Head in the Clouds

30 07 2014

As an incoming graduate student working on my first independent project, I had no idea what to expect from the CAICE IMPACTS chemistry intensive. I quickly found out that this was going to be one of the most challenging but also most rewarding experiences I’ve had so far.

I am an incoming student in Dr. Tim Bertram’s group and am studying cloud condensation nuclei (CCN) activity. One of the least well understood aspects of climate modeling is the indirect effect of aerosols on cloud formation and lifetime. CCN are a subset of aerosol particles which are capable of having water vapor condense onto them. An increase in CCN concentrations means more cloud droplets being formed in the atmosphere as well as longer cloud lifetimes. These clouds can then reflect sunlight causing cooling of the atmosphere.image001

Salt particles are especially great at serving as CCN because of their ability to uptake water (just think how well salt dissolves a pot of water). Organic type particles are more hydrophobic (not attracted to water) meaning they are poor CCN species. When one thinks of the composition of seawater they almost always think about salt, however during a phytoplankton bloom and death a substantial amount of organic matter is released. What I hope to study is how the CCN activity of sea-spray aerosols changes with the course of the bloom and its release of organics.

As we approach the last few days of the intensive I am very thankful for the opportunity to contribute to this research and to work with so many great scientists in our CCI (Chemical Center of Innovation). I look forward to building on this research and this experience for a long time to come.

 

Gordon Novak, Graduate Student, Bertram Group at UC San Diego, Department of Chemistry and Biochemistry

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The study of ocean – atmosphere interactions

29 07 2014

When waves crash and underwater bubbles burst at the surface, tiny particles are ejected from the ocean into the atmosphere. As the water evaporates away, a particle is left behind that we call sea spray aerosol. Our research through the Center for Aerosol Impacts on Climate and the Environment (CAICE) is focused on understanding the physical, chemical, and biological processes that affect the composition sea spray aerosol. Knowledge of this composition is critical to understanding the effect of sea spray in the atmosphere, such as how it reacts and how it affects cloud formation.

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Marine Aerosol Reference Tanks (MART) provide a unique opportunity to capture sea spray aerosol in the laboratory

During the IMPACTS field experiment at Scripps Institute of Oceanography in La Jolla, California, we are collecting samples of ocean water, sea surface microlayer, sea foam, and sea spray aerosol from the wave flume and Marine Aerosol Reference Tanks (MART). We transport these samples back to our laboratories at the University of Iowa, where we measure individual organic molecules and inorganic ions. We use liquid chromatography (LC for short) that allows us to separate compounds of interest from the complex environmental sample. Conductivity, electrochemistry, and mass spectrometry provide sensitive methods of detection that allow us to quantify trace amounts of compounds. By determining the distribution of chemicals across the phases of the ocean and atmosphere relative to one another, we can characterize the selective processes that lead to organic molecule enrichment in sea spray aerosol. Collaborating in the IMPACTS field study means that we can combine our knowledge of chemistry with evolving ocean biology and the physical properties of the sea spray aerosol.

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CAICE researchers (clockwise) Hosiana Abewe, Olga Laskina, Jon Trueblood, Thilina Jayarathne, and Grace de Dieu Irumva testing a laboratory experiment on the measurement of surface reflectivity (a.k.a. albedo)

In addition to conducting research, CAICE provides an opportunity to engage with students and the community in learning about climate science. I had the pleasure of teaching at the California State Summer School for Mathematics and Science (COSMOS) while at UCSD earlier this month. I worked with undergraduate and graduate students to design and adapt curricula about global change and climate for high school students. Together, we explored how the earth’s surface affects our energy balance with the sun, how some gases cause greenhouse warming, and how different molecules interact with solar energy.

I am thrilled to be part of a dynamic research center that combines cutting-edge research, innovation, and education about climate science. Through this summer’s IMPACTS experiment, we have new capabilities to understand complex environmental processes through intricately-designed laboratory experiments.

Elizabeth Stone, Assistant Professor, Department of Chemistry, University of Iowa





Sea water; is it only Salt?

28 07 2014

I am a third year graduate student from Prof. Betsy Stone research group, University of Iowa. It was a tremendous opportunity for me to participate in IMPACTS (Investigation into Marine Particle Chemistry and Transfer Science) summer 2014 intensive campaign at the Center for Aerosol Impacts on Climate and the Environment (CAICE). These days SIO (Scripps Institution of Oceanography), UCSD is filled with budding atmospheric scientists who are exploring the largest indoor phytoplankton bloom in the world. It is awesome to see everybody is working hard towards the same goal day and night. I am so proud of myself for being a member in this team who are “IMPACTed” by the sea spray aerosols. Originally, I am from Sri Lanka, the island of paradise in Indian Ocean. Being an individual from a small island which is just 270 miles long and 140 miles wide with 800 miles of beaches I was never amazed by seeing the ocean. After I joined the CAICE project I got an opportunity to investigate the importance of ocean to atmospheric science and climate change which changed my perspective about the ocean.

Wimage001e think the ocean is full of salty water and the best place for a day out. However, ocean water is not only salt; it contain thousands of organic compounds. These organic compounds are results of phytoplankton and bacterial activities. Breaking waves on the ocean surface generate splash water droplets and air bubbles that scavenge sea salt and organic matter from the sea surface to the atmosphere. These small particles are called sea spray aerosols (SSA) which has important effects in cloud formation and earth’s radiative balance. However, all the organic compounds that can be seen in sea water is not transferred to sea spray aerosol. Some of these compounds get enriched in upper most layer of the ocean (sea surface micro layer) and selectively transferred in to the atmosphere. This selectively transfer mechanism is poorly studied and yet to be fully understood. Therefore, during this study I am collecting sea water, sea surface micro layer and sea spray aerosols and analyze them for organic molecules such as carbohydrates, carboxylic acids, proteins and lipopolysaccharides to understand the selective transfer mechanism of these organic compounds in the ocean to the atmosphere.

Thilina Jayarathne, Research Assistant, Stone Research Group, Department of Chemistry at University of Iowa.





DNA in the Clouds

25 07 2014

As a third year graduate student in a biochemistry lab, I don’t often get experiences like this. A giant wave-generating tank is novel to me and quite a bit different than the pipet-land I usually live in. Walking into the transformed hydraulics lab always leaves an impression on me. The facility has come alive. It is crammed full with buzzing whirring equipment, and buzzing, whirring people. Scientists and students from all over the country all pointed at a common goal. Every time I walk in there, I step back and really understand what I am a part of. I’m proud. This experience hasn’t always been easy, but it has been rewarding. Certainly, the unwavering dedication of everyone down at the waveflume day to day is truly inspiring.

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Author Jennifer Michaud in the lab extracting DNA


I am not the only biochemist/biologist involved in IMPACT, but definitely my work stands apart from what others are doing. The name of my game is DNA. My efforts are to collect cells from the waveflume and extract their DNA, which will then be used to identify all the species present.   I would like to characterize not only what microbes are there, but also how they change across a bloom and relate to a natural ocean phytoplankton bloom. More specifically, I am interested to learn which species transfer from bulk to the sea surface to aerosols (airborne particles) and how this changes in conjunction with the growth of phytoplankton and correspondingly bacteria. My highest hope is that certain phenomenon, like ice nuclei, particle types, and interesting organic molecules, might be able to be connected to the predominance of a species or group at the time of their occurrence.

To do this I collect water samples. Harvesting cells is done by vacuum filtration under sterile conditions serially with different sized filters to fractionate the samples into phytoplankton, bacteria, and viruses and vesicles. The major hurdle to my sampling is having enough. Cells are not overly abundant in the marine environment and many liters of water are generally required for DNA analysis. Here we are trying to optimize our methods so that that we get as much DNA from minimal sample amounts so that other analyses are not disrupted. Additionally, sampling cells from aerosols poses its separate challenges. We are using a SpinCon PAS 450-10A Wet Cyclone Portable Air Samplers (Sceptor Industries, Kansas City, MO) to concentrate cells in the aerosols. This instrument has previously been used to sample air above a NY city high-rise and other sites for microbes. The instrument pumps aerosols into a glass chamber containing buffer creating a vortex in which cells are trapped which then are collected by our standard methods. DNA is isolated using an optimized phenol chloroform extraction. Then our precious samples will be sent away for sequencing to identify species.

Yesterday was big sample collection day for me. Lots of filtration. Today, I am extracting DNA from the aerosol samples. I hope they have lots!

Jennifer Michaud, Graduate Student, Burkart Group, Department of Chemistry and Biochemistry, UC San Diego





CAICE IMPACTS a UCSD Undergrad

18 07 2014

After finishing my second year of undergrad at UCSD, I am thrilled to already be a part of the CAICE IMPACTS experiments. My interests revolve around understanding the surface chemistry of seawater and its impact on the selective transfer of species from the bulk seawater to the surface seawater and ultimately to the sea spray aerosols during the phytoplankton bloom in the wave-flume.

A Tensiometer measuring the surface tension of surface seawater via a Platinum plate

A Tensiometer measuring the surface tension of surface seawater via a Platinum plate

To get a sense of the changes occurring in the surface of the seawater, I have been measuring the surface tension in the sea-surface microlayer (upper most millimeter of the surface) and the bulk seawater (the water beneath the surface) using a tensiometer shown in the image on the right. Surface tension can be thought of as the force that causes a liquid’s surface to pull closely together for minimal surface area, and the tensiometer uses a platinum plate to measure the force the liquid exerts on it. I am looking for changes in the surface tension day-by-day in the wave-flume as the phytoplankton bloom progresses to see how this surface property changes and how it impacts the chemical properties of the surface water and sea spray aerosols.

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A preliminary infrared spectrum of dehydrated bulk seawater

To determine the changing chemical and biological composition of bulk seawater, sea-surface microlayer, and sea spray aerosols, I am using infrared (IR) spectroscopy, which essentially uses light in the infrared region to cause molecules to vibrate. These vibrations can be seen as peaks in the IR spectrum shown on the right, and each peak corresponds to a certain chemical group. It should be interesting to see if changes in functional groups are apparent to better understand the transfer of molecules from the surface of the ocean to sea spray aerosols.

While learning all of the chemistry behind CAICE is exciting, the true nature of its impact on my undergrad experience comes from the diversity and perseverance of everyone I have met. From biologists to oceanographers, I am so grateful to be around this atmosphere of scientists coming together to work on the impact sea spray aerosols have on our climate and environment. I have met numerous PIs, postdocs, and grad students, and they have all given me insight into what I want to do in the future. I want to continue to explore and help determine the true impact the changing environment has on our lives and how we can all make the effort to improve our understanding of the world’s scientific complexity.

Joshua L. Cox, Undergraduate Researcher, Prather Group, Dept. of Chemistry and Biochemistry, UCSD