Unprecedented Arctic ozone hole in 2011; a Florida tropical storm next week?
An unprecedented ozone hole opened in the Arctic during 2011, researchers reported this week in the journal Nature. Holes in the Antarctic ozone layer have opened up each spring since the early 1980s, but the Arctic had only shown modest springtime ozone losses in the 5% - 30% range over the past twenty years. But this year, massive ozone destruction of 80% occurred at altitudes of 18 - 20 kilometers in the Arctic during spring, resulting in Earth's first known case of twin ozone holes, one over each pole. During late March and portions of April, the Arctic ozone hole was positioned over heavily populated areas of Western Europe, allowing large levels of damaging ultraviolet rays to reach the surface. UV-B radiation causes skin damage that can lead to cancer, and has been observed to reduce crop yields in two-thirds of 300 important plant varieties studied (WMO, 2002.) The total loss of ozone in a column from the surface to the top of the atmosphere reached 40% during the peak of this year's Arctic ozone hole. Since each 1% drop in ozone levels results in about 1% more UV-B reaching Earth's surface (WMO, 2002), UV-B levels reaching the surface likely increased by 40% at the height of this year's hole. We know that an 11% increase in UV-B light can cause a 24% decrease in winter wheat yield (Zheng et al., 2003), so this year's Arctic ozone hole may have caused noticeable reductions in Europe's winter wheat crop.
Figure 1. Left: Ozone in Earth's stratosphere at an altitude of approximately 12 miles (20 kilometers) in mid-March 2011, near the peak of the 2011 Arctic ozone loss. Right: chlorine monoxide--the primary agent of chemical ozone destruction in the cold polar lower stratosphere--the same day and altitude. Image credit: NASA/JPL-Caltech.
What caused this year's unprecedented Arctic ozone hole?
Earth's ozone holes are due to the presence of human-emitted CFC gases in the stratosphere. The ozone destruction process is greatly accelerated when the atmosphere is cold enough to make clouds in the stratosphere. These polar stratospheric clouds (PSCs) act like ozone destruction factories, by providing convenient surfaces for the reactions that destroy ozone to occur. PSCs only form in the 24-hour darkness of unusually cold winters near the poles; the atmosphere is too warm elsewhere to support PSCs. Stratospheric temperatures are warmer in the Arctic than the Antarctic, so PSCs and ozone destruction in the Arctic has, in the past, been much less than in the Antarctic. In order to get temperatures cold enough to allow formation of PSCs, a strong vortex of swirling winds around the pole needs to develop. Such a "polar vortex" isolates the cold air near the pole, keeping it from mixing with warmer air from the mid-latitudes. A strong polar vortex in winter and spring is common in the Antarctic, but less common in the Arctic, since there are more land masses that tend to cause large-scale disruptions to the winds of the polar vortex, allowing warm air from the south to mix northwards. However, as the authors of the Nature study wrote, "The persistence of a strong, cold vortex from December through to the end of March was unprecedented. In February - March 2011, the barrier to transport at the Arctic vortex edge was the strongest in either hemisphere in the last ~30 years. This unusual polar vortex, combined with very cold Arctic stratospheric temperatures typical of what we've seen in recent decades, led to the most favorable conditions ever observed for formation of Arctic PSCs. The reasons for this unusual vortex are unknown.
Figure 2. Global lower stratospheric departure of temperature from average since 1979, as measured by satellites. The large spikes in 1982 and 1991 are due to the eruptions of El Chicon and Mt. Pinatubo, respectively. These volcanoes ejected huge quantities of sulphuric acid dust into the stratosphere. This dust absorbed large quantities of solar radiation, heating the stratosphere. Stratospheric temperature has been generally decreasing in recent decades, due to the twin effects of ozone depletion and the accumulation of greenhouse gases in the lower atmosphere. During Jan - Aug 2011, Earth's stratosphere had its 3rd coldest such period on record. Image credit: National Climatic Data Center.
Greenhouse gases cause stratospheric cooling
When ozone absorbs UV light, it heats the surrounding air. Thus, the loss of ozone in recent decades has helped cool the stratosphere, resulting in a feedback loop where colder temperatures create more PSCs, resulting in even more ozone destruction. However, in 1987, CFCs and other ozone-depleting substances were banned. As a result, CFC levels in the stratosphere peaked in 2000, and had fallen by 3.8% as of 2008, according to NASA. Unfortunately, despite the fact that CFCs are falling in concentration, the stratosphere is not warming up. The recovery of the ozone layer is being delayed by human emissions of greenhouse gases like carbon dioxide and methane. These gases trap heat near the surface, but cause cooling of the stratosphere and increased formation of the PSCs that help destroy ozone. We need only look as far as our sister planet, Venus, to see an example of how the greenhouse effect warms the surface but cools the upper atmosphere. Venus's atmosphere is 96.5% carbon dioxide, which has triggered a hellish run-away greenhouse effect. The average surface temperature on Venus is a sizzling 894 °F, hot enough to melt lead. Venus's upper atmosphere, though, is a startling 4 - 5 times colder than Earth's upper atmosphere. The explanation of this greenhouse gas-caused surface heating and upper air cooling is not simple, but good discussions can be found at Max Planck Institute for Chemistry and realclimate.org, for those unafraid of radiative transfer theory. One way to think about the problem is that the amount of infrared heat energy radiated out to space by a planet is roughly equal to the amount of solar energy it receives from the sun. If the surface atmosphere warms, there must be compensating cooling elsewhere in the atmosphere in order to keep the amount of heat given off by the planet the same and balanced. As emissions of greenhouse gases continue to rise, their cooling effect on the stratosphere will increase. This will make recovery of the stratospheric ozone layer much slower.
Greenhouse gases cause cooling higher up, too
Greenhouse gases have also led to the cooling of the atmosphere at levels higher than the stratosphere. Over the past 30 years, the Earth's surface temperature has increased 0.2 - 0.4 °C, while the temperature in the mesosphere, about 50 - 80 km above ground, has cooled 5 - 10 °C (Beig et al., 2006). There is no appreciable cooling due to ozone destruction at these altitudes, so nearly all of this dramatic cooling is due to the addition of greenhouse gases to the atmosphere. Even greater cooling of 17 °C per decade has been observed high in the ionosphere, at 350 km altitude. This has affected the orbits of orbiting satellites, due to decreased drag, since the upper atmosphere has shrunk and moved closer to the surface (Lastovicka et al., 2006). The density of the air has declined 2 - 3% per decade the past 30 years at 350 km altitude. So, in a sense, the sky IS falling due to the greenhouse effect!
Since any increase in solar energy would heat both the lower and upper atmosphere, the observed drop in upper atmospheric temperatures in the past 30 years argues against an increase in energy coming from the sun being responsible for global warming. The observed cooling of the upper atmosphere is strong evidence that the warming at Earth's surface is due to human-emitted greenhouse gases that trap heat near the surface and cause compensating cooling aloft. It should also give us additional confidence in the climate models, since they predicted that this upper atmospheric cooling would occur. Keep in mind, also, that 2010 was tied for Earth's hottest year on record, and the amount of energy coming from the sun during 2009 - 2010 was the lowest since satellite measurements began in the late 1970s. There has been no long-term increase in energy coming from the sun in recent decades, and the notion that global warming is due to an increase in energy coming from the sun simply doesn't add up.
Commentary
The development of an ozone hole in the Arctic is a discouraging reminder that humans are capable of causing harmful and unexpected planetary-scale changes to the environment. A 2002 assessment of the ozone layer by the World Meteorological Organization concluded that an Arctic ozone hole would be unlikely to occur, due to the lack of a strong Arctic vortex in winter, and the fact CFCs levels had started to decline. However, an Arctic ozone hole may now become a regular visitor in the future. "Day-to-day temperatures in the 2010 - 11 Arctic winter did not reach lower values than in previous cold Arctic winters," said the lead author of this year's Nature study, Gloria Manney, of NASA and the New Mexico Institute of Mining and Technology in Socorro. "The difference from previous winters is that temperatures were low enough to produce ozone-destroying forms of chlorine for a much longer time. This implies that if winter Arctic stratospheric temperatures drop just slightly in the future, for example as a result of climate change, then severe Arctic ozone loss may occur more frequently." I might add that its a very good thing CFCs were banned in 1987, or else the Arctic ozone hole would have opened up much sooner and would have been far worse. It turned out that the costs of the CFC ban, while substantial, were far less than the dire cost predictions that the CFC industry warned of. It is highly probable that we will see future nasty climate change surprises far more serious than the Arctic ozone hole if we continue on our present business-as-usual approach of emitting huge quantities of greenhouse gases. Humans would be wise to act forcefully to cut emissions of greenhouse gases, as the cost of inaction is highly likely to be far greater than the cost of action.
References
Manney, G.L., et al., 2011, Unprecedented Arctic ozone loss in 2011, Nature (2011), doi:10.1038/nature10556
Weather Underground Ozone Hole FAQ
World Meteorological Organization (WMO), "Scientific Assessment of Ozone Depletion: 2002 Global Ozone Research and Monitoring Project - Report #47", WMO, Nairobi, Kenya, 2002.
Zheng, Y., W. Gao, J.R. Slusser, R.H. Grant, C. Wang, "Yield and yield formation of field winter wheat in response to supplemental solar ultraviolet-B radiation," Agricultural and Forest Meteorology, Volume 120, Issues 1-4, 24 December 2003.
Figure 3. Morning satellite image of Tropical Storm Philippe. Philippe has a Central Dense Overcast (CDO) of high cirrus clouds characteristic of a tropical storm nearing hurricane strength.
Tropical Storm Philippe no threat to land
In the middle Atlantic, Tropical Storm Philippe has managed to grow a bit more organized in the face of high wind shear of 20 - 30 knots. Satellite loops show Philippe is a small system with a modest amount heavy thunderstorm activity, with the surface circulation partially exposed to view by wind shear. Wind shear will remain high today, but is expected to relax to the moderate range on Wednesday as Philippe recurves to the northeast. This may allow Philippe to intensify into a hurricane, as predicted by several of the intensity forecast models. It is unlikely that Philippe will trouble any land areas.
A Florida tropical storm next week?
Recent runs by all of the computer forecast models predict that an area of low pressure will develop near Florida this weekend or early next week. The counter-clockwise flow around this low will bring strong winds and heavy rains to Northeast Florida and the Georgia coast, and it is possible this storm will develop into a tropical or subtropical storm. The situation is similar to Subtropical Storm Four of October 4, 1974, according to the latest extended forecast discussion from NOAA's Hydrometeorological Prediction Center. That storm brought 10 - 14 inches of rain to the east coast of Florida and strong onshore winds of 30 - 40 mph that caused beach erosion and coastal flooding. The exact formation location of this weekend's storm is still in doubt, with the ECMWF and UKMET models predicting the storm will form in the Gulf of Mexico off the west coast of Florida, and the GFS model predicting formation over the Bahamas. We'll have to wait for future model runs before we can get a better handle on where and when this storm will most likely develop.
Jeff Masters
Reader Comments
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lol.
That absolutely horrible microwave pass.
11:39 PM GMT on October 04, 2011
Yes, ozone is created with sunlight. But this recent extreme in the Arctic hole just happened in the summer, and polar night didn't start until September 24th. Also, if the holes were just due to the lack of sunlight in the winter, this wouldn't be a relatively new phenomenon, but it is. It's most certainly caused by CFCs and a cold stratosphere.
000
ABNT20 KNHC 042341
TWOAT
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT TUE OCT 4 2011
FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...
THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
STORM PHILIPPE...LOCATED ABOUT 635 MILES SOUTH-SOUTHEAST OF BERMUDA.
ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
$$
FORECASTER BEVEN
Still Nothing new in TWO-Land.
In general, methane is not one of the most common materials ejected during a volcanic eruption. The most common compounds tend to be water vapor, carbon dioxide, and sulfur dioxide.
This makes me wonder if you might be confusing methane with carbon dioxide. Although methane is a stronger greenhouse gas, its concentrations and rate of accumulation are such that carbon dioxide is the primary driver of the enhanced greenhouse effect. Carbon dioxide emissions from volcanoes are estimated to be roughly 2 orders of magnitude smaller than emissions by humans (~1%), and another big difference would be that volcanoes are natural and thus part of the pre-anthropogenic equilibrium.
Good evening Angela, been a while since we've seen you.
Please also answer the latter part of my question I posted in the same post:
"I mean, what percentage of the hole is DIRECTLY attributed to no sunlight?"
Maybe a better phrased question on my part: What percentage of the depletion of both ozone locations at the poles is contributed to simply no sunlight being present? Compared to ozone depletion caused by man?
Angela!
Good to see you.
That's pretty good.
Thanks for posting that.
The only inevitable thing is the stupidity of humans.
dang, Lincoln. you are the oldest known member of this blog. glad this discussion brought you out to post! cool pic, too.
S67
If it had convection, it would've probably been classified.
12:20 AM GMT on October 05, 2011
There is a natural cycle/role but I haven't seen any hard numbers on attribution.
12:20 AM GMT on October 05, 2011
Hi everyone -- long time no blog.
lol.
Looks like we may see an active October.
Your opinion?
Arctic faces record ozone loss this spring
Earth’s protective layer down by half, scientists say
This image shows how large the Arctic ozone hole, shown here in blue, was in 2006. This year’s ozone hole will be at least as large, scientists predict. (IMAGE/NASA)
I've been a member of the site since high school. That's when I got a weather station for christmas and increased my dad's stress level by finding ways to attach the equipment to the deck overhang and the roof. Read the blogs from time-to-time as I worked through college and grad school, and now starting to post a bit more often on topics a bit more relevant to my areas of expertise - environmental science and GIS mapping. I think there are probably people on here that have been more active posters than me since back in that 2002 timeframe..
AL, 17, 2011100500, , BEST, 0, 244N, 601W, 55, 997, TS, 50, NEQ, 30, 30, 0, 10, 1014, 150, 15, 0, 0,
12:28 AM GMT on October 05, 2011
Yeah, the medium-range models have hinted at that as well, especially in the Caribbean. But, climatologically the month of October is elevated relative to the rest of the regions. There's about a 40% chance of seeing at least one TC in the Carib. this month, only around 20% in the MDR and GoM.
cool beans.
I am sure Jeff would be pleased to know this.
I hope you will post more often.
The nature of this site is educational.
12:31 AM GMT on October 05, 2011
It's possible that this research exists, but I haven't come across it.
12:32 AM GMT on October 05, 2011
I dont even have a weather station. :(
Not because I dont want one, I just have no good place to put it right now!
I think they have limited utility: analogs are what you fall back on when you have nothing better to offer.
I don't find them entertaining. I also find the reasoning behind them to often be simplistic. For instance, if the upcoming year is likened to five different years in the past, what have you really told me? Each of those years is guaranteed to be different from the others in significant ways.
Sometimes lists of analogs remind me of the swaggering "stone cold locks" offered by bookies--I mean sports news services--on who will beat the spread in the NFL this week. That would be hype-by-analog. It depends on the style of delivery. With a self-involved deliverer, they might function as a form of public self-amusement.
Dare to dream...
I tend to agree with you...it's sorta like assuming all brunettes are psycho just 'cause my first wife was brunette and psycho.....well...so was my second wife, actually...but you get my point...
yea...what's left of me...
have you seen the 18z GFS run?
The AGW crowd claims that AGW has everything to do with weather and climate, and that man is mostly responsible for the warming of the globe. So based upon that, I would think the AGW discussion is always on topic.
nnooooo.....but I don't think I like your tone....
take the sail boat out wed the 12th
funny you should say that....we're actually talking about taking a little cruise up the coast to Wilmington the weekend of the 14th....was gonna get serious about lookin' at weather tomorrow...You're gonna ruin it for me aren't you?
well just one run but it dont look good
ugh...buzzkill...
we are very seldom on that side of one huh?
Yeah, not much change in appearance either.
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