The scientific and societal uses of global measurements of subsurface velocity

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Szuts, Z. B., Bower, A. S., Donohue, K. A., Girton, J. B., Hummon, J. M., Katsumata, K., Lumpkin, R., Ortner, P. B., Phillips, H. E., Rossby, H. T., Shay, L. K., Sun, C., & Todd, R. E. The scientific and societal uses of global measurements of subsurface velocity. Frontiers in Marine Science, 6, (2019): 358, doi:10.3389/fmars.2019.00358.Ocean velocity defines ocean circulation, yet the available observations of subsurface velocity are under-utilized by society. The first step to address these concerns is to improve visibility of and access to existing measurements, which include acoustic sampling from ships, subsurface float drifts, and measurements from autonomous vehicles. While multiple programs provide data publicly, the present difficulty in finding, understanding, and using these data hinder broader use by managers, the public, and other scientists. Creating links from centralized national archives to project specific websites is an easy but important way to improve data discoverability and access. A further step is to archive data in centralized databases, which increases usage by providing a common framework for disparate measurements. This requires consistent data standards and processing protocols for all types of velocity measurements. Central dissemination will also simplify the creation of derived products tailored to end user goals. Eventually, this common framework will aid managers and scientists in identifying regions that need more sampling and in identifying methods to fulfill those demands. Existing technologies are capable of improving spatial and temporal sampling, such as using ships of opportunity or from autonomous platforms like gliders, profiling floats, or Lagrangian floats. Future technological advances are needed to fill sampling gaps and increase data coverage.This work was supported by the National Science Foundation, United States, Grant Numbers 1356383 to ZBS, OCE 1756361 to ASB at the Woods Hole Oceanographic Institution, and 1536851 to KAD and HTR; the National Oceanographic and Atmospheric Administration, United States, Ocean Observations and Monitoring Division and Atlantic Oceanographic and Meteorological Laboratory to RL; Royal Caribbean Cruise Ltd., to PBO; the Australian Government Department of the Environment and Energy National Environmental Science Programme and Australian Research Council Centre of Excellence for Climate Extremes to HEP; and the Gulf of Mexico Research Initiative Grant V-487 to LS

A Moving Magnetic Trap Decelerator: a New Source for Cold Atoms and Molecules

We present an experimental realization of a moving magnetic trap decelerator, where paramagnetic particles entrained in a cold supersonic beam are decelerated in a co-moving magnetic trap. Our method allows for an efficient slowing of both paramagnetic atoms and molecules to near stopping velocities. We show that under realistic conditions we will be able to trap and decelerate a large fraction of the initial supersonic beam. We present our first results on deceleration in a moving magnetic trap by bringing metastable neon atoms to near rest. Our estimated phase space volume occupied by decelerated particles at final velocity of 50 m/s shows an improvement of two orders of magnitude as compared to currently available deceleration techniques

The Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP): A platform for integrated multidisciplinary ocean science

The Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP) provides a globally coordinated network and oversight of 55 sustained decadal repeat hydrographic reference lines. GO-SHIP is part of the global ocean/climate observing systems (GOOS/GCOS) for study of physical oceanography, the ocean carbon, oxygen and nutrient cycles, and marine biogeochemistry. GO-SHIP enables assessment of the ocean sequestration of heat and carbon, changing ocean circulation and ventilation patterns, and their effects on ocean health and Earth’s climate. Rapid quality control and open data release along with incorporation of the GO-SHIP effort in the Joint Technical Commission for Oceanography and Marine Meteorology (JCOMM) in situ Observing Programs Support Center (JCOMMOPS) have increased the profile of, and participation in, the program and led to increased data use for a range of efforts. In addition to scientific discovery, GO-SHIP provides climate quality observations for ongoing calibration of measurements from existing and new autonomous platforms. This includes biogeochemical observations for the nascent array of biogeochemical (BGC)-Argo floats; temperature and salinity for Deep Argo; and salinity for the core Argo array. GO-SHIP provides the relevant suite of global, full depth, high quality observations and co-located deployment opportunities that, for the foreseeable future, remain crucial to maintenance and evolution of Argo’s unique contribution to climate science. The evolution of GO-SHIP from a program primarily focused on physical climate to increased emphasis on ocean health and sustainability has put an emphasis on the addition of essential ocean variables for biology and ecosystems in the program measurement suite. In conjunction with novel automated measurement systems, ocean color, particulate matter, and phytoplankton enumeration are being explored as GO-SHIP variables. The addition of biological and ecosystem measurements will enable GO-SHIP to determine trends and variability in these key indicators of ocean health. The active and adaptive community has sustained the network, quality and relevance of the global repeat hydrography effort through societally important scientific results, increased exposure, and interoperability with new efforts and opportunities within the community. Here we provide key recommendations for the continuation and growth of GO-SHIP in the next decade

Spatial and temporal evolution of a Gulf Stream crest-warm core ring interaction

An intensive, near-synoptic hydrographic study of the reabsorption of a warm core ring into the Gulf Stream at a meander crest was conducted near 70° W in fall 1988. Using a mixture of measurement techniques and statistical optimal interpolation to map the velocity and density fields, the study documents how the normally robust cross-stream structure of the Gulf Stream breaks down and the process by which a high pressure ridge between the stream and the ring develops. Examination of the layer potential vorticity (LPV) structure on two specific volume anomaly (δ) surfaces (approximately 18°C and 10°C) showed different characteristics of cross-stream LPV structure. On the shallower surface the cross-stream LPV structure was dominated by the cross-stream gradient of layer thickness; on the deeper surface the much weaker cross-stream LPV structure reflected the structure of the relative vorticity field. During the 10-day period of ring-stream contact, considerable water was exchanged, rupturing the ring and eventually resulting in the ring\u27s reentrainment by the Gulf Stream. Time-varying transports as large as 30 Sv were exchanged to the north and south between the surface and 5°C. The Gulf Stream bifurcates in such a way that the anticyclonic (southern) side continues through the meander crest uninterrupted, while the cyclonic side is diverted to the north to replace the low potential vorticity waters of the ring with waters of high potential vorticity. Contact between the ring and the stream is established first at the surface and progresses downward with increasing time. The decreased time needed to remove the ring\u27s vorticity in the lower layers is consistent with the geometrical picture of the Gulf Stream colliding with a bowl-shaped ring. The flushing time for the lens of δ (18°C) water in the ring is on the order of 5 days, slightly longer than the 2-3 days for the relative vorticity of the δ (10°C) surface. Copyright 1998 by the American Geophysical Union

Improving the Quality and Accessibility of Current Profile Measurements in the Southern Ocean

Like most modern oceanographic research vessels, RVIB Nathaniel B. Palmer and ARSV Laurence M. Gould are equipped with acoustic Doppler current profilers (ADCPs) for measuring the structure of ocean currents over a range of several hundred meters below the hull, both on station and while underway. It takes more than the ADCP itself, however, to yield good current measurements. The end result depends on how and where the sonar is installed; on the quality of ancillary information including position, heading, and, for some sonars, speed of sound at the transducer; on the data acquisition and processing techniques; and on ambient conditions of weather, ice, noise, and the availability of acoustic scatterers in the water (Firing and Hummon, 2010). In addition, the value of the measurements depends not only on their accuracy but also on their accessibility to scientific users both in near real time at sea and as a final product ashore

Five years of Florida Current structure and transport from the Royal Caribbean Cruise Ship Explorer of the Seas

Using ship‐of‐opportunity platform Explorer of the Seas, five years of full‐depth velocity data have been collected across the Florida Straits at 26°N. Between May 2001 and May 2006 the mean transport of the Florida Current was 31.0 ± 4.0 Sv. This compares to a mean transport of 32.4 ± 3.2 Sv inferred from cable voltages at 27°N over the same period, implying an average 1.4 Sv transport into the Straits through the Northwest Providence Channel. The climatological core of the Florida Current is 170 cms−1 and is positioned at 79.8°W, about 10 km east of the shelf break. The largest variability in velocity occurs over the shelf and shelf break and is likely related to shelf waves. A secondary maximum occurs across much of the Straits over the top 100 m of the water column and may be associated with wind events. The annual cycle of Florida Current transports has a range of 4.7 Sv, with a maximum in May–June–July and a minimum in January. The difference between the summer and winter current structure appears as a first baroclinic mode with zero crossing at 150 m. The maximum difference is about 15 cms−1 at the surface and is centered just offshore of the mean current core. On interannual timescales, low‐pass filtered Explorer and cable transports show similar downward trends between 2002 and 2005, but diverge over the last year or so of the record

Physical characteristics and evolution of a long-lasting mesoscale cyclonic eddy in the Straits of Florida

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Zhang, Y., Hu, C., Kourafalou, V., Liu, Y., McGillicuddy, D., Barnes, B., & Hummon, J. Physical characteristics and evolution of a long-lasting mesoscale cyclonic eddy in the Straits of Florida. Frontiers in Marine Science, 9, (2022): 779450, https://doi.org/10.3389/fmars.2022.779450.Ocean eddies along the Loop Current (LC)/Florida Current (FC) front have been studied for decades, yet studies of the entire evolution of individual eddies are rare. Here, satellite altimetry and ocean color observations, Argo profiling float records and shipborne acoustic Doppler current profiler (ADCP) measurements, together with high-resolution simulations from the global Hybrid Coordinate Ocean Model (HYCOM) are used to investigate the physical and biochemical properties, 3-dimensional (3-D) structure, and evolution of a long-lasting cyclonic eddy (CE) in the Straits of Florida (SoF) along the LC/FC front during April–August 2017. An Angular Momentum Eddy Detection Algorithm (AMEDA) is used to detect and track the CE during its evolution process. The long-lasting CE is found to form along the eastern edge of the LC on April 9th, and remained quasi-stationary for about 3 months (April 23 to July 15) off the Dry Tortugas (DT) until becoming much smaller due to its interaction with the FC and topography. This frontal eddy is named a Tortugas Eddy (TE) and is characterized with higher Chlorophyll (Chl) and lower temperature than surrounding waters, with a mean diameter of ∼100 km and a penetrating depth of ∼800 m. The mechanisms that contributed to the growth and evolution of this long-lasting TE are also explored, which reveal the significant role of oceanic internal instability.This work was supported by the NASA student fellowship program “Future Investigators in NASA Earth and Space Science and Technology” (FINESST, 80NSSC19K1358), the National Academies of Sciences, Engineering and Medicine (NASEM) UGOS-1 (2000009918), the NOAA IOOS SECOORA Program [IOOS.21(097)USF.BW.OBS.1], and the NOAA RESTORE Science Program (NA17NOS4510099)

CODAS+UHDAS Documentation

This website contains instructions for CODAS (Common Ocean Data Access System) processing of ship-mounted ADCP (Acoustic Doppler Current Profiler) data, and for operating the UHDAS (University of Hawaii Data Acquisition System) system for acquiring those data

CODAS+UHDAS Documentation

This upload had some extraneous information. See https://zenodo.org/record/8371260 This website contains instructions for CODAS (Common Ocean Data Access System) processing of ship-mounted ADCP (Acoustic Doppler Current Profiler) data, and for operating the UHDAS (University of Hawaii Data Acquisition System) system for acquiring those data

The Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP): A platform for integrated multidisciplinary ocean science

http://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr16-09_leg3/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr15-05_leg1/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr12-05_leg2/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr12-05_leg3/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr11-08_leg3/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr09-01_leg1/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr09-01_leg2/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr07-04/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr07-06_leg1/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr07-06_leg2/