Relaxing on the bow of the ship brings a fresh breeze, plenty of sunshine, and a fine mist from the waves. When the waves on the open ocean break, small droplets of salt, water and biological material are lofted into the air. These droplets are transported vertically by the wind and may become seed particles for clouds or drift over continents. We call these droplets aerosols.

Waves breaking on the side of the ship create small droplets of salt, water and biological material called aerosols. Photo by Lauren Frisch.

Aerosol particles, depending on their size and likelihood to be absorbed by a cloud, can travel globally to impact foreign regions of the Earth. Some parts of the Amazon are fertilized by African desert dust, and wildfires in Canada generate soot that’s easily detected in Europe. All kinds of particles make it into the atmosphere, from organic bacteria to solid quartz. Volcanoes contribute significant amounts of sulfur and glass to the atmosphere. Particles that transport globally are usually in the 10s to 100s of nanometers range, which means they’re too small to see with the eye. However, they can still scatter ultraviolet light and small amounts of visible light, which has an effect on the radiation balance of the atmosphere.

Aboard the R/V Sikuliaq, I’m attempting to measure how much sea spray aerosol is generated by wave activity. This involves walking around the deck and waving my aerosol spectrometer in the air. It counts and measures the sizes of particles, because number and size are relatively easy quantities to measure. With this knowledge, we can make some good guesses about where the particles will go, and how much light it will scatter from the sun.

Joseph Niehaus uses a spectrometer to measure the number and size of aerosol particles. Photo by Lauren Frisch.

The size and amount of aerosol in the atmosphere may also affect human health. Lots of glassy particles can be scarring to lungs, and significant amounts of micron-sized aerosol causes the condition known as Black Lung. Because of this, the Environmental Protection Agency (EPA) regulates the concentration of aerosol particles (PM10 and PM2.5) that are safe in the atmosphere. PM2.5 is the particulate matter larger than 2.5 micrometers, about the size of flour dust. PM10 is the particulate matter larger than 10 micrometers. For reference, a strand of hair is about 100 micrometers wide. Typically, you would not notice breathing in PM2.5, but inhaling PM10 can make you cough. Thankfully the air out here is very clean, with virtually no particles larger than 5 micrometers.

Back in the lab, we have a mesocosm tank to test the amount of aerosol spray being produced by waves in the Pacific. The mesocosm is basically an aquarium with attachments that we fill with artificial seawater. We can generate aerosols with a waterfall which causes bubble bursting. The amount and type is very similar to ocean waves breaking, where trapped air generates bubbles which rise to the surface and burst. Using the same instruments on the voyage, we’re hoping to close the circle on how sea spray enters the atmosphere, altering weather patterns and climate conditions across all continents.

With his remarkable beard, positive attitude and colorful shirts, Bern McKiernan is a pleasure to sail with on the R/V Sikuliaq.

Bern has been working as a marine technician on the R/V Sikuliaq since operations started in 2014. A marine technician is the liaison between the ship’s crew and the scientists. He is responsible for facilitating the science party’s needs based on the ship capabilities. Bern makes sure the scientists can access the Sikuliaq network, data and instruments while out at sea. His familiarity with the ship and the crew is extremely helpful for the scientists on board.

Bern McKiernan, a marine technician for the R/V Sikuliaq, is hard at work on an icy day. Photo courtesy of Bern McKiernan.

Before working on the Sikuliaq, Bern spent a total of 12 years working for Columbia University. The last 6 of those years he spent working as a marine technician on the R/V Marcus Langseth, a research vessel operated by Columbia. The similarity between equipment on the Marcus Langseth and the Sikuliaq, as well as the opportunity to work on a brand new ship, made the opening with Sikuliaq very appealing.

Unlike Bern’s previous ship, the Sikuliaq is ice capable, so the ship is best at conducting scientific research in cold weather regions. Bern explained that working in a cold weather environment can be challenging.

One of the largest differences between working in the open ocean and in areas with ice is the sea state. Unlike the open ocean, areas with ice are relatively calm due to the dampening effect of the ice cover. As the ship approaches iced covered areas, waves are not able to grow so the sea state becomes calmer. Bern describes sailing in ice-covered regions “like riding on a train”, which is smoother than the open ocean.

Despite the usually calmer sailing, working at higher latitudes presents unique obstacles related to the cold temperatures. For scientists and the crew, the cold brings higher personal risk and requires proper clothing when working outside. Likewise, the instruments also face a risk of getting too cold and even freezing when working in the ice. Sometimes sea ice can close over the deployed underwater instruments. Deploying instruments on the ice is even more hazardous and great safety precautions need to be taken.

In addition to working in Alaska, Bern has sailed to several exotic locations including Tahiti, Easter Island and Antarctica over the past 25 years (working for the Navy and on research vessels). While out at sea, he has seen a fair amount of sea life including Mola mola, killer whales, sharks, and flying fish. Although he has traveled to many places, he finds some of the most picturesque locations to be near his home port in Alaska. In particular, he described sailing by the Alaska coast as “just beautiful”.

Bern was hired before the ship was launched, and is a plank owner of the ship. This means he will get a physical piece of the ship once it is retired. This honor is only granted to the original crew of a ship.