At the Cosmos Club, Washington, DC
January 5, 2018
President Larry Millstein called the 2,386th meeting of the Society to order on January 5, 2018 at 8:07 PM in the Powell Auditorium of the Cosmos Club in Washington, DC. He announced that this was the annual Presidents’ Lecture. He then announced the order of business, noted that the meeting was being live-streamed on the internet, and welcomed new members to the Society.
Corresponding Secretary Robin Taylor read excerpts from the Anniversary Address of the first president of the Society, Joseph Henry. The Address, given in the year of the Society's founding on November 18, 1871 is published in Volume I of the PSW Bulletin. In the Address, Henry stated the purposes of the Society and discussed the challenges to doing good science and communicating it to the public. He warned the Society not to be under the influence of amateurs and politicians.
President Millstein then introduced the speaker for the evening, Margaret Leinen, Director of the Scripps Institution of Oceanography and Vice Chancellor for Marine Science at the University of California, San Diego. Her lecture was entitled “Taking the Pulse of the Ocean in a Changing World.”
She began her talk by noting that recent technological advances and the capture and analysis of large data sets have transformed the field of ocean science and our understanding of the ocean. She noted that the measurement of ocean temperatures and fluctuations in them, of great concern recently, are areas that have benefitted from these advances. Historically, scientists relied upon ships traversing the ocean to make occasional measurements to chart ocean temperatures. The ships were only able to provide several hundred samples per year. But, starting in the year 2000, scientists have been able to deploy autonomous floats that collect better data and transmit every five days. There are now over 4,000 such floats operating around the globe. This technological advancement has allowed scientists to comprehensively identify both warming and cooling patterns in the oceans, and to measure ice melt and ocean salinity.
With respect to sea level, from the 1880s until around 1990, scientists principally relied upon tide gauge measurements to track sea level. Then in the 1990s, satellite altimetry provided scientists with dense enough data for scientists to map sea levels and identify their uneven distribution around the globe. The data generated from this technology allows scientists to better predict the specific effects of sea level rise on different parts of the world.
Technology which allows for consistent sampling has also revealed dramatic ocean changes. For example, sampling for surface ocean acidity, which is linked to increased CO2 levels in the water, shows that the oceans are 30% more acidic than they were in 1850.
In the mid-2000s, scientists began to understand the impact of ocean acidification on the ocean’s biota. Research on terapods, which are ocean snails, shows that they have become less able to make pristine shells. Scientists believe this is due to ocean acidification which decreases the availability of carbonate ions.
In addition to increasing acidification, the increase of carbon in the ocean, along with rising ocean temperatures, has led to an increase in biota growth and consumption of oxygen. This has resulted in ocean deoxygenation, which has caused some ocean life, such as fish, to be displaced. Further effects are still being studied.
Technological advancements have also led to an increase in the quality and quantity of deep sea field research. This is important because laboratory work cannot account for all of the factors necessary to fully understand ocean life and to answer questions about how that life will cope with ocean change.
In sum, Dr. Leinen said large data sets allow scientists to explore new ways of doing ocean science. Much of 20th century scientific thinking was deductive hypothesis testing, using a sampling strategy designed to answer those specific questions. This methodology often precluded other insights. In contrast, the availability of larger and denser data sets has allowed scientists to identify trends and reach conclusions, largely by induction. Dr. Leinen said she encourages scientists and funders of science to continue adding to existing data sets and to conduct more science in the field.
President Millstein then invited questions from the audience.
One member asked how ocean deoxygenation affects zooplankton migration. Dr. Leinen said that during the night zooplankton reside on the ocean surface and migrate down into the ocean during the day. She said there is data suggesting zooplankton are not migrating as deeply into some deoxygenated zones.
A livestream viewer asked whether scientists have considered the effects of carbon in deep ocean water that is now mixing with surface waters. Dr. Leinen said that scientists have considered the matter, but lack the data to reach any conclusions at this time.
After the question and answer period, President Millstein thanked the speaker, made the usual housekeeping announcements, and invited guests to join the Society. At 10:05 p.m., President Millstein adjourned the 2,386th meeting of the Society to the social hour.
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