Space Weather Sub-Group Web Meeting 2024-12-18

Agenda

1. The need and requirements for CrossCal acivity for L1 in-situ measurements (presented by Prof. Dibyendu Chakrabarty)
2. Data Levels
3. PRBEM document on data analysis procedure
4. GSICS Annual Meeting 2025
5. Action Items
6. Next Subgroup Meeting
7. AOB

Minutes

CrossCal Activity at L1

Prof. Dibyendu Chakrabarty gave a highly informative talk about the needs and requirements for Cross-Cal activity for L1 in-situ measurements, mainly focused on Aditya-L1.

Aditya-L1 and ASPEX

• 7 experiments on spacecraft: 4 remote sensing experiments, 3 in situ: ASPEX (2 instruments: SWIS and STEPS), PAPA, magnetometer
• Launched 02 Sept 2023, cruise phase started 19 Sept 2023, inserted into halo orbit 6 Jan 2024
• PAPA: plasma analyzer - electrons and ions
• MAG: showed comparison with DSCOVR
• ASPEX: Prof. Chakrabarty is the PI
• SWIS: solar wind ion spectrometer (100 eV - 20 keV), measures in two planes. Two top-hat analyzers (THA)
• STEPS: suprathermal and energetic particle spectrometer (20 keV/n - 6 MeV/n), 6 directions - 4 on front (including along the Parker spiral), 2 on back (one looking at Earth, one looking down)
• Described SWIS and STEPS data levels
• SWIS/THA-1 energy-time spectrogram (ecliptic plane) and THA-2 (out of plane): distinct H+ and He++ lines
• Velocity and temperature comparisons: indicate need for xcal and xcorr length determination (spatial inhomogeneity) - how to separate the two effects?
• May 8-12, 2024 storm: SWIX/THA-1 energy-time spectrogram and STEPS line plot. Mode change after shock arrived improved SWIS energy coverage.
• SWIS has multiple modes: limited energy scan (e.g. proposed by an investigator) may not permit derivation of bulk parameters
• Unprecedented opportunity starting next year: 6-7 satellites at L1

Discussion:

Brian Kress: we are interested in cross-comparisons with Aditya-L1. May we get a copy of the presentation? Yes, through Hasan.

Manik Bali: invites Prof. Chakrabarty to contribute an article to the GSICS newsletter

Nagatsuma-san: we would expand our scope to include L1 plasmas, particles & magnetic field. Prof. Chakrabarty emphasized distinguishing spatial inhomogeneity from cross-calibration differences.

Piers Jiggens: do we have the expertise in this group to do these cross-calibrations? energy range, magnetic field? Remote sensing observations are outside the scope of this group? Start with expanding particle/plasma measurements to lower energies 'low hanging fruit'.

Nagatsuma-san: agreed, need to invite experts for this activity. Perhaps NOAA?

Brian Kress: NOAA/NCEI will be leading SWFO-L1 plasma instrument, particle instrument and magnetometer validation efforts.

Prof. Chakrabarty: in case of differences, teams need to work closely together to properly resolve them.

Data Levels

We have received feedback from CMA, KMA, JAXA, NOAA, and NICT.

It is apparent that the definition of data levels defined by each organization is different - see table in charts. Nagatsuma-san asked us to review the table for correctness.

Piers: broadly agrees with this. Thinking about ESA's modified approach: L1b is first level converted to physical units - some calibrations applied but does not take advantage of in-flight experience. L2 - still relying only on individual instrument. L3 - incorporates results of intercalibration with other instruments (e.g. via conjunctions)

L3 'Derived' not clearly enough defined to include or exclude crosscal.

Questions:

• Which level of data should we use for Cross-Calibration? “partially-processed” or “Calibrated” or “Derived”?
• How should we treat product from “Cross-Calibration”? Should it be used for producing “Derived” data? Or should we update “Calibrated” data based on “Cross-Calibration”?

Jesse Andries: why are WMO definitions not suited for in situ instruments? Provided this morning [inserted below].

Nagatsuma-san: need to evaluate carefully and discuss further. Jesse will add the WMO definitions to the spreadsheet. [Done immediately after meeting]

PRBEM Document on Data Analysis Procedure

Have not received any updated information from COSPAR Bureau via PRBEM chair (Miyoshi-san)

GSICS Annual Meeting 2025

In Changchun, China in March (17-21)

Urgent: visa application - send info to CMA by 5 Jan 2025 (see charts for details)

Action Items

1. Work plan wording to define GSICS deliverables - ongoing - Piers will remind

3.1 Data level definitions from institutions - close. Will follow with new action item to define unified definition.

3.2 proposing application produced from multiple satellite data - ongoing

7.2 common code base - PRBEM gitlab - ongoing. Piers: PRBEM trying to schedule more frequent working meetings (than every 2 years) to make progress on items like this.

9. After COSPAR/PRBEM resolution is endorsed (we will ask chair of PRBEM(Miyoshi-san)), the member of SWx sub-group will discuss how to update PRBEM data analysis procedure with COSPAR/PRBEM members. -> Pending

Next Meeting

Feb 5, 2025 12 UTC?
A. Boudouridis: postpone 1 week to avoid NOAA instrument reviews? yes.

Agreed on Feb 12, 2025 12 UTC

AOB

No other business.

Meeting ended at 13:15 UTC.

Attendees

CMA: Cong Huang

CU: Juan Rodriguez (minutes), Athanasios Boudouridis, Brian Kress

ESA: Piers Jiggens

ISRO: Mohammad Hasan

KMA: Daehyeon Oh

NICT: Tsutomu Nagatsuma (Chair)

NOAA: Christian Naylor, Manik Bali

PRL: Dibyendu Chakrabarty

SPARC: Ingmar Sandberg

WMO: Jesse Andries