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Journal Club Week 6

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D. J. Knipp et al., The May 1967 great storm and radio disruption event: Extreme space weather and extraordinary responses, Space Weather, 14, 614–633

Summaries and answers now available

The article can be accessed at https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2016SW001423

This week we have a two-week deadline to accommodate everyone's half-terms (but we do have an additional activity to get involved in if you want to keep busy here).

You can also download the Cornell notes template for this paper (which includes the same questions) as a Word Document or PDF. Teachers, feel free to download this and forward it on to your students.

This week’s article focusses on the fascinating subject of space weather. This is something we have probably not even considered before but is a series of dramatic events within the sun that can have cataclysmic effects on earth. The paper details one such solar storm, explaining the events of the solar storm itself, exploring how this storm affected the earth and the consequences of this storm to humankind due to its effect on our communication channels. As always, pay attention to the questions as we go along as there are some sections we might skip.

We’re going to start with a skim read. Don’t worry if it doesn’t make complete sense, or if you skim some sections quicker than others as you’re feeling uncomfortable with them, that’s fine. There are a LOT of acronyms and initialisms in this paper which make understanding it more complicated for novices, but we’ll create a dictionary of them in a second. But for the moment, give the article an initial skim-read now to get a feel for what we’re going to study.

Rather than doing our SKIM-READ QUESTIONS this week, we’re going to concentrate on KEY DEFINITIONS that’ll be important to understand for a thorough reading of this article. Below is a list of key terms that you’re probably less familiar with from the article. Write a short but clear definition for each and submit these along with your SUMMARY QUESTIONS at the end of the article.

Coronal Mass Ejection

 

Geomagnetically induced currents

 

Geomagnetic storm

 

Ionospheric storm

 

Magnetosphere

 

Plasma eruptions

 

Solar cycle

 

Solar flare

 

Solar radio burst

 

Sunspot

 

Below is an alphabetised list of the acronyms and initialisms in this paper to refer to if you forget what they mean (I used this all the time – I don’t expect you to remember these). NOTE ON PEDANTRY: an acronym is a series of initials from a phrase that can be pronounced as a word e.g. LASER and NASA, an initialism is a similar abbreviation, but isn’t pronounced as its own word e.g. FBI and DVD.

4WW

Fourth Weather Wing

AF

Air Force

AFB

Air Force Base

AFGWC

Air Force Global Weather Central

AR

Active Region

AWS

Air Weather Service

BMEWS

Ballistic Missile Early Warning System

CME

Coronal Mass Ejection

DMSP

Defense Meteorological Satellite Program

DOD

Department of Defense

ESSA

Environmental Science Services Administration

EUV

Extreme Ultraviolet

GIC

Geomagnetically Induced Currents

GNSS

Global Navigation Satellite Systems

GPS

Global Positioning System

HF

High frequency

ICBM

Intercontinental Ballistic Missiles

NOAA

National Oceanic and Atmospheric Administration

NORAD

North American Air Defense

PCA

Polar Cap Absorption

RFI

Radio Frequency Interference

SAC

Strategic Air Command

SDFC

Space Disturbances Forecast Center

SDL

Space Disturbances Laboratory

SEON

Solar Electro-Optical Network

SESS

Space Environment Support System

SID

Sudden Ionospheric Disturbance

SOFNET

Solar Observing and Forecasting Network

SPE

Solar Proton Event

SRB

Solar Radio Bursts

SSC

Sudden Storm Commencements

SWPC

Space Weather Prediction Center

USAF

United States Air Force

 ABSTRACT

Analyse the phrase “intense fluxes of ionizing solar X-rays” word-by-word to understand its meaning.

 

 

What positive outcomes were there from the “Great Storm” of May 1967?

 

 

Summarise the abstract in two sentences.

 

 

1.1 Intersection of Nature and Politics

What happens during a ‘rise’ in a solar cycle?

 

What is the hydrogen-alpha line?

 

Why is the hydrogen-alpha line important to astronomers?

 

How do astronomers obtain an image of the sun in the hydrogen-alpha region of the spectrum?

 

 

What is the interplanetary medium? What does it contain?

 

Considering the quote at the bottom of page 1, why is it crucial for space weather information to be widely shared?

 

 

 

1.2 Cold War and Military Background

Describe how radio communication works. This will be one of our SUMMARY QUESTIONS but try to answer this now. You may find this video helpful

 

What is the doctrine of ‘mutually assured destruction’?

 

 

Why would radio disruptions significantly affect Strategic Air Command (SAC) communications?

 

 

What does the frequency of a wave tell us?

 

What frequency band do Strategic Air Command (SAC) communications use? What part of the electromagnetic spectrum is this in?

 

What frequency does the Ballistic Missile Early Warning System (BMEWS) use? What part of the electromagnetic spectrum is this in?

 

“NORAD and SAC operations were inextricably linked as they shared early warning data; however, decisions related to the data could result in independent actions” What does this tell you about how people handle data?

 

What motivated the setup of space weather observations leading up to 1967?

 

 

Why did NORAD, and specifically its radars, need the support of solar weather understanding?

 

 

 

1.3 A Brief Guide to Solar and Geomagnetic Disturbances With Emphasis on Radio Effects

Look carefully at figure 2, what are the two events that occur within the sun that cause this ‘myriad of space weather radio effects’?

 

 

In figure 2, which space weather disturbance takes the longest to affect earth?

 

 

In figure 2, which space weather disturbance lasts for the shortest amount of time (be careful and remember it’s a log scale).

 

 

In the figure caption there is an example description of one of the events – it begins ‘as an example, energetic protons…’ Read this and understand how they’ve written this from the information in the figure. Write one of your own for a different solar weather disturbance in the figure.

 

 

What are Active Regions (ARs)?

 

“ When energy density in AR magnetic fields reaches a tipping point, the fields reconfigure, producing bursts of electromagnetic energy (flares) across a broad spectrum of wavelengths: X-ray, extreme ultraviolet (EUV), UV, visible, and radio emissions. Some very strong flares produce gamma ray and intense white-light emissions”. Using the video at this link, explain briefly the process of magnetic reconnection that is being discussed here.

 

At what speed do the electromagnetic waves emitted by the sun travel?

 

 

What are the two ways that radio communications can be affected by the influx of electromagnetic radiation? (HINT: These come under the category of sudden ionospheric disturbances).

 

What is plasma?

 

What are supersonic speeds?

 

Why can’t the coronal mass ejection (CME) travel at the speed of light?

 

 

How do coronal mass ejections (CMEs) lead to an increased amount of radio transmission?

 

 

If a CME takes 2-4days to reach earth, on average, then lets assume it takes 3days. At what speed has the CME travelled?

 

 

 

What are solar energetic particle events?

 

Why are solar energetic particle events normally called solar proton events?

 

 

Why can solar energetic particle events travel faster than a CME?

 

 

How can radio communication be affected by solar energetic particle (or solar proton) events?

 

Why do the equatorial latitudes experience these radio interferences “primarily from dusk to dawn”.

 

 

 

Now, section 2 (May 1967 Solar-Geophysical Background and Details— What We Know Now) is a bit on the heavy side. I’d encourage you to read it to see if what you’ve researched so far makes this section more understandable, but we’re not going to have questions on this section as it’s quite dense. The section gives all of the detail about the storm of May 1967 – the timings of events and the types of solar events that happened and whereabouts on the sun. We’re going to dip back into questions at the end, section 2.4

2.4 How Severe Were the May 1967 Storms?

What is a solar flux unit?

 

Why is it difficult to list which solar storms are ‘worst’?

 

If this storm is not top of all of the quantifiable lists, and would actually seem to be a not uncommonly large storm by many metrics, what made it so bad?

 

3. Discussion: Storm Impacts and Legacies

3.1. May 1967 Storm Impacts: Radio Frequency Interference and Space Weather Support

What is military jamming?

 

Why would a solar radio burst be misinterpreted as jamming?

 

What role did NORAD play in calming the tensions?

 

If military bombers has been launched, why might it have been difficult to recall them had the NORAD message come through later?

 

 

3.2. Legacy: U.S. Air Force Space Environment Support System

What data can optical instruments give us about solar weather?

 

 

What data can radio instruments give us about solar weather?

 

Why is it valuable to have staff trained across several areas e.g. Air Weather Service staff being trained in space weather.

 

 

THE AURORA

One consequence of space weather on earth that is less catastrophic is the aurora borealis or northern lights. One of our summary questions this week will be to explain this phenomenon in relation to space weather. Here are a few links to get you started:

https://www.aurorahunter.com/what-are-the-northern-lights.html

https://earthsky.org/earth/what-causes-the-aurora-borealis-or-northern-lights

SUMMARY QUESTIONS

Describe how radio communication works.

 

In the case of space weather, why are science and politics often intertwined?

 

How might the modern world be affected by significant solar weather effects?

 

Why does the aurora borealis (northern lights) occur? Your answer should include some of the specifics of what elements of space weather cause it and how these space weather events occur. Also, I want you to keep your explanations SIMPLE. Imagine this being read by the general population, but you wanted to help them understand the real science that is going on. I don’t want your answer to be EASY, that’s not the goal, I want your writing to be SIMPLE but DETAILED. This is very difficult, but a good thing to practice. This should take more than one draft.

 

FURTHER READING

NASA have a lot of pages dedicated to space weather: https://www.nasa.gov/mission_pages/rbsp/science/rbsp-spaceweather.html

This WIRED article looks at some of the extreme effects of space weather

https://www.wired.com/2013/03/rethinking-space-weather/

This BBC World Service piece discusses space weather and its effects

https://www.bbc.co.uk/sounds/play/w3csy1ql

GENERAL INFORMATION

Remember, reading a paper isn't like reading a piece of fiction or a newspaper article. Don't get frustrated if it doesn't immediately make sense - you might need to do a little research of your own to understand some of the ideas. This article gives you an idea of how scientists read differently.

Each question refers to a specific part of the paper e.g. Page 2, Column 3 is written as (P2, C3).

Next week, we'll publish solutions to the questions and the best submitted summaries from students across the country.

NEXT WEEK

As it's (a very unusual) half term for a lot of you, we won't be running Journal Club in the usual way. We're keen to ensure you all take a well-earned break so there'll be no official Journal Club. However, if you are looking for something to do, why not use the skills you've developed so far by helping us out with a future Young Person's Journal Club. We'd like you to find some more popular science writing, aimed at a more general audience, and have a go at writing the sorts of questions for it that we've been providing for you each week. More details can be found here.