Where The Air Meets the Sea

Written By: Sarah Amiri

Walking in to the H-Lab at Scripps is like walking in to an enormous wooden spacecraft.

With a flume stretched across the floorplan filled with thousands of liters of coastal seawater.  This mesocosm is surrounded by an almost unearthly network of sophisticated analytical machines specialized in better understanding atmospheric chemistry as it relates to air-sea exchange.  Or more simply, how the ocean interacts with the air to influence atmospheric processes. 

I’m climbing up the stairs to get a synoptic view of the scene.  It’s chaotic, loud, buzzing and electric.

On the left, I see the flume’s paddle making the iconic sinusoidal wave pattern across the suite of experiments I pass by each morning, then my eyes scan the artificial beach used to break the waves to make sea spray.  The seeds for aerosols and cloud condensation nuclei. 

Hydraulics Laboratory @ Scripps Institute of Oceanography

It turns out that the transport of sea spray is significant for the exchange between the sea and the atmosphere and the organic material it ejects.  As someone who is pursuing experiments with research questions centered on chemical oceanography, I often think of biological material being exported down to depth or laterally advected across the coastal and global ocean.  With all the mesoscale processes that this includes. 

However, I now think of the ocean more like our P.I. Dr. Kimberly Prather does: With an allegorical arrow pointing up out of the waves and in to the clouds.  Signatures of the sea up there, volatile and roaming.

Illustration of airborne microbes

I walk back down the stairs and head towards the right panel of the flume where our team is running samples on a benzene cluster cation chemical ionization time of flight mass spectrometer that will look at gases in the seawater using a cryo purge and trap. 

We lovingly call this mass spec, Clifford. It has its own good luck candle with instructions to keep it alive in the event of an apocalypse.  Of course it does.

Our team is primarily interested in the types of trace volatile gasses that phytoplankton and bacterioplankton can produce and get released into the lower atmosphere (after a series of production and consumption pathways). 

This can have larger effects on increasing albedo that can lead to a climate cooling, or to the release of deleterious trace gasses that can lead to ozone depletion in the stratosphere.  To better understand how these nuanced processes works, I now look under the green saltwater line of the wave flume where the marine biota lives.  

Phytoplankton are sometimes referred to as micro algae and fix carbon with light to make energy. 

They interact with other phytoplankton, bacteria, archaea, and viruses to make big impacts on Earth.  Sometimes this interaction is a war zone.  Other times, it’s like exchanging ingredients amongst friends to share a meal.  It’s the ultimate competition and exchange under the waves for nutrients, light, trace metals, vitamins and a space to grow.  In the open ocean it can be more like a daily recycling ritual, or uneventful until a pulse of nutrients or iron deposition feed phytoplankton and bacterioplankton blooms that provide an assortment of options for protists and viruses to feast on.  Sometimes viruses can wipe out a whole population of phytoplankton within a single day.  You can see it from space.  If you’ve ever seen the iconic NASA images of seemingly swirling turquoise water color paintings from ocean color satellites, you are probably seeing a massive coccolithophore bloom.  A whole group of phytoplankton taxa that can calcify tiny plates or coccoliths that make them look like small rotund chalk spheres. 

NASA image of coccolithophore bloom (in turquoise) near a diatom bloom (darker green) and sediments (yellow brown)

This group of phytoplankton is also known to contribute to a significant pool of dimethyl sulfide (DMS) from the sea to the air, where this eventually serves as a source of sulfate for cloud condensation nuclei.  It turns out many other phytoplankton taxa can make DMS and numerous bacterioplankton can cleave the more abundant DMSP to DMS or make it as well.  Biological sulfur chemistry is a cryptic, tendrilled and a non-linear series of step-wise functions. This also holds true for many other VOCs or volatile organic compounds in the ocean coming from the biology of the surface ocean to the deep sea.  Making it a tough thing to measure. There are a myriad of biotic and abiotic processes and mechanisms affecting trace gas chemistry in the ocean at any given time, making it particularly difficult to constrain. However, it makes it all more worthwhile to study when thinking about the pool of these biologically derived gasses from the oceans to the atmosphere as it relates to climate change. 

A fractional representation of the types of VOCs phytoplankton and bacterioplankton can make.

Ah, climate change.  A topic that would be myopic to avoid when talking about the oceans.  A massive body of saltwater that has buffered much of the anthropogenic brunt.  Only for so long. 

How long?  What phytoplankton and bacterioplankton taxa will be affected?  Which ones will be resilient to regional changes? What gasses will they make that will offset or onset the process further? What about the bacterioplankton?  These are the questions I am left with at the end of each day when I leave the H-lab.  These are the questions that we all ought to think about when considering their invisible role over cycling key elements we depend on.

Where ½ of the oxygen on earth comes from these micro algae, we must ask ourselves how comfortable we are with changing Earth’s biogeochemistry if these tiny but mighty drivers decline in certain regions or change in global community composition in others.

More importantly, their interaction with the microbial majority on Earth is also a major black box that must be further explored when thinking of biological roles on atmospheric processes.  This is where experiments like CAICE’s SeaScape help us all better understand how a warming and stressed ocean will interact and connect with the atmosphere and affect global air-sea exchange rates.  And future missions like the upcoming NASA PACE satellite that will measure phytoplankton and aerosols/ clouds from space can also benefit from.  Eventually paving a data pathway where humans can better understand, adjust, and care about the oceans outstanding role on the climate.  

Illustration by Sarah Amiri of phytoplankton community structure across the wave flume in the H-Lab.

Written by: Sarah Amiri, UCSB Assistant Researcher

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).

Down the Tube: A Two-Part Story of Characterizing Marine VOCs

Written By: Delaney Kilgour (Upper Section) & Margaux R.E. Winter (Lower Section)

When you roll down your car windows after a long drive to the beach, what are your first reactions? Do you listen to the waves crash, feel the humid air, or take in the smells? Can you taste the salt in the air? Do you ever know you’re at the beach because, for some reason, it just smells like the beach? Well, it turns out, that characteristic “beach smell” is created by a complex mixture of volatile organic compounds (VOCs) emitted by microorganisms living in the ocean. What is commonly referred to as the smell of the beach comes from sulfur-containing compounds, specifically.

VOCs are emitted by phytoplankton and bacteria that live in the ocean in response to various environmental and biological activities. The most well-studied marine biogenic VOCs include dimethyl sulfide (DMS), isoprene, and monoterpenes. Once emitted, evaporation processes at the air-sea interface can cause these gases to be emitted into the atmosphere, where the gases can then be further aged by oxidation processes to form secondary marine aerosols. These aerosols affect cloud formation, and thus have the capacity to greatly affect our climate.

From Left to Right: Margaux Winter and Delaney Kilgour in front of the Vocus PTR-MS in the Hydraulics Lab
(courtesy of @bertramlab Instagram page)

During SeaSCAPE, Margaux and I study these VOCs emitted at the air-sea interface. We are using a chemical ionization time-of-flight mass spectrometer to measure the gases that are emitted over the course of an induced phytoplankton bloom. One of our primary goals is to characterize a variety of gas emissions, in addition to well-studied gases like DMS, to understand how the gas emission profile varies in response to biological processes in the ocean and how the emission of different gasses relates to the suite of aerosol particles produced.

We work closely with two other teams of researchers (namely Jon Sauer and Alexia Moore from the Prather group at UC San Diego and Emily Barnes from the Goldstein group at UC Berkeley) that also measure VOCs. As a group, we sample from the headspace of the wave flume, in addition to two separate chambers that circulate wave flume water through large, cylindrical glass tubes. Because we all use different instruments with improved sensitivities for certain classes of molecules, our hope is that we can combine our collective data from the various instruments and sampling locations to form a more complete profile of gas emissions during the bloom.

As SeaSCAPE comes to a close, I feel very lucky to have been able to participate in such a large-scale, collaborative experiment during my first year of graduate school. While I was nervous about the intensity of this experiment and working away from my lab in Madison, I quickly realized that everyone here was invested in helping each other and making sure the experiment as a whole was the best possible. I look forward to continuing to work together in the future and for all of our exciting findings.

Similar to many of the undergraduate interns at CAICE, SeaSCAPE has been my first experience on a field campaign. Having studied VOCs and aerosols in two labs prior, I thought I had some baseline as what to expect out of my experiences in the Hydraulics Lab at Scripps Institute of Oceanography (SIO). Of course, past lab and course work familiarized me with the material, but working through CAICE at SIO has been an experience all its own.

In contrast with the sterile, fluorescent environment of my organic chemistry laboratory courses, or the secluded basement that serves as our experimentation space where I work in the Keutsch group, the Hydraulics Lab is of a vastly different nature. The first time walking into the space was overwhelming. The tall, sloping ceiling is reminiscent of a cathedral, or an overturned ark. Despite the few windows, sunlight streams in through the loading dock doors, which are kept open during the day, when the phytoplankton are allowed to fully photosynthesize. Simply arriving in the building, the presence of SeaSCAPE, and the immediacy of the work cannot be overlooked.

Of course, this feeling isn’t generated exclusively from the physical space. Defining my experience at CAICE was the omnipresent and continual collaboration among researchers across different groups. The work demands it.

Photo by Riaan Myburgh on Unsplash

Not only must the three different gas-phase instrumentation teams work together to compare measurements, but if we are interested in seeing how these gasses inform aerosol production we must be in constant communication with everyone working on particle sizing and counting. No matter how much work any one person puts into the quality of their data collection, of equal or perhaps even more importance is the ability of this data to be shared and productively utilized in collaboration with data collected by other groups. Information must be efficiently shared and cross-analyzed each day – sometimes a significant challenge if your own data collection isn’t running smoothly.

So yes, the work demands collaboration, and at CAICE, that collaboration is given freely. Never before I have I been in an environment when so many people are required to work together, and where scientists of different backgrounds and with various skill sets are so willing to give their time and intellectual capacity to all those around them. There is a visceral sense that the work at CAICE is greater than the sum of its parts. Every person in the Hydraulics Lab is committed to the success of the project, and to that end, every person is committed to making the most out of their work, by also making the most out of the work of others.

As the summer comes to a close, I am able to reflect on my experience at CAICE. Of course, the engaged training and education in the field of atmospheric chemistry that I have received is irreplaceable. Learning how to use a Vocus PTR-MS and getting hands-on experience every single day in lab solidified my interest in the field of atmospheric chemistry, augmented what I learn in my school-year course work, and accentuated my ongoing commitment to research.

In the coming weeks, I am incredibly excited to synthesize the research Delaney and I have conducted this summer into a final presentation, and to share the work done here with non-CAICE affiliates when I return to Cambridge in the fall. However, one of the notable takeaways of my experience is the capacity for science to function collaboratively and around the clock. Attempts to answer large-scale, interdisciplinary questions, such as the ones presented at CAICE require the kind of work ethic and ingenuity that I have been fortunate enough to be surrounded by this summer. Bringing a group of dedicated workers together provides the groundwork for action, and I hope to bring this sentiment into my work in the upcoming school year and as I continue my efforts in chemistry in the Keutsch group and in my future graduate studies.

Written by: Delaney Kilgour, Graduate Student in the Bertram Research Group at the University of Wisconsin-Madison and Margaux R.E. Winter, Undergraduate Student in the Keutsch Group at Harvard University

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).

Sizing Up the Situation

If you’ve never read the whimsically titled Tale of Two Blooms paper that covered key findings from the IMPACTS (Investigation in Marine PArticle Chemistry and Transfer Science) wave flume campaign CAICE undertook five years ago, do yourself a favor and look through it. For an undergraduate like me, the article was recommended reading for the Summer Undergraduate Research Program, so I took a look at it on a slow day at my lab back home. I found myself in admiration of the scope of the project, amazed by the rich variety of data collected, and overwhelmed by how densely packed the article was with information. To me, it almost seemed like all the bits and pieces of IMPACTS fell together perfectly and produced this paper. I went into SeaSCAPE expecting smooth sailing.

Of course, any researcher knows better.

Chi-Min Ni (left) and Cristina Bahaveolos (right) performing daily maintenance 
on the sizing instruments. Photo: Erik Jepsen / UC San Diego Publications

Indeed, I’ve come to understand what Gil Nathanson, my PI back home, meant when he talked about being “exposed to many of the agonies and ecstasies of research.” This story begins with “Sizing Island”, a dense cluster of fifteen or so instruments located near the wave flume’s sampling ports. On this Island you can find multiple SMPS (Scanning Mobility Particle Sizers), APS (Aerodynamic Particle Sizers), and CCN (Cloud Condensation Nuclei) Counters. The SMPS and APS together can size particles ranging between 3 nm and 10 μm, while the CCN counters gauge how well water condenses onto aerosol particles, a process that governs cloud formation in the atmosphere. Not all aerosols can act as cloud condensation nuclei, and their activity is governed by both their size and composition. These characteristics can then impact cloud properties such as their lifetime and ability to reflect incoming radiation (also known as albedo). These measurements are important as aerosol impact on cloud formation is one of the largest uncertainties in our understanding of climate change.

One of our main tasks is performing daily maintenance checks on these instruments, which includes making sure the instruments are pulling the correct flow rates or leak testing the instruments, as well as changing the silica gel dryers that dessicate aerosols from the wave flume. These checks keep Sizing Island running smoothly and allow us to identify any instruments that may need troubleshooting to generate the best measurements possible.

Catherine Mullenmeister (left) and Margaux Winter (right) conversing
 near the the Secondary Marine Aerosol Dome 2.0. Photo: Erik Jepsen/UC San Diego Publications

To muddy the waters further, we sample three different forms of aerosols. First, in our nascent aerosol line we are sampling aerosols in real time directly from the headspace of the wave channel in order to reduce the effects of any secondary processes. In our heterogenous aerosol line, we take nascent aerosols and gaseous molecules partitioning off the water and oxidize them in an Oxidative Flow Reactor, which simulates aging of particles in the atmosphere by •OH radicals. Finally, our secondary marine aerosol line solely samples gases partitioning off the water inside a dome and oxidizes them in another Oxidative Flow Reactor. Oxidized gases aggregate and condense to form “secondary marine aerosols”. We size all three of these aerosol types, allowing us to compare and contrast their size distributions, as well as see how these distributions change as biological activity in the flume swells and wanes. The CCN counters also take in these aerosols, which lets us study the ability of these different forms of aerosols to act as cloud nuclei for forming cloud droplets. 

Did you get all of that? It’s gonna be on the test next week. But back to those “agonies and ecstasies.” It took a lot of trial and error to get used to performing the dozens of maintenance checks we’re in charge of, as well as multiple drafts for our standard operating procedures. We’ve come a long way from being lost among a sea of instruments to keeping watch over Sizing Island. Of course, there are still hiccups, like when instruments malfunction or when data logging programs crash, but we can’t expect everything to run perfectly all the time. I like to think of our experience working on Sizing Island as a microcosm of SeaSCAPE as a whole: iterative troubleshooting has created successes out of woes. Just as we’ve gone through various approaches to maintenance, the wave flume has gone through multiple fillings, each with its own quirks. We rinse and repeat (literally, in the wave flume’s case!), and step closer day by day to a better understanding of the chemistry and biology of sea spray.

We would like to end by sending a special thank you to our mentors Kathryn Mayer and Chris Cappa who shared their knowledge with us and provided their guidance throughout this summer experiment.  We would also like to acknowledge Kim Prather, CAICE, and NSF for the opportunity to contribute to this experiment and learn from our experiences here at SeaSCAPE.

Written by: Chi-Min Ni, Undergraduate Student, UW-Madison
Catherine Mullenmeister, Undergraduate Student, UC San Diego
Cristina Bahaveolos, Undergraduate Student, UW-Madison

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).

Shedding Light on the Effects of Biology and Organic Matter in the Ocean

Living near the ocean for almost my entire life, I grew up in a coastal town called Quy Nhon in Vietnam and moved to San Diego almost 10 years ago. Despite this, I was aware that I knew very little about the sea. I did, however, understand how we all tend to take the ocean for granted: for our mini weekend vacation, for the amazing seafood, and many more reasons!

The ocean is threatened by the negative effects from our now-changing climate. The key to mitigation is being able to first understand the underlying chemistry and interactions between the ocean and the atmosphere. A great example of this was the discovery that chlorofluorocarbons (CFCs) could form ozone-destroying radicals on the surfaces of polar stratospheric cloud aerosols; knowledge that allowed us to ban such chemicals to help reverse the progression of the ozone hole in the 80’s and 90’s.

The ocean is home to a diverse ecosystem, whose activities directly and indirectly control its surroundings. It becomes very fascinating once we begin to understand the activities of the microscopic species, such as bacteria, phytoplankton, viruses, etc. These microbes are able to emit volatile organic compounds (VOCs) as resistance to environmental stresses, communications, and allelopathic and defense mechanisms. Once emitted into the air, these VOCs can act as a sink for hydroxyl radicals and form secondary marine aerosols – a focus of the SeaSCAPE study. Such aerosols are the single largest uncertainty in our quest to understand climate change (see IPCC AR5). 

For my project, bloom water collected from the wave flume is irradiated with a solar simulator for approximately 2 to 3 hours. The reaction chamber is a horizontal column capped with quartz windows on both sides and inlet/outlet at the top for N2 gas flow through the headspace, carrying the emitted VOCs into the Orbitrap Elite mass spectrometer. The VOCs are ionized using a modified gas-phase atmospheric pressure chemical ionization (APCI) method to directly measure gases using high resolution mass spectrometry. We use a timeline to collect samples for each bloom for a temporal analysis, going from when the seawater is added, to the addition of nutrients, to the peak and the death phase of the bloom. We also analyze both unfiltered and filtered (0.2 microns) bloom water to specify the biotic and abiotic VOCs. During the first bloom cycle, we observed little signal overall with the bloom water collected on June 5th, when the nutrients were just added. However, the sample on June 10th, 6 days after the nutrients are added, showed promising details with the detection of isoprene, fatty acids, aldehydes, and other compounds such as dimethyl sulfide (DMS) and terpenes that are commonly known as algal VOCs. Some signals were observed on sample collected on June 15th, just a day after the nutrient spike on the second bloom cycle; however, it was very weak. Though, similar to the first bloom cycle, an enhanced signal was observed in the sample collected on June 18th on the second bloom, 4 days after the nutrients were added! The signal intensities seem to be confidently detected with at least 4 days after the nutrients. An interesting point to make is that samples from the second bloom presented a trend in an enhancement of VOCs approximately 30 to 60 minutes from when the irradiation started. Furthermore, another enhancement typically occurred around 60 minutes after the first mysterious peak. It was hypothesized that there may be delayed (and probably multiple) metabolic processes among the marine species, that caused the pattern.

With the complexity of the biology inside the bloom water, it is difficult to pinpoint the environmental factors and species that are responsible for those mysterious peaks. The next step in this project will involve analyzing the VOC emissions of monocultures of bacteria and phytoplankton observed in the microbiome of the wave flume blooms, to create a library of VOC emissions distinctive to each bacteria strain as the reference point for future analysis.

In addition to the analysis of the volatile components of the bloom water, I work closely with David Gonzales on his project on characterizing the composition of the marine-dissolved organic matter (m-DOM), which we collected from the same water using solid-phase extraction. Together, our data presents the whole temporal compositional change of the water in the wave flume, with respect to the change of its biology. Perhaps we may be able to understand how light affects the composition of the gaseous and liquid phase at our ocean surface.

Written by: Duyen Dang, Undergraduate Student in the Grassian Research Group at UC San Diego

As I grew up, I noticed the human impacts on the environment – the increasing occurrence of hurricanes near my home, flash flooding, tornado warnings, and smog-laden air. Our daily routines affect the ecosystems around us. I started to think about how we influence our surroundings in ways in which I could study and possibly mitigate these impacts. This brought me to study chemistry at Pace University in New York City in order to gain experience that could be applied to my research and future career on the environment. 

I wanted to work at CAICE to experience the approach that atmospheric science has in studying environmental chemistry. My project in SeaSCAPE, is to characterize the broad structure and reactivity of marine dissolved organic matter (m-DOM) in the bulk water of the 30 m long wave flume. With the help of Duyen, working on VOC characterization, much of our work overlaps in terms of identifying chemical components found in seawater. To date, m-DOM is poorly understood in terms of its composition as well as its role in the ocean and atmosphere (as an aerosol). It can have anywhere from 1,000 to 10,000 or more molecular signatures. m-DOM, or specifically the chromophoric (light interacting) portion of it, has been shown to chemically enhance photo-induced reactions in the lab. This marine photochemistry is important to how m-DOM, being entrained in aerosols, can affect the composition of its surroundings.  

Throughout the summer, I have been working on different ways in which we can achieve our goal of characterizing m-DOM. We’ve tried direct injection into the Orbitrap to see if we can account for any differences with respect to biology and time. In the first bloom experiment, I’ve seen the Hydrogen:Carbon (H:C) ratio decrease with time suggesting that there are processes that are converting compounds into unsaturated molecules. An unsaturated compound of interest is benzothiazole, a natural marine product formed from the photolysis of 2-mercaptobenzothiazole. Benzothiazole was found to be the highest peak in mass spec the last day of the first wave experiment. It’s possible that this could have come from photo products as mentioned above or naturally produced from bacterium in the wave flume. We further want to characterize m-DOM by using infrared spectroscopy as another perspective on the different functional groups within the samples. We are currently in the process of thinking of different ways in which we can characterize or potentially look at its reactivity.

Written by: David Gonzales, Undergraduate Student in the Grassian Research Group at UC San Diego

There is nothing more fulfilling and exciting than to contribute through these collaborations with other researchers here at CAICE, in an attempt to answer some of the many uncertainties concerning the ocean and the atmosphere. We are extremely grateful for our mentor, Michael Alves, for his guidance throughout this summer. We would also like to give thanks to Dr. Vicki Grassian for her advisements and continued support. Finally, we want to express our gratitude to CAICE for this opportunity and other fellow researchers who have helped us along the way.  

Header photo credit: Nigella Hillgarth

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).

Those Pesky but Important Ice Nucleating Particles — Honest, It Is Not an Obsession

This ain’t my first rodeo, as they say, but I love it just the same and I still have so much to learn. That sums up my feelings about SeaSCAPE. I participated in my first wave flume study of sea spray aerosols in the Scripps Institution of Oceanography Hydraulics Laboratory in 2011, and then again in 2014. We were blown away at the possibilities for studying the production and properties of nascent sea spray particles. I was blown away by the ability to isolate oceanic emission of ice nucleating particles, or INPs, which have an outsized ability to transform clouds and precipitation due to the action of very small numbers of ice crystals on scavenging water vapor and transforming otherwise stable populations of supercooled cloud droplets into larger ice crystals that sediment and bring water to the surface as snow or rain.

Do you think that all water freezes at 0 °C? You are wrong then, as Tom Hill, my colleague and also a SeaSCAPE participant, will enthusiastically tell you. Pure water distributed in the volumes present in clouds will not freeze spontaneously until close to -40 °C, and otherwise freezing must be initiated by a particle (an INP) present in the water. This makes them special and powerful.

Ice nucleation is my thing, and the INPs that come from oceans are both unique and vitally important amongst the atmospheric populations (mineral dust being the most well-known) of INPs. Oceanic INPs emitted via sea spray production mechanisms are wholly organic, unless the near-surface ocean has been seeded by terrestrial emissions. While we know that SSA INPs emanate both from dissolved and particulate carbon compartments in varying proportions, we do not yet understand these sources chemically to the degree necessary for accurately predicting their emissions using large scale coupled ocean-atmosphere models. Yet this is critically important for understanding influences on clouds over vast remote oceans that control both the amount of solar energy reaching the ocean surface or scattered to space, and the global hydrological cycle. 

Photo (credit: Paul DeMott): Tom Hill, Josephine Rudd, Kathryn Moore and Russell Perkins (front to back) chat over details around our sampling location for INPs in SeaSCAPE.

During SeaSCAPE, our team of Kathryn Moore, Russell Perkins, Thomas Hill, summer student Josephine Rudd and myself will use real-time and offline techniques, in concert with our collaborators in the Grassian, Tivanski, and Stone groups, to further isolate the chemical compositions that constitute the few (“needles in the haystack”) INPs present in SSA. Furthermore, we will seek to understand the fate of these particles following atmospheric oxidation that will occur following emission, using flow reactors. 

I am energized once again in seeing and working in a laboratory full of young scientists. They are learning together with career scientists. Learning about discovery, the process as much as any success, learning to work within a team, learning about the value of patience and persistence. These are the days you will remember.

Written by: Paul DeMott, Senior Research Scientist, Dept. of Atmospheric Science, Colorado State University

Header photo credit: Erik Jepsen/UC San Diego Publications

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).

Acidic Aerosols and Supporting Scientists: A Tale of Two Atmospheres

Some of my happiest memories are of walking on the beach with my family. There is something so relaxing about being by the vast ocean and smelling the salty air. But even while relaxing, we have to be careful. Laying in the sun feels good, but too much of it is definitely bad. Is the same true for the air by the sea? How good or bad for our health is breathing in the sea spray from crashing waves?

This is a very involved question, and answering it correctly will require many little pieces to be understood first. My piece involves looking at some of the smaller aerosols emitted from the ocean and figuring out how acidic or alkaline they are. To do this, I first use an instrument called a MOUDI to separate the aerosols based on size, and then impact them onto litmus paper. I can then use computer methods to analyze the color and calculate a pH, that is, put a number on how acidic the aerosols are. This is key to our understanding of the safety of sea spray, since the most acidic aerosols are correlated with negative health effects. In particular, I am planning to track how aerosol acidity changes over the course of a bacterial bloom. Ultimately, this could allow us to predict ocean air conditions and determine which days are and are not safe for strolls along the beach.

Need to size-separate your aerosols? Don’t be moody, use a MOUDI!

In addition to allowing me to investigate some important scientific questions, being a member of SeaSCAPE has been very valuable to me personally. Until this summer, most of my past research projects have been largely solo efforts. Although I have always had supportive advisors, I performed most experiments by myself or with a single mentor. Initially, the thought of working with so many other people was very stressful to me. If I make a mistake and it only impacts me, that is fine, but it is much harder to forgive myself if I waste someone else’s time. Fortunately, everyone has been very supportive. Many people have gone out of their way to help me and teach me things, and despite the stresses and difficulties, I can always find plenty of smiles. Being here has made me more comfortable working with many different kinds of people and appreciate the power of a team effort coming together to achieve common goals. I am thankful for the opportunity to be part of the SeaSCAPE team and excited for the rest of the summer!

Suds (left) and Kyle (right) measuring chlorophyll

Written by: Kyle Angle, Grassian Research Group, Department of Chemistry & Biochemistry at UC San Diego

Header photo credit: Erik Jepsen/UC San Diego Publications

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).

Water Water Everywhere

Walking up to the Hydraulics Lab for the start of each day of SeaSCAPE sampling is a truly awe-inspiring experience.  From the parking lot outside I have a breathtaking view over the endless misty extent of the Pacific Ocean; as soon as I walk through the doors I am greeted by the eerie breathing and hypnotic motion of the 30 m wave flume hard at work.  For a researcher who has previously focused on aerosols from forests, born and raised in the decidedly arid, landlocked state of Colorado, that is a disconcerting, and at times deeply frustrating, amount of water.  

My name is Emily and I am a graduate student researcher in the Goldstein Group at UC Berkeley.  I study the organic ‘goo’ that previous CAICE studies have observed coating salty sea spray particles during algal blooms.  Breaking waves cause tiny, salty droplets to be flung into the air, and in the presence of intense biological activity, many of these particles in the size range with the longest atmospheric lifetime become coated with an outer layer of carbon-based compounds from the microorganisms in the water.  The compounds in this coating can play a variety of different roles in aerosol fate and climate; they can alter how the aerosols interact with each other, how clouds form, and how light scatters from particles. My instrument is ‘offline’, meaning that instead of directly connecting to the wave tank itself, I collect particles on filters for analysis on an offsite instrument.  I do this by sucking air out of the wave flume just past the breaking wave, running it through a cyclone to screen out large droplets, then passing it through a filter which captures all of the tiny, salty, gooey particles. When I return to Berkeley, I will separate and identify the organic compounds in the particles using 2-D gas chromatography.

Being an offline sampler is an exercise in planning and delayed gratification- because my instrument is at home in Berkeley, I have no way to do preliminary checks on my samples and fine-tune my system.  All I can do is identify, mitigate, and document any potential sources of contamination, carefully design the sampling apparatus, and pay attention to any visual clues that something might be wrong. If I do everything right, the samples should, to the naked eye, be exquisitely boring.  Sea spray aerosols are generally white and so is the filter material, so they should look pretty much the same when I take them out as when I put them in. White is what I was hoping and expecting to see the first morning after the beginning of sampling- what I got was a sad and sodden grey.

The humid air coming off of the wave flume was condensing onto the insides of my metal sampling lines, collecting into droplets, and then hurtling through the sampler to soak my poor filters in a siege of tiny water balloons.  While I had anticipated that this was likely to be a problem and had built a short condenser, nothing I had tested it on prior to reaching CAICE was as humid as the wave flume and my system just wasn’t cutting it.  

In the grand scheme of things, a 47 cm water saturated filter is inconsequential.  In my world however, it spelled disaster. Wet filters do not collect aerosols in a uniform manner, and the compounds I am hoping to document can undergo reactions when they are dissolved in water.  What is more, my instrument back at Berkeley is quite sensitive (in both the scientific and, to my anthropomorphizing mind, emotional sense) and does not particularly appreciate having large amounts of salt water dumped into its internal workings. If I could not figure out a way to keep my filters dry, I would have no usable samples from the summer.   

Here I would like to take a moment to say thank you.  Thank you to my advisor Allen, our instrumentation consultant Nathan, and my mentor Lindsay for promptly answering my questions and guiding me from afar. With their advice, I swapped the 50 cm straight steel water condenser for a 3 m copper coil condenser, adjusted the slope of the collection area, added a heater to the lines, and achieved my first dry filters less than 48 hours into the campaign. Thank you to our lab manager Robin and my labmate Yutong for rushing to the rescue to overnight me the parts needed to put together the new system.  Thank you to Kathryn and Kathryn, to Jon, to Ryan, to Dan, to Brock, and to all of the others at CAICE who took time away from their own hectic schedules to offer advice, lend/look for equipment, or simply offer consolation and encouragement. When I imagined myself to be alone because I am the only CAICE student to call UC Berkeley home, I was very, very wrong.   

It would be nice to tie this anecdote up in a bow and say that with the addition of a big copper coil, all problems were solved.  However, that would be a lie. There have been a few more waterlogged filters, a few more late nights in the lab disconnecting, cleaning, drying, testing, and adjusting my setup.  As of this writing the filter collection has been successful with no water issues for nearly a week and I am cautiously confident that the current setup is ideal; then again, maybe I just jinxed myself.  What I do know for certain is that with each mishap I am learning more, panicking less, gaining confidence in myself, and deepening my appreciation for my collaborators, advisors, and H-lab friends. Most importantly, each dry filter sample collected is another tool to probe the composition of organics in sea spray aerosols in the months and years to come.

Written by: Emily Barnes, Graduate Student of Prof. Allen Goldstein at UC Berkeley

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).

CAICE SeaSCAPE Experiment Featured on KPBS News

KPBS’s Erik Anderson stopped by the Hydraulics Lab to check out our SeaSCAPE Summer Experiment, which was being toured by students who are participating in UC San Diego’s COSMOS educational program. Hear the interview with CAICE Director Kimberly Prather and Managing Director Christopher Lee and learn more about what the SeaSCAPE team is up to here:


Aerosols: A Coming of Age Story

The atmosphere is a dynamic chemical reactor. In the Slade group, we are interested in the processes that control the chemical and physical state of marine aerosols as they travel out of the ocean and through the atmosphere – ending up in the clouds that control our climate and in the air we breathe. Intense sunlight and exposure to oxidants like ozone (O3) and hydroxyl radicals (•OH) can “age” gases and particles. Short term weather and long-term climate trends lead to drastically different environments with varying temperatures and relative humidities. These processes control aerosol’s chemical composition – what molecules they are made of – and physical state – how solid/liquid-like they behave. 

My focus this summer is to investigate the composition of secondary marine aerosol – particles that form in the atmosphere from gases released from the ocean. I’m working with an Extractive Electrospray Ionization Time of Flight Mass Spectrometer (EESI-TOF-MS,) a powerful instrument that can analyze molecular composition of aerosol in real time. I hope to learn more about how secondary marine aerosol evolve under different amounts of •OH exposure and at different relative humidities to simulate how they might behave in the real world and predict their environmental fate.


Like the atmosphere, the Hydraulics Laboratory is a dynamic environment. Between the mesmerizing pattern of the generated waves and the whirrs and hums of instrumentation, dozens of researchers dart around. Over the past several weeks, I’ve seen the lab transform from a near empty barn to a bustling village of researchers. Oceanographers, biologists and chemists came together with targeted missions and a wealth of information. Being a first-year graduate student with little prior atmospheric chemistry experience, I have thrived in the learning environment offered by being surrounded by such a diverse group of people. I’m excited to share my newfound understanding and learn a lot about this multidisciplinary project!

Written by: Adam Cooper, Graduate Student, UC San Diego

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).

A Deep Dive

A view of the Pacific Ocean from La Jolla, California

What do you see when you look out over the Pacific Ocean?  One time, I saw a colorful sunset with promise of a green flash. Another time, I saw a pod of dolphins jumping along the coastline. Now, I see the opportunity to dive deep into chemistry and the vast complexity of the atmosphere and ocean.  

Microscopic marine algae, called phytoplankton, turn carbon dioxide from the atmosphere into different chemicals. Some of these chemicals store energy, while others may be incorporated into cell walls.  An individual phytoplankton lives only a few days, and ultimately returns these chemicals back into the ocean. Some of these newly formed chemicals accumulate on the ocean surface, similar to oil rising to the surface of a puddle. The chemicals at the ocean surface can be transferred back into the atmosphere as sea spray particles when waves crash. Once in the atmosphere, these particles interact with sunlight, act as seeds for clouds and ice, and undergo chemical reactions that can alter these properties.

Glorianne Dorcé and Elias Hasenecz, graduate students at the University of Iowa, preparing equipment to collect sea spray aerosol particles that have undergone chemical aging.

In the Sea Spray Chemistry And Particle Evolution Experiment (called SeaSCAPE for short), dozens of talented, dedicated, and inspiring scientists are working tirelessly to study sea spray particle chemistry, transformations, and impacts on the environment. Sea spray particles are collected onto carefully cleaned filters and then shipped to the University of Iowa where we analyze the naturally occurring and man-made chemicals. Other particles first undergo chemical reactions, similar to those that occur in the atmosphere in the presence of sunlight and oxidants, and are then collected. In this case, we examine how reactions alter the chemistry of sea spray particles. 

Our journey only begins this summer and will be followed by years of chemical measurements, discussions, and research collaborations.

Written by: Betsy Stone, Associate Professor, University of Iowa

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).