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Earth Matters

A Less Hardy Hardiness Map

The USDA has unveiled a new version of its plant hardiness map, which gardeners use to gauge which plants will survive in which climate zone. (Check your nearest seed packet.)  In the newest iteration, many zones have shifted northward because winters aren’t as cold as they were 22 years ago when the agency last updated the map — good news if you’re trying to grow, say, figs in Boston. On the new map, most parts of the United States are a half-zone warmer — about 5 degrees Fahrenheit (2.7 Celsius). Global warming surely underlies much of the change, but the USDA points out that more sophisticated mapping techniques, plus the inclusion of data from additional weather stations, has also affected the distribution of the zones.

Why the Arctic Ocean Isn’t Freshening
Rapid freshening on the North American side of the Arctic Ocean in recent decades has prompted speculation that rapid melting of sea ice might be causing a slowing of the “conveyor belt” that keeps water circulating through the world’s oceans. New research led by scientists at the University of Washington helps allay such fears. The researchers conclude that freshwater from the Eurasian part of the Arctic Ocean, which comes originally from rivers in Russia, has simply found a new route that brings more of it toward Canada. The cause for the new freshwater route: changes in winds associated with a weather pattern known as the Arctic Oscillation. In fact, the analysis of satellite and oceanographic data shows that overall salinity in the Arctic Ocean remained constant between 2005 and 2008; as the Canadian portion became fresher, the Eurasian portion grew saltier. The shifting path of the fresh water is shown in red in the animation below.

Temperature Ranking-palooza
There’s always a flurry of media activity in January when scientists at NASA, NOAA, and the UK Met Office tally up the year’s temperature measurements and rank how warm the past year was. This January was no exception. In NASA’s analysis, 2011 came in as the 9th warmest year on the modern meteorological record. However, the longer-term trends are what really matter. Look at the whole record – and here are a few interactive charts that are useful for doing that – and it’s clear that the last decade has been the hottest on record. Another remarkable stat: 9 of the 10 hottest years have occurred since 2000. For more details, the science team that manages NASA’s analysis has published a thorough temperature update here.

Image Gallery: Top Climate and Weather Events of 2011
As part of an annual review of Earth’s climate, scientists from NOAA and other institutions have compiled lists of the ten most significant climate and weather events of the past year.In making their recommendations, judges considered the scope, how unusual the event was, and how much human and economic damage it caused. For the United States, the spring rash of tornadoes in the Southeast, extreme drought in the South, a tornado in Missouri, and spring flooding of the Ohio and Mississippi Rivers topped the list. For Earth as a whole, extreme drought in East Africa, flooding in Thailand and Eastern Australia, the persistence of La Nina, and Tropical Storm Washi all made the list.

A Climate Stopgap (That’s Good for Your Health)
Scanning the coverage of a study published recently in Science could leave you thinking scientists have come across a miracle cure for global warming, while simultaneously saving lives and boosting agricultural yields. The good news is that researchers have demonstrated how a set of simple control strategies for methane and black carbon – such as patching up gas pipelines or using existing technology to reduce vehicle emissions – could markedly slow the pace of climate change AND produce health and agricultural benefits. But the flip side is that such actions would provide only a short-term benefit. In the longer term, societies still have to tackle carbon dioxide emissions to get the climate back to a state of equilibrium.

Explore Ignite@AGU
If you get a kick out of TED talks — those rapid-fire, information-packed lectures that have turned many little-known academics into YouTube stars — it’s time you also check out Ignite. Whereas TED talks can be up to 18 minutes, Ignite allows speakers just five minutes and a maximum of 20 slides. Above, watch NASA Goddard’s Richard Kleidman use his five minutes at an Ignite event to explain why the world needs a more robust network of ground sensors for monitoring air pollution.


Parade of Volcanoes

January 17th, 2012 by jallen

It’s been a really active time for the Earth Observatory and volcanoes. In the past three weeks, we’ve posted images of a night-time eruption of Shiveluch, ongoing activity at Puyehue–Cordón Caulle, daytime activity at the Kizimen Volcano, and my own favorite, a brand new island in the Red Sea. And those are just the images we published!

In recent weeks, we had a good shot of activity at Kilauea, but we skipped it since it only had Halema’uma’u activity — which is much like previous images and not the new ocean entry point, which we’ve yet to glimpse in cloud-free satellite imagery. We received an excellent ALI scene of the submarine El Hierro volcano (which we published) and then the next day we received an image of the same volcano from Landsat 7  (which effectively got scooped by ALI).

Another of the moderately recent and interesting images of volcanoes we didn’t use is a very nice ALI shot of the Cerro Hudson volcano in Chile.

We do have a good reason for not using the image. Notice the volcanic activity? Yeah, we didn’t see anything either. What makes this image interesting (to me anyway) is that just two weeks earlier, it looked like this:

We did publish that one. There’s actually not much in the way of activity in that one either, but in the published image, you can see a lot of ash that’s fallen on the ground from activity in October at the volcano.

Just two weeks later, with no new activity, almost all the ashfall seems to have “disappeared.” Fresh snow fell and covered much of it. Also, we got a much better shot with ALI of the volcano, getting a very nice view of the entire caldera, the glacier draining it out of the northeast, and forests in the alpine valleys. The ashfall was nowhere near as extensive and damaging as the Puyehue eruption, which at one point spewed out ash that circled the globe.

The new feature story, Seeing Forests for the Trees and the Carbon, discusses the need to form a three-dimensional picture of the world’s forests. Such a three-dimensional picture includes tree canopy height (below). Although canopy height in the Amazon Rainforest doesn’t match those of the Pacific Northwest or Southeast Asia, it still far exceeds the canopy height of Western Europe.


The height differences call to mind the adventures of a European naturalist who set out from Amsterdam in 1699 and spent two years exploring the jungles of Suriname. Bugs were the main attraction; namely, bugs that transformed from caterpillars into moths and butterflies. The scientist became one of the foremost experts on insect metamorphosis, braving tropical fevers, poisonous flora, slave rebellions, and a near shipwreck. What people found most audacious about the expedition was the age (52) and gender of the person who undertook it.

Maria Sibylla Merian was born in 1647 in Frankfurt, Germany, to a family of printers. Besides helping with the family business, she nurtured her interest in bugs from an early age. By the late 1690s, she was living in the bustling metropolis of Amsterdam. Among her many contacts were missionaries who were converting “heathens” half a world away. Merian was invited to visit, giving her the chance to study insects and plants that few other naturalists had ever seen. Teenage daughter in tow, she crossed the Atlantic.

Once she arrived in Suriname, however, Merian faced a challenge she probably hadn’t anticipated. In Germany and the Netherlands, she collected caterpillars from gardens designed for human enjoyment. That meant that her prized bugs could be found on plants that were waist high at most. The tropical jungle was different—not just different from the well-manicured gardens, but from any forests she might have known.

Long before Merian’s time, Europeans had cleared the land on much of their continent, making way for farming and pasture. Suriname, however, was covered in dense forest, with trees soaring 150 feet skyward. Bugs lived high over Merian’s head, completely out of reach most of the time. And in the vertical yards of tree trunk overhead, different insect communities thrived at different levels: The bugs living 30 feet above ground might be completely different from bugs living 60 feet above ground.

She made the most of the situation, collecting and drawing the insects that were within reach, and studying detritus that fell from the forest canopy. In one instance, she even had a mighty tree chopped down to collect its caterpillars and cocoons. Illness forced Merian to cut short her trip, originally planned for five years. She did, however, return to Europe with enough samples, drawings, and notes to assemble Metamorphosis Insectorum Surinamensium (Insects of Surinam), published in 1705.

Image credit: UF Digital Collections. Some rights reserved.

The same tall tropical trees that occasionally hampered Merian’s research continue to provide homes and food for insects, birds, and mammals today. While Merian could only gaze at the trees from the ground, modern satellite sensors can monitor the trees from above, gauging their height, and helping scientists understand how much carbon they hold.

Further reading: Todd, Kim. (2007). Chrysalis: Maria Sibylla Merian and the Secrets of Metamorphosis. Harcourt, Inc., Orlando.

Happy birthday, Steno

January 11th, 2012 by mscott

On January 11, 2012, Google celebrated the 374th birthday of geology pioneer, Nicolaus Steno, with a special Google Doodle.

Steno was a 17th-century anatomist and pioneering geologist. After dissecting a shark head, he realized that “tongue stones” — believed to belong to snakes turned to stone — were actually shark teeth.


In Steno’s era, many people believed fossils were just weird objects created by rocks. But he realized that fossils were the remains of ancient organisms.

Besides studying fossils, Steno examined rocks around Tuscany. He found that they were deposited in layers, with older rocks underlying newer rock layers. This basic principle of geology helped later scientists piece together the history of life on Earth.

You can learn more about Steno’s life and work in this Earth Observatory feature story published in 2004.

Coming Soon to a Theater or Billboard Near You

January 9th, 2012 by Mike Carlowicz

For a month in the fall of 2011, NASA staff conducted an experiment of a different kind. They shared satellite images and maps with Chicagoans, but not in a classroom or a museum. The images of Earth were posted at malls, at bus and train stations, in O’Hare Airport, and on roadside billboards. The experimental question was: would compelling images of the city and planet provoke people to learn more about earth science?

“We wanted to try and grab the attention and interest of an ‘on-the-go’ audience, one that might not seek out NASA information unless they had a primer,” said Brian Campbell, a NASA Earth science education specialist who led the effort. “The health of our planet is in jeopardy, and we want the public to know why and how we are trying to understand what is happening.”

The idea was to meet Americans where they live; that is, to bring science to the people, instead of waiting for the people to find science. Twelve NASA missions collaborated on images, messages, and strategic development of the Know Your Earth public awareness campaign. (Click on the link to see all of the images.)

A secondary goal was to make the public aware that NASA does Earth science. So many Americans think the agency is just human spaceflight, big astronomy, and planetary probes. But in fact NASA is one of the world’s largest funders and employers of earth scientists.

Know Your Earth first launched in 2010 with the premiere of video segments shown in 291 movie theaters across the United States. The full-length video is available here on YouTube. Below is the shorter teaser that also hit theaters in July 2010.

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Results and evaluations of the fall 2011 awareness campaign are still being compiled, but early reactions are positive. So what do you think of the Know Your Earth campaign?  Does it make you want to learn more?  Where should they take this project next?  See