Dan's Wild Wild Science Journal

El Nino has returned.

The NOAA scientists, who monitor the tropical Pacific, sent out the notice this week. Temperatures in what is called the NINO 3.4 region of the Equatorial tropical Pacific, have increased to the point that we can say an El Nino has begun. (The threshold is an anomaly of .5 C) The official definition is a bit more technical and you can find it on this more technical summary for Meteorologists put put by the Climate Prediction Center. If you want to really understand how El Nino’s begin and end, then Taichiro Sakagami has made it easy. His videos are highly recommended.

El Nino’s CAN have a major impact on the climate around the world. Each one is different, however and we do not know yet how strong this particular event will be. Most of the effects happen in the Northern Hemisphere winter months.

One aspect of El Nino that does show up well in Summer is the effects it has on tropical cyclones in the Atlantic Basin. The increased wind shear caused by all that warm water tends to reduce the number of named storms.

It’s important to remember that El Nino is a natural oscillation. It was first noticed by a Meteorologist named Gilbert Walker. He was asked to look into why the Indian Monsoon had failed and to see of such failures were predictable. He collected weather observations, and noticed that when the average pressure at Darwin, in Australia, was close to the pressures much farther east in the Pacific, that the Monsoon would fail.  Australia would suffer severe droughts and other changes were noted as well. In normal years, the pressure would be much lower in Darwin, and higher to the East of Tahiti.

He named his affect the Southern Oscillation.

The atmospheric affects of this were first shown by Jacob Bjerknes. He is the son of one of the greatest Meteorologists ever, William Bjerknes. (Father was the first to give a name to cold fronts). Jacob realized that the pressure oscillations were actually the sloshing of warm water in the Western Pacific back to the East. It would later be realized that this had a profound affect on the atmosphere.

In “normal” years the Northeast trade winds blow the warm surface water in the Pacific westward toward Asia. The warm water piles up and seal level there is actually about half a meter higher than it is off the coast of Central America! The depth of this warm water is nearly 300 meters in the West, but the thermocline in the Pacific is much shallower near the Americas.

All this warm water in the Pacific, adds incredible amounts of moisture to the atmosphere, and keeps Indonesia very wet. When the warmth moves eastward, the rains follow. This warm air changes the pressures in the upper atmosphere and these cause changes in the storm tracks. El Ninos usually push the jet stream to the north in the Pacific. This causes a trough to develop many times near California, that brings intense winter storms. These changes don’t just show up in the Pacific, but around the world. Think of the atmosphere as a water bed. Jump on one side and what happens on the other? Now you get the idea!

Temperature anomalies in the Nino 3.4 region over last 12 months. From NOAA NCEP

Bjerknes named this entire process of ocean atmosphere interaction the Walker Circulation in honor of Gilbert Walker who discovered it in the 1930′s, by pouring over pressure records of thousands of stations. Meteorologists tend to call it ENSO for El Nino Southern Oscillation.

The strongest known El Nino, of modern times, was in 1997. This event was a monster, with affects felt around the world. The warm waters transferred an incredible amount of heat to the atmosphere. The jet stream sped up so much that it actually slowed the Earths rotation by a measurable amount! (The jet stream flows from West to East and since every action has an EQUAL and opposite reaction, the Earth slowed a tiny bit. The days were a few thousandths of a second longer!).

Sea Surface Temps. Ctsy NOAA CPC

Because of the El Nino of 1997, the global temperature was very warm. 1997 is among the warmest years ever measured. Because of differences in how the calculations are done, NASA ranks 97 and 2007 as tied for the warmest year, where the Hadley Center folks in the UK have it as 1998. The last few years have been slightly cooler because of the La Nina which brings large areas of colder than normal water across the Pacific. (The temperatures have still been well above those of the past because of increasing greenhouse gases).

The 1997 El Nino has been responsible for much of the silliness among climate skeptics. (Who claim that global warming stopped in 1998.) Now you know why this stuff is so silly. Many climate scientists believe that with greenhouse gases steadily increasing, the next strong el nino will bring yet another all time record global temperature (instrumental record dating to the 1880′s).

Image courtesy NOAA

They are very likely right, but there are other oscillations that have to be considered as well. The Pacific Decadal Oscillation is just one. Another is the North Atlantic Oscillation. I pay close attention to that in the winter, because it can be a harbinger of polar air deep into the southeast United States.

Claiming that climate change has stopped because this year is not as hot as last year is like saying that spring has stopped because the temperature on April 14th is not as warm as it was from April 10th through April 12th. If you look at the average temperature from the first week of April and compare it to the last week of may, you will see that this of course is ridiculous.

You would be shocked at how many emails and twitter messages I get from people who make this claim.  I cannot give them the science education they never had. Sad, still the same.

Dan

Note: A great fact sheet, with a much more detailed explanation, of the Walker Circulation has been written by my friend Bob Henson at the National Centers for Atmospheric Research (NCAR). He and Kevin Trenberth put together one of the best written pieces I have seen. I used it heavily in writing this post. The other information is from the NOAA- CPC El Nino page, and the COMET program modules on ENSO.

I wrote a post a while back entitled “How To Make Your Local Weather Person Very Happy“. It was about all of these hoax weather photos going around on the internet. Evey Meteorologist I know gets these by the dozen, from well intentioned friends and viewers.

We aired a story on this last night. It was fun to put together, and we even interviewed the guy who took the famous water spout and lightning photo. (It was not a tornado)

You can see it by clicking on the image below. Our web content producer Claire Aiello produced the piece.

Yes they all have something in common.

One of the negatives of working as a Meteorologist in TV, is that you are usually the only one on duty who has a background, and avid interest in science. The rest are (and I love them) News Weasels! ( I actually work with a bunch of supremely talented people, who save me from my grammar frequently)

Image from 1908 Tunguska Blast in Siberia

One of our directors is the son of two scientists, His Mother is a Chemist and his late Father had a PhD in Physics and was an expert in materials. We talk daily about science topics, and I really feel he should go into science, he has an incredibly inquisitive mind, and loves a mystery (Kids never seem to follow their parents careers- do they?).

Daniel is moving to Orlando soon and I will miss our conversations greatly. When I found out the Universe could expand faster than c, he was the only one at work who really appreciated the glory of the idea!

He told me today of Michael Kelley, an Atmospheric Scientist at Cornell, who noticed something weird. Often, three days after a shuttle launch, a display of Noctilucent clouds shows up in Alaska! Sure enough Kelley has a paper in press about this in Geophysical Research Letters.

Noctilucent Clouds credit NASA/Veres Viktor

Noctilucent clouds are very rare clouds that form about 50 miles high at the edge of the Thermosphere and Mesosphere. They are called night shining clouds, because at that altitude they can be lit by the sun when it is totally night below (No I have never seen them, but I carry extra underwear just in case).

He apparently discovered this from research into these clouds, and he also discovered a brilliant display in England in 1908. Right after the famous Tunguska blast in Siberia. It’s long been thought this blast, which leveled trees for hundreds of miles, and produced the energy of 200 atom bombs, was a meteoroid hitting Earth’s atmosphere. This may very well confirm that it was a comet that did it! The Tunguska meteorite blew up before hitting the ground, and this leads us to the TV show Mythbusters.

In a recent episode, they guys were amazed that if you put thermite in a can on top of a block of ice, the ice would explode! (see the video boys and girls!)

Daniel and I watched the video and discussed the Physics of it. We were uncertain. Daniel thought to call his Mom, who NASA trusts for chemistry knowledge. She knew the answer immediately! The block of ice turned to vapor so quickly that the expansion caused the explosion. When water turns from a liquid to a gas the volume increases (We looked it up) by 1096 times. (Thanks to Physicist Robert Muller of UCB, I remembered it was about 1000 times.) So mystery solved.

The Tunguska meteorite blew up for possibly similar reasons, Comets are really just dirty snowballs. The change to gas caused by the intense heating may have caused it to explode. Just like the block of ice on Mythbusters. This is apparently the conclusion Michael Kelley reaches in his soon to be published paper.

Time after time in science, an observation or a strange occurrence will lead to such interesting explanations. That’s why I so avidly support Science education. I want today’s kids to experience and appreciate the giddy wonder of how the Universe works!

Note: After writing this I discovered a story on space.com about it. The original story that caught Daniel’s eye was in National Geographic. They did not talk enough about the Meteor versus comet though!

A fascinating article has been published in Nature this week. It concerns the levels of atmospheric CO2 in the past, and it is sure to elicit plenty of comment in the scientific community. Understand that when a paper like this is published, it is not accepted as an answer, but as only a beginning of a discussion.

First some background- trust me this is interesting- even if your not a weather weenie like me.

You might be surprised to know that 33 million years ago, the CO2 levels in Earths atmosphere were very high. Nearly 1400 parts per million. Compared with about 390 ppm today. The Earth was VERY warm because of this too. Then levels began dropping.

CO2 levels past 500 million years. Ctsy. Robert Rohde

We know this from proxy measurements of CO2, in the deep past. Primarily  from measurements made in ocean bottom cores.  (super geeks go here) You can measure certain isotopes and come up with the level of CO2 at the time. You can then check your measurements with ice cores from Antarctica and the current instrument measurements to see if you are getting an accurate measurement. This is SOP in the science world.

So what caused the drop. Weathering of rocks is one way. Decreasing output from volcanoes likely played a role as well.  The primary way was probably increased weathering as mountains rose. CO2 today is taken from the atmosphere by chemical reactions and eventually gets buried as silt in the oceans. This process is part of the carbon cycle. It’s understood quite well.

Something seems to stop the drop when the CO2 levels reach 200 ppm. If it had dropped below 200 ppm, the Earth possibly would have remained in a permanent ice age. At the least it would have gotten much colder. The question is why did it never go below 200 ppm even when the earth was in an ice age. Why has it stayed much lower over the last 5 million years?

This mystery just MIGHT have an answer.

PLANTS

Mark Pagani of Yale and others have proposed that when the levels of CO2 dropped below about 300 ppm the forests disappeared and were replaced by grasslands. Grasslands, unlike trees, do not have big roots that break up rocks as they grow. Breaking up rocks speeds up weathering and the CO2 cycle. It’s long been thought that CO2 levels started dropping at the end of the Eocene, (about 30 million years ago) because of the uplift of mountains. As the mountains rise up the weather rates increase, and more CO2 is sequestered under the oceans.

Pagini et.al have proposed this negative feedback kicks in and that keeps the levels from going too low.

Carbon Cycle (Greatly simplified) from Dep. of Energy U.S.

Are they right? Time may tell. It is very dangerous to jump onto any just published paper to support a cause. Gavin Schmidt explains why, much better than I can in a post today on Real Climate.

As the editor of Nature wrote. It’s bold and provocative!

If you are wondering how this relates to Climate change today, then the answer is that anytime we better understand the past, we can better predict the future. CO2 levels by the end of this century could be approaching 1000 ppm. Still well below that of the Eocene.

From IPCC 2001 We can only replicate the real world warming by including all the factors. If you leave out the CO2 increase, the planet would have cooled.

The difference is that this time it’s not natural. It’s us. The results will likely be the same though. The physics of CO2 has been well understood for 100 years. (Despite some of the silly junk science put out online by those who find science does not work well with their politics)

We do know that CO2 levels dropped and by the time of the Holocene the Earth underwent multiple ice ages, interrupted by brief warming periods. We came out of the last one completely around 10,000 years ago and have had rather stable temps. since. (Until the late 20th century). The climate system is complicated. Solar output, changes in Earths orbit and internal feed-backs all play a role.

The public tends to try and focus on only one cause and effect. They all play a role though and most are understood quite well.

The Sun for instance would have caused us to cool slightly or hold steady over the last 50 years. (So much for “It’s the sun stupid” Solar Expert  Judith Lean in video) Earth’s orbital changes would have also left us pretty much stable, and perhaps a bit cooler.

Guess what? Cosmic Rays have almost no effect despite that book on the shelves of many  bookstores. Real science shows that any “cosmic” effect would have actually cooled us, not warmed us.

The Nature article is interesting for what is tells about the past, more than what it might say about the future. If they are right, we have discovered another of mother natures climate mechanisms. That would be good in itself. How it will play out in future predictions is a long way off. At this stage, it seems like it will not be a major factor either way.

We are heading in the direction of too much CO2- not too little! Is there a feedback that will kick in and save us if we get the CO2 too high? Maybe. You wanna find out? I don’t.

While in Portland, Oregon for a Climate seminar and weather conference last month, I was told that I MUST visit Powell’s books.

I’m glad I did.

It has to be one of the best bookstores around. My daughter swears that Shakespeare Books in Paris is better, but I have not been in that one. Still, if you are in either city, take this as a hearty recommendation!

Powell's Books in Portland Oregon. Portland has a great light rail system.

Powell’s is huge with stacks of books on any subject. Their science collection is exceedingly excellent. My friend Jim Gandy who does on air weather in Columbia South Carolina (exc person-forecaster, you folks in Columbia are very lucky.) found a rare Meteorological text, and had it sent home by mail. My friend Bob Henson of NCAR found a great book on cloud identification.  Luckily they had another copy. Guess who has it! (I suspect with one hundred weather geeks in town, their Meteorology section has been thinned somewhat!)

Bob Henson wrote “THE ROUGH GUIDE TO WEATHER” and The ROUGH GUIDE TO CLIMATE CHANGE“. Both fabulous books. They have them at Powell’s. (It’s kind of weird being in a bookstore and seeing books written by people you know. I spotted four titles in weather written by friends and acquaintances!)

Even with the rapid spread of Kindles, and reading on your i-Touch etc, there is still something comfortable about reading an “old fashioned” book! I have read some really good ones recently, and have been planning a post to tell you about them. This is it…

I have already mentioned The Rough Guide books, but the other book I picked up is THE CLOUD BOOK by Richard Hamblyn. It was published in association with the UK Met. Office and has gorgeous photos. If you do not know the difference between a cumulus and an arcus, this book is for you. It would make a great birthday present for young person interested in Science. (Do it before their brains melt over guys/girls as the case may be- they will pick it back up after their hormones settle down.)

SIX EASY PIECES by the late Richard Feynman is also a must read. Also his THE PLEASURE OF FINDING THINGS OUT. I kick myself that I have just read it in my 49th year. Surely Feynman was one of the greatest minds in Physics of the twentieth century. Perhaps ANY century. If you appreciate Science, you will love Feynman. If you do not, you will after reading his other book. SURELY YOU ARE JOKING MR. FEYNMAN.(I have Oscar Wilde’s THE PICTURE OF DORIAN GRAY on my bed stand, and I should have read that before now as well!)

Gavin Schmidt is another very smart person. He is a NASA Climate Scientist. His book along with Photographer Joshua Wilde has received rave reviews. Gorgeous pics and a look at climate change for non scientists and scientists alike. CLIMATE CHANGE-PICTURING THE SCIENCE is the title.

My biggest surprise of the Summer so far, was a book by Richard Dawkins I grabbed off the shelf. THE OXFORD BOOK OF MODERN SCIENCE WRITING is just an all around fascinating read. Everything from Carl Sagan to Evolutionary Biology is covered. The book has excerpts from dozens of the best minds in science.

For those who are not afraid of a little math and some thinking, David Archer’s book GLOBAL WARMING- UNDERSTANDING THE FORECAST is one of my faves. I am re-reading it now. Archer has one of my favourite quotes about the politics of his subject. “The target audience of denialism is the lay audience. It’s made to look like science, but it’s PR“. This is posted on Jules Klimaat Blog which is always a good read. (Mentioned in my blog on the Oregon Institute of Science)

I encounter this dressed up science that’s really PR frequently. Calling it out is one reason I started writing this blog. The other is to learn something new. I force myself to write about things I know little about sometimes. It’s  great way to learn! I am not a fan of Summer, and I count the days until September and the blue skies and dry air of autumn. One way I survive is to hole up in my bedroom, turn the AC on high, and READ. It’s not a bad way to escape the heat. Who knows, I bet I learn something too.

Vive Le Tour De France!

Dan

PS just go to Amazon, or your favourite online book dealer and you can find al of these books.