The transport and cycling of green-house gases, aerosol particles, microbes, and nutrients between ocean and atmosphere is essential for understanding marine ecosystem functioning and has large impacts on global biogeochemical cycles. However, our ability to understand physical, chemical, and biological interactions in the ocean and how they influence, and are influenced by atmospheric processes has been historically and methodologically constrained. Current development and implementation of high-quality sensors and state-of-the-art technologies for the continuous in situ characterisation of the upper ocean and the lower atmosphere have dramatically increased the spatial and temporal resolution of our measurements. These new technological achievements, in combination with traditional measurements and experiments allow for in-depth integral interdisciplinary studies at different temporal (from diurnal to annual) and spatial (from microhabitats to global) scales. With this session, we address participants that are working with high resolution data and fine scale measurements to shed new light on open questions related to marine ecosystem functioning and ocean-atmosphere interactions. We are particularly interest in data that facilitate understanding of marine microbial communities’ response to ecological gradients and anthropogenic disruption, ocean productivity, and air-sea exchange of biologically active gases, aerosols and microbes, all of which plays a pivotal role in ocean carbon sequestration and Earth’s radiative balance. We hope that the session will inspire novel conceptual frameworks and will help identifying essential tools (or set of tools) to accurately monitor and study climate vulnerable processes.
Lead Organizer: Maria Calleja, University of the Balearic Islands (UIB) (marialluch.calleja@gmail.com)
Co-organizers:
Ralf Schiebel, Max Planck Institute for Chemistry- MPIC (ralf.schiebel@mpic.de)
Iris Hendriks, Mediterranean Institute of Advanced Studies - IMEDEA (CSIC-UIB) (iris@imedea.uib-csic.es)
Sara Ferron, University of Hawaii (sferron@hawaii.edu)
Presentations
06:30 PM
Phytoplankton reaction to an intense storm in the north-western Mediterranean Sea (4702)
Primary Presenter: Stéphanie Barrillon, CNRS - MIO (stephanie.barrillon@mio.osupytheas.fr)
The study of extreme weather events and their impact is challenging due to the difficulty involved with collecting in situ data. However, recent research has pointed out the major influence of such physical forcing events on microbiological organisms. Moreover, the occurrence of such intense events may increase in the future in the context of global change. In May 2019, an intense storm occurred in the Ligurian Sea (NW Mediterranean Sea) and was captured during the FUMSECK cruise. In situ multi-platform (vessel-mounted ADCP, thermosalinometer, fluorometer, flow cytometer, moving vessel profiler, glider) measurements along with satellite data and a 3D atmospheric model were used to characterise the fine-scale dynamics occurring in the impacted oceanic zone. The most affected area was marked by a 1°C colder water, a factor of 2 increase in surface chlorophyll a, and a factor of 7 increase in the nitrate concentration, with strong gradients with respect to the surrounding waters. Our results show that this storm led to a deepening of the mixed-layer depth from 15 to 50 m and a dilution of the deep chlorophyll maximum. As a result, the surface biomass of most phytoplankton groups increased by up to a factor of 2. Conversely, their carbon/chlorophyll ratio decreased by a factor of 2, evidencing significant changes in the phytoplankton cell composition. These results suggest that the role of storms on the biogeochemistry of the Mediterranean Sea may be underestimated and highlight the need for high-resolution measurements during these events coupling physics and biology.
06:30 PM
SPATIAL EXPLICIT UNCERTAINTY OF HIGH RESOLUTION NATIONWIDE SATELLITE DERIVED BATHYMETRY OF BELIZE AND ITS USAGE (6760)
Primary Presenter: Spyridon Christofilakos, German Aerospace Center (DLR) (spyridon.christofilakos@dlr.de)
Cloud platforms have given access to scientists in a vast database and processing power. This has allowed several breakthroughs in big data management, processing, and spatio-temporal scalability. However, the accuracy of these big data analytics and products is spatially restrained and it does not offer spatial information on the confidence of these analyses. Here, we provide a semi-automated workflow that estimates the spatial explicit uncertainty of a Belize-wide satellite derived bathymetry (SDB) procedure— roughly 7,017 km². The workflow optimizes the final bathymetry output through the training dataset by including additional reference points of lower uncertainty. We utilize the cloud-based by-products to acquire the probability of successful depth estimations and estimate uncertainty. The reference dataset comes from the ICEsat2 satellite resampled to the 10-m spatial resolution of the Sentinel-2 Level 2A products. For active learning and retraining reasons, the reference data are divided into six subsets. Thus, the uncertainty is estimated for each individual subset and then the retraining based on the rest of the subsets takes place. Our results indicate that our demonstrated data-driven approach is able to achieve better accuracies compared to the initial SDB and map spatially-explicit nationwide uncertainty. Moreover, scientists could exploit our approach for the identification of biased reference data that mess with their models. Our novel tool can aid uncertainty-aware policy and decision making regarding the protection and conservation of coastal ecosystems.
06:30 PM
Probing the open ocean with the research sailing yacht Eugen Seibold for climate geochemistry (5286)
Primary Presenter: Ralf Schiebel, Max Planck Institute for Chemistry (ralf.schiebel@mpic.de)
The 72-foot sailing yacht Eugen Seibold is a new research platform for contamination-free sampling of the water column and lowermost atmosphere for biological, chemical, and physical properties, and the exchange processes between the two realms. Operations started in 2019 in the Northeast Atlantic, and will focus on the tropical East Pacific from 2023 until 2025. Laboratories for air and seawater analyses are equipped with down-sized and automated state-of-the-art technology. Plankton nets and seawater samplers and probes are deployed over the custom-made A-frame at the stern of the boat. Near Real-Time Transfer (NRT) of underway data via satellite connection allows dynamic expedition planning to maximize gain of information. Data and samples are analyzed in collaboration with the international expert research community. Quality controlled data are published with the Data Publisher for Earth & Environmental Science PANGAEA. The entire suite of measurements is available for proxy calibration of planktic paleo-archives at high temporal and spatial resolution in relation to seawater and atmospheric parameters. The ultimate goal of the project is a better understanding of modern and past ocean and climate.
06:30 PM
Modern planktic foraminifers in the eastern North Atlantic: Combining shell chemistry and in-situ hydrology for proxy calibration (5174)
Primary Presenter: Lena Heins, Max Planck Institute for Chemistry (lena.heins@mpic.de)
Predicting the response of the future ocean to climate change requires understanding the past ocean through reliable proxy data. Planktic foraminifers are a widespread tool for accessing paleoceanographic and paleoclimatic conditions due to the high preservation potential of their calcareous tests, which accumulate on the sea floor. Inhabiting mostly the first 200 m of the water column makes them particularly useful for reconstructing the dynamics and biogeochemical cycles of the upper ocean. Nevertheless, the interpretation of proxy data derived from the shell chemistry of planktic foraminifers requires fundamental knowledge of their distribution and ecology. The present study aims to characterize modern planktic foraminiferal assemblages in the eastern North Atlantic Ocean at a latitudinal transect from the polar circle to the equator. Plankton tow samples were taken onboard S/Y Eugen Seibold during 2020 and 2021. A wide spectrum of in-situ measurements of seawater properties and discrete samples was obtained during the expeditions and complements the dataset. Element to calcium ratios (El/Ca) of the foraminiferal tests are compared to the geochemistry of ambient seawater and discussed for the varying biogeographical provinces sampled along the transect. This will provide important insights into the use of planktic foraminiferal shell chemistry for the reconstruction of the dynamics of the surface ocean.
06:30 PM
CHARACTERIZING THE SOURCES, ABUNDANCE, AND PROPERTIES OF THE MARINE AEROSOL IN THE NORTH ATLANTIC OCEAN (6336)
Primary Presenter: Isabella Hrabe de Angelis, Max Planck Institute for Chemistry (bellahrabe@gmail.com)
Aerosols influence atmospheric cycling and climate by affecting the Earth’s radiation budget as well as the formation of clouds and precipitation. Even though a lot of these processes are well studied, the net effect of aerosols on radiative forcing still bears large uncertainties. To better understand the formation and dynamics of marine aerosols, we measured, sampled and analyzed the lower atmosphere and surface ocean with the research sailing vessel Eugen Seibold on a 20°W latitudinal transect covering all oceanic provinces of the Eastern North Atlantic. Aerosol abundance and physicochemical properties were continuously investigated with particular focus on the biogenic aerosol fraction in the marine background atmosphere. Low particle concentrations, multimodal particle size distributions and a pronounced coarse mode suggest that air masses mainly originated from marine background conditions throughout most of the transect. These measurements are complemented by air and surface water sampling, satellite-based remote sensing, meteorological reanalysis data, as well as long-term data sets from continental monitoring stations in the area. Here, we present (bio-)aerosol and surface ocean data using different techniques such as continuous aerosol measurements and microscopy providing insights into biotic and abiotic processes occurring in the boundary layer between ocean and atmosphere. First conclusions can be drawn on the exchange of particles and microorganisms between the ocean and the atmosphere, as well as on aerosol transport and processing.
06:30 PM
Quantifying airborne microbes over the oceans (5585)
Primary Presenter: Jesús Arrieta, Spanish Institute of Oceanography (IEO-CSIC) (jesus.arrieta@ieo.csic.es)
The airborne transport of microbes over the World’s Oceans is relevant to ecosystem health and possibly to the hydrological cycle. We have previously developed new methodologies for the quantification of airborne bacteria and viruses in oceanic air, in particle laden environments such as desert dust over the Red Sea and produced the first global estimates of microbial abundance over the oceans and air-sea exchange of microbes. Our estimates revealed that the atmosphere is teeming with microbes with an estimated global load of ~4x1021 microbes in the Atmospheric Boundary Layer (ABL), half of which could be traced to an oceanic origin. Although oceanic air masses contain microbes of mixed origins, both marine and terrestrial, most of these airborne microbes will find their final destination on the surface of the sea given that the oceans cover over 70% of the Earth’s surface. However, UV radiation and desiccation are efficient disinfectants, and many of these airborne microbes will not survive their atmospheric voyage. Estimating the abundance of airborne bacteria in the air over the oceans is challenging because of the low abundances observed. Thus, we have developed several approaches to collect and count airborne microbes including improved instruments adapted to sampling on board research vesels.
SS006P High Resolution Data for a Better Understanding of Marine Ecosystem Functioning and Ocean-Atmosphere Exchange Processes
Description
Time: 6:30 PM
Date: 7/6/2023
Room: Mezzanine