Editor’s note: This is a first-person account of ongoing research.
“Last year we had no snow here,” the hotel desk clerk in Anchorage said.
That got my attention, because this is Alaska, after all.
We were collecting our room keys for an overnight stay before our journey’s end, a flight to Utqiaġvik, Alaska, the “top of the world.” The village, which was formerly known as Barrow, is situated along the Arctic’s North Slope that abuts the Chukchi Sea, a part of the Arctic Ocean.
It is the northernmost settlement in the United States. No roads lead here.
Last September, I traveled to this far north outpost as part of a research team from the Scripps Institution of Oceanography, which also included principal investigator and climate atmospheric chemist professor Lynn Russell and Ph.D. student Sourita Saha.
We were headed to the National Oceanic and Atmospheric Administration’s Global Monitoring Laboratory in Utqiaġvik as part of a five-year project to collect atmospheric aerosol data. The measurements will add to the data set previously collected here over some 30 years and include novel measurements as well.
“Aerosols are important because they may cause warming or cooling, either directly by reflecting or absorbing radiation, or indirectly by making clouds,” said Saha.
Utqiaġvik is ideal for aerosol studies, as the Arctic has experienced warming that is around three times faster than in the lower latitudes. The remote location also reduces interference from locally generated human activities.
Part of aerosols’ claim to fame is their ability to promote cooling via cloud formation during summer’s sunny days. To make a cloud, aerosol particles (e.g., salt, dust) must first form cloud seeds, and these must be able to make cloud droplets that culminate in a cloud.
Not all cloud seeds lead to droplets, and not all droplets result in clouds, making this complex process critical to understand. To be clear, the warming effect of greenhouse gases is larger than the cooling effect of aerosols on clouds, but if it was not for aerosols, Earth would be even warmer than it already is.
Another thing: don’t confuse aerosols with greenhouse gases like carbon dioxide, though they both affect the climate. For one thing, aerosols aren’t gases; they are solid, liquid, or a mix of solid and liquid particles. For another, they don’t travel the planet and linger in the atmosphere for years or centuries like gases. Instead, aerosols may remain airborne for less than a week, so their effects are primarily local.
We landed at the airport in Utqiaġvik, population less than 5,000, where it was a brisk 35F degrees. Locals like to say that Utqiaġvik has two seasons: ice and mud; we were here for the latter. After navigating mud and puddles to access our ready-for-all-Arctic-conditions pickup truck, we headed to the Alaska Commercial Company for provisions.
Prices were breathtaking. A cylinder of Old-fashioned Quaker Oats was $19.69, a small bottle of Kraft Grated Parmesan Cheese was on sale for $12.06, and a single avocado was $6.69. What a deal!
Shopping finished, we drove to our rental home to unpack for the week.
Utqiaġvik’s unique and seemingly stark tundra environment may have no trees, but it is well landscaped by low-lying plants. The limited land mass, perched barely above sea level, meanders around several lagoons and is made up of permafrost, a frozen layer consisting of soil, gravel, and sand bound together by ice.
For this reason, there are no paved sidewalks or roads, and most structures are built on stilts. By keeping buildings elevated, cold air can circulate underneath so that a building’s heat doesn’t thaw the permafrost. This hasn’t stopped the permafrost from premature melting due to relentless climate warming.
The next morning, I drove the team to the lab where they set up equipment for aerosol calibrations. I planned to head into town to learn firsthand from long-time locals how their lives have been affected by the changing climate. Before taking my leave, I checked out the experimental setup.
Aerosols are collected through a chimney-like inlet that draws Arctic air into an apparatus with three lines: Two lines trap microscopic aerosol particles (e.g., salt, sulfate, dust) onto Teflon filters. One line takes the particles into two instruments, with one determining different particle sizes and the number of particles at each size, and one counting the number of particles forming cloud seeds (technically called cloud condensation nuclei) that condense to cloud droplets. Filters are changed on a schedule; spent filters are frozen, then shipped to Russell’s lab at SIO for analysis.
I climbed back in the truck and headed to the shoreline off Stevenson Street, where serious flooding from high water washed out an adjacent road and destroyed some homes. Navigating down the shallow, artificial bluff, I crunched over rough, dark-gra,y gravelly sand, so different from the fine-grained and fair-colored sand beaches in San Diego. It’s not hard to see the problem, as there is almost no beach here.
Looking to the horizon, I don’t see a single chunk of ice. It used to be that even in summer, it wasn’t unusual to see ice floes bobbing close to or along the coastline. Now ice is hundreds of miles offshore. With no ice to stop wind-waves from forming, and with ice forming later in the year, storms strike the shore with much greater impact, driving the ocean further inland. A seawall is in the works, but only in downtown Utqiaġvik. Realistically, the project is just kicking the can down the road.
The locals were kind and friendly and always had time for a chat. At Liliana’s Fresh Baked, I bought some coconut macaroons (recommended) and spoke with owner Liliana Penuelas, who told us she originally arrived in what was then called Barrow 35 years before, in 1990, from Cuba, to work at the Naval Arctic Research Station.
“At that time, my husband and I lived at Barrow Point. We would walk 100 yards from the road to the ocean,” she said.
“Over time, storms kept pushing the water closer and closer. We were finally forced to move closer to town eight years ago, before the ocean took our house. About five to six years ago, we saw that the ocean was now nearly up against Stevenson Street. It’s not safe to drive there.
“No one lives at Barrow Point anymore.”
Looking toward the horizon, the line separating sea from sky was knife-sharp. Being here at the end of an aerosol summer, the air is at its cleanest both because of the season’s favorable atmospheric circulation pattern and rains washing particle pollutants out of the atmosphere.
Summer air still carries aerosols, but mostly from natural sources like sea spray and marine life emissions. Sea spray aerosols are generated by winds driving saltwater particles to the surface. As retreating ice exposes more open water to the atmosphere, more aerosols can form.
Historical data shows that sea spray droplet sizes have increased, while their numbers have decreased. Russell and Saha aim to suss out the relationship between warming ocean temperature, wind speed, and sea spray aerosol formation.
Accruing this knowledge is central to understanding the ways aerosols contribute to making cloud seeds that are brighter and reflect more sunlight into space (called the albedo effect) and, so, promote cooling.
Concentrations of one-celled algae called phytoplankton are also ramping up as more ice-free ocean translates to more photosynthesis due to more direct sunlight striking more sea surface. One influential waste product from photosynthesis is dimethyl sulfide, or DMS.
DMS breaks down and recombines to make sulfate particles, which are released into the air. During summer, clouds made from sulfate seeds result in cooling by reflecting sunlight into the atmosphere (as opposed to winter, when there is little to no sunlight, so clouds instead result in warming).
To what extent phytoplankton’s expanding sulfate contributions may be significant in cloud making is of interest to Russell and Saha. They will identify sulfates produced specifically from phytoplankton emissions and compare their concentrations to those of other sulfate sources previously identified in the historical data.
In the meantime, residents continue to adapt to the changes around them. Even insects are making themselves stand out.
Resident Brian Person shared one striking marker of climate change.
“I remember in 2007, the first BBQ we had of the summer,” he said. “Swarms of mosquitoes that breed inland joined us. Then, the next day, winds typically blow them away, so annually we had one to two days of intense mosquitoes, then none. Within five years, and trending beginning mid-2010, because of warming, we’ve had mosquito swarms for an entire week.”
On that itchy note, I look forward to what Russell and Saha learn regarding predictions on what magic mix of aerosol characteristics leads to cloud making.
“Aerosols have unknown and unquantified impacts on clouds and, consequently, the Arctic,” said Russell. “We need to understand more about what they are and where they are.”
Saha added, “Understanding more about aerosols will improve climate models and help better prepare us to address and adjust to the effects of climate change now and in the years ahead.”
The next article will focus on winter’s unique blend of human-made and transported aerosol pollution, along with natural aerosols, and the ensuing clouds that form during this season.
(Although largely underreported to the public, aerosols are the elephant in the room because they are responsible for instigating clouds, and clouds are the most uncertain part of our understanding of climate. Distinct seasonal changes in aerosols during summer (July-October), winter (November-March), and spring (April-June) reflect each’s influence on cloud making. This article focuses on summer aerosols.)