Monday, 15 February 2016

Mini Ice Age and Ice Age

Factors relating to Mini Ice Age and Ice Age

Ice age not only occur from global warnings but the sun solar system.  Our knowledge of the affect of solar activity on Earth’s current and past climate is improving, but there is clearly still more to uncover. Given current evidence, there is no reason to think that warming over the last 35 years was down to the sun, or that the occurrence of the Little Ice Age undermines the idea that more recent climate change is man made. 



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We yet have to find all the answers!!




We lean more by 
looking for the
answer to a question
and not finding it
than we do from learning the
answer itself


Mini Ice Age 
The last mini ice age happed 300 years ago.  The last mini ice age, according to The Independent, lasted from 1645-1715. The cold winters associated with it apparently caused the River Thames in England to freeze over. the mini ice age was called the Maunder Minimum.

Maunder Minimum
The Maunder Minimum, also known as the "prolonged sunspot minimum", is the name used for the period starting in about 1645 and continuing to about 1715 when sunspots became exceedingly rare, as noted by solar observers of the time.




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The River Thames frozen over






What are sun spots
Sunspots are darks spots on the sun.  They can measure about 10,000 kilometers across, about the size of the earth.  They often occur in groups and come and go.  At times the sun may have hundreds of sunspots, while at other times have almost none.  Individual spots may last from 1 to 100 days.  A large group of spots last for 50 days.
Sunspots have a lighter outer section called the penumbra, and a darker middle region named the umbra. Sunspots are caused by the Sun's magnetic field welling up to the photosphere, the Sun's visible "surface".

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Sunspots are actually the harbingers of magnetic activity on the Sun which can accelerate particles near the Sun to high energies, and eject them during flare events and Coronal Mass Ejections (CMEs). It is the CME events, most common when sunspots are in evidence, which travel to Earth in a few days and can interfere with the terrestrial plasma environment, causing magnetic sub-storms, auroral activity, and influence everything from telecommunications to the electrical power grid.
Also, there seems to be a correlation between years of enhanced solar activity (heightened sunspot numbers) and the severity of weather systems in the northern hemisphere. No one really understands what the connection is. 

The small changes in solar irradiance that occur during the solar cycle exert a small influence on Earth’s climate, with periods of intense magnetic activity (the solar maximum) producing slightly higher temperatures, and solar minimum periods such as that seen in 2008 and early 2009 likely to have the opposite effect. Periods of intense magnetic activity on the Sun can spawn severe space weather that damages infrastructure in our high-tech society.


The next mini ice age is due to happen in the 
next 15 years.
At issue are the sun's solar cycles, according to the report, which last about 11 years. The magnetic poles at the northern and southern ends of the planet flip during each cycle. Normally nothing out of the ordinary occurs when this happens, but this time around, the sun's solar activity is expected to drop by 60 percent during a 10-year period beginning in 2030.


Scientists predict the disruption will occur during solar cycle 26 — we're in cycle 24 now, and cycle 25 is expected to hit its peak in 2022, according to the report.
"[In the cycle between 2030 and around 2040] the two waves exactly mirror each other — peaking at the same time but in opposite hemispheres of the sun," Researcher Valentina Zharkova said, according to The Telegraph. "Their interaction will be disruptive, or they will nearly cancel each other."

The prospect of facing an mini ice age is nothing new, however. Scientist John L. Casey presents evidence in his book "Dark Winter" that suggests the earth is already on its way to a 30-year cold spell that could cause chaos across the world.

What is climate change
a change in global or regional climate patterns, in particular a change apparent from the mid to late 20th century onwards and attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels.

Climate Change
To understand climate change, the obvious first step would be to explain the colossal coming and going of ice ages. Scientists devised ingenious techniques to recover evidence from the distant past, first from deposits left on land, then also from sea floor sediments, and then still better by drilling deep into ice. These paleoclimatologists succeeded brilliantly, discovering a strangely regular pattern of glacial cycles. The pattern pointed to a surprising answer, so precise that some ventured to predict future changes. The timing of the cycles was apparently set by minor changes in sunlight caused by slow variations of the Earth's orbit. Just how that could regulate the ice ages remained uncertain, for the climate system turned out to be dauntingly complex. In particular, it turned out that"greenhouse" gases like carbon dioxide played a surprisingly powerful role in governing global climate. One lesson was clear: the system is delicately poised, so that a little stimulus might drive a great change. (There is a separate essay on shorter-term climate fluctuations, lasting a few years to a century or so, possibly related to Variations of the Sun.)


Ice ages occur every 100,000 years
Science has struggled to explain fully why an ice age occurs every 100,000 years. As researchers now demonstrate based on a computer simulation, not only do variations in insolation play a key role, but also the mutual influence of glaciated continents and climate


What is an Ice Age

 An ice age is a long interval of time (millions to tens of millions of years) when global temperatures are relatively cold and large areas of the Earth are covered by continental ice sheets and alpine glaciers. Within an ice age are multiple shorter-term periods of warmer temperatures when glaciers retreat (called interglacials or interglacial cycles) and colder temperatures when glaciers advance (called glacials or glacial cycles).

Currently, we are in a warm interglacial that began about 11,000 years ago. The last period of glaciation, which is often informally called the “Ice Age,” peaked about 20,000 years ago. At that time, the world was on average probably about 10°F (5°C) colder than today, and locally as much as 40°F (22°C) colder.



What causes an ice age and glacial-interglacial cycles? Many factors contribute to climate variations, including changes in ocean and atmosphere circulation patterns, varying concentrations of atmospheric carbon dioxide, and even volcanic eruptions. The following discusses key factors in (1) initiating ice ages and (2) the timing of glacial-interglacial cycles.


One significant trigger in initiating ice ages is the changing positions of Earth’s ever-moving continents, which affect ocean and atmospheric circulation patterns. When plate-tectonic movement causes continents to be arranged such that warm water flow from the equator to the poles is blocked or reduced, ice sheets may arise and set another ice age in motion.

Today’s ice age most likely began when the land bridge between North and South America (Isthmus of Panama) formed and ended the exchange of tropical water between the Atlantic and Pacific Oceans, significantly altering ocean currents.

How do we know about past ice ages? Scientists have reconstructed past ice ages by piecing together information derived from studying ice cores, deep sea sediments, fossils, and landforms.

Ice and sediment cores reveal an impressive detailed history of global climate. Cores are collected by driving long hollow tubes as much as 2 miles deep into glacial ice or ocean floor sediments. Ice cores provide annual and even seasonal climate records for up to hundreds of thousands of years, complementing the millions of years of climate records in ocean sediment cores.
Within just the past couple of decades, ice cores recovered from Earth’s two existing ice sheets, Greenland and Antarctica, have revealed the most detailed climate records yet.

Do ice ages come and go slowly or rapidly? Records show that ice ages typically develop slowly, whereas they end more abruptly. Glacials and interglacials within an ice age display this same trend.

On a shorter time scale, global temperatures fluctuate often and rapidly. Various records reveal numerous large, widespread, abrupt climate changes over the past 100,000 years. One of the more recent intriguing findings is the remarkable speed of these changes. Within the incredibly short time span (by geologic standards) of only a few decades or even a few years, global temperatures have fluctuated by as much as 15°F (8°C) or more.
For example, as Earth was emerging out of the last glacial cycle, the warming trend was interrupted 12,800 years ago when temperatures dropped dramatically in only several decades. A mere 1,300 years later, temperatures locally spiked as much as 20°F (11°C) within just several years. Sudden changes like this occurred at least 24 times during the past 100,000 years. In a relative sense, we are in a time of unusually stable temperatures today—how long will it last?
Glacials and interglacials occur in fairly regular repeated cycles. The timing is governed to a large degree by predictable cyclic changes in Earth’s orbit, which affect the amount of sunlight reaching different parts of Earth’s surface. The three orbital variations are: (1) changes in Earth’s orbit around the Sun (eccentricity), (2) shifts in the tilt of Earth’s axis (obliquity), and (3) the wobbling motion of Earth’s axis.


What is Global Warming?
a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants.

How Might Global Warming Affect a Coming Ice Age?


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According to one school of thought, a warming planet is one that's less likely to wind up in an ice age. Because the Earth is always going through warming and cooling cycles, and we've been in one of the warming cycles for about 12,000 years now, scientists say it's inevitable that we'll hit another big chill sometime in the next 10,000 to 100,000 years. If that happens, much of the world -- including Europe and North America -- would be covered in a thick sheet of ice.
According to some researchers, the heat trapped in the Earth's atmosphere from the greenhouse effect will offset this cooling -- essentially preventing the Earth from entering another ice age [sources: Science DailyCosmos]. Though averting an ice age sounds like good news, the researchers caution that global warming isn't any picnic, either. It could lead to other drastic and unpleasant effects on the planet (think rising sea levels and dwindling global food supplies).




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