 2025.
[#img-pas-late-jan-2025]
.High-speed stream, shock, ICME on Jan 28 - Feb 8, 2025.
image::images/Interesting-event_28Jan-8Feb_2025.png[several structures on Jan 28 - Feb 8, 2025]
=== ICME on 31 Dec 2024 – 3 Jan 2025
[#img-pas-icme-newyear2025]
.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.
image::images/ICME_31Dec2024-3Jan2025.png[ICME on Dec 31 - Jan 3, 2025]
=== A few stream interfaces on Dec 7 - 14, 2024
[#img-pas-sir-nov12]
.Interface between slow and fast streams on Dec 7th, and perhaps also on Dec 3rd and14th.
image::images/SIs_Dec7-14_2024.png[stream interfaces on 7 - 14 Dec 2024]
=== Interval with clear presence of alphas on Nov 25, 2024
[#img-pas-sir-nov12]
.Interval with clear presence of alphas.
image::images/PAS_clear-alpha_25Nov2024.png[clear alpha interval 25 november 2024]
=== Stream interaction region on Nov 16, 2024
[#img-pas-sir-nov12]
.A familiar structure looking like either a stream interface or an ICME in the slow/intermediate-speed wind.
image::images/SI_16Nov2024.png[stream interface 16 Nov 2024]
=== Stream interaction region on Nov 12, 2024
[#img-pas-sir-nov12]
.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.
image::images/PAS_SIR_11Nov2024.png[stream interface 11 Nov 2024]
=== IP Shock in slow wind on Nov 6, 2024
[#img-pas-ip-shock-nov6]
.Interplanetary shock with V jump of 60 km.s^-1 (Ratio Nd to Nu is about 2). Clear alpha particles. Non-thermal proton intervals.
image::images/PAS_IP-shock_slowwind_6Nov2024.png[IP shock in slow wind 6 Nov 2024]
=== High-speed stream on October 27, 2024
[#img-pas-l2-missed-data-oct27]
.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.
image::images/PAS_missed-data_27Oct2024.png[PAS missed data 27 Oct 2024 during WOL]
=== Slow ICME-like structure on October 13, 2024
[#img-slow-icme_october-2024]
.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.
image::images/PAS_slow-icme_12Oct2024.png[ICME in slow wind 12 Oct 2024]
=== Overview of October 2024 perihelion ===
[#img-perihelion_october-2024]
.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.
image::images/PAS_October_perihelion_2024.png[October perihelion 2024 data]
=== Shock, ICME on 9 - 10 October 2024
[#img-icme_oct9-2024]
.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.
image::images/PAS_icme_9-14Oct2024.png[ICME on 9 - 14 October 2024]
=== Shock 4 October 2024
[#img-icme_oct4-2024]
.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?).
image::images/PAS_Shock_Oct4_2024.png[Shock on 4 October 2024]
=== Interesting structure at the perihelion on Sep 29 – Oct 2, 2024
[#img-icme_oct2-2024]
.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).
image::images/PAS_Sep24-Oct2_2024.png[Interesting structure on 2 October 2024]
=== Data near Oct 2024 perihelion (0.3 AU)
[#img-spiky-oct-2024]
.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.
image::images/PAS_perihelion-Oct2024.png[Spiky structures near Oct perihelion 2024]
=== Intermediate-speed wind with spiky features near Oct perihelion (0.3 AU)
[#img-spiky-intermediate-wind-oct-2024]
.Slow/intermediate fast wind intervals. Clear small-scale (hours) spiky features. Very dense SW interval after Sep 24.
image::images/PAS_intermediate-wind-Oct2024.png[Intermediate-speed wind with spiky features perihelion 2024]
=== Slow, steady wind near Oct 2024 perihelion (0.3 AU)
[#img-slow-steady-oct2024]
.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.
image::images/PAS_slow-steady-wind-Oct2024.png[slow steady wind Oct 2024]
=== ICMEs on Sep 9 – 14, 2024
[#img-icmes-sep9-2024]
.ICME with max H+ speed~ 700 km/s. Clear presence of non-thermal H+/He2+ populations (complex distribution functions).
image::images/PAS_shock-icme_9-14Sep2024.png[icmes on sep 9 2024]
=== ICMEs on Sep 4 – 9, 2024
[#img-icme-sep4-2024]
.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.
image::images/PAS_shock-icme_4-9Sep2024.png[icme on Sep 4, 2024]
=== Shock, ICME on 24 - 31 July, 2024 (PAS 1s cadence)
[#img-icme-july24-2024]
.Shock-ICME sampled with PAS 1s cadence.
image::images/PAS_shock-icme_24-31July2024.png[icme on july 24 2024]
=== Shock, ICME on 24 - 28 July 2024
[#img-icme_jul24-2024]
.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.
image::images/PAS_shock-icme_24-28July2024.png[ICME on 24 - 28 July 2024]
=== Fast, hot stream on 10 July 2024
[#img-fast-hot-stream-jul10-2024]
.Fast and hot stream (correlated velocity and temperature).
image::images/PAS_fast-hot-stream_10Jul2024.png[Fast-hot stream on 10 July 2024]
=== ICME on 19 - 22 June 2024
[#img-icme_jun19-2024]
.ICME detected at 0.94 AU with clear alpha particles and some additional ion species. Cold materials.
image::images/PAS_ICME_19-22June2024.png[ICME on 19 - 22 June 2024]
=== Two shocks on 13 - 14 June 2024
[#img-shock_jun12-2024]
.Two-step shocks on 13 - 14 June 2024.
image::images/PAS_two-shocks_12June2024.png[Shocks on 12 - 16 June 2024]
=== ICME on May 21st
[#img-icme_may21-2024]
.An ICME preceded by a shock. Velocity jump > 200 km/s. Photoelectron contamination visible as uniform energy flux at all energies.
image::images/PAS_L2_ICME21May2024.png[ICME on 21st May 2024]
=== ICME on May 9th (0.68 AU)
[#img-icme_may9-2024]
.An ICME preceded by a shock. Velocity jump ~ 200 km/s. Plausibly clear flux rope structure. Clear alpha energy flux throughout.
image::images/PAS_L2_ICME9May2024.png[ICME on 9th May 2024]
=== ICME at 0.45 AU with some heavy ions
[#img-icme-0.5au-apr-2024]
.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.
image::images/PAS_L2_20June2024.png[ICME on 20th April 2024]
=== Dense wind and a shock in slow wind
[#img-slow-wind-perihelion-apr-2024]
.Slow (V~ 350 km/s) and dense (200 /cc) wind with multiple populations and additional species.
image::images/PAS_L2_13Apr2024.png[Slow wind interval near perihelion April 2024 with multiple populations]
=== Fast wind near the perihelion with jets
[#img-fast-wind-perihelion-jets-apr-2024]
.Fast-/intermediate-speed wind on April 8th – 12th at 0.35 AU with a presence of jets throughout.
image::images/fast-wind_jets_8-12Apr2024.png[Fast wind interval near perihelion April 2024 with jets]
=== Dense wind near the perihelion (0.32 AU)
[#img-dense-wind-perihelion-apr-2024]
.Dense wind interval preceding a high-speed stream. Presence of jets and sub-populations.
image::images/Dense-stream_7Apr2024.png[Dense wind interval near perihelion April 2024]
=== Perihelion Mar - Apr 2024
[#img-perihelion-mar-2024]
.March – April 2024 Perihelion data (0.29 AU).
image::images/Mar-April2024_perihelion.png[Perihelion Mar - Apr 2024]
=== Stream in the vicinity of the perihelion
[#img-stream-perihelion-30mar2024]
.Slow and high-speed streams with broad energy flux. Presence of strong non-thermal H+ population.
image::images/broad-stream_30Mar2024.png[stream-perihelion-30mar2024]
=== Shock, ICME on 23rd March 2024 (0.39 AU)
[#img-icmes-17oct-2023]
.Overview.
image::images/ICME_23March2024.png[Shock, ICME on 23rd March 2024]
[#img-icmes-17oct-2023]
.Zoom-in.
image::images/ICME_23March2024_zoom.png[Shock, ICME on 23rd March 2024, zoomed-in]
=== Overview on Dec 2023 – March 2024
[#img-overview-dec2023-mar2024]
.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.
image::images/PAS_Dec2023-March2024.png[overview-dec2023-mar2024]
=== Shock, ICME on 29th - 30th Nov 2023
[#img-icmes-17oct-2023]
.PAS was in 1s cadence, some partial VDF with 5 elevations. Nice wave activities upstream of the shocks seen by MAG.
image::images/shocks_29-30Nov2003.png[Shock, ICME on 29th - 30th Nov 2023]
=== Shock, ICME on 11th Nov 2023 (0.68 AU)
[#img-icmes-17oct-2023]
.IP shock or shock/ICME in moderate speed wind, calm upstream conditions.
image::images/ICME_11Nov2023.png[Shock, ICME on 11th Nov 2023]
=== Shock, ICME on 17th Oct 2023 (0.3 AU)
[#img-icmes-17oct-2023]
.Shock/ICME in slow wind with high alpha density in the trailing edge.
image::images/ICME_17Oct2023.png[Shock, ICME on 17th Oct 2023]
=== Shock, ICME on 11th Oct 2023 (0.3 AU)
[#img-icmes-11oct-2023]
.Dense ICME. Only partial VDF at the beginning of the interval.
image::images/ICME_11Oct2023.png[Shock, ICME on 11th Oct 2023]
=== Shock, ICME on 4th Oct 2023 (0.3 AU)
[#img-icmes-4oct-2023]
.Hot, slow streams at 0.3 AU. Some visible reflected ions upstream of the shock.
image::images/PAS_shock_4Oct2023.png[Shock, ICME on 4th Oct 2023]
=== Perihelion Sep - Oct 2023
[#img-perihelion-sep-2023]
.Mostly slow-intermediate speed wind with a few ICMEs. PAS static mode (window changes every 6h, 4s cadence). Distance 0.29 AU.
image::images/Perihelion_Sep-Oct2023.png[Perihelion Sep - Oct 2023]
=== ICMEs on the 4th of Sep 2023
[#img-icmes-4sep-2023]
.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.
image::images/Two_ICMEs_4Sep2023.png[ICMEs on the 4th of Sep 2023]
=== A high density interval with clear He2+ on the 21st August 2023
[#img-ip-21aug-2023]
.A high density interval with clear He2+ (and possibly another ionized species above He2+?).
image::images/High-density_21Aug2023.png[High-density interval with clear He2+ on the 21st of August 2023]
=== Alternating hot/cold intervals with clear He2+ on the 18th of Aug 2023
[#img-ip-18aug-2023]
.Alternating hot/cold intervals with clear He2+. There is possibly an IP shock on 20th of August at 4:00.
image::images/IP_hot_cold_18Aug2023.png[Hot/cold intervals with clear He2+ and possibly an IP shock on the 18th of August 2023]
=== An IP shock on the 10th of Aug 2023
[#img-ip-10aug-2023]
.An IP shock, with some possible partial IP crossings.
image::images/IP_10Aug2023.png[IP on the 10th of August 2023]
=== An enhanced density interval on the 8th of Aug 2023
[#img-density-enhancement-8aug-2023]
.An interval with the ion density enhancement.
image::images/Ion-density_enhancement_8Aug2023.png[Density enhancement on the 8th of August 2023]
=== An IP shock on the 3rd of Aug 2023
[#img-ip-3aug-2023]
.An interplanetary (IP) shock in the slow wind.
image::images/IP_3Aug2023.png[IP on the 3rd of August 2023]
=== An ICME on the 26th of July 2023
[#img-icme-26july-2023]
.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.
image::images/ICME_24July2023.png[ICME on the 26th of July]
=== An ICME on the 18th of July 2023
[#img-icme-18july-2023]
.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).
image::images/ICME_18July2023.png[ICME on the 18th of July]
=== An ICME on the 14th of July 2023
[#img-icme-14july-2023]
.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).
image::images/ICME_14July2023.png[ICME on the 14th of July]
=== Cold then hot wind strems on the 26th of June 2023
[#img-cold-hot-wind-26jun-2023]
.A hot ion stream with intermediate/high speed wind, preceded by an intermediate/slow wind interval with clear He2+.
image::images/Cold_hot_stream_26June2023.png[cold then hot wind on 26th June 2023]
=== Slow, hot wind on the 20th of June 2023
[#img-slow-hot-wind-20jun-2023]
.Slow, hot solar wind with some clear (dense) He2+.
image::images/Slow-hot-wind_20June2023.png[Slow,hot wind on 20th June 2023]
=== Stream Interface on the 10th of June 2023
[#img-SI-10jun-2023]
.Stream interaction region with clear H+ and He2+ in the trailing part (slow wind).
image::images/SI_10June2023.png[SI on 10th June 2023]
=== Stream Interface on the 29th of May 2023
[#img-SI-29may-2023]
.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.
image::images/SI_29May2023.png[SI on 29th May 2023]
=== ICMEs on the 1st of May 2023
[#img-icmes-1may-2023]
.ICMEs in intermediate/slow wind with hot sheath and cold plasmas (0.5 AU).
image::images/ICMEs_1May2023.png[ICMEs at 0.5 AU]
=== A stream interface during the April 23 perihelion
[#img-sir-mar-2023]
.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.
image::images/PAS_sci_stream-interface_dense_10Apr2023_perihelion.png[Stream interface at the perihelion]
=== An ICME on the 20th of March 2023
[#img-icme-mar-2023]
.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.
image::images/ICME_20Mar2023.png[An ICME]
=== A shock on the 14th of March 2023
[#img-shock-mar-2023]
.A shock arrival.
image::images/Shock_14Mar2023.png[A shock]
=== A shock and/or stream interface on the 19th Feb 2023
[#img-ip-jan-2023]
.A shock and/or stream interface with preceded cold plasma.
image::images/stream_interface_stp244.png[A stream interface]
=== An interplanetary shock on the 17th Jan 2023
[#img-ip-jan-2023]
.An interplanetary shock.
image::images/PAS_L2_IP_17012023.png[An interplanetary shock]
=== Possible ICME on 11th Jan 2023
[#img-cme-jan2023]
.A potential Coronal Mass Ejection with a broaden shock region and a flux-rope structure at the trailing edge.
image::images/PAS_L2_CME_11012023.png[A coronal mass ejection]
=== Ion density dropout (also observed by MMS on 25/12/2022)
[#img-iondropout-dec-2022]
.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.
image::images/iondensity_drop_24122022.png[A drop in ion energy flux on the 24th of December 2022. Also observed by MMS.]
=== Perihelion Oct 2022 (0.29 AU) plausibly featured by switchback patches
[#img-perihelion-oct-2022]
.Slow and dense solar wind at 0.33 AU and high-speed streams plausibly containing switchback patches at 0.3 AU.
image::images/Potential_SB_patches_Oct2022.png[slow wind and high-speed streams during the perihelion in October 2022]
=== Shock/ICME on 6th September 2022
[#img-shock/icme_06092022]
.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.
image::images/CME_06092022.png[CME 6th September 2022]
=== SIR/HSS or ICME on 3rd September 2022
[#img-hss_03092022]
.A stream interaction region / high-speed stream or an ICME arrival on the 3rd of September, 2022.
image::images/CME-HSS_03092022.png[SIR/HSS or ICME 3rd September 2022]
=== Shock/ICME on 1st September 2022
[#img-cme_01092022]
.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.
image::images/CME_01092022.png[ICME 1st September 2022]
=== Interplanetary shock on 17/06/2022
[#img-shock_25072022]
.Interplanetary shock. Warning - data quality factor exceeding the lower threshold before IP shock.
image::images/IP_shock_17062022.png[Interplanetary shock]
=== Shock/ICME on 25/07/2022
[#img-shock_25072022]
.Shock/ICME arrival on 25/07/2022 with the proton bulk reaching ~1000 km/s.
image::images/shock-25072022.png[Shock/ICME arrival]
