Author: AOML Communications

OSSE Assessment of Underwater Glider Arrays to Improve Ocean Model Initialization for Tropical Cyclone Prediction

Halliwell Jr, G. R., Goni, G. J., Mehari, M. F., Kourafalou, V. H., Baringer, M., & Atlas, R. (2020). OSSE Assessment of Underwater Glider Arrays to Improve Ocean Model Initialization for Tropical Cyclone Prediction. Journal of Atmospheric and Oceanic Technology, 37(3), 467-487.

Abstract: Credible tropical cyclone (TC) intensity prediction by coupled models requires accurate forecasts of enthalpy flux from ocean to atmosphere, which in turn requires accurate forecasts of sea surface temperature cooling beneath storms. Initial ocean fields must accurately represent ocean mesoscale features and the associated thermal and density structure. Observing system simulation experiments (OSSEs) are performed to quantitatively assess the impact of assimilating profiles collected from multiple underwater gliders deployed over the western North Atlantic Ocean TC region, emphasizing advantages gained by profiling from moving versus stationary platforms. Assimilating ocean profiles collected repeatedly at fixed locations produces large root-mean-square error reduction only within ~50 km of each profiler for two primary reasons…

Read Full Paper .

Read Full Article

Highly variable upper and abyssal overturning cells in the South Atlantic

Kersale, M., Meinen, C. S., Perez, R. C., Le Henaff, M., Valla, D., Lamont, T., … & Garzoli, S. L. (2020). Highly variable upper and abyssal overturning cells in the South Atlantic. Science advances, 6(32), eaba7573.

Abstract: The Meridional Overturning Circulation (MOC) is a primary mechanism driving oceanic heat redistribution on Earth, thereby affecting Earth’s climate and weather. However, the full-depth structure and variability of the MOC are still poorly understood, particularly in the South Atlantic. This study presents unique multiyear records of the oceanic volume transport of both the upper (<~3100 meters) and abyssal (>~3100 meters) overturning cells based on daily moored measurements in the South Atlantic at 34.5°S. The vertical structure of the time-mean flows is consistent with the limited historical observations. Both the upper and abyssal cells exhibit a high degree of variability relative to the temporal means at time scales, ranging from a few days to a few weeks. Observed variations in the abyssal flow appear to be largely independent of the flow in the overlying upper cell. No meaningful trends are detected in either cell.

Download full pdf.

Read Full Article

Autonomy, Artificial Intelligence, and Telepresence: Advancing Ocean Science at Sea in the COVID-19 Era

Tim Gallaudet, Jamese Sims, Elizabeth Lobecker, Amanda Netburn, Charles Alexander,Kelly Goodwin, and Alexandra Skrivanek. Autonomy, Artificial Intelligence, and Telepresence: Advancing Ocean Science at Sea in the COVID-19 Era. Journal of Ocean Technology, 15(4) 2020

The COVID-19 pandemic has impacted all aspects of society, including seagoing marine science. Social distance measures and quarantine restrictions have required smaller scientific teams and crews on oceanographic ships. Advances in technology offer the potential to continue marine science discovery as the impacts of the pandemic persist. Robotics and uncrewed systems are already widely used in place of in-situ, human-operated systems, while autonomy and artificial intelligence are dramatically increasing the efficiency and effectiveness of nearly every ocean science discipline, including biological observations. Telepresence is a proven capability that can transform any vessel into a virtual international laboratory. We will describe how these tools are applied at the National Oceanic and Atmospheric Administration (NOAA), and how they provide capabilities to move ocean science forward over the course of the COVID-19 pandemic and beyond.

Read the Full Essay

Read Full Article

Celebrating Black History Month with Evan B. Forde

February is Black History Month; in celebration we sat down to talk with oceanographer and Miami native, Evan B. Forde. In 1973, Forde began his career at NOAA’s Atlantic Oceanographic and Meteorological Laboratory, and in 1979 he became the first African American scientist to participate in research dives aboard a deep-sea submersible. During his career Forde has conducted research across various oceanographic and meteorological disciplines and remains one of the few African American oceanographers in the U.S.

Read Full Article

Scientists at AOML Awarded Ocean Observing Team Award for Western Boundary Time Series Project

NOAA’s Western Boundary Time Series (WBTS) project, alongside partner projects RAPID and MOCHA, have been awarded the inaugural “Ocean Observing Team Award” by The Oceanography Society (TOS). This award recognizes innovation and excellence in sustained ocean observing for scientific and practical applications. The WBTS/RAPID/MOCHA team is recognized for significantly improving our understanding of Atlantic circulation through the breakthrough design of a basin-wide observing system using endpoint measurements to measure the variability of the overturning circulation across wide areas of the ocean. This design provided continuous, cost-effective measurements that led to a transformation in ocean observing and advances in scientific knowledge.

Read Full Article

Drones that hunt hurricanes? NOAA puts some to the test

Originally Published January 25th, 2021 at NOAA.Gov

“We’re hopeful this new technology, once it can be successfully tested in a hurricane environment, will improve our understanding of the boundary layer and advance NOAA forecast models used in forecasts,” said Joseph Cione, lead meteorologist at NOAA’s Atlantic Oceanographic and Meteorological Laboratory Hurricane Research Division. “Ultimately, these new observations could help emergency managers make informed decisions on evacuations before tropical cyclones make landfall.”

Read Full Article

Eye of the Storm: Observing Hurricanes with a Small Unmanned Aircraft System

Cione, J. J., Bryan, G. H., Dobosy, R., Zhang, J. A., de Boer, G., Aksoy, A., … & Chen, X. (2020). Eye of the storm: observing hurricanes with a small unmanned aircraft system. Bulletin of the American Meteorological Society, 101(2), E186-E205.

Abstract: Unique data from seven flights of the Coyote small unmanned aircraft system (sUAS) were collected in Hurricanes Maria (2017) and Michael (2018). Using NOAA’s P-3 reconnaissance aircraft as a deployment vehicle, the sUAS collected high-frequency (>1 Hz) measurements in the turbulent boundary layer of hurricane eyewalls, including measurements of wind speed, wind direction, pressure, temperature, moisture, and sea surface temperature, which are valuable for advancing knowledge of hurricane structure and the process of hurricane intensification. This study presents an overview of the sUAS system and preliminary analyses that were enabled by these unique data. Among the most notable results are measurements of turbulence kinetic energy and momentum flux for the first time at low levels (150 m) in a hurricane eyewall. At higher altitudes and lower wind speeds, where data were collected from previous flights of the NOAA P-3...

Read Full Paper.

Read Full Article

AOML Contributes to Global Carbon Budget 2020

On December 11, 2020 researchers with the Global Carbon Project released their annual update for the Global Carbon Budget. Daily global CO2 emissions are estimated to have decreased by a maximum of about 17% by early April 2020 compared to average levels in 2019. About half of this change is due to changes in surface transport, especially road transport, during the COVID-19 pandemic.

Read Full Article

Inferring Florida Current Volume Transport From Satellite Altimetry

Volkov, D. L., Domingues, R., Meinen, C. S., Garcia, R., Baringer, M., Goni, G., & Smith, R. H. (2020). Inferring Florida Current volume transport from satellite altimetry. Journal of Geophysical Research: Oceans, e2020JC016763.

Plain Language Summary: Florida Current (FC) is one of the major conduits of heat, salt, carbon, nutrients and other properties in the subtropical North Atlantic, with profound influences on regional weather, climate, sea‐level, and ecosystems. Daily monitoring of the FC volume transport with a submarine cable has been maintained nearly continuously since 1982. Because of the extremely high value of these measurements for Earth system studies, efforts are underway to find a suitable backup observing system for the inevitable future when the cable fails. Satellites have been providing accurate measurements of sea level for nearly 3 decades. Due to the Earth’s rotation, the direction of major oceanic currents is parallel to the lines of constant sea level, which for the FC translates into sea level near the Bahamas being about 1‐m higher than sea level along Florida east coast. Variations in the FC…

Read Full Paper.

Read Full Article

Interannual Variability of the South Atlantic Ocean Heat Content in a High‐Resolution Versus a Low‐Resolution General Circulation Model

Gronholz, A., Dong, S., Lopez, H., Lee, S. K., Goni, G., & Baringer, M. (2020). Interannual variability of the South Atlantic Ocean heat content in a high‐resolution versus a low‐resolution General Circulation Model. Geophysical Research Letters, e2020GL089908.

Plain Language Summary: In this study we analyze heat content changes of the upper South Atlantic Ocean and the impact of model resolution on these changes. Results from two numerical simulations are compared. One simulation with high‐resolution allows smaller‐scale processes directly, while the other simulation with low‐resolution does not. In both simulations oceanic heat transport dominates the ocean heat content changes on interannual time scale, while atmospheric fluxes play a secondary role. The heat anomalies, however, originate from different regions in the two simulations. While the oceanic heat transport from the south dominates in the high‐resolution simulation, oceanic heat transport from the north dominates in the low‐resolution simulation. Furthermore, wind‐induced surface heat transport plays a significant role in the low‐resolution while the heat transport in the high‐resolution simulation is dominated by…

Read Full Paper.

Read Full Article