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Langseth: The paravanes are out!

Mapping the Galicia Rift off Spain - Tue, 06/04/2013 - 00:24
Most of the science team came out on deck this afternoon to watch the starboard-side paravane deployed in relatively calm waters under partly cloudy skies. The technical and engineering crew proceeded slowly and carefully through the deployment procedure, and after about a couple of hours the paravane and attached streamer were over 300 m off the starboard side of the Langseth.

The second paravane went in the water at 22:00 this evening, and streamer 2 is currently being uncoiled into the water behind the ship. Despite a few delays, we are making good progress!

Marianne Karplus
4th June

email outage

IT Announcements - Tue, 01/29/2013 - 09:40

 Email for most users was down earlier this morning, January 29.   Service was restored around 9:30 AM..  We are

investigating the cause.

LDEO email back up

IT Announcements - Mon, 12/17/2012 - 10:05

email outage

IT Announcements - Sun, 12/16/2012 - 08:22

Currently email service is down for most users due to multiple hardware failures.  We are working on the problem.  There is no estimate as to when we will be back up.

mail service outage

IT Announcements - Sun, 12/16/2012 - 03:38

 Mail service for many users is down due to mutiple hardware failures.  We are working on the problem.

LDEO email/web outage

IT Announcements - Wed, 11/07/2012 - 15:06

The Meaning of Water

In Mongolia, water is energy. Photo: A. Hessl

What is the meaning of water? In my everyday life, water is a given.  Even this year, when at least one quarter of the US has been stricken by drought, water continues to flow from the tap and my family is unaffected by its scarcity.  I remember the California droughts of the 1970s, when my brother and I shared bathwater, I learned not to flush so much, and water was rationed.  Even still, our very sustenance, our wealth was not threatened by the lack of water.  In Mongolia, as in many other developing countries, people depend on water not just to slake their thirst but to sustain their livelihoods.  Mongolian herders must bring their animals to a water body daily.  In times of drought, most lakes dry up, leaving only a few “permanent” lakes available to dozens of herders and thousands (hundreds of thousands?) of animals.  Steppe lakes also serve as virtual “gas stations” for migratory birds and waterfowl – they are hotspots of diversity. Without water, animals perish, food disappears, and people and ecosystems suffer.  In a semi-arid region like the steppe, water allows people and ecosystems to transform solar energy into a mobile and flexible product via photosynthesis and primary consumption by livestock. In Mongolia, water is energy.

John sampling a large lake in Mongolia. Photo: A. Hessl

As part of our new project, we will be collaborating with Avery Cook-Shinneman (University of Washington) to use lake sediments to reconstruct the ecology of lakes and livestock during the Mongol Empire.  Lake sediments can provide a broad array of proxies for past ecosystems.  We plan to use some of these proxies to estimate past water quality and a relatively new proxy, Sporormiella, to assess the numbers of livestock present during the Mongol Empire.  This summer, my student John Burkhart and I visited a number of lakes near the Orkhon Valley, seat of the Mongol Empire, to recon possible sample sites.  In the process, we learned to appreciate the role of permanent lakes in Mongol herders’ livelihoods.

Before leaving for Mongolia, we had worked with Avery to identify more than a dozen lakes to recon.  We were going to collect water and surface sediment samples from each lake to assess their potential.  But upon our arrival in the Orkhon region, we quickly learned that those lakes no longer existed.  The decade-long drought that might be only ending in 2012 had left only a few permanent lakes; we noticed much standing water along the highway compared to 2010.  Though the large lakes we identified on Google Earth were starting to fill up again, the fact that they had dried up during a recent drought suggested they had dried up in the past, leaving only an intermittent record of past ecology.  We began visiting local herders homes (“gers”) to inquire about permanent lakes.

A Mongolian ger (the so-called yurt). PHoto: A. Hessl

We had used this approach before to look for old trees but Mongolians are no better than Americans at identifying old trees.  They always point you to the biggest, most beautiful tree and claim it’s the oldest – when in fact the scraggliest, ugliest tree is usually much older (Editor’s note: Beauty is in the eye of the beholder).  But in the case of lakes, these Mongolian herders were true scholars.  Ask any old herder about where to find permanent lakes, and they will tell you in detail the characteristics of all lakes in their region – when they thaw, when they freeze, what kind of plants grow around it and in it, and how likely it is to dry up.  I should not have been surprised – their life and livelihood depends on their knowledge and careful management of these lakes.

A moist landscape of life in Mongolia. Photo: A. Hessl

This kind of ecological knowledge is not new.  Mongolians have cultivated knowledge of lakes for millennia.  The first permanent lake we visited was less than 5km away from an Uyghur fortress dating to the 8th century.

Ruins of an 8th century Uyghur Empire fortress. Photo: A. Hessl

Categories: TRL

Oceans of Ancient Wood and Coming Full Circle

We have just made it back to Ulaanbaatar after 11 days of in-country travel and field work. While being a bit field worn from working on a lava field for 6 days, we are simultaneously thrilled and in good spirits. It is a bit too early to say, but it seems that Summer 2012 in Mongolia was a success*. It certainly felt like a success to me on the day we came full circle from 2010.

Amy, John, and Sanaa were a day ahead of us and, with John being down with a case of Chinggis’ revenge, Amy and Sanaa spent a full day on the lava field revisiting and re-visioning how we would sample over the following week. The hopeful goal was to collect enough wood to push the chronology near 2000 years in length while having enough samples over the last 1000 years to be able to say something with statistical significance. Sanaa and Amy intensely studied where to find wood and what pieces might be from an earlier era. They accomplished this while collecting 24 cross-sections of deadwood. It was an impressive and hugely helpful first day.

It was necessary to study the characteristics of the deadwood and its geographic distribution across the lava field because, honestly, our first discovery is pretty much the definition of, “a blind hog will find an acorn every once in a while“. During Amy’s and Sanaa’s first day of discovery in 2012, Sanaa came up with the term ‘ocean’ for the large, open areas of lava that are virtually devoid of trees. Because the ocean as a whole can be considered a kind of desert, we found that term ‘ocean’ was correct: this part of the lava field truly resembled a desert. Thus, over the course of our fieldwork, the first verse and drifting characteristics of A Horse with No Name came to mind. The heat was hot. There were plants and birds and rocks and things. Oh yeah, there were a few rocks.

A 360 pan of a large ‘ocean’ of lava. Can you spot Amy and Kevin? Photo: N. Pederson

Together we learned that it was on the margins of these oceans that we could find what appeared to be ancient wood. It wasn’t until the penultimate day, however, that we had any sense of what we had accomplished.

Being 5 days in and having collected ~150 pieces of deadwood, we were all a bit burnt, literally and figuratively. Though we had sunscreen and hats, it wasn’t quite enough. We all looked a bit beety. We were also running on fumes. Constantly hiking on jumbled and sharp pieces of lava jars the body and mind. So, on Day 5 we set out for a low-pressure ‘cleanup’ of the lava field. Almost anything we collected that day would be bonus material.

We decided to head towards some of the sample locations from 2010 to see if we could find some of the oldest pieces. Many of the oldest pine cross-sections from 2010 were not GPS’ed due to time, energy, and the afterthought nature of that collection. So, on Day 5 in 2012 we wandering an area we mostly missed in 2012 while at the same time trying to recollect the hazy afternoon in 2010.

About 45 minutes to an hour in, we had our first success. We re-discovered ‘The Logo Tree’. While the day on the lava field in 2010 is still very hazy in my mind (due to my state of being in day 3 of undiagnosed and untreated tonsillitis), the sharpest memory of that day is The Logo Tree.

The Logo Tree, a dead and likely ancient Siberian pine. Photo: N. Pederson

In 2010 The Logo Tree symbolized the potential for this site. We had spotted some Siberian pine trees, a species I did not see during my first brief visit to this site in 1999 with Gordon Jacoby, Baatarbileg Nachin, and Oyunsanaa (Sanaa) Byambasuren. This tree, though dead, captures many of the characteristics of old trees (charismatic megaflora) while also having the weathered, ‘stressed’ form of trees living on the edge of survival. These trees are often the ones tree-ring scientists use to reconstruct past climate. The Logo Tree screamed, “I, and many other pines like me, are ancient. You might better pay attention. This area could be filled with xylemite.”

So, it was with great joy that on Day 5 of 2012 The Logo Tree was re-discovered. Many picture were taken. Champagne corks were unleashed (in the form of taking the top off our water bottles and taking a swig of water). It certainly lifted me to a higher energy state.

We then spent much of the next few hours scouting for more samples from 2010 and passing through what can be considered a pine graveyard, an area filled with much deadwood and ancient, stunted pine trees.

Three generations of trees in the ‘pine graveyard’: deadwood, ancient, but stunted living trees, and tall, spritely young trees. Photo: N. Pederson

A specific goal on Day 5 was to locate the oldest piece from 2010, a sample dating to the middle portion of the first millennium of the Common Era. Having not yet found it as the day was drawing to a close, we decided to narrowly focus on finding that piece. We wandered. We scratched our heads. We saw a horse with no name. And then…and then, we hit an area with signs of our past chainsaw work.

Could it be? Might that be The One?

Yes, it had to be. See, that sample, The Eldest of 2010, sits near my desk. It is within arm’s reach in case of impromptu lab tours. I know that sample. The Elder is a bit oval with a characteristic hole that makes it easier to carry or hold up with two fingers. This seemed to be it.

The joy and shock of this confirmation, of coming full circle, was that this log didn’t look as old or as weathered as many of the pieces we had collected over the prior 4.75 days. It didn’t look exceptional. It nearby cousin, cut 2/3rds of the up a dead stem, was equally unimpressive. Yet, The Elder’s cousin dates to the late-1200s.

Sanaa, Amy, and Neil with The Elder, Day 5, 2012. Photo: B. Nachin

This particular re-discovery floated us for the remainder of the day and trip back to Ulaanbaatar. We cannot yet say with any certainty, but it seems we really hit our research goal. In fact, we are now concerned that we might have some pieces so old that they will not date – they might actually predate any long chronology we might build from this site. But, if this is a problem, we wish this kind of problem to all of our colleagues.

Now, to some scenes from the field:

Hi ho, hi ho, it’s off to work we go. Photo: N. Pederson

Neil and Amy, ocean walking. Photo: K. Anchukaitis

Amy sawing a piece of dead wood on the edge of a sea of lava. Photo: N. Pederson

Sample KHO415. Photo: K. Anchukaitis

John taking a plunge cut from a snag. In addition to taking samples from logs, we took some samples from standing dead trees. Photo: N. Pederson

Some snags took on a colorful beauty. Photo: N. Pederson

Some of the ancient-looking pines were quite short compared to their compatriots. For example, Amy is ~1.6 m tall. The 400? 500+? yr old pine to the left of Amy might be a little over twice her height. Photo: N. Pederson

Despite being low in productivity, the lava field holds much life. Can you spot the wolf scat? Photo: N. Pederson

Kevin says, “You’re still here? It’s over. Go home. Go.”** Photo: N. Pederson

*No living trees were harmed in the creation of this post

** respect

Categories: TRL

What Would Chinggis Do?

Saturday dawned a beautiful morning the air was crisp and cool, all of Mongolia had just gotten up at 4 in the morning to watch the opening ceremonies of the London Olympics, and traffic was light.  It seemed an auspicious beginning for our 2012 field work.  The opening ceremonies for our fieldwork had never run so smoothly: Baatar had arranged for our favorite driver, Chukha, to meet us at our hotel at 9am to get an early start.  It would be a solid 6-8 hour drive to the first lake we wished to sample Oygi Nuur, 9am did not seem too early. Drs. Baatar and Sanaa plus an undergraduate student, Balja, packed Chukha’s Russian military van at an astounding 7am (does Chukha really get up that early?) allowing us to leave Ulaanbaatar less than 36 hours after we arrived.  It was truly unprecedented.

Chinggis seated at the front of the Mongolian Parliament. Photo: N. Pederson

We made several stops on our way out of town, additional groceries, toothpaste, fuel, bar oil for chainsaws and a fruitless search for distilled water (why would we think we could get that here?) but we were still headed out of the smog bubble that is UB before noon.  It was a bit later than I had hoped, but still remarkable given our previous trips when it had taken several days to resist the gravitational force of the city.  As we left UB and the smog behind, we began to see small signs of the countryside: a few gers (circular felt tents), small herds of sheep for sale, and a couple of trucks loaded with wool.  John, my new PhD student, even saw his first Mongolian horses.  We could literally taste the Mongolian countryside.

Tsagaan takhi in northern Mongolia. Photo: N. Pederson

But as we drove up the last rise out of the Tuul River valley, the van sputtered, then stalled.  Things seemed routine Chukha was under the van in no time complaining of a loose battery connection.  In 15 minutes we were back on the road. At the next rise, the van stalled again, and this time Chukha looked truly distraught.  The rest of us piled out of the van, had a picnic lunch, and watched Mongolia clouds.  Chukha emerged from under the van looking like his best dog had just died.  He couldn’t eat, didn’t want to talk.  His van had literally blown a gasket.

On our way back to UB, after a beer and a couple shots with Chukha, we did our best to keep our chins up.  After all, what would Chinggis do?  We would try again tomorrow.  Until then, here’s looking forward to dinner.

Categories: TRL

Chasing Ghengis Khan

People have been looking for 800 years. Looking for Chinggis Khaan, né Ghengis Khan. From the people searching for his birthplace to the people searching for his last resting place. After more than 800 years since his rise from the mountains of Mongolia, Chinggis lives on as a charismatic and almost mythical person. He seemingly rose from obscurity, quelled feuds between tribes, and created the largest land empire in world history. If you read beyond what you likely learned in high school or college, you will see his leadership skills were progressive and exceptional. You will learn that Chinggis has an influence on our world nearly 800 years after his death. From paper money to the pony express, from war strategy to the structure of the human genome, his life has touched generations of humans over the centuries.

The new Chinggis Khaan statue, Photo: U. Aria

When you begin working in Mongolia it is absolutely essential that you learn the importance of the man. Soviet communism attempted to quell his spirit and his importance in Mongolian culture. Mongolians were not allowed last names so everyone could be equal, so no one could trace their family history to the royal family. This, of course, did not work. In a culture that has songs and stories dating back centuries, if you, a native Mongolian, meet a stranger in the woods on the other side of the country and drink tea, break bread, and just lounge, you will soon break into a song that you and the stranger know from the depth of your soul. You will sing, smile, and enjoy a wonderful afternoon with this once distant, now close cousin. That kind of cultural bind does not break under any kind of political pressure. Perhaps it only made it stronger? See, in the late-1990s, soon after the fall of communism, Chinggis essentially rose from the ashes. He was everywhere in Mongolia – TV commercials for cell phones or a brand of vodka. And once you, as an outsider, spend considerable time in Mongolia, especially during Naadam and especially in the open Gobi steppe with people who still live as their ancestors did centuries ago, you understand the importance of the man and you will also begin to chase Chinggis. And, it is with this new project that our group of geographers, paleoclimatologists, ecologists, historians, and ecosystem modelers begin our pursuit of Chinggis Khaan.

Unlike other chasers who came before us, our search for Chinggis is not directly a pursuit of him as an individual. We understand he was an incredible leader who was the life force for the great Mongol Empire. Our pursuit is more contextual. We seek to understand the environmental conditions before, during, and after the rise of the Mongol Empire. In many ways, the success of the Mongol Empire is a historical enigma.  At its peak during the 13th century, the empire controlled areas from the Hungarian grasslands to southern Asia and Persia. Powered by domesticated livestock, the Mongol Empire grew at the expense of farmers in Eastern Europe, Persia, and China.  Two commonly asked questions of this empire are “What environmental factors contributed to the rise of the Mongols?, and “What factors influenced the disintegration of the empire by 1300 CE?  . For a long time (centuries?),  it was thought that drought partly drove the Mongols on their conquest in Eurasia. Luckily enough for us, a serendipitous collection of a few pieces of deadwood and old Siberian pine trees suggests essentially the opposite. Our collection of an annual record of drought, currently dating to the mid-600s CE, suggests that the early-1200s were unusually wet. Of course, these findings are very, very, very preliminary – we only have two trees through this time period.

Old trees and older lava. Photo: N. Pederson

So, with funding from the Lamont Climate Center, National Geographic Society, West Virginia University, and the Dynamics of Coupled Natural and Human Systems program of the National Science Foundation, we are headed back to Mongolia for a fourth straight year to scour the study site that yielded a 1,300 year record for more old, dead wood. With a combined crew from the National University of Mongolia, West Virginia University, and the Tree Ring Laboratory of Lamont-Doherty Observatory, Columbia University and the Earth Institute, we will spend 10 days in the field seeking, documenting, and collecting wooden gold, xylemite if you will.

Terkhiin Tsagaan Nuur, the Great White Lake of Mongolia. Photo: N. Pederson

Part of our crew will also spend about three days at upper tree line on a mountain in the western Khangai Uul (uul is Mongolian for mountain) updating and expanding the collection that suggested that it was warmer during the rise of the Mongol Empire. We are so excited. We have a great crew, will be spending our time mostly in one place, and will have some of the finest scenery in Mongolia in our eyes everyday.

Solongotyin Davaa, Mongolia. Photo: N. Pederson

Frankly, we are also excited about our larger project. We honestly do not know what the end results will be. The idea that wet conditions aided the expansion of the Mongol Empire is simply a hypothesis built upon ecosystem ecology, human ecology, and our preliminary results. See, energy is critical for human and natural systems to function, yet few studies have examined the role of energy in the success and failure of past societies. Increased rainfall on the Great Gobi Steppe should allow the grassland to capture more solar energy. Greater grass production logically would have allowed the Mongol Empire to capture, transform, and allocate this energy through their sheep, horses, yak, etc. In turn, this should have allowed greater energy from which Chinggis could develop a larger and more complex social, economic, and political system.

A lone takhi in the northwestern edge of the Gobi, Uuvs Aimag, Mongolia. Photo: N. Pederson

Feeding tree ring based climate history into an ecological model, we plan to investigate how past climate influenced grassland productivity, herbivores, and, thus, energy flow through the Mongol ecosystem. These data will be compared to historical records on the empire and sediment records from lakes that can estimate herbivore density.

Much has been made about the demise of cultures as a result of a downturn in climate or degradation of their environment. Our estimates of energy availability and environmental quality allows us to investigate whether the contraction of the empire was related to drought, cold, declining grassland productivity, or poor water quality associated with rapid urbanization and climate change.Thus, as part of our larger project, we will test the hypothesis that the arc of the Mongol Empire was influenced by the energy available to nomadic pastoralists for building a mobile military and governmental force sufficient to conquer and govern a significant portion of Asia and Eastern Europe.

The diverse Mongolian landscape. Photo: N. Pederson

We leave in less than two weeks.  As happens each year around this time, memories of past trips are revived and we begin seeping back into the Monglish culture that develop on these trips. We look forward to re-uniting with colleagues like Baatarbileg Nachin and his students like Bayaraa. A highlight this year will be working alongside a Mongolian postdoc, Sanaa, who Neil met as an undergrad in 1998. It will be an honor and pleasure to work with Sanaa again. Mongol phrases and words are bubbling up from the depths of our grey matter. Mongolian music is spinning nearly full-time in one household; a soundtrack for this year’s fieldwork is coming into shape.

We hope to catch a set of Altan Urag, a rising rock band in Mongolia. To us, they represent some of the cultural struggle in Mongolia today: “How to we maintain the qualities we are so proud of during the height of our empire, as new or external culture moves into our land?” and “As commercialization in the post-communism era (including a ‘gold-rush’ in the mining industry that created one of the fastest growing economies in the world) pushes and pulls us, how do we maintain who we are?” Altan Urag and young Mongolian artists are reaching back in their history for symbols and sounds that make them distinctly Mongolian. At the same time, these artists keep their eyes and ears open to the new possibilities of their larger world. Similar to how Chinggis melded European and Chinese technology to forge his great empire, many of today’s young Mongolians blend their history with external elements to create a new Mongolia. We cheer these efforts on. We are big fans.

Categories: TRL

Lamont-Doherty Earth Observatory: Milestones in Climate Science

The 2015 Paris Climate Summit - Thu, 06/14/2012 - 14:41

(Note: This feature first appeared in 2012; it was updated November 2015 for the Paris Climate Summit.)

Much of the modern understanding of climate has been shaped by pioneering studies done at Columbia University’s Lamont-Doherty Earth Observatory. Starting in the 1950s and extending through today, researchers in oceanography, atmospheric physics, geochemistry and other disciplines have shown how natural climate cycles work; how carbon dioxide is now influencing earth’s temperature; the hidden roles that oceans play in regulating climate; and, most recently, how ongoing rapid climate change is affecting nature and human societies. Here is a timeline of studies that have changed the way the world looks at climate.

Climates of the distant past are often studied using cores taken from ocean bottoms; Lamont scientists have been the leaders in collecting and studying these, and the institution holds the world’s largest repository. Above, deputy director J. Lamar Worzel and director Maurice Ewing on the research vessel Glomar Challenger, 1968.

1956: A theory of ice ages Maurice Ewing and William Donn, Science   Maurice “Doc” Ewing, one of the world’s most influential oceanographers and Lamont’s first director, teamed with geologist Donn to propose that ice ages are driven by self-perpetuating natural cycles of freezing and thawing of the Arctic Ocean. This paper and two followups were seized upon in popular literature of the time to suggest that a new ice age would arrive soon. Although scientists’ views shifted radically as more evidence came in, this initiated Lamont’s tradition of studying large-scale climate swings.

1960: Natural radiocarbon in the Atlantic Ocean Wallace Broecker et al., Journal of Geophysical Research   Wallace Broecker, one of the founders of modern climate science, showed how isotopes of carbon produced by natural and human processes could be used to map ocean currents that we now know form a series of global-scale loops. This led to an overarching model of the “Great Ocean Conveyor Belt” and the idea that changes in the conveyor may bring sudden, powerful shifts in the global climate.

1966: Paleomagnetic study of Antarctic deep-sea cores Neil Opdyke et al., Science   By systematically examining Antarctic seabed sediments, Opdyke and colleagues showed that periodic shifts in earth’s magnetic polarity could be used to accurately date sediment layers back beyond 2 million years—and thus climate shifts from those ancient times. Previously, the limit was only 25,000 years. This set the stage to test theories of climate change in deep time.

Wallace Broecker, who joined Lamont 60 years ago, is considered one of the founders of modern climate science. He has made some of the most important discoveries about oceanography and climate, and continues his work today.

1973: Are we on the brink of a pronounced global warming? Wallace Broecker, Science   This is the paper generally credited with coining the phrase “global warming” in scientific literature. The planet at that time was emerging from a decades-long natural cooling cycle, which Broecker postulated had been masking an ongoing warming effect caused by rising industrial carbon-dioxide emissions. Broecker predicted that as the cooling cycle bottomed out, global temperatures would rise swiftly. He was right.

1976: The surface of the ice-age Earth CLIMAP, Science   CLIMAP, an international project in the 1970s-80s, reconstructed the world’s sea-surface temperatures, and thus overall climate, during the last glaciation. The main evidence was deep-sea cores—many taken by Lamont scientists and held in the Lamont Deep-Sea Core Repository, the world’s largest. It was the first comprehensive look at earth’s temperature for a time markedly different from our own.

1976: Variations in earth’s orbit—pacemaker of ice ages James Hays, John Imbrie, Nicholas Shackleton,  Science   In the 1920s, Serb mathematician Milutin Milankovic proposed that earth’s ice ages coincide with cyclic changes in the eccentricity, axis orientation and wobble of the earth as it orbits the sun. The idea was long debated. This paper finally proved to most scientists’ satisfaction that Milankovic cycles are real. Lamont’s James Hays worked with two other giants of modern science: Brown University’s John Imbrie and Cambridge’s Nicholas Shackleton.

1978: The Marine oxygen isotope record in Pleistocene coral, Barbados, West Indies Richard G. Fairbanks et al., Quaternary Research   This paper documented the magnitude and rapidity of sea-level rises when ice sheets and glaciers melted at the ends of several previous ice ages. Other Lamont researchers have followed with many more studies to the present quantifying past changes in sea level. These studies are key to understanding how current melting of ice may affect us in the near future.

1986:  Experimental Forecasts of El Niño Mark Cane, Stephen Zebiak et al., Nature   El Niño is earth’s most powerful natural climate cycle, shifting precipitation and temperature patterns, to affect crops, disease outbreaks and natural hazards globally. Its physics and variable timing were long cloaked in mystery. Cane and Zebiak were the first to construct a model that explained how it worked, and could successfully predict an El Niño. This and related work led to forecasts that are now used worldwide to plan for crop planting, public-health initiatives and emergency relief efforts.

1986: Inter-Ocean Exchange of Thermocline Water Arnold Gordon, Journal of Geophysical Research In conjunction with earlier oceanographic work, laid out how differences in the temperature and salt levels in different layers drive the exchange of water between oceans, and, ultimately, affect climate over vast distances.  Gordon and colleagues continue to work on questions of large-scale ocean circulation in Indonesia, the Southern Ocean and elsewhere.

1989: The role of ocean-atmosphere reorganizations in glacial cycles Wallace Broecker and George Denton, Geochimica Cosmochimica Acta   This study explored the role of freshwater inflow into the northern North Atlantic, via melting ice, in governing the oceanic “conveyor belt,” and its possible association with disruptions of currents that could cause sudden, large-scale climate changes. Followed by many other papers including 1992’s Evidence for Massive Discharges of Icebergs into the North Atlantic Ocean During the Last Glacial Period (Gerard Bond et al., Nature).

With glaciers now melting worldwide, understanding their dynamics past and present is key to projecting the future. Lamont scientists study ice trends all over the world. Here, a researcher on an expedition to core the waning glacier atop Indonesia’s Puncak Jaya, earth’s highest peak between the Andes and the Himalayas.

1995: Temperature histories from tree rings and corals Edward Cook, Climate Dynamics Cook, now head of Lamont’s Tree Ring Lab, showed how tree rings dating back as far as 1,000 years correlated with both modern instrumental records and marine corals to show anomalous warming during the 20th century in many parts of the world. Working from places ranging from Tasmania and South America to Mongolia, North America and Scandinavia, lab scientists have since published many more papers on how tree rings illuminate regional and global climate histories. These include a monumental drought atlas of Asia, published in 2010.

1995: Plio-Pleistocene African climate Peter de Menocal, Science This connected the evolution of humans with a shift toward more arid conditions in the east African climate after 2.8 million years ago. The change resulted in the development of open savannahs where newly upright human hunters are thought to have thrived. It was one of the early papers suggesting climate’s basic effects upon humans. Many uncertainties persist about early human evolution, but many scientists continue investigations of the evolution-climate link.

2000: Climate change and the collapse of the Akkadian Empire: evidence from the deep-sea Heidi Cullen, Peter de Menocal et al. Geology   The sophisticated Akkadians ruled the Middle East  until 4,200 years ago, when their empire suddenly collapsed. Heidi Cullen (who later became a popular TV personality covering climate) linked it with an abrupt 300-year drought, using layers of dust found in seabed deposits. This helped nourish the emerging awareness of how environmental change may affect societies. Later related Lamont papers include a 2010 study exploring the collapse of southeast Asia’s Angkor culture, and other Asian societies, also apparently due to drought.

2002: Global sea-air CO2 flux based on climatological surface ocean pCO2, and seasonal biological and temperature effects Taro Takahashi  et al., Deep-Sea Research Part II   Based on some 940,000 measurements taken over four decades, Taro Takahashi and colleagues mapped for the first time on a global scale the exchange of carbon dioxide between the atmosphere and oceans—a flux that plays a key role regulating climate. This was followed by papers including 2009’s Reconstruction of the history of anthropogenic CO2 concentrations in the ocean (Samar Khatiwala et al., Nature), which indicated that since 2000, the world’s oceans may have begun losing their ability to absorb rising human emissions of carbon.

2004: Long-Term Aridity Changes in the Western United States Edward Cook et al., Science   Tree rings showed that an ongoing drought in the U.S. Southwest paled in comparison to one during an unusually warm period about 1,000 years ago. It suggested that the region is vulnerable to disastrous drying due to global warming. An influential 2007 paper followed, led by climate modeler Richard Seager: Model Projections of an imminent transition to a more arid climate in southwestern North America,” Science.  This added evidence that the region will dry significantly in the 21st century–a transition now probably already underway.

2008: In Situ Carbonation of Peridotite for CO2 Storage Peter Kelemen, Juerg Matter, Proceedings of the National Academy of Sciences   With the recognition of the problems caused by rising carbon dioxide, Lamont scientists in several disciplines have been among the first to look into possible ways to capture and store emissions. This paper documents efforts to use natural chemical reactions within deep-earth rocks in Oman to “freeze” emissions into underground reservoirs. Projects by other researchers are looking into piping emissions into the seabed off the U.S. Northeast, or using rocks common on the U.S. mainland.

Tree rings contain exquisitely detailed records about past climates. Members of the Tree Ring Lab travel to many remote places to collect and study samples. Here, researchers work at the edge of the northern Alaska tundra.

2011: Civil conflicts are associated with the global climate Solomon Hsiang et al., Nature   In the first study of its kind, Hsiang and his colleagues linked periodic increases in civil conflicts to the arrival of El Niño. The study found that the characteristic hotter, often dryer weather in certain areas doubled the risk of warfare across some 90 tropical countries, and accounted for a fifth of worldwide conflicts in the past 50 years. There is now speculation (though no proof) from studies done at Lamont and elsewhere that El Niño cycles themselves could be intensified by rising global temperatures in the future.

2012: The geological record of ocean acidification Bärbel Hönisch et al., Science Lead author Bärbel Hönisch and her colleagues showed that the world’s oceans are turning acidic at a rate unprecedented over at least the last 300 million years, apparently due to reactions with human emissions of CO2. This could affect marine ecosystems, and may already be having effects in regions such as the U.S. Pacific Northwest.

2015: Climate Change in the Fertile Crescent and implications of the recent Syrian drought  Colin P. Kelley et al., Proceedings of the National Academy of Sciences   This study asserts that a record 2006-2010 drought in Syria was stoked by climate change–and that the drought in turn helped propel Syria and surrounding nations into the vast war that has evolved into one of the worst disasters of modern times.  It made worldwide headlines, and has become one of the most highly cited pieces of research linking ongoing climate trends with drastic consequences for humanity.

2015: Contribution of anthropogenic warming to California drought during 2012-2014  A. Park Williams et al., Geophysical Research Letters   With record-breaking drought devastating California starting in 2012, many scientists began looking at whether global warming was playing a role. Bioclimatologist A. Park Williams and his colleagues showed that while natural factors probably caused the lack of rainfall, global warming played a measurable role in the drought by drying out soils further. The study was instantly seized by politicians and others as hard evidence that climate change is already affecting agriculture, economy and environment in the United States.


Click here to view the embedded video.



Transitions: Climate, Fire, and Forests in Mongolia

The silence you may have heard since our last post was the sound of microscope lights flickering, measuring stages gliding, brains grinding, numbers crunching, and poi dogs pondering. We wrapped up all planned field work last summer for our research grant on climate, fire, and forest history in Mongolia. We have transitioned from the field-intensive portion of the grant to the data and publication phase of the scientific process. We have presented research in various meetings and settings and have earnestly begun to put our findings to our peers to begin the publication process. We are also transitioning to a new vein of research in Mongolia that gets to the title of this blog. It has been a long time coming.

First, Dr. Amy Hessl was inspired by the forest in transition on Solongotyin Davaa. This is the famous forest where global warming was first reported in Mongolia. High elevation forests are rare to burn. So, the thought that a landscape with wood that has been on the forest floor for more than 100o years became an important part of Amy’s summary on “Pathways for climate change effects on fire: Models, data, and uncertainties“.

The 2010, post-fire landscape of Solongotyin Davaa from Figure 1 in Hessl’s “Pathways for climate change effects on fire: Models, data, and uncertainties”

Next, Amy led a slew of us in a publication summarizing our initial findings of fire history from the northern edge of the Gobi Steppe to Mongolia’s border with Russia near Sükhbaatar City. With the glaring exception on Bogd Uul, this paper, “Reconstructing fire history in central Mongolia from tree-rings“, gives a quick glimpse into the fairly persistent fire regime across central Mongolia over the last 280-450 years.

Four centuries of fire history in central Mongolia: initial results

NPR recently finished a series of reports on the environmental and cultural transitions currently happening in Mongolia as a result of climate change and the massive mining boom underway. The post that caught our attention was the one on “Mongolia’s Dilemma: Who Gets The Water?” Water has been a focus or the Mongolian-American Tree-Ring Project (MATRIP) since the beginning (see MATRIP’s major publications on this subject here, here (get the streamflow data here), here, here). So, we are happy to announce that this rich vein of research has continued with the fire history research grant by first filling an important gap in the MATRIP network and then having several manuscripts on this subject in revision or review.

One paper that we are quite excited about is an analysis of drought variability across Mongolia’s ‘Breadbasket’. We were taken aback in throughout the last three field seasons by the large-scale revitalization of Mongolia’s agricultural sector. It was surprising to see center-pivot irrigation and large tracts of fields in northern Mongolia. This cultural change is intended to transition Mongolia towards agricultural independence for its growing population. Our analysis highlights important differences in drought variation for the eastern and western portions of the breadbasket region. Stay tuned!

Finally, we are headed back to Mongolia this summer to begin pilot work on new research currently funded by the Lamont Climate Center, The National Geographic Society, and West Virginia University. As hinted in our last post, we will begin field work to determine if there was a warmer and wetter climate during the rise of Chinggis Khaan’s Mongol Empire.

Really –  stay tuned!

Categories: TRL

Problems with myUNI, password tools

IT Announcements - Thu, 04/26/2012 - 13:59

Columbia University IT group is investigating intermittent problems with the myUNI services for password changes and resets.  Some users are experiencing long wait times and a <

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Network Maintenance Successful

IT Announcements - Thu, 02/23/2012 - 20:31

CUIT successfully updated network maintenance in Lamont-Doherty on Thursday, February 23rd, from 5:00 PM to 6:00 PM, as previously scheduled/announced. During this network configuration change

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Internet's Primary Link Maintenance

IT Announcements - Wed, 02/22/2012 - 10:09

CUIT Network Operations will be performing maintenance on Lamont's primary link to the downtown Columbia campus (our link to the internet) 5-6 PM this Thursday, February 23.

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LDEO mail outage

IT Announcements - Sun, 02/19/2012 - 04:53

 Most outgoing mail was turned off from Sunday, ~12:30 AM until ~3:31 AM because a compromised account was being used to send spam.

More Rain & More Horses Leads to a Stronger Chinggis? It is a thought!

Bayrbaatar & Amy the day before our fateful discovery

Amy Hessl is featured on National Geographic radio about our team’s discovery of ancient deadwood that suggests the rise of Chinggis Khaan was associated with increased rainfall. Listen to learn more.

an ancient Siberian pine

Categories: TRL

the devil shivered in his sleeping bag

By Neil Pederson

As discussed in the previous post, the first half of the field season would be the scientific highlight of the 2011 field season. While we had highlights later on, in terms of finding new stuff, that was it. We knew that would be a highlight because we had a fairly good idea of what was coming next. To our delight, we would be heading back to the small mountain village called Bugant. This is a delight because the family we stay with on trips to the northwestern Khentii Moutains are exemplary in terms of Mongolian generosity.

We knew that we would immediately not only be served fresh tea and plenty of candies and snacks upon our arrival, we also knew that no matter what time ae arrived we would be served a meal. We arrived at about 9 pm and, sure enough, by 9:45 we were fully into our meal.

As always, it was a fun and spirited meal. All the extended family came to visit with us and each other:

We looked forward to the next day’s field work because we were going to one of the most interesting forests we’ve seen in Mongolia – it was an intact, old-growth forest….

the OG forest at high elevation in the northwestern Khentii Mountains

However, not all scientific fieldwork is full of exploration and discovery like those fueled by sawdust and mosquito wings. Sometimes, quite often actually, scientific research is monotonous. Even in the field. The work ahead, while in beautiful places, was akin to making the doughnuts. We had to go back to areas we had sampled before, install plots and just core whatever trees fall in those plots. There would be no bird-dogging or seeking out great old trees. What fell in our plots, randomly-located so that they best represented the average forest, ended up being our study trees. Ah, we are not complaining. It is just not as thrilling as the hunt. It feels almost industrial – industrial ecology.

We were a bit leery of this forest as well. When we last sampled in 2009, it turned out to be a cold and wet visit. 2011 turned out to be very much the same. In fact, it turned out to be wetter and colder. It definitely had us shivering in our sleeping bags.

We had expected to complete our work in the first day at the site pictured above. But, after a couple passing showers that were fairly heavy for Mongolia, the temperatures dropped quickly and, well, we started getting cold. We were prepared for this, but somehow this day got to us. We really started shivering and making mistakes. When you start making mistakes when you are cold and wet, that is a good sign to call things off. Not much good can come from continuing. What one can expect is potentially bad data, more mistakes and more mistakes that could become dangerous. So, we called it a day and went fishing.

OK, Baljaa went fishing. Specifically, he went wood fishing. It is a method commonly used to gather firewood in areas with little wood. As you can see, Baljaa, despite being a Mongolian cowboy with more than a hundred horses [he’s a good catch, ladies!], struck out. Time to call in the pro:

As you can see, Baatarbileg is still the master!

What did we cook with this wood? Our clothes, of course:

cooking clothes

Actually, the fire and wonderful soup for dinner warmed us up. I do not think the devil actually shivered in his sleeping bag.

The next day turned out to be sunny and we finished off this site. We did get one new discovery: a Mongolian lizard. It got so used to being held, or perhaps it was so hungry from the previous cool, wet day, it itself ‘fished’ for food while being held:


The next day found us heading back to the ‘cement patio’ site. This is a favorite site for us as we had a wonderful Mongolian cookout in 2009. What we had forgotten was how far back we had driven into the Khentii Mountains to find this site.

Talk about monotonous [and desperate…like the beginning of 2011, we were desperate in 2009 to find a goldmine site], we drove 20 km on the road below just to find this site. You can hear below how we had forgotten how far back we drove in 2009.


We hit the slopes as soon as we re-discovered the cement patio; it took about 3 hrs of driving to get to this spot. I had not been up this slope yet as I sampled a different slope in 2009. When Amy said it was steep, I really didn’t know what she meant. As you can see, the slope was nearly a 40% slope:

the footing was tough


While in the midst of conducting this industrial ecology, the sky decided to open up again. However, the storm didn’t seem as serious as the prior day and we hunkered down for about 20 minutes. Sure enough, the storm passed as we completed most of our work at this site.

The views from this site are pretty spectacular.

Bugant forest landscape

Indeed, it is such a special forest that we will have a special post regarding the state and potential future of this part of the Khentii Mountains.

We headed down the mountain back to the patio and found an incredible patch of berries. There were two types of currants and one type of blueberry. It was delicious. In fact, as it was Chuka’s birthday (our other driver in 2009 and 2011), we gathered as much fruit as possible and re-created our 2009 cook out night to celebrate Chuka. It was a fantastic night until yet another thunderstorm crashed the party and sent us scurrying for the tents. All in all, it was a pretty great night.

There is not too much to report for now about this site. It is definitely another old-growth site that Amy has already written about. We saw some amazing specimens for the main conifer species in Bugant and hiked some cool ridges. We saw wolf and bear scat. We were lucky to spend time in that exceptional Mongolian Wilderness. Here are a couple more pictures.

the gang, Bayaraa, Amy and Baljaa, in a wonderful birch forest


Baljaa, proud of his effort and work (as he should be) and happy to be in the Khentii Wilderness


more of that Bugant birch forest - note the wonderful Nars (Scots pine) to the right


Categories: TRL

Celebrating the end of the Antarctic field season

Using Rocks to Decode Antarctic Climate - Thu, 02/17/2011 - 22:18

We decide today is the last day for our camp, and we pack up and drive back to our base camp, the Central Transantarctic Mountain camp (CTAM). A sadness in a way, because it was our cozy home for a week. We ate, slept, and joked around here night after night. Also, we realize that packing up camp represents the end of the field season, except for one more day. For the last day of work we will fly by helicopter to the Achernar area from the CTAM camp.

Moraines at the Lewis Ice Tongue, the location of the last rock surface sampled during the field season

The last day at Mount Achernar. We use the helicopter to go near the southernmost part of the area, near the Lewis ice tongue, which comes off the East Antarctic ice sheet. After a long day, we collect our last samples, and wait for the helo to pick us up – the end of the field work for this season. We realize we had a very successful field season. Not one day of work was lost at either Mt Howe or Mt Achernar (a very rare experience for Antarctica). We think about how we accomplished our goals in terms of getting to both remote sites and collecting samples.

Spontaneous dance performance celebrating the end of the highly sucessful field season

Back at CTAM camp, we scramble to get all our stuff packed up ready to be shipped back to McMurdo. They are closing the CTAM camp for scientific work in a week because they need to take everything down by the middle of February. The middle of February represents the end of the field work for everyone in Antarctica. It starts to get too cold, and the sun starts setting in some areas farther north. People start to go home then and McMurdo gets ready for the winter.

The 'Antarctica's Secrets' team (Mike Roberts, Mike Kaplan, Nicole Bader, Kathy Licht, Tim Flood) getting ready to fly back to McMurdo station

We all fly back to McMurdo. A bed and running toilets (!) for the first time since we left for our camping trips. Also, the dorms have dark curtains that go over the windows. So, darkness, a bed, and a toilet – who would have known life can get so good!

Mike Kaplan (Lamont)

The Twin Otter, ready to fly the team back to McMurdo

Glacial deposits: A clue to reconstructing the history of the Antarctic ice sheet

Using Rocks to Decode Antarctic Climate - Thu, 02/10/2011 - 11:44

We set out on the snowmobiles with all the sleds to Mount Achernar with all our stuff. After about three hours we reach the site (crossing the flagged crevasse zone with no problem). We are joined by a fifth team member, Tim Flood, a Professor at St. Norbert College in Wisconsin. Tim has expertise in petrology or rock composition. So, we will have one additional person for the Achernar part of the trip.

Kathy Licht, Tim Flood and Nicole Bader exploring glacial deposits near Mt Achernar

At first we only find ‘blue ice’ to set up camp. Blue ice gets its name mainly because – in contrast to the typical situation of having a layer of snow on top of the ice sheet – there is only ice. The snow layer that normally covers the top of the ice sheet is blown away where the winds blow pretty fast and consistently. This means there is no good place for camp right in the Achernar area because all the blue ice is a sign of strong winds. We decide to back up a few miles to where the snow starts again and camp a little but away from Mount Achernar. This means we will have a ‘daily commute’ to get to where we want to work, but at least we have a nice place to live for the week. It is less windy where we decide to set up camp and a nice layer of snow in which to pitch the tents and walk around. Blue ice is very difficult to walk on – it is just what it sounds like – walking on ice!

Setting up just another field camp at Mt Achernar

We set up camp. Unlike at Mount Howe, here each person will have their own tent. In addition, we set up the bathroom tent and a huge kitchen tent, named the ‘Arctic oven.’ The arctic oven will act as a kitchen and dining area. It is about 25 feet long, enough to be comfortable. And, when we have two stoves going inside, the temperature gets up to a comfortable 60 degrees or even higher (hence, its name); comfortable enough to start peeling off all our jackets while eating. Two little speakers that Tim picked up in an airport, attached to ipods, means we even have a stereo system in the arctic oven cook tent.

The first day we drive out to where we want to work. It takes about an hour and a half each way by snowmobile. This is quite a bit of time. In addition, the glacier deposits we want to study are much larger in area compared to at our first site at Mount Howe. It is not practical for us to drive everywhere and get to all the places by walking. We realize we will need to utilize the helicopter from nearby CTAM. So, the next week or so we alternate: a “snowmobile day” when we commute by snowmobile from camp to the field site and “helo days”. On the helo days, the helicopter flies out to our camp (a short flight by helicopter from the CTAM camp) picks us up, takes us exactly where we want to go around Mount Achernar, and then at the end of the day, comes back out to bring us back to our camp. All these trips only take the helicopter folks about 75 minutes in total each day, given how fast they go.

Collecting samples from the top of boulders that got left back by the retreating glaciers. At home in the lab at Lamont, we will use a method called 'Surface Exposure Dating' to figure out when the ice sheet left these boulders behind when it retreated.

We spend the next 8 days or so doing the same sort of work as at our first site Mount Howe. We map the glacier deposits (how red or oxidized are they – how do their elevations changes? How do the deposits themselves change in terms of shape and composition and other characteristics?). Mike K and Mike R (with occasional assistance from others) collect samples for the surface exposure dating, so they can eventually figure out how old all the deposits are. Kathy, Nicole and Tim study the composition and types of glacier rocks and sediments left behind.

Similar to our finding at Mt Howe, we find pronounced changes in the glacier moraine deposits around Mt Achernar. This indicates there are likely deposits of different ages, left behind at different times by the ice sheet when it was bigger. All the team members continue to collect samples that will be analyzed later in the lab.

Running water in Antarctica at Mt Achernar

Mike K, Kathy, Mike R, Nicole and Tim



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