Author: Emma Shipley

Investigating the Role of Sea Spray in Gas Exchange

When considering the oceans’ role in climate change, many people focus on the capability of the oceans to store gases from the atmosphere. However, the transfer of gases between the atmosphere and the ocean is actually a complex process facilitated by multiple mechanisms, including sea spray. Sea spray moves matter and energy between the surface ocean and the atmosphere, and its contribution to gas exchange is not yet fully understood by researchers. Strongly linked to wind conditions, sea spray is predicted to increase as long-term climate trends increase wind speeds, particularly in extreme conditions such as hurricanes. Improving the modeling of gas exchange in these scenarios can help inform climate predictions of the future.

In a recent publication, former graduate student Allison Staniec, Professor Penny Vlahos and Emeritus Professor Edward C. Monahan modeled the sea spray gas exchange of non-reactive gases including argon, helium, neon, nitrogen, and oxygen. The goal of the project was to understand the magnitude of flux of these gases between the ocean and the atmosphere via sea spray. Staniec explained the motivation for the work, “There’s been a lot of exploration about how sea spray can carry things like heat and momentum. People have started looking at how it can carry organic compounds. There hasn’t been a ton of work on gases, and part of that is because it’s really difficult to measure in situ or in the laboratory. We wanted to do a proof of concept of whether this spray-mediated gas exchange could theoretically contribute to overall gas exchange.” 

There are several challenges to creating a sea spray model. First, there are many different calculated sea spray generation fluxes from previous work to choose between. Staniec explains that the Anguelova number flux was chosen because it fell right in the middle of the many literature values, but that the range of orders of magnitude of sea spray droplet generation can further complicate calculations. In addition, sea spray droplets have two stages after creation, in the first they cool after separating from the ocean surface and in the second they shrink and evaporate. However, not all droplets have the same fate. Some cool but fall back to the surface before beginning to evaporate, some evaporate entirely, and many fall somewhere in between. Since the studied gases are more soluble at lower temperatures, droplets that cool but then drop back into the ocean transfer gas into the ocean, but droplets that cool and evaporate completely transfer gas into the atmosphere. 

The typical evolution of a sea-spray droplet on injection into the atmosphere. G represents a gas molecule; T, the temperature; R, the radius; white dots represent the salt ions in solution. (Staniec et al. 2021)

After carefully considering how to represent all these factors in their model, the group determined that for gases like He and Ne, sea spray will not have much effect even at high wind speeds. However, for gases like O2, sea spray could have a significant impact on gas flux between the ocean and the atmosphere, particularly at high wind speeds. While this paper doesn’t focus on gases that are relevant to climate change, future models can expand the understanding of gas flux to more complicated and climate-relevant gases, such as CO2. Staniec explains, “We didn’t do specifically climate change relevant gases because CO2 is complicated by the fact that it reacts when it enters the water. But this is a stepping stone for that.” More investigation is needed to understand sea spray mediated gas exchange, particularly in areas of high wind speed such as the Southern Ocean, which is known for high winds and carbon sequestration. Future studies can use the findings and relevant code presented in Staniec’s work to further constrain gas exchange in these regions. 

The percentage change in gas volume (oxygen) of a 100-µm-radius droplet reaching final equilibration, with both steps combined. Darker colors represent regions that will experience higher impacts of gas exchange. (Staniec et al. 2021)

Citation: Staniec, A., Vlahos, P. & Monahan, E.C. The role of sea spray in atmosphere–ocean gas exchange. Nat. Geosci. 14, 593–598 (2021).

Where are they now? Meet Yan Jia

Dr. Yan Jia is a recent graduate of the Marine Sciences Department – he finished his PhD with Prof. Mike Whitney in 2019. His graduate research used drifters and models to understand the seasonal variation of freshwater discharge from the Connecticut River into Long Island Sound. Yan is currently working as a postdoctoral research associate for the Connecticut Institute for Resilience and Climate Adaptation (CIRCA). In his free time, he likes to collect matchbox cars and spend time with his family and his three children. This interview was carried out by Emma Shipley on October 12, 2021.

Yan Jia (Photo: CIRCA)

Q: How did you end up in your current position, and what do you do now?

When I worked as a PhD student, I didn’t pay too much attention to my future work. I knew I wanted to do research, but I didn’t try to apply to that many places, maybe 7 or 8 institutions. Sometimes you get denied, and you have to learn not to take it personally. Sometimes it’s just the job market, or the time window for the position doesn’t line up with your graduation and they are urgently looking for someone to fill the position. Eventually, Jim (Prof. James O’Donnell, UConn) offered this position to me. He was looking for postdocs.

Right now, CIRCA has two postdocs, me and my colleague Chang (Chang Liu, postdoctoral research associate, CIRCA). We are running more realistic studies on how to react to climate change and climate change’s impacts on the local area. We established a 100-year return period chart about how strong the storm surge and highest waves will be. We also run simulations more locally, specifically around New Haven harbor and neighboring coastal towns. One of the projects I finished earlier this year was about salt marsh flooding in Guilford. There is a small inlet with a width of only 8 meters, but it controls the water exchange of a 120-acre salt marsh. The local residents want to build a bridge over an old route that goes across the salt marsh; because of the sea level rising there has been more frequent flooding. It may cost millions of dollars, so they want to know what the flooding conditions are like. We run model simulations, but we also want to know if the results are reasonable. Normally people just run one numerical model, like ROMS (the Regional Ocean Modeling System), but what I did was compare four different hydrodynamic models. We can see why each model is different from the rest and which one is better to be applied in Guilford, and that will help future coastal modeling. Also, we simplified those hydrodynamic models to an idealized mathematical model that can predict the water levels inside the salt marsh much, much quicker. This idealized model is 1000x faster than the original hydrodynamic model and can be easily used by other non-modelers.

Q: It sounds like most of what you do on a day-to-day basis is work on models?

Yes, generally I help supply the scientific results for management and decision making.

Q: What does typical modeling work look like for you?

Since the summer, I have been working on adding wave forecast to an established operational model. It supplies surface current information for the Coast Guard in case they need to rescue a boat or a person in the Sound. Jim and his team have been collecting buoy-observed wave data for over 15 years. It’s one of the longest wave records in a US estuary. We can run hindcast simulations with the historical observations to tune the wave model and find a good set of parameters to support the operational forecast. 

As an aside, Yan shared with me a joke about his work:

In Chinese, ‘physical oceanographer’ has a similar pronunciation as the words meaning “an oceanographer who sits inside the room,” so that’s my job. I just sit inside the room. Very occasionally, I am sent to the field. I think field observations are very necessary. Last spring, I spent several months trying to improve the Guilford simulation, but it wouldn’t give the right answer. So, in the summer, I decided that we needed to have a field trip. When I saw the inlet, I realized it was totally different from what the model was trying to predict. That was the starting point to drag me back to the right place. So, I shouldn’t stay in the room all the time!

Yan uses a side-looking ADCP to measure the inflows at a Guilford salt marsh inlet (Photo: Kay Howard-Strobel)

Q: What about your grad school experience at UConn prepared you the best for this job?

I worked with Mike and got more familiar with ROMS, which laid the foundation for what I do now. Mike and Jim allowed me freedom, they did not regulate me in certain directions, they allowed me to use my wisdom to decide what direction or question I thought was good to pursue, and they always gave good advice. When I worked with Mike, he encouraged me to learn more simulations not just on the ocean side, but also on the atmospheric side. That helped my work with Jim because to make a good simulation of storm surge, you have to have a good simulation of wind.

Q: Do you have any advice for current students?

One of the good courses I learned from was Jim O’Donnell’s mathematical modeling course. I took that course twice. You can bring your own question and get his advice on the direction you should take. My classmates and I all learned a lot from his lecture. And of course, everyone knows to read a lot of papers.

Quarantine Cruising: Oceanographic Cruises During COVID

In early May of 2021, two faculty members and four students from our department set out for an Arctic research cruise. Led by faculty member Prof. Rob Mason, the group spent two weeks quarantining on the remote island of Unalaska in the Aleutian chain before departing on a three-week oceanographic cruise.

The Arctic, defined as the region of the Earth within the Arctic Circle located at approximately 66° 34’ N, contains several seas and parts of the United States, Canada, Scandinavia, Iceland, Greenland, and Sweden. The region is unique, with cold temperatures, varying snow and ice cover, and seasonal sea ice. Prevailing water and air currents facilitate the transport of many long-range pollutants to the Arctic, and the region is heavily impacted by climate change. Global warming has caused the loss of annual and seasonal sea ice cover, increased river discharge, and thawing of permafrost. Many climate models predict greater warming in the Arctic than the global average, compounding the effects of these changes. One of the most effective ways to gather data about these ecosystems is through oceanographic cruises.

Multi-week cruises are the backbone of much research in the oceanographic field. The occurrence of these cruises can often be reduced to a few sentences in the methods section, but the execution requires years of work prior to departure. Planning for this trip began in 2017, when Prof. Mason first submitted a proposal to the National Science Foundation (NSF) along with co-investigator Dr. Dave Kadko of Florida International University. He requested funding for a cruise to the Arctic to examine the role of ice in controlling mercury levels in seawater. 

While the RV Sikuliaq, operated by the University of Alaska Fairbanks, can typically host 20 scientists, due to the COVID-19 pandemic, the cruise was limited to 10. COVID-19 required other changes to the typical cruise experience, too. Everyone on the ship had to undergo a two-week quarantine and two COVID-19 tests prior to boarding. The UConn science party quarantined in Unalaska, Alaska, commonly known as Dutch Harbor. During the quarantine, the group hiked to several different sites on the island, including two sites of WWII bunkers and two different mountains. 

The UConn crew hikes Mt. Ballyhoo in Dutch Harbor. From left to right: Lauren Barrett, Emma Shipley, Penny Vlahos, Hannah Inman, Yipeng He, Rob Mason. (Photo: Yipeng He)
The view from the 03 deck of the Sikuliaq where continuous air sampling instruments were located. During the summer, the sun never sets in the Arctic, but dips close to the horizon before beginning to rise again. This photo was taken near midnight. (Photo: Emma Shipley)

After boarding the ship, the group settled in for three weeks of data collection. To meet research objectives, UConn’s team collected air, water, snow, and ice samples. One unique aspect of cruises to the Arctic is the ability to collect samples from sea ice. During this cruise effort, the science party sampled at 5 different ice stations within the marginal ice zone, the region of seasonal sea ice surrounding annual ice. Sampling on sea ice is a carefully orchestrated process. The ship’s captain and crew meticulously select a section of ice that looks large and stable enough to support several members of the science party. Scientists are briefed on the safe places to walk on the ice, and the Science Operations crew members test the ice before allowing the science party to sample. Equipment and people are typically transported between the ship and the ice using a “man-basket,” or a cage attached to a winch. While on the ice, the science party uses ice-corers to collect ice cores, large augur drills to create holes for collecting ice brine and under-ice water, and shovels for snow. The Arctic environment can be harsh and dangerous, and a team of crew and scientists work as look-outs on the bridge for any potential threats, such as roaming polar bears. In fact, the UConn team saw four different polar bears while on the cruise, three of which were visible while ice sampling was taking place. Seeing polar bears in the wild is a truly unique experience, and observing these animals in their natural habitat was commonly mentioned by the science party as one of their favorite parts of the cruise. Rob adds, “Seeing the bears up close was definitely a highlight. Sampling in the ice and getting out there off the ship was special, but overall being in such a remote beautiful place where very few people go was a highlight.”

The science party poses on the ice in front of the RV Sikuliaq. From left to right, Ethan Roth (Sikuliaq Science Operations Manager), Marissa Despins (Wright State University), Yipeng He (UConn), Doug Hammond (University of Southern California), Laurie Juranek (Oregon State University), Steve Roberts (Sikuliaq Science Systems Engineer), Mark Stephens (Florida International University), Rob Mason (UConn), Emma Shipley (UConn), Hannah Inman (UConn), Penny Vlahos (UConn), Lauren Barrett (UConn), Dan Naber (Sikuliaq Science Systems Technician). (Photo: Siyu Chen)
Ice sampling, as seen from the Sikuliaq. Shown in the foreground is the “man-basket” that is used to transport personnel and supplies between the ship and the ice. In the background, Rob Mason and Dan Naber take an ice core and Ethan Roth, Laurie Juranek, and Emma Shipley take brine and under-ice samples. (Photo: Lauren Barrett)
Two polar bears observe the Sikuliaq from a nearby ice floe. (Photo: Siyu Chen)

Meet Dr. Claudia Koerting, a Woman who Wears Many Hats

Dr. Claudia Koerting has been working in her current professional faculty position for the past 16 years, although she’s had various positions at UConn since 1997. Almost every graduate and undergraduate who gets a degree in the Department of Marine Sciences has had the opportunity to work with Claudia. Her current position includes serving as the marine science undergraduate coordinator and the honors advisor for the major, coordinating the Early College Experience (ECE) Marine Sciences Program, teaching several courses at Avery Point, and maintaining and helping students use the instrumentation in the SMALER (Suspended Matter Analytical Laboratory for Education and Research) Lab. 

Claudia graduated from the University of Rhode Island (URI) with a double degree in chemistry and microbiology, received a Master’s from UConn in Oceanography, and completed a PhD in pharmaceutical sciences at URI. Her interdisciplinary background allowed her to work on a variety of research projects, from Lyme disease to marine pathogens to the inhibition of bacteria that degrade oil and fuel. She emphasized the importance of interdisciplinary projects: “I like to combine all my backgrounds, cell biology, chemistry, and microbiology, (in the context of marine sciences) because any of them alone is boring to me.” She is particularly apt at analytical work, which made her the perfect fit to run the SMALER Labs at Avery Point. After taking on the role of a PhD level academic assistant for DMS in 2005, she has continued to add to her responsibilities by naturally filling vacuums she has observed, such as oversight of undergraduate lab courses. Of her career path, she says “It’s a great example of how everything you’ve done in your life, no matter how irrelevant it seems at the time, can be relevant to your future work.” When asked what a typical day on the job looks like, she laughs and says there is no typical day. 

Her favorite parts of the job center around helping students grow as scientists and researchers. “A big part of what I love to do is connecting undergraduates and high school students with research and ideas. I get to see them coming in as freshmen, and I get to see them going out as seniors. At the end of the day, when I look back and know that I’ve helped someone in some way, then I feel like I’ve done my job. It’s gratifying.”

Outside of work, Claudia has a passion for being outside, particularly sailing. She loves to be on the water year-round, but when she cannot get out onto the water, she also has a passion for hiking. 

Claudia driving the skiff (photo: Charlie Woods)

Dierssen Hosts the NASA PACE Science Team at Avery Point

Professor Dierssen hosted the 3-day Plankton Aerosol Cloud and ocean Ecosystem (PACE) Science and Application Team Meeting at the University of Connecticut, Avery Point in a hybrid format with 32 in-person attendees and 77 virtual attendees. Twenty-two in-person and twenty-eight virtual presentations were given, including 5 minute lightning talks from each science and application team member.  The hybrid meeting format facilitated a best-of-both-worlds opportunity to collaborate, to resolve sticking points, and to build partnerships, while sharing mission and programmatic updates and while advancing the science and societally relevant applications of the PACE mission.

The PACE satellite mission is slated to launch in January 2023 with new hyperspectral and polarimetric sensors to revolutionize the way we monitor the oceans and atmosphere from space. 

In-person attendees of the PACE Meeting pose on the Avery Point Campus. Dierssen is third from the left. (Photo: Oskar Landi)

Professor Ed Monahan’s “Message in a Bottle” reaches Russia

(This story includes excerpts from “From Galway Bay to Kola Bay – Research bottle set adrift 40 years ago reaches Russia” published in the Irish Examiner, 10/25/2021)

A message in a bottle cast into the ocean off Ireland’s West coast roughly 40 years ago has turned up in Murmansk, Russia last week – some 4,000km away. The bottle was discovered at Kola Bay, an estuary north of the port city of Murmansk, the biggest city in the Russian Oblast of the same name. Contained within the bottle was a small yellow postcard bearing the address of University College Galway – now NUI Galway’s – Oceanography Department, along with a request to return the bottle with details of where and when it was found. Current members of NUI Galway’s faculty identified the bottle as part of a drifter program run by Prof. Ed Monahan in the late 70s and early 80s. Dr. Monahan previously worked at NUI Galway, but is now emeritus faculty at the University of Connecticut. While at NUI Galway in the late 1970s and early 1980s, he conducted research with ‘drifters’ off Ireland.

The bottle, looking a little worse for wear after decades at sea (Photo: Ed Monahan via NUI Galway).

While it is possible the bottle was picked up by a fishing vessel somewhere in the North or the Norwegian Sea and discarded close to the Russian coast, Dr. White, an oceanographer NUI Galway, believes the most likely explanation is that the bottle simply drifted there via natural currents. “Currents in the Rockall Trough region will flow generally into the northern North Sea area and across to the Scandinavian side and beyond into the Arctic. However, the route would be determined by the winds and at any locality the weather systems so the route could have been very indirect,” Dr. White said.

The man who found the bottle in Kola Bay got in touch with NUI Galway’s College of Science and Engineering by email last week to notify them of his discovery and attached some photographs of it. The photographs appear to show that the serial number on the card – which would allow NUI Galway’s researchers to learn exactly where and when the bottle was sent to sea – has faded over time. Attempts to get back in touch with the man who discovered the bottle have so far been unsuccessful, but Dr. White’s Russian-speaking wife plans to send him another on behalf of the University in a bid to learn more about the bottle’s long journey from the west of Ireland to the Northwest of Russia.

Speaking on the re-emergence of one of his projects, he said “For this drift-bottle to be found 35 years after I returned from Ireland, and 15 years after I retired to emeritus status at UConn, was like “a welcome echo from the past.” I am pleased that my former colleagues in NUI, Galway, remembered my role in this study, and flattered that they saw fit to mention it to the press. It’s rare for a drift-bottle to be found so long after it was set adrift, but I am aware of drifters that have floated longer distances.”