Sunspots, Space Weather, and Climate

Presentation Transcript

Sunspots, Space Weather, and Climate Dr. David H. Hathaway NASA Marshall Space Flight Center Capstone Banquet 2009 August 5

Outline Sunspots "Found" The Sunspot Cycle Solar Flares and Solar Activity Solar Activity and Space Weather Solar Activity and Terrestrial Climate

Sunspots "Found" Sunspots were "found" on the Sun inside months of the principal utilization of the telescope for watching heavenly questions in 1609. Be that as it may, spots on the Sun were already noted by Chinese onlookers as ahead of schedule as 28 BC. Galileo Galilei Thomas Harriot

Sunspots are dim (and cooler) districts on the surface of the Sun. They have a darker inward locale (the Umbra) encompassed by a lighter ring (the Penumbra). Sunspots typically show up in gatherings that shape over hours or days and keep going for quite a long time or weeks. These early sunspot perceptions showed that the Sun turns once in around 27 days.

The Sunspot Cycle

Discovery Astronomers had been watching sunspots for more than 230 years before Heinrich Schwabe , a beginner cosmologist in Dessau, Germany, found in 1844 that the quantity of sunspot gatherings and the quantity of days without sunspots expanded and diminished in cycles of around 10-years. Schwabe's information for 1826 to 1843 Number of Sunspot Groups every Year Number of Spotless Days

Wolf's Sunspot Numbers Shortly after Schwabe's revelation of the sunspot cycle, Rudolf Wolf in Switzerland understood the requirement for persistent day by day perceptions and sorted out a system of eyewitnesses that began in 1849. He perceived the trouble of checking individual sunspots and conceived a "Relative" sunspot number, R , given as: R=k(10g+n) Where k is a rectification calculate, g is the quantity of sunspot gatherings, and n is the quantity of individual sunspots. He discovered records from before onlookers and reproduced sunspot numbers back to 1749. Rudolf Wolf (1816-1893)

23 Cycles of Wolf Sunspot Numbers While there were numerous days without perceptions preceding 1849, sunspots have been relied on consistently since. Right up 'til the present time we keep on using Wolf's Relative Sunspot Number and his sunspot cycle numbering. The normal cycle keeps going around 11 years, however with a range from 9 to 14. The normal sufficiency is around 100, yet with a range from 50 to 200.

Sunspot Latitudes In 1858 Richard Carrington noticed that sunspots show up in two groups on either side of the equator and that these groups float toward the equator as the cycle advances. This was discussed until E. Walter Maunder's "Butterfly Diagram" of 1904.

A Dozen Butterflies We can now observe that sunspot cycles cover by 2-3 years and that greater cycles have more extensive sunspot zones that reach out to higher scopes.

The Maunder Minimum In 1890 Maunder investigated the work of Sp ö rer : " For a time of around seventy years, finishing in 1716, there appears to have been an extremely wonderful interference of the normal course of the spot cycle ." The presence of the "Maunder Minimum" is presently settled after the endeavors of Eddy (1976). Specifically Hoyt and Schatten (1998) have arranged day by day perceptions with about entire scope over this period.

The Key to Sunspots: Magnetism In 1908 George Ellery Hale detailed " On the plausible presence of an attractive field in Sun-spots ." This was the way to understanding sunspots. It additionally ended up being the way to understanding numerous different parts of the sunspot cycle and sun oriented movement. George Ellery Hale (1868-1938)

Spectral Analysis If a bit of light from the Sun is gone through a crystal we can see its full range of hues. A few hues are consumed by iotas and particles in the Sun's air. The consumed shading speaks to the exact vitality expected to knock an electron into a higher circle around the core of the molecule or particle. The circles of electrons are changed within the sight of an attractive field. Electrons circling in one heading will have more vitality than electrons going the other way. The light consumed will be moved to the red or blue and the quality and heading of the attractive field is uncovered by this move!

Sunspot Structure Sunspots are districts where extraordinary attractive fields get through the surface of the Sun and spread out over its surface. The attractive field qualities are normally around 6000 circumstances more grounded than the Earth's attractive field. Weiss, Thomas, Brummell, & Tobais (2004) (x 6000)

Sunspot Structure Details SOHO/MDI and Swedish Solar Telescope (Scharmer)

Hale's Magnetic Polarity Law In 1919 Hale (alongside Ellerman , Nicholson, and Joy) found that the attractive field in sunspots took after a clear law, "Solidness' Law" to such an extent that: "… the former and taking after spots … are of inverse extremity, and that the relating spots of such gatherings in the Northern and Southern sides of the equator are likewise inverse in sign. Moreover, the spots of the present cycle are inverse in extremity to those of the last cycle".

Active Region Tilt-Joy's Law In that same 1919 paper Joy noticed that sunspot gatherings are tilted with the main spots nearer to the equator than the accompanying spots. This tilt increments with scope.

Polar Field Reversals In 1959 Babcock noticed that the attractive polarities of the Sun's frail polar fields additionally switch starting with one cycle then onto the next, and that this inversion occurs at about the season of sunspot cycle most extreme.

Sunspot Cycle Behavior notwithstanding these attractive extremity changes and the equatorward float of the sunspot scopes, there are vital streams at first glance and inside the Sun that impact the sunspot cycle: Differential Rotation – speedier at the equator, slower close to the shafts; and Meridional Flow – spill out of the equator toward the posts.

Probing the Sun's Interior We can test the temperature, thickness, and streams inside the Sun utilizing Helioseismology – the investigation of the properties of sound waves seen going along the surface of the Sun. Thompson et al. (1996)

Babcock's Dynamo (1961) Dynamo models have been produced to clarify the sunspot cycle. a) Dipolar field at spin least strings through a shallow layer underneath the surface. b) Differential turn shears out this poloidal field to deliver a solid toroidal field (first at the mid-scopes then dynamically bring down scopes). c) Buoyant fields emit through the photosphere giving Hale's extremity law and Joy's Law. d) Meridional stream far from the dynamic scopes gives cancelation close to the posts and equator.

Solar Flares and Solar Activity

Solar Flares Discovered In 1859 Richard Carrington announced watching a huge sunspot aggregate on the evening of September 1 st when "… two patches of strongly splendid and white light broke out … " R. Hodgson watched and investigated a similar occasion which he depicted as having "… the presence of an extremely splendid star of light, substantially brighter than the sun's surface … "

Flares over the Solar Cycle Solar flares have been checked by x-beam finders on NOAA's GOES satellites since 1976. They are ordered by how brilliant they are in x-beams with X-Class flares being the brightest. The quantity of X-Class flares every month increments with the quantity of sunspots yet huge flares can happen at whatever time sunspots are available.

The 1972 Seahorse Flare The "Seahorse" flare of August 7 th , 1972 discharged what might as well be called more than 10,000,000 nuclear bombs through the span of around 60 minutes. This occasion could have made mischief space explorers had they been on the moon around then.

Prominences are billows of plasma held over the surface of the sun by attractive fields. They can be seen amid aggregate sun oriented shrouds and with particular gear. Peaceful prominences can remain suspended for a considerable length of time or weeks. Eruptive prominences lift off of the Sun in hours. Conspicuousness Drawings (1872) Total overshadowing of August 11, 1999

The Granddaddy Prominence The biggest eruptive noticeable quality was seen in 1945 and is alluded to as "The Granddaddy Prominence."

Quiescent? Prominences High determination pictures from the Hinode satellite demonstrate that even Quiescent Prominences are constantly dynamic.

Coronal Mass Ejections The Sun's Corona, its hot dubious external air, must be seen amid aggregate obscurations before the space age. It wasn't until then that Coronal Mass Ejections or CMEs were found. At the pinnacle of the sunspot cycle many can be found in a day. At the base of the sunspot cycle days can pass by without one. SMM Coronagraph (HAO) SOHO Coronagraph (NRL)

Solar Activity Solar Flares, Prominence Eruptions, and Coronal Mass Ejections are all types of sun based action. Each can happen all alone yet they regularly happen together as in "The Bastille Day Event."

Solar Magnetism – The Key

Solar Activity and Space Weather

Space Weather Space climate alludes to conditions on the Sun and in the space condition that can impact the execution and dependability of space-borne and ground-based mechanical frameworks, and can jeopardize human life or wellbeing.

CME Impact on Earth The polarized billows of plasma launched of the Sun as CMEs can affect the Earth's condition – twisting the attractive field encompassing the Earth and delivering vivacious particles that stream into the polar locales to make aurorae .

Geomagnetic Activity Variations in the quality and course of the Earth's attractive field have been routinely measured at various geographic areas since the mid-1800s. The wellspring of these variati