The EPA's Lake Guardian, based in Milwaukee.

Nature is full of heartwarming stories about partnerships. One of my all-time favorites is the three-way mutualism between Western ponderosa pine trees, tassel-eared squirrels and mycorrhizal fungi. The trees house the squirrels in their branches and the fungi on their roots. The mycorrhizae break down nutrients in the soil for easier absorption by the tree roots, and the trees supply sugar to the fungi. The squirrels eat the fruiting bodies of the fungi, called truffles, then defecate the spores throughout the forest, thereby inoculating new trees. Everybody benefits; forest health improves.

Pan east about a thousand miles to the Great Lakes region. Lurking beneath Lake Michigan is another partnership that’s just as impressive. But its effects on the Lake Michigan ecosystem are anything but beneficial, at least the way we perceive a healthy freshwater scene.

Earlier today, about 30 of us attending the Society of Environmental Journalists conference toured the University of Wisconsin’s Great Lakes Water Institute in Milwaukee. We also cruised the lake for a couple of hours aboard the EPA’s research vessel, called the Lake Guardian. Of all the research, I was most struck by new insights into the efficient relationship between quagga mussels and an algae called cladophora.

Quagga mussels fresh off the lake floor.

Ten years ago, scientists were sounding alarms about zebra mussels, Russian stowaways that hitched rides to the Great Lakes aboard ocean liners in the late 1980s and quickly expanded to cover the lake bed close to shore. The inch-long invaders proved annoying and costly, covering anchors, buoys and submerged ladders, and cutting bathers’ feet with their sharp shells.

But already, the zebra mussels have been crowded out by their even more prolific cousins: quagga mussels. Hardier and more adaptable, quagga mussels can live in colder, deeper parts of lakes where zebra mussels can’t. Each quagga mussel filters 1.5 quarts of water a day, extracting nutrients like phosphorous that would otherwise be available for native species, and concentrating it at the lake floor. That means visibility above the mussels is much improved — but the entire food chain is on the decline.

Cladophora. Photo by Linda Preskitt.

What’s even more amazing is that the quagga mussels transform the lake into a nursery for another invader: cladophora. The long, filamentous algae can take advantage of the rich phosphorous around the mussels, and it likes the extra sunlight that filters through the newly cleared water. The algae turns rocks into gardens wherever it takes hold. But in rough water, cladophora breaks off and floats free, covering beaches with stinking bacterial breeding grounds and costing power companies  millions of dollars in clogged pipes.

Now, would-be lake stewards find themselves in a bind. Markets for quagga mussels aren’t obvious. They’re terrible eating, and burning them as biomass would require destructive dredging of the already beleaguered lake floor. Harvey Bootsma, a UW-Milwaukee scientist, said in smaller water bodies, chemicals could be added to kill the mussels — but “there’s virtually nothing you can do in a body of water as large as Lake Michigan.”

Even reducing the amount of available phosphorous in the lake with tighter pollution controls, which might seem like a no-brainer, carries unsavory risks — especially for the open-water fisheries that are already suffering the reduction in available nutrients.

Speaking of drama, check out my iPhone's little color freakout on the boat. Whoa!

I can’t help trying to take a step back on this one, avoiding a view of it as a “bad” environmental story. I’m impressed with the rapidity of the changes — with the sheer natural action of the story. Wherever quagga mussels and cladophora take the lake from here, this eco-drama will be one to watch.

This post also appears on the SEJ blog, at http://sej2009.sej.org/.

Still, early indications are that my co-producer and I showed some raw talent today. Note the reaction of Ted Chamberlain, editor at National Geographic News: “FABULOUS! I love the silent, almost heartbreaking ending… I’ll have my people call yours. Don’t do anything until you have a chance to hear me out. If I end up in a bidding war with Discovery over this, you’ll never eat lunch in this town again!”

Enjoy!

Fluorite at an abandoned mine near Jamestown, Colorado

Back in the 1880s, George W. Coffin lived along St. Vrain creek, which flows in a mountainside ponderosa pine forest northeast of Boulder, Colorado. He made good use of the water, for irrigation. So did the Left-Hand Ditch Company, even though they lived a ways south of it — closer, actually, to another drainage called Left Hand Creek. Left Hand Creek ran smaller than the St. Vrain, with not enough water to supply the company’s business. So the company dug ditches to divert water from the St. Vrain into James Creek, and from there into Left Hand Creek, and then through still more ditches so they could sell it to irrigators. One year, there was a bit of a drought. Ol’ Mr. Coffin tore out part of the Left Hand Ditch Company’s dam, effectively restoring the natural flow of St. Vrain Creek — toward his own property where by rights, he thought, it ought to go.

The Colorado Supreme Court decided otherwise, thereby laying down (in 1882) one of the still-standing cornerstones of Western water law: first come, first serve, even though the Left Hand Ditch Company diverted the St. Vrain into an entirely different drainage to the exclusion of people living on its banks. They’d gotten to it first, and Coffin was out of luck.

This week, more than 100 years later, we studied the case for Charles Wilkinson’s environmental law class at CU Boulder. And today, in a happy convergence, I got to see Left Hand Creek for myself.

The occasion was a field trip for mineralogy class to an abandoned fluorite mine near Jamestown, presumably named for the once controversial James Creek. I’m learning through my law classes and mineralogy that this whole area was a hotbed of discovery. For example, the nearby resort town of Telluride, Colorado is named for tellurium, the only element with which gold will partner to make an ore (otherwise, gold occurs by itself).  We saw several historic mine shafts along the road to Jamestown, which in places parallels Left Hand Creek.

And at the fluorite mine, I learned one amazing way the Earth spewed forth the minerals that so richly rewarded the first white Westerners.

TA Dave Brown performs a secret handshake with a streak of granite (unrelated to the fluorite mine)

Dave Brown, the lab teaching assistant and a master’s student in the CU Boulder geology department, explained it like this:

Much earlier in Earth’s history — many millions or even several billion years ago — a blob of magma was cooling just beneath the Earth’s crust at what would become Jamestown. Trapped inside of it was water.

As the magma cooled (which took hundreds of millions of years), more and more water was concentrated in that wet little prison until the pressure became so extraordinary and the heat so intense that the water flashed to steam and escaped, up into fissures near Earth’s surface. It carried with it all the minerals that hadn’t crystallized in the magma — including some, like fluorite, that are valuable to people.

Fluorite so purple, it rivals a student's notebook. Notebook courtesy of Rae Ann Orkild-Norton.

Fluorite is used in processes to manufacture steel, aluminum, glass and enamels. In some cases it’s used to make telescope lenses (aha! a connection with my astronomy interest!).

I continue to be fairly shocked that I like mineralogy so much. Somehow it didn’t hit me nearly two decades ago — when I was a distracted undergrad — how cool it could be to take a walk outside and notice all around you the story of Earth in its rocks.

We saw several other mineral environments on this field trip — sedimentary, igneous and metamorphic. I won’t go into more detail here, but if you’re interested for any reason, feel free to check out this Picasa photo album (my study guide) showing some examples.

Meteorite!

I’m completely enamored with mineralogy class, in the geology department. I was hooked the first day, when our encyclopedic instructor, Joe Smyth, passed around a meteorite somewhere around 5 billion years old. It was black (iron) but metallic, and really heavy to hold; a true marvel. Mineralogy has sent me back to the chemistry textbooks I thought I escaped years ago, but willingly now, because I want to understand what rocks are made of (e.g., the minerals) as a window into the structure of the Earth and other planets. And of course there’s my special interest in the mineral apatite, the source of much of the world’s phosphate — and a pretty gem, as it turns out.

There’s a bit of a conflict between what I’m learning in mineralogy class and in my mining law class. Geologists say a mineral is (among other things) a solid that is not formed by biological processes. But United States mining laws for more than two centuries have included coal, oil, gas and even water as minerals. Nope, that’s not a typo.  The U.S. Supreme Court decided in 1978 (Andrus v. Charlestone Stone Products) that water is indeed a mineral. Bit of a mind-bender, yes?

There are other opportunities that come with the fellowship. On Friday, all of us fellows took a field trip up to Niwot Ridge. The high-altitude site is home of the Mountain Research Station, a facility of the Institute of Arctic and Alpine Research (INSTAAR).

We started our short hike in the subalpine ecotone, and quickly ascended above treeline.

There, we ran into this crew. They’re installing a system to warm the ground by 4 degrees C in isolated plots, and they’ll watch to see which plants will still germinate. The idea is to try to foresee plant responses to climate change. I wonder why there aren’t any intermediate temperature tests, maybe with 1 or 2 degree temperature increases to which plants might actually be forced to adapt in the short term. I asked, but didn’t get much of an answer; the crew wasn’t exactly expecting a pack of camera-toting journalists.

The warming apparatus over one experimental plot.

I think that field tech said each light will use one kilowatt of electricity when the project is up and running. I wasn't taking notes, and I'm numerically challenged. In any case, it's going to be quite an energetically intensive operation!

Historically, Niwot Ridge has made great contributions to ecology. I wrote a story for National Geographic News back in June about the work of Steve Schmidt, who investigates the edges of retreating glaciers to see which microbes move in first to colonize the newly exposed soil. He and his colleagues got their start at the Niwot Ridge Long Term Ecological Research Site and have expanded to investigate the edges of glaciers in South America. (My story is here.)

The ridge also hosts the Tundra Laboratory at 11,600 feet (3,528 meters) above sea level. And it’s the home of the world’s second-oldest sample of atmospheric CO2. Kurt Chowanski, a climatologist at the Mountain Research Station and our tour guide, showed us a couple of the sampling vessels inside the CO2 sampling shack, which was built in the 1950s.

Tom Yulsman, the Scripps fellowship co-chair, takes a video clip of Kurt and some CO2-sampling equipment.

CO2 has pretty much been rising ever since …

This printout was hanging on the wall in the main research station, where people actually have office space.

We made it to the top just as black clouds were starting to convene, so I ate lunch quickly and beat a hasty retreat back down the mountain (I’m more wary of lightning than most), about an hour ahead of the rest of the crew. They assured me they thought I was much weirder for wearing a frog hat than for being scared of lightning! Good crew …

The 2009-2010 Ted Scripps Fellows in Environmental Journalism at CU Boulder. From left: Jim Mimiaga, Laura Frank, Suzie Lechtenberg, Anne Minard (sporting the frog hat) and Michael Kodas.

Thanks to Scripps program co-chair Tom Yulsman for supplying us with much pre-trip information, some of which made it into this post.

Sunset over the Pacific at Arica, Chile. Image courtesy of the University Corporation for Atmospheric Research (UCAR) in Boulder, CO.

When it comes to teasing out the factors affecting Earth’s climate, the Sun is a compelling character. A rare breed of enthusiasts got pretty vocal about the Sun in the past year, when the great orb stayed quiet about a year longer than expected between the end of Solar Cycle 23 and the beginning of Solar Cycle 24, which has now begun — maybe. More about that in a minute.

The “enthusiasts” I mean are the ones who suspect that natural factors (e.g., not human-caused carbon emissions) are major players in any warming or cooling trends on Earth. They point to the Maunder Minimum in the 17th Century, when a lull in solar activity (as measured by sunspots) was linked with cooling in parts of the globe, especially Europe. Some members of the “global warming is a hoax” camp even latched onto the idea that if we were to succeed in reducing our carbon emissions, we could actually sabotage a sort of blanket that would help insulate us should the Sun stay mum. Sounds to me like a cop out — a cheap way to avoid cleaning up our act. Chances are we won’t get to find out if they’re right anyway, because the Sun appears to be ramping up toward another maximum around 2013.

Regardless, the Sun’s power to influence Earth’s climate is highlighted anew in a Science study this week.

The new study is suggesting a sun-climate connection that’s disproportionately large given the small overall variation in the Sun’s output (up to a tenth of one percent) during different parts of its cycle. And Earth’s response isn’t all about temperature, the authors report. Their models reveal a three-way interaction between the Sun, the atmosphere and the ocean, such that a peak in solar activity results in more precipitation over the western tropical Pacific, and cooler, drier conditions over the equatorial eastern Pacific.

Earth and the Sun, as viewed by the Space Shuttle Discovery. Credit: NASA

The connection between peaks in solar energy and cooler water in the equatorial Pacific was first discovered by study co-author Harry Van Loon of the National Center for Atmospheric Research in Boulder, Colorado and Colorado Research Associates.

Long-term records show precipitation increases up to 10 or 15 percent that coincide with solar maxima, said lead author Gerald Meehl, also of NCAR.

Meehl and his colleagues have now described the underpinnings of the connection.

First, they confirmed that the slight increase in solar energy during the peak production of sunspots is absorbed by stratospheric ozone.

The energy warms the air in the stratosphere over the tropics, where sunlight is most intense, while also triggering the production of ozone there that absorbs even more solar energy. Stratospheric winds are altered and, through a chain of interconnected processes, end up strengthening tropical precipitation.

At the same time, the increased sunlight at solar maximum causes a slight warming of ocean surface waters across the subtropical Pacific, where Sun-blocking clouds are normally scarce. That small amount of extra heat leads to more evaporation, producing additional water vapor. In turn, the moisture is carried by trade winds to the normally rainy areas of the western tropical Pacific, fueling heavier rains and reinforcing the effects of the stratospheric mechanism.

The top-down influence of the stratosphere and the bottom-up influence of the ocean work together to intensify this loop and strengthen the trade winds. As more sunshine hits drier areas, these changes reinforce each other, leading to less clouds in the subtropics, allowing even more sunlight to reach the surface, and producing a positive feedback loop that further magnifies the climate response.

These stratospheric and ocean responses during solar maximum keep the equatorial eastern Pacific even cooler and drier than usual, producing conditions similar to a La Nina event. The cooling of about 1-2 degrees F is focused farther east than in a typical La Nina, is only about half as strong, and is associated with different wind patterns in the stratosphere.

Solar maximum could potentially enhance a true La Nina event or dampen a true El Nino event. The La Nina of 1988-89 occurred near the peak of solar maximum and yielded an unusually mild and dry winter in the southwestern United States, for example.

The Indian monsoon, Pacific sea surface temperatures and precipitation, and other regional climate patterns are largely driven by rising and sinking air in Earth’s tropics and subtropics. The authors say their new work could help scientists use solar-cycle predictions to estimate how that circulation, and the regional climate patterns related to it, might vary over the next decade or two.

That is, if the Sun behaves itself.

The Sun normally goes through 11-year activity cycles, measured most commonly by the number of sunspots. Solar cycle 23 bottomed out in 2007 and we should have seen an uptick in sunspots — heralding Solar Cycle 24 — last year. But the Sun didn’t start stirring again until this spring. (I wrote about that for National Geographic News, here.)

Doug Biesecker, a physicist at NOAA’s Space Weather Prediction Center, also in Boulder, said the Sun seems to have started Solar Cycle 24, but he’s not willing to guarantee it yet.

“We’re clearly seeing an uptick in the long-term smoothed number [of sunspots] in the early part of 2009,” he said. Biesecker tries to look at the overall trend rather than individual monthly numbers, but the past couple of months have been a bit puzzling. “July was one of the bigger months of late,” he said, “but we haven’t had a single sunspot in all of August. “The odds are in favor that we’re already in the new cycle,” he said. “I would argue it will be the end of the year before we know definitively.”

Sources: University Corporation for Atmospheric Research (UCAR), Science, and a brief interview with Biesecker. See a previous blog post on solar behavior here.