Identification of solar wind detected on Earth in Voyager data

This project aims to give students an opportunity to experiment with cosmic ray counts data, especially the unique measurements of the Voyager missions. From the viewpoint of data analysis techniques, the project’s main task is to correlate two-time series and maximize the correlation via shifting the offset of one time series to maximize its correlation the other. The task is to identify a solar flare inside the Voyager data, which realizes its measurements several AUs (astronomical units) from the Sun, and then identify the identical solar flare in data that 1AU from the Sun. In this case, IMP-8 data could be used. The main inspiration for this project is a paper by Wang and Richardson (https://doi.org/10.1029/2004JA010379).

The result of the work should be an analysis of several slides of the Voyagers’ and IMP-8’s dataset, attempting to show the correlation between the two. Students should attempt to develop an approach that would detect a solar flare in the data. The detection should be applied to both dataset, and then students should attempt to correlate the two. The analyzed slices of the data should also be visualized in the final analysis. The final analysis can be presented as one or more Jupyter notebooks or as a simple document briefly describing the realized experiments and showing plots of the analyzed data.

The aforementioned paper by Wang and Richardson documents multiple solar flare events in the Voyager data. These events could be used by students for the development of their own detection method.

Input data are Voyager (1 and 2) data, IMP-8 and/or ACE data. All could be taken from NASA OMNIWeb Plus (https://omniweb.gsfc.nasa.gov/). But there are also other sources available. See the section “Data access”. The variable of interest should be the “Flow Speed” [km/sec]. Typically the data is under the category related to plasma. For Voyager 1, there are data only until 1980, for Voyager 2, there are data at least until 2018.

Some steps of the work

Review the paper by Wang and Richardson
Attempt to download and read data (Voyager, ACE, IMP-8) from NASA OMNIWeb
Prepare a toy dataset containing events mentioned in the paper by Wang and Richardson
Work on the development of the solar flare detection method.
Apply the solar flare detection method to the data in the toy dataset.
Think about the time delay between the detection of the solar flare.
Visualize the IMP-8 and the associated Voyager data together, discuss the success rate of the developed method.
Prepare a presentation of the results.

Computational resources

A remote computer for long-running code can be provided to students after discussion.

Semester 2020/2021

This project is assigned to Yevhenii Podzolkin and Denys Panov.

Data access

Voyager data

OMNIWeb

The data at the OMNIWeb should be accessible via the interface called “Listings with filtering”.

The same data should be also accessible via the directory browsing interface at the Space Physics Data Facility’s web:
https://spdf.gsfc.nasa.gov/pub/data/voyager/
Check-out the “readme” files to get more information about the organization of files.

There is also an interface for visualization:

MIT Space Plasma Group

Besides the OMNIWeb, the data are available at the FTP server provided MIT Space Plasma Group.

http://web.mit.edu/afs/athena/org/s/space/www/voyager/voyager_data/voyager_data.html
- See section “Acquiring the Voyager 1 and 2 Data”, focus on downloading either hourly averages (probably preferable) or fine resolution data
- The website states the following regarding the data access:
  - Voyager plasma data are available from MIT through the links below or directly through anonymous ftp to space.mit.edu. (cd pub/plasma/vgr). Please look at the README files in each directory before using these data.
    Voyager 1: hourly averages and fine resolution data are available by year for 1977-1980.
    Voyager 2: daily averages , hourly averages and fine resolution data are available by year for 1977-heliopause (November, 2018). In addition, currents (L-modes) and (M-modes) are available (2018-present).

OMNI 2

This form might be sufficient to provide all the necessary data at 1AU. Thus, it might not be necessary to use IMP-8 or ACE data directly. In this form, you should select “Flow Speed, km/sec” for Plasma. There is an option to download data in four temporal resolutions and it is possible to produce plots, lists, or to create a file. Maybe it might be useful to check-out data access from the command line.

https://omniweb.gsfc.nasa.gov/form/dx1.html

IMP-8

For IMP-8, the OMNIWeb mentions the following (for 1-hour, IMP8 MIT plasma, there are also others)

ASCII files via FTP (Space Physics Data Facility; https://spdf.gsfc.nasa.gov/pub/data/imp/imp8/plasma_mit/solarwind_hr/)
Plots, listings, subsetted files (This might be useful)
Distributions, averages, std. deviations

Please check it out at the OMINIWeb.

This section might be extended

ACE

For ACE, the OMNIWeb mentions CDAWeb and the following (for 1-hour, plasma data, Earth-shifted)

HDF files, all experiments, via FTP site (Space Physics Data Facility; https://spdf.gsfc.nasa.gov/pub/data/ace/)
- Probably, this is the directory you should be looking at: https://spdf.gsfc.nasa.gov/pub/data/ace/merged/4_min_merged_mag_plasma/
Plots, listings, subsetted files (this might be useful)
Distributions, averages, std. deviations

Coordinated Data Analysis Web (CDAWeb)

The data for Voyager, ACE, IMP-8, and others should be also accessible via forms at https://cdaweb.gsfc.nasa.gov/index.html/