How things work...cool animal videos from NPR's Science Friday

I'm often in awe at how the world works.  I'm also amazed at the creativity scientists show as they find ways to answer interesting questions, like why we sometimes slip on ice.  The researchers didn't use people in their studies though...they had to find another biped, something else that walks on two legs...guinea hens.

This first video shows how scientists things that move, and how much energy they use as they do.  Walking, sure, hopping, sure, but how can you collect physiological data on a bird in flight?  Check it out!



The second video has made the rounds, but it's a real goodie!

In this one someone is interested in finding out how the octopus is able to take camouflage to a whole new level.

You will probably want/need to watch this film more than once.  To start with...before you run the video, where's the octopus?  It's right in plain sight.  BTW, I just showed this to my son, A HS senior, and his reaction was, "What the HECK!?  Play that again!"




The really incredible thing is that an octopus can't see in color, and it's still able to match its surroundings' texture and color nearly perfectly...all by sight!  Keep in mind that the video is not digitally enhanced...octopus actually do this!

Really cool stuff!

"The Heat is On" - Arctic Sea Ice Melt 2012 Is Now Underway

Winter 2012 wasn't that severe for most parts of the country, but don't you still love signs of spring?

One sure sign of Spring is the start of the annual sea ice melt in the Arctic Ocean.

The National Snow and Ice Data Center (NSIDC; http://nsidc.org/arcticseaicenews/) reported this week that the Arctic Ocean Sea Ice melt is now underway.  Or, at least, that it looks like we've reached maximum sea ice extent.  Next stop? Summer!

I love maps and graphs - data rock!  Here is a map from the NSIDC showing maximum sea ice cover this winter.

The orange lines show the average extent of sea ice cover for the years 1979-2000.  The white area shows the current sea ice extent with at least 15% sea ice cover.  

This was an interesting sea ice year.  If you look at the map you'll see that we have much more sea ice than average in the Bering Sea, west of Alaska and north of the Aleutians.  At the same time there was not as much ice as usual in the Barents Sea north of Scandinavia and Russia.  Remember the tough time ships had reaching Nome, AK, this year?  That's because of all the sea ice.  

So, how does this winter's maximum extent stack up against recent years?

2011-12 sea ice cover is shown in light blue in the graph above.  

The maximum sea ice extent for this winter didn't reach historical averages...again.  But this year it got within about 600,000 square kilometers of the 1979-2000 average sea ice maximum.  Even so, the NSIDC reports that this year's sea ice extent is the 9th lowest sea ice extent reported since 1979.  You might also be interested to know that all of the past nine years, 2004-2012, are the nine lowest sea ice maximum extents on record.  

So what!?  

Here's what this means.  First, less ice is forming now than it used to.  Second, this means that the edges of the sea ice melts away from coastlines sooner,  This makes it tougher for animals that need the pack ice to get there - like polar bears.  This is especially tough on females and their young cubs.  Mothers and cubs often aren't able to move far from the den and move out onto the ice until the ice melt is well underway.  By this time bears often can't reach the ice pack unless they do a LOT of swimming.  In recent years polar bears have been been seen swimming across huge stretches of open water.  Bears have reportedly been spotted 100s of miles from land or ice...but this takes a toll, especially on cubs.  Sadly, increasing numbers of cubs aren't making it...they fatigue and drown.  It's even getting tougher for adults to make this kind of swim.

Photo - Eric Lefranc Freelance

"DISTRESSED POLAR BEARS"

Polar bear - Ursus maritimus - Olga Strait, Svalbard, Norway - Mother and cub trapped on a little ice floe drifting 12 miles from the nearest coast in Olga Strait. Polar bears are usually good swimmers however the cubs can not swim for so long and will probably not make it. (http://www.poyi.org/67/01/ae01.php)

Polar bears need to pack ice to hunt for their main prey - seals.  The seals live on the ice year round and give birth to their pups in dens under the surface snow.  This is what bears are looking for.  But if the ice is too thin or short-lived both bears and seals have a hard time.  And that's just the effect on these animals.  A bigger effect is the role that sea ice plays in something called the albedo.

The albedo of an object refers to its ability to absorb or reflect light.  

A perfectly black body will absorb all light that strikes it, and we see black.  If it is perfectly white it will reflect all light and it looks brilliant white.  

So what!?

When the Arctic Ocean is covered by sea ice it is closer to white and reflects most of the light that strikes it.  This keeps the Arctic colder than it would otherwise be, but, as the ice melts dark seawater is exposed, and because it is so dark it absorbs most of the light that strikes it.  This can warm the water, melt more ice, and - worse case scenario, eventually warm the Arctic Ocean seafloor.  

Why is this such a bid deal?  Scientists have discovered that some areas of the Arctic Oceans sea floor is actually permafrost - frozen sediment - that contains methane hydrate.  Methane hydrate is methane trapped in ice.  Methane is a greenhouse gas. If the Arctic seafloor warms enough the methane will be released and the Arctic Ocean will "burp" methane into the atmosphere, accelerating warming even more.  

This is a model of methane hydrate.  The methane is the green and gray molecule in the middle, and the red and white molecules are water frozen into ice, trapping the methane inside.  

Methane hydrate is really interesting stuff.  It can, for example, burn...

The white stuff is ice, and the methane is released and burns as the ice melts.  Similarly, methane will be released by sediments in the Arctic Ocean sea floor if the sediment warms enough for the ice to melt.  This photo shows methane being released underwater.  

Bears and ice and methane, oh my!

Reflections on climate change

I teach a course on climate change. (If you haven't figured this out yet, you're just not paying attention - come on people!).  Anyway, my students are mainly non-science majors, and that makes this adventure even more exciting.

One of the challenges of teaching this class is that some of my students get the mistaken idea that I "like" climate change and "hope" global warming is happening.  Eh!?  You'd have to be nuts to want that...who in their right mind would want global warming and its effects?  Granted, I live in a northern tier state so warming wouldn't be all bad locally, but globally!?  No way!

Another challenge is that my brain is routinely stuck in a scientific rut where I constantly experience the bizarre desire to want to find out exactly what's happening and why - data, data, data - strange I know, but that's what graduate school and a couple of decades of teaching can do to a guy.  Non-scientists, however, (especially in the USA) live in a media-rich world where sound bites and buzz rather than data creates opinion.  So you see the dilemma.  It keeps life interesting in a sort of east-meets-west kind of way.  By the end of the semester though, I have made some progress in helping my students see what's happening.  How do I know?

For example, last semester I had two students who were heavy duty "Tea Party" guys.  They were both openly skeptical and occasionally confrontational (but not belligerent) about climate change.  They made it clear that they thought global warming was either a hoax or totally blown out of proportion.  At the end of the semester though these guys came to see me at different times and for different reasons.  During our chats and without prompting they hung their heads and confessed that "There really is something to this global warming thing"...Ah success!!

These two guys epitomize the state of understanding...er...misunderstanding that prevails in the USA.  So where does this misunderstanding come from?  The combination of American media, politics, and deep-pocketed special interest groups.  The fact is that there is overwhelming consensus in the scientific community about climate change.  But politics and special interest groups continue to use PR and media messages to cloud the water and keep the reality of this consensus clouded as long as possible.  The current effort to cloud the general public's understanding of climate change is comparable to the tobacco industry's strategy to cloud the scientific message about confirmed links between tobacco and various forms of cancer over the past 60 years, and for which the tobacco industry was convicted on conspiracy and racketeering charges in 2006.  The tobacco industry appealed, of course, but the the original ruling was upheld in May 2011.
(http://www.dwlr.com/blog/2011-05-12/rico-convictions-major-tobacco-companies-affirmed )

If you want read about the tactics small groups of well-connected people use to misdirect public opinion and  cloud the issues on topics like climate change, I've got a recommendation for you: read the book "Merchants of Doubt" by the science historian Naomi Oreskes. (http://www.merchantsofdoubt.org/ )  It's an eye-opener!

 

The work of these "message clouders" is effective.  They use PR campaigns, editorials in sympathetic newspapers and other media outlets to promote their message.  They do not engage in scientific discussion, research, or publication in peer-reviewed scientific journals.  Sadly their methods work.  How do we know?  Climate scientists consistently and repeatedly demonstrate connections between human-produced carbon emissions and global warming in thousands of peer-reviewed publications each year, but this information is not communicated very effectively to the general public.  In the meantime, the slick PR machines of the contrarians spin out message after message of doubt in those results, and the public buys it.  Again, how do we know?  The American general public is expressing lower levels of concern and acceptance of this scientific conclusion than ever.  It's heartbreaking.

Here are some results from a  2011 GALLUP poll on climate change...
(http://www.gallup.com/poll/126560/americans-global-warming-concerns-continue-drop.aspx )
...48% of Americans said that they believed the seriousness of global warming was exaggerated in the news. This is up nearly 20% from 30% in 1998 and 2006 (see the graph below):



Then when people were asked whether they thought global warming had 1) Already started or would soon; 2) That it would occur within their lifetime; or 3) That it would not occur during their lifetime or not at all, 35% of respondents said that they thought it would not happen within their lifetime or even at all!  Yikes!



Fewer people also accept the conclusion that human activities affect climate.  Last year nearly 50% or respondents said they thought climate change was driven only by natural causes.  Sigh...the testable, confirmed scientific message is getting lost somewhere...it's in the muddied water stirred up by the PR machines.



Because these numbers are slipping farther all the time, I feel compelled to continue to teach and share thoughts about our climate.  Fortunately, I see a great deal of change in my students' perceptions about climate as they learn the science and see the data.  The bottom line is that climate change is affecting the atmosphere, the land, and the ocean.  Its bigger than pollution alone. ozone depletion alone, water issues alone, it's bigger than, well, any of our current environmental challenges, because it's global and will affect everyone.

Here's to ongoing efforts to communicate the messages of science. Cheers!.

Boring! My posts...NOT the book

I've been reading a REALLY good book called "Don't be Such a Scientist" by Randy Olson.  The subtitle is: "Talking Substance in an Age of Style."

I've been talking tons of substance, but without virtually any style...here's to the hopeful demise of deathly boring postings!

Climate Change 3: The Atmosphere

This is the third installment in my series on understanding climate change.  In order to really understand climate and climate change, you need to understand something about the structure of the atmosphere and the ocean.  This posting focuses on the composition and structure of the atmosphere.

Composition of the Modern Atmosphere

Our atmosphere has gone through significant changes since it was formed, eventually producing the atmosphere we have today.  The composition of our modern atmosphere is shown below:

Gas	Symbol	Content
Nitrogen	N2	78.084%	77.30%	76.52%	75.74%	74.96%
Oxygen	O2	20.947%	20.74%	20.53%	20.32%	20.11%
Water Vapor	H2O	0%	1%	2%	3%	4%
Argon	Ar	0.934%	0.92%	0.91%	0.90%	0.89%

Gas	Symbol	Content
Nitrogen	N2	78.084%		99.998%
Oxygen	O2	20.947%
Argon	Ar	0.934%
Carbon dioxide	CO2	0.033%
Neon	Ne	18.20 parts per million
Helium	He	5.20 parts per million
Krypton	Kr	1.10 parts per million
Sulfur dioxide	SO2	1.00 parts per million
Methane	CH4	2.00 parts per million
Hydrogen	H2	0.50 parts per million
Nitrous oxide	N2O	0.50 parts per million
Xenon	Xe	0.09 parts per million
Ozone	O3	0.07 parts per million
Nitrogen dioxide	NO2	0.02 parts per million
Iodine	I2	0.01 parts per million
Carbon monoxide	CO	trace
Ammonia	NH3	trace

(Atmospheric data courtesy of NOAA.gov http://www.srh.noaa.gov/jetstream/atmos/atmos_intro.htm)

Water vapor, carbon dioxide, methane, nitrous oxide, ozone, and carbon monoxide are all greenhouse gases. A greenhouse gas is a substance in the air that can absorb light as it enters the atmosphere.  Different greenhouse gases absorb different spectra of light.

* - Water vapor is an extremely important greenhouse gas and it plays a significant role in climate, but it is different than other greenhouse gases because it cannot accumulate in the atmosphere beyond local relative humidity thresholds.  Once the relative humidity gets high enough water vapor condenses and falls as precipitation.  BTW, the average length of time it takes for all of the water vapor in that atmosphere to be replaced is between 5-9 days.  Other greenhouse gases don't do this, they accumulate in the air.

** - The amount of ozone in the troposphere varies greatly with proximity to industrialized areas.  Plus, ozone is a reactive gas with other atmospheric compounds like CO2 and CH4, removing them from the atmosphere.  Alas, ozone is itself harmful to us, so a strategy of producing ozone to remove other greenhouse gases is not advisable.  Ozone in the stratosphere, however, is extremely beneficial to us since it absorbs UV radiation that can cause things like skin cancer and cataracts in our eyes.  But human-produced ozone tends to stay in the lower troposphere.

Physical Structure of the Atmosphere

There are four successive layers of the atmosphere, starting from the ground and increasing in elevation they are the troposphere, the stratosphere, the mesosphere, and the thermosphere.

(Image courtesy of NOAA - http://www.srh.noaa.gov/jetstream/atmos/atmprofile.htm)

The troposphere extends from the surface to an altitude of ~12km in altitude (~8 miles); it's thinnest at the poles.  About 80% of the mass of the atmosphere and 99% of all water vapor is found in this layer.  The average global temperature of the troposphere is about 15oC (~60oF) at the Earth's surface, cools to about -50-60oC at the top of the troposphere.  The troposphere is warmest near the surface because this is where greenhouse gas concentrations are highest.  Virtually all weather takes place in the troposphere.  The creation of surface winds and large-scale movement of air masses in the troposphere will be the topic of another posting.

The stratosphere is between ~12-50km (~8-32 miles) in altitude.  Most of the remaining 20% of the mass of the atmosphere is found here, as is most of the rest of the water vapor.  The ozone layer that protects us from dangerous UV radiation is found here.  The lower part of the stratosphere is warmest (this is where most of the ozone is), and it cools to about 0oF at its highest altitude.  Ozone is formed naturally here as O2 molecules are split apart by energy from the sun and individual oxygen atoms bond with molecules of O2 to form O3 (ozone).  While ozone is extremely effective at absorbing UV radiation, other wavelengths of light are not captured here.

The mesosphere is between ~50-85km (~30-55 miles) in altitude.  Though atmospheric concentration is dwindling greatly at these heights, there are still enough molecules here that this is where most meteorites burn up producing "shooting stars."  Since there are fewer air molecules the higher you go in this part of the atmosphere less light is captured, and less heat is released, so the higher you go in this layer, the colder it is (see the figure above).

The thermosphere is between ~85-140km (~55-87 miles) in altitude.  There is so little atmosphere in this layer that if you were there you would be subjected to the full intensity of the sun's energy.  This is why the top of the thermosphere is the hottest layer in the atmosphere at ~60oC (~140oF).  Though the thermosphere is the top layer of the atmosphere, the space shuttle flies at even higher altitudes (~300-530km (~190-330 miles).

OK, so what!?  You need to know something about the atmosphere if you want to understand climate, because climate is determined by long term averages of weather events including precipitation, relative humidity, temperature, and seasonality.  That's why this matters.  Enjoy!

Thoughts on the Sendai, Japan, earthquake and tsumani

This was originally posted in March 2011, and is being reposted in commemoration of this terrible tragedy.

Thoughts on the Sendai, Japan, earthquake and tsunami

I used to live in Japan and experienced my first earthquakes while I was there. The good thing about that is that I know that Japanese construction codes and building practices require that buildings there, large and small, are good at shaking without failing when the earth shakes.


The earthquake that shook that country last Friday (9.0 on the Richter scale - two magnitudes more powerful than the 6.9 magnitude Loma Prieta earthquake that hit the San Francisco/Santa Cruz area in 1989) pushed the country right to the edge of its limits, and in some cases beyond. The Sendai earthquake's epicenter was about 80 miles east of northern Honshu Island and at a depth of about 24 miles. Fortunately we have heard no reports of large buildings collapsing, though there are confirmed reports that some skyscrapers swung as much as 20' from side to side during the quake. Unfortunately, however, the quake triggered a massive tsunami.


There have been more than 150 aftershocks over a very large region. The map below shows the locations and relative strengths of aftershocks (so far).

Sadly, NPR reported this morning that the death toll from the earthquake and devastating tsunami that followed is now estimated to be around 10,000.


Scientists have reported that this earthquake was so powerful and that the slippage significant enough that stationary GPS reference location points in Japan shifted 8 feet (2.4 meters) - that's right, the entire country shifted 8 feet. Scientists also discovered that the angle of the axis of the earth shifted by about 4" (10 cm).


The resulting tsnuami waves devastated the northeast coast of Japan's main island of Honshu, striking near the large, coastal city of Sendai. The main tsunami wave that struck there was 23 feet (7 meters) tall. The size and force of that wave caused it to smash through low-lying coastal regions, destroying structures, farms, and killing ~19,000 people. This image from NOAA (The National Oceanographic and Atmospheric Administration) shows the wave height of the Sendai earthquake tsunami as it moved across the Pacific Ocean.

If that's not enough, some nuclear power plants in Japan suffered damage, and there are justified concerns that reactors are leaking radioactive materials. Recent reports state that over 180,000 people have been evacuated from areas where damaged reactors are located. One reactor has suffered two massive explosions, and there are further concerns about the possibility of core melt-downs.


My heart goes out to the people of Japan in these times of terrible natural disasters.

Climate Change 2: The only constant is change

I think the best word to use to describe the Earth is "Change".  Mountains are pushed up and eroded away, temperatures heat and cool, sea levels rise and fall, and even continents get pushed around.  In this posting I focus on one particular kind of change that has occurred during Earth's history - atmospheric change.

When the Earth first formed its atmosphere contained hydrogen, helium, methane, ammonia and water vapor, but no free oxygen!  That atmosphere was so hot (130-300oC) and produced so much pressure (256 atmospheres) that all the water on the planet was water vapor.  By comparison, Earth's atmosphere today has 1.0 atmosphere of pressure at sea level and an average temperature of about 15oC.  So, getting back to our story...

About 100 million years later Earth's atmosphere had changed and was made mainly of water vapor, carbon monoxide, carbon dioxide, ammonia, nitrogen, sulfur dioxide, and methane.  It was still too hot for liquid water, and there was no free oxygen.

Around 4by (billion years) ago the atmosphere cooled that it rained, and rained and rained and rained, for 1000s of years...and filled the oceans.  Within "only" another half a billion years, life showed up - prokaryotes (bacteria), and a group called cyanobacteria could do photosynthesis!

These are living species of cyanobacteria:

As I'm sure everyone recalls from those heady, exciting days in biology class, during photosynthesis sugar is made combining carbon dioxide and water, oh, and a waste product is also produced - oxygen.  The equation looks like this CO2 + H2O = C6H12O6 + O2.  (Apologies to the chemical purists out there - I didn't balance the equation, heh heh).

Cyanbacteria sat there doing their thing (photosynthesis and making more cyanobacteria) for a LONG time, and oxygen gradually accumulated in the atmosphere.  The presence of oxygen changed things...lots of things.  For one thing, oxygen is a toxic element and it killed most of the bacteria of the day.  Doesn't it seem weird that oxygen probably caused Earth's first major extinction event?

It took from  3.5by until about 1.8by for oxygen to make up 2-5% of the atmosphere.  While oxygen concentrations increased other other gases decreased: carbon dioxide, carbon monoxide, and methane.  The atmosphere wasn't the only thing changing either.  By about 1.5by other kinds of life show up - eukaryotic life.  Eukaryotic cells have a nucleus and membrane-bound organelles, like mitochondria and chloroplasts.  Plus about this time the oceans reached their current degree of salinity (saltiness).

The atmosphere stayed pretty much the same between 1.8by and 0.8by ago, and this time period is referred to as "The Boring Billion" years.  Then, however, things really started to happen!  Between 0.8by and 0.5by oxygen levels climbed to 10-20% of the atmosphere, and plants and animals showed up.  The temperature of the Earth, however, fluctuated between hot-house conditions and ice-ball conditions.

Around 350 million year ago there was a massive spike of oxygen in the atmosphere.  It made up about 35% of the atmosphere.  This spike occurred during the time when Earth's first massive forests 400-300 appeared.  These forests then died off and formed some of the huge coal reserves that we use today.

This is an artist's rendition of those forests.  Image courtesy of the Smithsonian [http://www.mnh.si.edu/highlight/riola/].

Around 300 million years ago atmospheric oxygen made up about 21% of the atmosphere, and it's been pretty constant ever since.

So what's the bottom line about Earth's atmosphere?  Like everything else on Earth...it changes!

These two links take you to parts one and two of a fantastic video based on The National Geographic Society's production, "The Story of Earth".  It has background music but no narration.  The video depicts our current scientific interpretation of the history of this planet we call home.  Enjoy.

http://www.youtube.com/watch?v=KCzXOxeY-60

And here's part 2, just in case you wanted to see the rest...I know I did!

http://www.youtube.com/watch?v=KNrti-9_nOg&feature=related