August 27, 2008
Clouds at the Edge of Space
Two years after the 1883 eruption of Krakatoa, the Indonesian supervolcano, Robert Leslie published a note in the journal Nature describing wispy blue filaments in the night sky. He is now credited with the discovery of noctilucent clouds (NLCs).
Photograph from the International Space Station, positioned 340 km over western Mongolia on July 22, 2008. Clouds estimated to be 83km above earth (at the edge of space). Credit to NASA at http://science.nasa.gov/headlines/y2008/25aug_nlc.htm
According to Gary Thomas, atmospheric scientists at the University of Colorado, the clouds are thought to be spreading and their first sightings coincide with the Industrial Revolution.
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Thanks to Willem for the link.
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June 30, 2008
Global Warming for Dummies (Part 3)
The prediction of how much manmade global warming we will see in the future (as well as how much past warming was manmade) depends upon something called "climate sensitivity".
For many years, climate researchers have struggled to diagnose the Earth's climate sensitivity from measurements of the real climate system. It's almost a "holy grail" kind of search, because if we could discover the true value of the climate sensitivity, then we would basically know whether future global warming will be benign, catastrophic, or somewhere in between.
Here I present a new method of satellite data analysis which I believe reveals the climate sensitivity, and I also show why it has been so hard to diagnose from observations.
When the Earth warms, it emits more infrared radiation to outer space. This natural cooling mechanism is the same effect you feel at a distance from a hot stove. The hotter anything gets the more infrared energy it loses to its surroundings.
For the Earth, this natural cooling effect amounts to an average of 3.3 Watts per square meter for every 1 deg C that the Earth warms. There is no scientific disagreement on this value.
Climate sensitivity is how clouds and water vapor will change with warming to make that 3.3 Watts a bigger number (stronger natural cooling, called "negative feedback"), or smaller (weaker natural cooling, called "positive feedback").
While there are other sources of change in the climate system, cloud and water vapor changes are likely to dominate climate sensitivity. The greater the sensitivity, the more the Earth will warm from increasing atmospheric greenhouse gas concentrations being produced by humans through the burning of fossil fuels.
There are three possibilities for climate sensitivity:
1. If clouds and water vapor don't change as we add CO2 to the atmosphere, then the expected warming by 2100 would only be about 1 deg. C, which would not be a very big concern for most people. This is called the "zero-feedback" case.
2. If low clouds decrease, high (cirrus) clouds increase, or water vapor increases, then warming will be magnified. Most, if not all, climate models predict that clouds and water vapor will change like this, resulting in an amplification of the CO2-only warming of 1 deg C to as much as 4.5 deg. C or more. This is called the "positive-feedback" case, and the greater the positive feedback, the greater the warming. (NOTE: If the sum of all positive feedbacks more than cancel out the 3.3 Watt natural cooling, then the climate system is inherently unstable…this is why you sometimes hear of climate change "tipping points".)
3. If the climate modelers are wrong -- and low clouds increase, high clouds decrease or water vapor decreases with warming -- then the effect will be to reduce the warming to less than 1 deg. C. For instance, if that 3.3 Watts of natural cooling mentioned earlier increased to as much as 8 Watts from cloud changes, the warming would be reduced to about 0.5 deg C by 2100. This is called the "negative feedback" case.
Read more from Roy Spencer here: http://www.weatherquestions.com/Climate-Sensitivity-Holy-Grail.htm
In this simplied version of a paper entitled 'Chaotic Radiative Forcing, Feedback Stripes, and the Overestimation of Climate Sensitiviy' submitted on June 25, 2008 to the Bulletin of the American Meteorological Society Dr Spencer goes on to conclude that:
1. Current satellite estimates of climate sensitivity have a spurious bias in the direction of high sensitivity.
2. This bias is probably due to small, natural fluctuations in cloud cover.
3. The true climate sensitivity only shows up during those shorter periods of time when non-radiative forcing (e.g. evaporation) is causing a relatively large source of temperature variability compared to that from cloud variability.
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Read Global Warming for Dummies Part 1 here: http://www.jennifermarohasy.com/blog/archives/000959.html
And Global Warming for Dummies Part 2 here: http://www.jennifermarohasy.com/blog/archives/002844.html
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May 15, 2008
We Live in an Electric Universe (Part 3) by Louis Hissink
In a NASA media release entitled ‘Electric Hurricanes’ it was suggested that because Emily, Rita and Katrina were all exceptionally powerful hurricanes, their sheer violence somehow explains their lightning. But in the same media release, Richard Blakeslee, from the Global Hydrology and Climate Centre, says that this explanation is too simple.
"Other storms have been equally intense and did not produce much lightning," he says. "There must be something else at work."
That "something else at work" is the electric Birkeland currents that power the hurricanes, operating in dark current plasma mode, so little or no lightning is observed.
Birkeland currents are really filaments of electric current that from magnetic attraction are free to rotate around each other, but at the same time coming closer together generates a short range repulsive force that insulates them from each other, thereby maintaining their identity and forming a twisting rope that as the filaments get closer, just like a spinning ice skater bringing in her arms, start to spin even faster. Paired Birkelands are really just electric whirlwinds or a plasma vortex.
The movement of hurricanes over the earth’s surface seems much like that observed for sunspots.
Kristian Birkeland showed the gross features of sunspots in his Terrella experiments where electric discharges, from a donut of plasma around the magnetised sphere, move from mid to low latitudes on the sphere as the electric current increased.
The sun’s plasma torus in UV from the SOHO Mission.
The simplest model for the 22 year magnetic sunspot cycle involves modulation of the electrical power input from the galaxy to the solar circuitry which seems to behave like a secondary winding on a transformer responding to varying DC currents to produce a magnetic field which switches polarity.
The earth is linked to the sun by enormous magnetic flux ropes (or Birkeland currents), and from the behaviour of the auroras and sunspot activity it is entirely likely that the earth’s weather might also be an electrical phenomenon linked to the magnetosphere.
Birkeland rope
Louis Hissink
Perth
We Live in an Electric Universe, Part 1
http://www.jennifermarohasy.com/blog/archives/003038.html
We Live in an Electric Universe, Part 2
http://www.jennifermarohasy.com/blog/archives/003047.html
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May 10, 2008
We Live in an Electric Universe (Part 1) by Louis Hissink
One of the basic working rules in empirical science is the Donald Duck Factor, that when something novel looks, waddles and sounds like a duck, then in all probability it might also be a duck, or at least of the same species. And when a similar structure or shape is found in two disparate phenomena, there is a good chance that both might be formed by a similar process. Such might be in the case of tropical cyclones and spiral galaxies.
cyclone Nargis
spiral galaxy
It is cyclone season in the northern hemisphere of the equatorial regions and yet again humanity has discovered how puny it is in the face of a tropical cyclone when Cyclone Nargis devastated parts of Burma recently. However tropical cyclones, or hurricanes, are not well understood weather phenomena and the formation of tropical cyclones is the topic of extensive ongoing research.
A spiral galaxy is a one belonging to one of the three main classes of galaxy originally described by Edwin Hubble in his 1936 work “The Realm of the Nebulae” and, as such, forms part of the Hubble sequence. Spiral galaxies consist of a flat, rotating disk of stars, gas and dust, and a central concentration of stars known as the bulge. These are surrounded by a much fainter halo of stars, many of which reside in globular clusters.
The origin of the spiral arms in galaxies is not as easy to identify as one may first think. After all, whatever it is that creates the spiral arms must be able to account for a wide variety of spiral structures. Some galaxies have a well-organised spiral structure (grand design spirals), while others are patchy (flocculent spirals). The arms may be wound tightly around the galaxy or may be more open. Some spiral arms originate at the end of bars, others directly from the galactic bulge.
Louis Hissink
Perth
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April 13, 2008
Cosmic Rays, Clouds and Climate (Part 1)
There are a couple of emerging theories on clouds, and how they form, and in time these theories may blow away the current so-called consensus on anthropogenic global warming from carbon dioxide as a key driver of climate.
One of these theories concerns cosmic rays.
A couple of weeks ago I mentioned the words "cosmic rays" with some enthusiasm at a Sunday lunch and everyone looked a me with a degree of apprehension and no one asked me to "explain further". I could see the minds of the 10 or so others at the table ticking over. They were probably thinking, "What on earth is she talking about?".
Well, I was about to attend a lecture by Dr Eigil Friis-Christensen, the director of the Danish National Space Centre.
This centre has published research suggesting that satellite observations of cloud cover and laboratory observations of aerosol formation indicate climate is signifcantly affected by the cosmic ray flux, modulated by the solar magnetic field.
Slide from presentation by Eigil Friis-Christensen, Mittagong, April 5, 2008
Current United Nation's IPCC climate models do not incorporate the influence of cosmic rays and therefore according to Dr Friis-Christensen can not hope to predict future climate.
The week before Dr Friis-Christensen gave his lecture at Mittagong, a paper was published suggesting the potential influence of cosmic rays was over-rated. Bloggers Lubos Motl and Nir Shaviv discuss the problems with the Sloan & Wolfendale paper which was given significant exposure by the BBC.
More to come on cosmic rays in part 2 of this post.
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see also my blog post:
Graeme Pearman Claims Antarctica is Warming (Global Warming and The Cosmos, Part 1)
http://www.jennifermarohasy.com/blog/archives/002905.html
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April 11, 2008
Absence of Clouds Caused Cretaceous and Eocene Supergreenhouse
Biological productivity controls cloud formation and may be the lever that caused supergreenhouse episodes during the Cretaceous and Eocene, according to Penn State paleoclimatologists.
"Our motivation was the inability of climate models to reproduce the climate of the supergreenhouse episodes of the Cretaceous and Eocene adequately," said Lee R. Kump, professor of geosciences. "People have tried increasing carbon dioxide in the models to explain the warming, but there are limits to the amounts that can be added because the existing proxies for carbon dioxide do not show such large amounts."
In general, the proxies indicate that the Cretaceous and Eocene atmosphere never exceeded four times the current carbon dioxide level, which is not enough for the models to create supergreenhouse conditions. Some researchers have tried increasing the amount of methane, another greenhouse gas, but there are no proxies for methane. Another approach is to assume that ocean currents changed, but while researchers can insert new current information into the models, they cannot get the models to create these ocean current scenarios.
Kump and David Pollard, senior research associate, Earth and Environmental Systems Institute, looked for another way to create a world where mean annual temperatures in the tropics were above 100 degrees Fahrenheit and polar temperatures were in the 50-degree Fahrenheit range. Changing the Earth's albedo -- the amount of sunlight reflected into space – by changing cloud cover will produce supergreenhouse events, the researchers report in today's (April 11) issue of Science.
"The model reduces cloud cover from about 64 percent to 55 percent which lets in a large amount of direct sunlight," Kump says. "The increased breaks in the clouds, fewer clouds and less reflective clouds produced the amount of warming we were looking for."
EurekAlert: Absence of clouds caused pre-human supergreenhouse periods
National Geographic: Lack of Clouds Amplified Dino-Era Warming, Study Says
Amplification of Cretaceous Warmth by Biological Cloud Feedbacks
Lee R. Kump1* and David Pollard2
The extreme warmth of particular intervals of geologic history cannot be simulated with climate models, which are constrained by the geologic proxy record to relatively modest increases in atmospheric carbon dioxide levels. Recent recognition that biological productivity controls the abundance of cloud condensation nuclei (CCN) in the unpolluted atmosphere provides a solution to this problem. Our climate simulations show that reduced biological productivity (low CCN abundance) provides a substantial amplification of CO2-induced warming by reducing cloud lifetimes and reflectivity. If the stress of elevated temperatures did indeed suppress marine and terrestrial ecosystems during these times, this long-standing climate enigma may be solved.
1 Department of Geosciences and Earth System Science Center, Pennsylvania State University, University Park, PA 16802, USA.
2 Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA 16802, USA.
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