the coupling of the solar-terrestrial systems. earth’s internal structure, atmospheric structure,...

The coupling of the Solar-terrestrial systems

• Earth’s internal structure, atmospheric structure, and magnetosphere

• Solar General Structure

• Solar activity at or above the photosphere

• Space Weather

Unit Outline

Earth structure

The Atmosphere

Geo-magnetismSources for any natural magnet

•Imbalanced atomic dipole moments result in orientation of field lines and bulk magnetic properties of some elements and compounds.

•Geomagnetism a form of ferromagnetism resulting from the atomic properties of the iron, cobalt, and nickel that make up the internal portions of the earth as well as the coupling forces of the crystal lattices in the solid state which serve to align the atomic dipoles and generate bulk magnetic fields.

•Further reading on magnetism http://www.rare-earth-magnets.com/t-magnetism.aspx

Complex Fields that are ever changing

Images on wikipedia common media license

Solar Structure

General Structure

Radius 690,000 km

Average Density

1410 kg/m3

Surface Temp

5780 K

Luminosity 3.86 x 1026 W

• The sun contains no solid matter

• Light we ‘see’ is from photosphere (very thin, 500 km thick)• This gives the sun the

appearance of having a sharp edge to it.

Interior Model• Assume Hydrostatic

Equilibrium • Outward

pressure of hot gas balances the inward pull of gravity

Outward force = inward force

General Structure

Patterns of Density and Temperature

Both decrease with distance from the core

General Structure

Evidences of internal structureSpectral lines of certain elements are doppler shifted

General Structure


Evidence of internal structure

Surface of the sun oscillates or vibrates with certain frequency•Surface patterns result from internal pressure waves that reflect off of the photosphere•Propagation of these pressure waves through the interior allows scientists to model the density and temperature profiles as well as internal movement of material.

General Structure


Evidence cont.• From the photospheric expression of

moving (doppler shifted) gas, we can map out the internal structure

• Models match observations quite well

General Structure


Active features of the photosphere

Sunspots appear dark because slightly cooler than surroundings.


9.4 The Active Sun

Sunspots come and go, typically in a few days.

Sunspots are linked by pairs of magnetic field lines.


http://www.windows2universe.org/sun/sun_polar_regions.html

9.4 The Active Sun

The Sun has an 11-year sunspot cycle, during which sunspot numbers rise, fall, and then rise again.

The Active Features of the Photosphere

9.4 The Active Sun

This is really a 22-year cycle, because the spots switch polarities between the northern and southern hemispheres every 11 years.Maunder minimum: few, if any, sunspots.




Areas around sunspots are active; large eruptions may occur in photosphere.

Solar prominence is large sheet of ejected gas.

http://soho.nascom.nasa.gov/gallery/

9.4 The Active Sun

The rotation of the Sun drags magnetic field lines around with it, causing kinks. A Prominence can be seen when a loop is near the edge.


A Solar flare is a large explosion on Sun’s surface, emitting a similar amount of energy to a prominence, but in seconds or minutes rather than days or weeks.


A coronal mass ejection emits charged particles that can affect the Earth.


9.4 The Active Sun

Solar wind escapes Sun mostly through coronal holes, which can be seen in X-ray images.


9.4 The Active Sun

Solar corona changes along with sunspot cycle; is much larger and more irregular at sunspot peak.

Solar wind – a fast moving flux of radiation and charged particles interacting with earth’s magnetic field.

"Parts of the Sun." SOHO-Gallery. Web. 01 Aug. 2014. http://soho.nascom.nasa.gov/gallery/

Solar inputs and Earth’s Outputs

http://earthobservatory.nasa.gov/Features/EnergyBalance/page4.php

The paths of energy through the atmosphere


Detection of a Solar Flare- Solar Flare events happen in stages

- The first stage, or the precursor

stage, the build-up of magnetic

energy triggers the event and can

be seen via soft x-rays

- The second stage, impulsive stage

is where the massive amount of

energy is released across almost

all spectra- Especially the Radio Spectrum!!!

Space Weather

The Ionosphere -

As a boundary between

the solar wind

magnetosphere and

atmosphere, it can be a

sensor for the influence

of space weather on the

atmosphere

Space Weather

Interactions of solar wind and earths magnetosphere

Space Weather

Coronal Mass Ejections (CMEs)

- Often associated with solar flares

- Extremely large ejections of solar wind and

energy

- Has a larger push on Earth’s magnetosphere

than normal causing more extreme

disturbances in our upper atmosphere

- http://en.wikipedia.org/wiki/File:Solar_Storm_on_August_1,_

2010.OGG

- http://en.wikipedia.org/wiki/File:Close-up_on_launching_filament_%28SDO-AIA,_304_%

C3%85%29.ogv

- http://en.wikipedia.org/wiki/

File:A_Coronal_Mass_Ejection_strikes_the_Ea

rth.ogv

Space Weather

Case Study: The 2003 Halloween Storm

This solar CME caused a massive geomagnetic storm that resulted in power outages in northern Europe.

"Parts of the Sun." SOHO-Gallery. Web. 01 Aug. 2014. http://soho.nascom.nasa.gov/gallery

Space Weather

Aurora Borealis (The Northern Lights)Space Weather


The Halloween storm of 2003 created many disturbances in the atmosphere were studied for years afterward

Space Weather

Two methods:

Ionosonde

Use radar from the ground or from satellite.

• A huge pulse of radio waves (Megawatts) is reflected off of ionosphere

• Return signal contains information about the structure, temperature, and ion content of the ionosphere.

Studying the Ionosphere with Radio waves

Image from: http://www.amateur-radio-wiki.net/index.php?title=File:Ionosonde.jpg

Use current GPS/GNSS system

•For GPS navigation our receivers are constantly sending radio signals back and forth from the satellites.

•The ionosphere interferes with these signals and the level of interference can be used by scientists to estimate properties of the ionosphere.

Studying the ionosphere with Radio

A. Coster 2013 MIT Haystack

Geospace environment includes solar inputs of radiation and high energy particles

Variations in the solar wind from events like CMEs, flares, promenances, faculae,…. May cause geomagnetic disturbances or storms

Monitoring the ionosphere is important for understanding the effect of solar variability on earths environment for engineering purposes as well as climate change.

Summary

References• http://www.rare-earth-magnets.com/t-magnetism.aspx

• Free GNU license agreement http://www.gnu.org/copyleft/fdl.html

• "Parts of the Sun." SOHO-Gallery. Web. 01 Aug. 2014. http://soho.nascom.nasa.gov/gallery/

• http://gnss.be/atmosphere_tutorial.php

• Hathaway, David H. "Sun Spot Cycles." NASA/Marshall Solar Physics. NASA/Marshall, 4 July 2014. Web. 04 Aug. 2014. http://solarscience.msfc.nasa.gov/SunspotCycle.shtml

• http://earthobservatory.nasa.gov/Features/EnergyBalance/page4.php

• "Climate and Earth’s Energy Budget : Feature Articles." Climate and Earth’s Energy Budget : Feature Articles. Web. 08 Aug. 2014. <http://earthobservatory.nasa.gov/Features/EnergyBalance/page4.php>.

• Shapley, Patricia. "Our Energy Budget." Our Energy Budget. University of Illinois, 2012. Web. 08 Aug. 2014. <http://butane.chem.uiuc.edu/pshapley/GenChem2/C1/1.html>.

the coupling of the solar-terrestrial systems. earth’s internal structure, atmospheric structure,...

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