Rising mountains dried out Central Asia

Something has come of those two summers spent bouncing around Mongolia in Russian vans! Work led by my fellow grad student and travel companion Jeremy Caves has been presented, submitted for publication, and picked up by a few science news aggregators. This piece, written by Stanford's earth science writer Ker Than, puts some of our findings into English...-----------------------------------------------------------------------------------------------------------------------------Rising mountains dried out Central AsiaA record of ancient rainfall teased from long-buried sediments in Mongolia is challenging the popular idea that the arid conditions prevalent in Central Asia today were caused by the ancient uplift of the Himalayas and the Tibetan Plateau.Instead, Stanford scientists say the formation of two lesser mountain ranges, the Hangay and the Altai, may have been the dominant drivers of climate in the region, leading to the expansion of Asia's largest desert, the Gobi. The findings will be presented on Thursday, Dec. 12, at the annual meeting of the American Geophysical Union (AGU) in San Francisco."These results have major implications for understanding the dominant factors behind modern-day Central Asia's extremely arid climate and the role of mountain ranges in altering regional climate," said Page Chamberlain, a professor of environmental Earth system science at Stanford.Scientists previously thought that the formation of the Himalayan mountain range and the Tibetan plateau around 45 million years ago shaped Asia's driest environments."The traditional explanation has been that the uplift of the Himalayas blocked air from the Indian Ocean from reaching central Asia," said Jeremy Caves, a doctoral student in Chamberlain's terrestrial paleoclimate research group who was involved in the study.This process was thought to have created a distinct rain shadow that led to wetter climates in India and Nepal and drier climates in Central Asia. Similarly, the elevation of the Tibetan Plateau was thought to have triggered an atmospheric process called subsidence, in which a mass of air heated by a high elevation slowly sinks into Central Asia."The falling air suppresses convective systems such as thunderstorms, and the result is you get really dry environments," Caves said.This long-accepted model of how Central Asia's arid environments were created mostly ignores, however, the existence of the Altai and Hangay, two northern mountain ranges.Searching for answersTo investigate the effects of the smaller ranges on the regional climate, Caves and his colleagues from Stanford and Rocky Mountain College in Montana traveled to Mongolia in 2011 and 2012 and collected samples of ancient soil, as well as stream and lake sediments from remote sites in the central, southwestern and western parts of the country.The team carefully chose its sites by scouring the scientific literature for studies of the region conducted by pioneering researchers in past decades."A lot of the papers were by Polish and Russian scientists who went there to look for dinosaur fossils," said Hari Mix, a doctoral student at Stanford who also participated in the research. "Indeed, at many of the sites we visited, there were dinosaur fossils just lying around."The earlier researchers recorded the ages and locations of the rocks they excavated as part of their own investigations; Caves and his team used those age estimates to select the most promising sites for their own study.At each site, the team bagged sediment samples that were later analyzed to determine their carbon isotope content. The relative level of carbon isotopes present in a soil sample is related to the productivity of plants growing in the soil, which is itself dependent on the annual rainfall. Thus, by measuring carbon isotope amounts from different sediment samples of different ages, the team was able to reconstruct past precipitation levels.An ancient wet periodThe new data suggest that rainfall in central and southwestern Mongolia had decreased by 50 to 90 percent in the last several tens of million of years."Right now, precipitation in Mongolia is about 5 inches annually," Caves said. "To explain our data, rainfall had to decrease from 10 inches a year or more to its current value over the last 10 to 30 million years."That means that much of Mongolia and Central Asia were still relatively wet even after the formation of the Himalayas and the Tibetan Plateau 45 million years ago. The data show that it wasn't until about 30 million years ago, when the Hangay Mountains first formed, that rainfall started to decrease. The region began drying out even faster about 5 million to 10 million years ago, when the Altai Mountains began to rise.The scientists hypothesize that once they formed, the Hangay and Altai ranges created rain shadows of their own that blocked moisture from entering Central Asia."As a result, the northern and western sides of these ranges are wet, while the southern and eastern sides are dry," Caves said.The team is not discounting the effect of the Himalayas and the Tibetan Plateau entirely, because portions of the Gobi Desert likely already existed before the Hangay or Altai began forming."What these smaller mountains did was expand the Gobi north and west into Mongolia," Caves said.The uplift of the Hangay and Altai may have had other, more far-reaching implications as well, Caves said. For example, westerly winds in Asia slam up against the Altai today, creating strong cyclonic winds in the process. Under the right conditions, the cyclones pick up large amounts of dust as they snake across the Gobi Desert. That dust can be lofted across the Pacific Ocean and even reach California, where it serves as microscopic seeds for developing raindrops.The origins of these cyclonic winds, as well as substantial dust storms in China today, may correlate with uplift of the Altai, Caves said. His team plans to return to Mongolia and Kazakhstan next summer to collect more samples and to use climate models to test whether the Altai are responsible for the start of the large dust storms."If the Altai are a key part of regulating Central Asia's climate, we can go and look for evidence of it in the past," Caves said.

Lhotse: Full photos and video

Hey everyone,Thanks for following along this spring! I've finally had a chance to get through all of my images. Here's a look back at the best of Nepal:Best of Lhotse  [embed width="420" height="315"]http://www.youtube.com/watch?v=K3sFlAaw5EA[/embed]

Getting dressed for an 8000er

[embed width="420" height="315"]http://www.youtube.com/watch?v=2F2WeQZ1Nng[/embed]

Big Up: Announcing the Everest-Lhotse Research Expedition

 "I am nothing more than a single narrow gasping lung, floating over the mists and summits"  -Reinhold Messner on the first ascent of Everest without supplemental oxygen

When did it all start? Thinking back, it's hard to pinpoint a specific moment. I've definitely had defining moments hiking in the Canadian Rockies and certainly on Colorado's Longs Peak, but I sense the idea had a more subtle beginning. As early as age five, the cover of our family's copy of the world almanac started to develop a visible crease. I would repeatedly flip to the same page and scan the list of the world's highest mountains, memorizing and typing spreadsheets of the 14 peaks that reach over 8000m. I drew maps of Asia, annotated with locations of great peaks in Nepal, Pakistan and Sichuan.So when I sat down with a group of researchers with a group of researchers interested in conducting a study on decision making on 8000m peaks this spring, I didn't exactly need to do any background research. When the conversation turned to the subject of me getting support to climb and collect vital data, I had to ask repeatedly ask the obvious, "You want me to go climbing?!?"I always told myself that if I was offered the chance to climb a really big peak, I'd take it. Well, it wasn't so simple. First, I had to clear some initial hurdles: "You need to think about your priorities." My advisor wasn't trying to limit me, but rather to make sure I'd considered that there's an opportunity cost in every decision we make. Then came the talk with my parents, who have had to bear the unfair emotional burden of my climbing. I get to experience all the adventure, challenge, and connection with the natural world, all while leaving cryptic messages about stomach illness and whiteouts in my wake. After my accident last summer, I considered dropping big expeditions altogether for my family's sake.Then things turned to the reality of the trip and the complicated set of office tasks it takes to pull off a major expedition. This fall, I've taken on this side project...a part time job of sorts. I've been working tirelessly writing grants, discussing details with expedition organizers, equipment manufacturers and the like, all for a shot at a big peak. I ended up convincing the research team that climbing the West Face of Lhotse, the world's 4th highest mountain, without supplemental oxygen was the objective that spoke to me most while meeting team needs. The style and objectives of this expedition align with my interests in a way that I can put my full effort into making sure that we succeed on a number of levels. Lots more on that later. So...what are we actually doing?Extreme Environments, Everyday DecisionsThis expedition will produce the most comprehensive study of what it takes to climb the world’s highest peaks and the organizational framework necessary to return from them safely. Our research is led by Associate Professor Markus Hällgren, whose Extreme Environments – Everyday Decisions (www.tripleED.com) group examines how organizations operate in settings where the wrong decision endangers lives (he's also working on emergency rooms). The increasingly commercialized nature of high altitude mountaineering provides an excellent laboratory to examine the challenges of upholding safety in the face of changing conditions. Previous studies of decision-making at high altitudes have focused almost exclusively on disasters, while everyday organizational behavior has been largely ignored. We feel that this research will be of great value, not only to the mountaineering community but to the greater pubic, as many parallels exist between expeditions and team projects of all kinds.So I'll be part of a team of researchers documenting the entire course of an Everest expedition, starting with the preparation we've begun months ago until well after we head home in June. Several researchers will trek to base camp and conduct ethnographic interviews of climbers, expedition leaders, Sherpas and doctors. In addition, we will collect other qualitative data such as photos, video of team meetings, recording radio communications, etc. I'll be in charge of data collection on the upper mountain. While I'll be personally attempting Lhotse, I will be interviewing Everest climbers on the upper mountain, recording climbing and impromptu decisions with a helmet camera, taking field notes and research photos from some of the highest altitudes on the planet. I will also continue my work with Adventurers and Scientists for Conservation, and I'll include several climate change research projects to the expedition as well. If you want to see more about this, my work with ASC last summer was recently profiled by Outside.Stay tuned for lots more on this spring!Hari

Himalaya Trip Report Added

My first expedition climb was a trip to Nepal in 2010. The climbing itself ended up being a pretty small portion of the three week trip, but my first trip to Asia was filled with adventure from start to finish. Some highlights from one of the world's magical places are here.

Welcome to the Blog!

Hey everyone, I’m Hari and welcome to my blog. Here you’ll find posts ranging from trip reports, photos and video to thoughts on my style, technique and spirit of adventure in the high alpine. The blog will also feature live coverage from my expeditions, including summer 2012’s monster trip to Asia for paleoclimate research in Mongolia followed by a triple-header expedition to the three highest peaks in the Pamir of central Asia!