Stories tagged The Water Cycle, Weather and Climate


Bristlecone pine: photo by Art Oglesby
Bristlecone pine: photo by Art Oglesby

Hurricane evidence found in tree rings

Human records of hurricanes go back less than 100 years. Can we somehow look at nature's record of weather within tree rings?

The moisture carried by hurricanes carries a different ratio of oxygen-18 to oxygen-16 than the normal rain that trees absorb. When that moisture falls near a tree, it is absorbed, and that ratio of oxygen is reflected in that year's ring.
Comparing the tree-ring data to the National Weather Service data over a 50-year period, the tree-ring data showed only one year in which their data reported a hurricane that was not in the list of recorded storms. Tennessee Today

Two University of Tennessee professors, Claudia Mora and Henri Grissino-Mayer, noted that this opens the door for research to go back even further than 220 years, as older trees are discovered in hurricane-prone areas, perhaps as old as 500 years.


Too bad bristlecone pines don't grow in the hurricane zones. The tree ring record in bristcones go back over 7000 years. Dendrochrology is the dating of past events (climatic changes) through study of tree ring growth. If you want to look tree rings of various trees, come to Collections Gallery at the Science Museum of Minnesota. We have one tree slice with 522 rings.

Abstract of the Proceedings of the National Academy of Sciences article


There's been a rash of cool weather sites written up in the Twin Cities newspapers and other media lately.

Here are just a few:

Skeetobiteweather is one of the most popular hurricane sites run by amateurs. Jonathon Grant, of Lakeland, Florida, runs it. He says the site gets 1.8 million page views a week, and you can plug in your zip code and get a prediction of wind forces for your block, hour-by-hour, before a hurricane hits. (Not even the National Weather Service does that.) And pretty soon, you'll be able to enter your exact address.

Mark Sudduth, of Wilmington, North Carolina, runs HurricaneTrack and HurricaneLiveNet. He deploys several battery-powered, waterproof cameras at the exact points where hurricanes are expected to hit. He also collects weather data to accompany the live, streaming video.

Jesse Bass, of Hampton Roads, Virginia, is a weather chaser who posts photos and commentary on his website, VAStormPhoto.

HurricaneCity, despite its name, is one of the more comprehensive severe weather sites. Jim Williams, of Delray Beach, Florida, focuses on the city being hit, and you can see all live, streaming radio stations or TV from the site. He also has a towercam on his roof, which captured images from Hurricane Wilma last year, and he hosts "The Hurricane Warning Show" from his living room.

Mike Watkins, of Coconut Creek, Florida, covers Atlantic hurricane action on TropicalUpdate. And if there's no news on the hurricane front, he hosts an Internet radio show where he interviews the "celebrities" of the weather world--guys like Max Mayfield, of the National Hurricane Center, or William Gray, the Colorado State University professor who's known for his hurricane season forecasts.


Farming the Wind: photo by Dirk Ingo Franke.   licensed under Creative Commons Attribution ShareAlike 1.0
Farming the Wind: photo by Dirk Ingo Franke. licensed under Creative Commons Attribution ShareAlike 1.0

Want to make a difference?

Did you know that you can insist that the amount of electricity you use be produced without generating carbon dioxide emissions or other forms of pollution (mercury, sulfer). Windsource electricity is produced without air emissions, such as carbon dioxide and sulfur dioxide, both considered to contribute to greenhouse gases. Wind-generated electricity also uses no water and therefore requires no water treatment during production. I am doing this by joining the Windsource program.

Xcel Energy will be held accountable for using Windsource funds appropriately: it must file annual reports with the Minnesota Department of Commerce and Minnesota Public Utilities Commission, accounting for program revenues and expenses and wind generation and sales. In addition, all wind facilities supplying the Windsource program will be certified by the Minnesota Department of Commerce. Sierraclub

What does it cost?

I have agreed to pay $2 per 100 kWh extra on my electric bill. This month I used 304 kWh so I was billed an extra $6.08. Since my electricity is pollution free I was rebated the Fuel Cost Adjustment that I otherwise would have paid ($2.76). So I paid an extra $3.32 last month know that I am helping rather than hurting our future environment. When fuel cost rise enough the rebate can become greater than what you pay for Windsource. You can sign up for Windsource here or call 1-800-895-4999 anytime.


Amazon Rainforest: Rainforest could become desert.   photo from NASA
Amazon Rainforest: Rainforest could become desert. photo from NASA

Amazon rainforest could become a desert

And that could speed up global warming with 'incalculable consequences', says alarming new research. Studies by the blue-chip Woods Hole Research Centre, carried out in Amazonia, have concluded that the forest cannot withstand more than two consecutive years of drought without breaking down. And that process, which would be irreversible, could begin as early as next year.

The Amazon rainforest is huge

For those who'd like some perspective, the Amazon rainforest represents half the rainforests in the world. It encompasses 1.2 billion acres, or 1.875 million square miles. That's 3.25% of the planets land mass. That’s a huge chunk of land. So if this report is accurate, it’s far from being insignificant.
The Amazon now appears to be entering its second successive year of drought, raising the possibility that it could start dying next year. The immense forest contains 90 billion tons of carbon, enough in itself to increase the rate of global warming by 50 per cent.
Read more from The Independent (U.K.), July 23, 2006


Scientists are studying a 70-mile "dead zone" off the coast of Oregon.

First noticed in 2002, the dead zone is larger this year than in previous years.

What is a dead zone? It's an large area of water that's very low in oxygen and can't support life. (Scientists call this "hypoxia.") Dead zones are caused by the explosive growth of tiny aquatic plants called phytoplankton. When the phytoplankton die, they are decomposed by bacteria. Massive numbers of bacteria use up the oxygen in the water. Any animals that can swim out of the low-oxygen water--like many fish--do so. Others--some fish, many crabs, and others--suffocate because they can't get enough oxygen to live.

Dead crabs: Dead Dungeness crabs on beach, Oregon Coast (Photo by Jane Lubchenco)
Dead crabs: Dead Dungeness crabs on beach, Oregon Coast (Photo by Jane Lubchenco)

In this case, the phytoplankton blooms are caused when north winds cause upwelling in the water column. The cooler water is rich in nutrients, providing a feast for the phytoplankton. When the wind dies down, the upwelling stops, and many phytoplankton die a natural death. Their decomposition results in water that is deadly because it lacks oxygen needed for life.

This year, the upwelling started in April, stopped in May, and started up again in June. The off-and-on upwelling creates a thick mat of organic material that rots and uses up the oxygen in the water. Then, when a new upwelling occurs, the oxygen-depleted water moves toward shore, killing the plants and animals that can't get out of its way.

Measuring oxygen levels: Chris Holmes (left) and Dr. Francis Chan (right), PISCO researchers measuring oxygen levels off the Oregon coast from the OSU research vessel Elakha (Photo by Jane Lubchenco)
Measuring oxygen levels: Chris Holmes (left) and Dr. Francis Chan (right), PISCO researchers measuring oxygen levels off the Oregon coast from the OSU research vessel Elakha (Photo by Jane Lubchenco)

So, why the upwelling? Jane Lubchenco, professor of marine ecology at Oregon State University and a member of the Pew Oceans Commission, told the Associated Press:

"We are seeing wild swings from year to year in the timing and duration of the winds that are favorable for upwelling. ... This increased variability in the winds is consistent with what we would expect under climate change."

Global warming is also the suspect in dead zones off Namibia, South Africa, and Peru.

(The dead zone in the Gulf of Mexico at the mouth of the Mississippi River is caused by agricultural runoff containing fertilizers. The river carries all those nutrients into the Gulf, creating algal blooms that use up all the oxygen.)


Global Warming: NASA photo of Earth taken from Apollo 17
Global Warming: NASA photo of Earth taken from Apollo 17

Have you been following the comments in Cari's Buzz Blog post about Gore's movie, An Inconvenient Truth. I find it interesting that very intelligent people can look at the same data ("truths") and yet totally disagree as to what to accept as reality?

A Global Warming Skeptic Challenge

George Musser on the Scientific American Blog has been moderating a discussion about global warming titled Are You a Global Warming Skeptic? Part IV He started the discussion March 6, 2006 with this statement:

In the comments field, explain which aspects of climate change you don't accept (e.g. you might not think Earth is warming at all, you might not think the warming is due to greenhouse gases, you might not think that the gases are produced by humans, or you might not think warming will cause trouble in the future), what exactly has led you to this conclusion, and -- most important -- what it would take to convince you otherwise. Let's get everything out into the open, so that we can have a real discussion.

The discussion is presented in four parts with hundreds of comments. I am recommending this thread because Musser first listens to, then presents a summary of the skeptics' arguments. I find the fairest way to make up my mind on an issue is to thoroughly understand both sides of the argument. Musser explains how scientists crunch the various data to answer difficult questions. He uses the analogy of examining fingerprints during a crime scene investigation.

Climatologists have maps and time series showing how a boatload of climate variables -- mean temperature, temperature ranges, air pressure, precipitation, and so on -- vary in time and in space, horizontally across the surface and vertically through the atmosphere. These data sets are a gold mine for resolving ambiguity, because the different forcings leave distinct fingerprints. Such patterns make it possible to tease out their relative contributions. Over the years, researchers have considered ever more variables besides temperature and ever more forcings besides greenhouse gases. They have merged spatial and temporal patterns, looked at regional as well as global scales, and developed more sophisticated mathematical tools.

View from the Crime Scene

"Fingerprints" included solar variability, volcanic eruptions, greenhouse gasses, ozone, aeosols, and various generic effects. When climatologists run the fingerprinting analysis for different historical epochs, they find that temperature fluctuations prior to the Industrial Revolution were driven primarily by solar and volcanic forcings. In the early 20th century, natural and anthropogenic forcings seem to contribute equally. From midcentury onwards, greenhouse gases rule(temporal pattern). Since 1979, when continuous satellites observations began, the surface and troposphere have warmed and the stratosphere has cooled(vertical pattern). Pretty much the entire surface has gotten warmer, high latitudes more than lower ones(horizontal pattern). All the oceans have warmed; there isn't the zero-sum game of warming and cooling you'd expect from natural variability(energy variability).

Musser concludes,

"unless I'm missing something, it seems to me that the case for anthropogenic warming is pretty strong...Based on the knowledge we have so far, however, I have to call 'em as I see 'em."

To appreciate the use of critical thinking and scientific method I recommend wading through the four installments of "Are you a global warming skeptic?" Part I (673 words); Part II (2219 words); Part III (2617 words); Part IV (3516 words); and an Appendix


Canoeing on a Minnesota Lake: Courtesey zanzibar

Hey do you like to fish, canoe, or swim in Minnesota lakes? I can't imagine our hot humid summers without the relief of a dip in cool Lake Nokomis. But how are those wonderful lakes that make our state so unique doing? Well, our pals across the river at the Bell Museum of Natural History are hosting a cool event next week about just that:

Fishing for Trouble?

Tuesday, June 13, from 6 to 8 p.m., Varsity Theater, Dinkytown, Free

Deborah Swackhamer and Roland Sigurdson of the U's Water Resources Center will discuss the state of our lakes, including how chemicals can affect water quality, fisheries, and human health. The Café Scientifique event, hosted by the U's Bell Museum of Natural History, precedes a Thursday evening fishing trip with Sigurdson on the shores of Lake Como in St. Paul. To learn more about both events, call 612-624-7083.

Should be a cool event with some good discussion and a chance to get your questions answered. See you there.


2005 hurricane season summary map: (Image courtesy National Hurricane Center)

The Atlantic hurricane season begins on June 1 and runs through November 30. The 2005 Atlantic hurricane season was the most active in recorded history. How will 2006 compare?

Check back often for updates and the latest news.


Monarch butterfly: Courtesy Matt Stratton
Monarch butterfly: Courtesy Matt Stratton

The number of butterflies migrating through California has dropped to a forty year low, according to researchers at the University of California, Davis. One-half of the usual species of butterflies have not appeared this season, and other species have been observed in very low numbers. Climate change related to global warming and habitat destruction may be the cause.

Global warming is the increase in the Earth’s average temperature over recent decades primarily attributable to human activities.

Habitat destruction is a change in land use in which one habitat is replaced with another. The plants and animals which previously used the site are destroyed or displaced in the process.

A mild winter in Northern California has caused many species to not end their winter dormancy at the right time. This means that many butterflies emerged too late in the season. The proper climate for breeding was disrupted by a wet spring.

In Southern California, an unusually dry desert left little food for caterpillars of some species to feed on. A late snow in the Sierra Nevada may have killed many insects used for food.

Some species of butterflies that breed several times a year may rebound from these events, but for other species the effects may be devastating for up to a decade.

Read the original press release here.


Spray: Spray being deployed by Brian Guest, at WHOI, in 2004. Courtesy: Jeffrey Sherman Research Specialist and designer of the SOLO microstructure profiler and 'Spray.'

Think you could swim 2,484 nautical miles
(1 nautical mile = 1.15 miles) across the Atlantic Ocean? This month, Spray, will embark on its mission to swim from the southern tip of Greenland to the coast of Spain. Spray is an autonomous underwater vehicle, AUV for short, created by the Woods Hole Oceanographic Institution in Massachusetts and the Scripps Institution of Oceanography in California.

    Spray's primary goals include:

  1. completing the lengthy swim;
  2. gathering signs of global warming;
  3. enabling scientists to have a constant telepresence in the ocean

Spray will act as an “aquatic sentinel” collecting data on temperature, currents and salinity. This information will assist scientists in furthering their knowledge base pertaining the role oceans have on global climate. Dr. Russ Davis, from the Scripps Institution of Oceanography in San Diego stated "The key is that Spray can stay at sea for months at relatively low cost, allowing us to observe large-scale changes under the ocean surface that might otherwise go unobserved." If Spray completes this mission, the robot will break its personal record of 1,864 nautical miles for the longest distance ever traveled by an AUV. GO SPRAY!!!

Check out this graphical representation of Spray in action.