A Race to the North

As Alaskan permafrost rapidly melts, Chemistry Professor J. Houston Miller and his students are designing new technology and preparing for an excursion to the ground zero of global warming.

J. Houston Miller and graduate student Michelle Bailey
J. Houston Miller and graduate student Michelle Bailey are designing laser sensors that will measure greenhouse gas concentrations in Alaska.
January 14, 2015

By John DiConsiglio

Summer in Fairbanks, Alaska, is far from the frozen landscape many imagine. The sun shines almost around the clock, the trees and grass are green and vacationers worry more about swarms of mosquitoes than blocks of ice. But here, amid thick spruce forests and layers of moss, is a region scientists are calling a climate time bomb—and ground zero for global warming.

“This is the center of climate change,” said Chemistry Professor J. Houston Miller. “It’s where everyone in the climate community is turning their attention.”

That’s because just below the mossy surface lies a layer of frozen earth known as permafrost. And while some of this icy rock, soil and peat has persisted for more than 10,000 years ago—since the last Ice Age—it is now melting rapidly. The thawing permafrost is releasing massive amounts of greenhouse gases into the air and, climate scientists contend, exacerbating global warming.

“Most people are aware of rising sea levels and temperature changes, but they don’t know about permafrost,” Miller said. “This is the big one. This is the one that really counts.”

This summer, Miller and a pair of graduate students will travel to the Alaskan hot spot on a mission to measure the effects of permafrost thaw—before it’s too late. Their work is part of a multifaceted project funded by a $980,000 grant from NASA's Terrestrial Hydrology Program. Other research partners include the NASA Goddard Space Flight Center and the University of Alaska, Fairbanks.

Miller's role is to take ground-level measurements of greenhouse gas concentrations during the summer melting season. Building on his 20 years of experience with sensors and lasers, he is devising a tool that will perform open-path, laser absorption measurements of damaging gas levels. From the Fairbanks field site, Miller hopes to collect ultra-precise measurements that can validate NASA’s satellite readings. It’s the first step in defining a long-term measurement strategy and establishing a protocol for permafrost-related climate modeling.

A Broken Cycle

Permafrost—perennially frozen ground that remains at or below zero degrees Celsius for two or more years—has existed for eons. During the last Ice Age, it swept as far south as Missouri and Illinois. Today, it covers 24 percent of exposed land in the high latitudes of the Northern Hemisphere. In the Southern Hemisphere, it reaches into Antarctica and the Patagonian region of Argentina and Chile. The U.S. accounts for 6 percent of the world’s total, almost all of which lies in Alaska.

Permafrost is known as a “carbon-sink,” its rich soil storing organic material from decaying plants and animals. There may be as much as 1,000 billion metric tons of carbon in the permafrost ground, more than double the amount currently in the atmosphere. Permafrost can be up to 5,000 feet thick, but it is the top “active” layer, which is just 30 to 100 centimeters deep, that most concerns climate watchers. The top layer thaws and refreezes each year; during the melting season, carbon—mostly in the form of carbon dioxide and the particularly damaging methane—is released into the air.

But that thaw-and-refreeze cycle is being thrown off-balance, Miller said. Alaska's temperatures are rising twice as fast as the rest of North America’s. Fairbanks’ ground temperatures now hover near the thaw point, resulting in more rapid permafrost melt and more greenhouse gases spewed into the atmosphere.

Although it is only within the last 10 years that scientists have recognized the dangers of accelerated thawing, current climate models paint a dreary picture. Some experts predict enough irreversible carbon emissions damage to radically alter the planet’s ecosystem by 2100. “We are looking at some frightening scenarios,” Miller said.

Most permafrost models rely on satellite projections that, while remarkably detailed, also present limitations. Cloud cover can obscure readings, and data can only be collected when the satellites are overhead—resulting in measurements that could be days, weeks or even months apart. Most disconcerting, satellite images are taken from as high as 50 kilometers, or about 30 miles away. Miller’s ground-level measurements should provide more precise readings to compliment his NASA partner's satellite shots.

“Our measurements on their own won’t be worth very much,” he explained. “The value will be in validating the satellite measurements, and creating a clear and consistent model.”

Racing the Clock

Time isn’t on Miller’s side. He and his team must reach the Fairbanks site by June, when the relatively hospitable summer weather allows for optimal measuring conditions. But once the project strategy was finalized, Miller was left with just eight months to design and test his instruments as well as prepare for month-long field research—a process that, he estimated, should take as long as 18 months.

“The pressure of racing the clock is definitely motivating,” said Michelle Bailey, a second-year chemistry graduate student working on the project. “This is impactful research that will contribute to the bigger [global warming] picture. An opportunity like this is worth all the hard work.”

Sacrificing nights and weekend, Miller and his students are constructing a device that uses laser sensors to measure gas concentrations. Then, through fiber optic technology, the sensors transfer their data to nearby computers, all while the team monitors the experiment from a mobile location.

Miller’s latest prototype may not look like much; his laser is mounted atop a store-bought telescope tripod and attached to a “spaghetti mess,” he said, of optical fibers, wires and electrical components. But he’s confident that the final product will mark the first step in correlating vital climate data. Even after the team returns to campus in July, Miller anticipates refining his instruments for continued Arctic excursions. “I’ve been doing this type of work a long time, so I know the technology is solid,” he said. “We will make it [to Alaska] in time and we will get a measurement. The issue is: How precise will it be, and how can we continue to make it more and more precise?”

Meanwhile, Miller and his students are preparing for the realities of field-work in Alaska, designing protective canopies to shield their lasers from winds and invading mosquitoes. They are even moose-proofing their tripod to guard against curious herds.

“We have to anticipate everything we could possibly need when we are out in the field,” he said. “If a moose knocks over our laser in the middle of a spruce forest, we can’t run to Loews for replacement parts. We’ll be ready for anything—elk, moose, even bears.”