Earth, Sun & Space
The Sun & Space Effects on Earth.
In Life one must: Battle On...
The Sun (EUV)
GOES Solar Ultraviolet Imager
Galactic Cosmic Rays
Galactic Cosmic Rays (GCR) are the slowly varying, highly energetic background source of energetic particles that constantly bombard Earth. GCR originate outside the solar system and are likely formed by explosive events such as supernova.
Sunspots/Solar Cycle
Sunspots are dark areas that become apparent at the Sun’s photosphere as a result of intense magnetic flux pushing up from further within the solar interior. Areas along this magnetic flux in the upper photosphere and chromosphere heat up, and usually become visible as faculae and plage – often times termed active regions. This causes cooler (7000 F), less dense and darker areas at the heart of these magnetic fields than in the surrounding photosphere (10,000 F) - seen as sunspots. Active regions associated with sunspot groups are usually visible as bright enhancements in the corona at EUV and X-ray wavelengths. Rapid changes in the magnetic field alignment of sunspot groups’ associated active regions are the most likely sources of significant space weather events such as solar flares, CMEs, radiations storms, and radio bursts.
Sunspots appear in a wide variety of shapes and forms. The darkest area of a sunspot (also the first to be observed) is called the umbrae. As the sunspot matures (becomes more intense), a less dark, outlying area of well-defined fibril-like structure develops around the umbrae - called penumbra.
Sunspots/Solar Cycle
Sunspots can grow from an individual unipolar spot into more organized bipolar spot groups; or even evolve into immense, very complex sunspot groups with mixed magnetic polarities throughout the group. The largest sunspot groups can cover large swaths of the Sun’s surface and be many times the size of Earth.
Sunspot groups that are clearly visible and observed by designated ground-based observatories, are assigned a NOAA/SWPC 4-digit region number to officially record and track the sunspot group as it rotates across the visible solar disk. Sunspot groups are analyzed and characterized based on their size and complexity by SWPC forecasters each day using the modified Zurich classification scale and Mount Wilson magnetic classification system. This daily sunspot analysis and classification is submitted at the end of each UTC-day as the Solar Region Summary report.
Sunspots can change continuously and may last for only a few hours to days; or even months for the more intense groups. The total number of sunspots has long been known to vary with an approximately 11-year repetition known as the solar cycle. The peak of sunspot activity is known as solar maximum and the lull is known as solar minimum. Solar cycles started being assigned consecutive numbers. This number assignment began with solar cycle 1 in 1755 and the most recent being cycle 24 – which began in December, 2008 and is now nearing solar minimum.
Sunspots/Solar Cycle
A new solar cycle is considered to have begun when sunspot groups emerge at higher latitudes with the magnetic polarities of the leading spots opposite that of the previous cycle.
A plot of sunspot number progression for the previous and current solar cycle, and that compares the observed and smoothed values with the official sunspot number forecast provided by the Solar Cycle Prediction Panel representing NOAA, the International Space Environmental Services (ISES), and NASA is available to view on our SWPC webpage at solar cycle progression.
The official daily and monthly sunspot numbers are determined by the World Data Center – Sunspot Index and Long-term Solar Observations (WDC-SILSO (link is external)) at the Royal Observatory of Belgium. Generally, sunspot reports from observatories calculate sunspot numbers whereby each sunspot group counts as 10, and every umbra within each spot group is individually considered as 1. Therefore, no sunspots on the visible Sun would be considered as zero; while the next possible number can only be 11 or higher.
More detailed information about sunspot number concepts and a thorough perspective about the solar cycle, can be learned by reading the scientific paper: “Revisiting the Sunspot Number, a 400-year perspective on the Solar Cycle” by F. Clette, L. Svalgaard, J. Vaquero, and E. Cliver; Space Sci Rev (2014) 186:35-103; DOI 10.1007/s11214-014-0074-2
*IMAGES courtesy of NASA
Solar Cycles
Sunspot Cycle peaks
should peak in 2025
Solar Radio Flux also
should peak in 2025
World Wide Volcano Eruptions
How do Volcanoes Erupt?
Deep within the Earth it is so hot that some rocks slowly melt and become a thick flowing substance called magma. Since it is lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually, some of the magma pushes through vents and fissures to the Earth's surface. Magma that has erupted is called lava.
Some volcanic eruptions are explosive and others are not. The explosivity of an eruption depends on the composition of the magma. If magma is thin and runny, gases can escape easily from it. When this type of magma erupts, it flows out of the volcano. A good example is the eruptions at Hawaii’s volcanoes.
How do Volcanoes Erupt?
Lava flows rarely kill people because they move slowly enough for people to get out of their way. If magma is thick and sticky, gases cannot escape easily. Pressure builds up until the gases escape violently and explode. A good example is the eruption of Washington’s Mount St. Helens. In this type of eruption, the magma blasts into the air and breaks apart into pieces called tephra. Tephra can range in size from tiny particles of ash to house-size boulders.
Explosive volcanic eruptions can be dangerous and deadly. They can blast out clouds of hot tephra from the side or top of a volcano. These fiery clouds race down mountainsides destroying almost everything in their path. Ash erupted into the sky falls back to Earth like powdery snow. If thick enough, blankets of ash can suffocate plants, animals, and humans. When hot volcanic materials mix with water from streams or melted snow and ice, mudflows form. Mudflows (lahars) have buried entire communities located near erupting volcanoes.
Earth's Magnetic Field
Is Earth's Magnetic Field on The Verge of Flipping Over? An Expert Explains.
by Ofer Cohen
The north magnetic pole's observed locations from 1831–2007 are yellow squares. Modeled pole locations from 1590–2025 are circles progressing from blue to yellow. (National Centers for Environmental Information)
The Earth's magnetic field plays a big role in protecting people from hazardous radiation and geomagnetic activity that could affect satellite communication and the operation of power grids. And it moves.
Scientists have studied and tracked the motion of the magnetic poles for centuries. The historical movement of these poles indicates a change in the global geometry of the Earth's magnetic field.
It may even indicate the beginning of a field reversal – a "flip" between the north and south magnetic poles.
I'm a physicist who studies the interaction between the planets and space. While the north magnetic pole moving a little bit isn't a big deal, a reversal could have a big impact on Earth's climate and our modern technology. But these reversals don't happen instantaneously. Instead, they occur over thousands of years.
Earth's Magnetic Field
Magnetic Field Generation
So how are magnetic fields like the one around Earth generated? Magnetic fields are generated by moving electric charges. A material that enables charges to easily move in it is called a conductor. Metal is one example of a conductor – people use it to transfer electric currents from one place to the other. The electric current itself is simply negative charges called electrons moving through the metal. This current generates a magnetic field.
Layers of conducting material can be found in the Earth's liquid iron core. Currents of charges move throughout the core, and the liquid iron is also moving and circulating in the core. These movements generate the magnetic field.
Earth isn't the only planet with a magnetic field – gas giant planets like Jupiter have a conducting metallic hydrogen layer that generates their magnetic fields.
The movement of these conducting layers inside planets results in two types of fields. Larger motions, such as large-scale rotations with the planet, lead to a symmetric magnetic field with a north and a south pole – similar to a toy magnet.
These conducting layers may have some local irregular motions due to local turbulence or smaller flows that do not follow the large-scale pattern. These irregularities will manifest in some small anomalies in the planet's magnetic field or places where the field deviates from being a perfect dipole field.
These small-scale deviations in the magnetic field can actually lead to changes in the large-scale field over time and potentially even a complete reversal of the polarity of the dipole field, where the north becomes south and vice versa.
Earth's Magnetic Field
The designations of "north" and "south" on the magnetic field refer to their opposite polarities – they're not related to geographic north and south.
Field Flips
Scientists map and track the overall shape and orientation of the Earth's magnetic field using local measurements of the field's orientation and magnitude and, more recently, models.
The location of the north magnetic pole has moved by about 600 miles (965 kilometers) since the first measurement was taken in 1831. The migration speed has increased from 10 miles per year to 34 miles per year (16 kilometers to 54 kilometers) in more recent years. This acceleration could indicate the beginning of a field reversal, but scientists really can't tell with less than 200 years of data.
The Earth's magnetic field reverses on time scales that vary between 100,000 to 1,000,000 years. Scientists can tell how often the magnetic field reverses by looking at volcanic rocks in the ocean.
Earth's Magnetic Field
The Earth's Magnatosphere, a Protective Bubble
The Earth's magnetic field creates a magnetic "bubble" called the magnetosphere above the uppermost part of the atmosphere, the ionosphere layer.
The magnetosphere plays a major role in protecting people. It shields and deflects damaging, high-energy, cosmic-ray radiation, which is created in star explosions and moves constantly through the universe. The magnetosphere also interacts with solar wind, which is a flow of magnetized gas sent out from the Sun.
The magnetosphere and ionosphere's interaction with magnetized solar wind creates what scientists call space weather. Usually, the solar wind is mild and there's little to no space weather.
However, there are times when the Sun sheds large magnetized clouds of gas called coronal mass ejections into space. If these coronal mass ejections make it to Earth, their interaction with the magnetosphere can generate geomagnetic storms. Geomagnetic storms can create auroras, which happen when a stream of energized particles hits the atmosphere and lights up.
Earth's Magnetic Field
During space weather events, there's more hazardous radiation near the Earth. This radiation can potentially harm satellites and astronauts. Space weather can also damage large conducting systems, such as major pipelines and power grids, by overloading currents in these systems.
Space weather events can also disrupt satellite communication and GPS operation, which many people rely on.
Field Flips
Scientists map and track the overall shape and orientation of the Earth's magnetic field using local measurements of the field's orientation and magnitude and, more recently, models.
The location of the north magnetic pole has moved by about 600 miles (965 kilometers) since the first measurement was taken in 1831. The migration speed has increased from 10 miles per year to 34 miles per year (16 kilometers to 54 kilometers) in more recent years. This acceleration could indicate the beginning of a field reversal, but scientists really can't tell with less than 200 years of data.
Earth's Magnetic Field
The Earth's magnetic field reverses on time scales that vary between 100,000 to 1,000,000 years. Scientists can tell how often the magnetic field reverses by looking at volcanic rocks in the ocean.
These rocks capture the orientation and strength of the Earth's magnetic field when they are created, so dating these rocks provides a good picture of how the Earth's field has evolved over time.
Field reversals happen fast from a geologic standpoint, though slow from a human perspective. A reversal usually takes a few thousand years, but during this time the magnetosphere's orientation may shift and expose more of the Earth to cosmic radiation. These events may change the concentration of ozone in the atmosphere.
Scientists can't tell with confidence when the next field reversal will happen, but we can keep mapping and tracking the movement of Earth's magnetic north.
