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Author Posting. © The Oceanography Society, 2017. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 30, no. 2 (2017): 74–87, doi:10.5670/oceanog.2017.224., The Arabian Sea circulation is forced by strong monsoonal winds and is characterized by vigorous seasonally reversing currents, extreme differences in sea surface salinity, localized substantial upwelling, and widespread submesoscale thermohaline structures. Its complicated sea surface temperature patterns are important for the onset and evolution of the Asian monsoon. This article describes a program that aims to elucidate the role of upper-ocean processes and atmospheric feedbacks in setting the sea surface temperature properties of the region. The wide range of spatial and temporal scales and the difficulty of accessing much of the region with ships due to piracy motivated a novel approach based on state-of-the-art autonomous ocean sensors and platforms. The extensive data set that is being collected, combined with numerical models and remote sensing data, confirms the role of planetary waves in the reversal of the Somali Current system. These data also document the fast response of the upper equatorial ocean to monsoon winds through changes in temperature and salinity and the connectivity of the surface currents across the northern Indian Ocean. New observations of thermohaline interleaving structures and mixing in setting the surface temperature properties of the northern Arabian Sea are also discussed., The authors were funded through NASCar DRI grants. Additional support from the Global Drifter Program, grant NA15OAR4320071 (LC, VH); the CSL Laboratory at the NCAR CISL (Yellowstone ark:/85065/d7wd3xhc) (JMC); and the Department of Energy ACME project DE-SC0012778 (JMC) are gratefully acknowledged.

SDPS is a menu driven interactive program designed to facilitate the display and output of image and line-based data sets common to telemetry, modeling and remote sensing. This program can be used to display up to four separate raster images and overlay line-based data such as coastlines, ship tracks and velocity vectors. The program uses multiple windows to communicate information with the user. At any given time, the program may have up to four image display windows as well as auxiliary windows containing information about each image displayed. SDPS is not a commercial program. It does not contain complete type checking or error diagnostics which may allow the program to crash. Known anomalies will be mentioned in the appropriate section as notes or cautions., Funding was provided by the Office of Naval Research under contract Number N00014-86-K-0751; and by the National Aeronautic and Space Administration under contract No. 957652.

Author Posting. © The Author(s), 2013. This article is posted here by permission of Sears Foundation for Marine Research for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 71 (2013): 47-81, doi:10.1357/002224013807343416., Internal gravity waves in an area northeast of Taiwan are characterized using data from multiple sensor types. The data set includes intermittent information collected from a ship and short time series from moorings. Modeled nonlinear waves are fitted to observed nonlinear waves to provide self-consistent estimates of multiple wave parameters. A nonlinear internal wave of over 50 m amplitude, observed in deep water, is examined in detail. This wave was moving northward from the southern Okinawa Trough toward the continental shelf, and presumably formed from internal tides propagating northward from the Ilan Ridge area. A possible scenario for the formation of this wave from the internal tide is compared to related behavior south of Taiwan. On the outer continental shelf, a few large internal waves with maximum displacement greater than one-quarter of the water depth were measured with moorings. Sensors aboard ship and satellite recorded waves in this area traveling in many directions. Two possible causes (not mutually exclusive) for the multiple wave directions are scattering of nonlinear internal waves arriving from the south, and variable local generation of nonlinear gravity waves by the strong tidal and internal tidal currents. Internal tides on the shelf are relatively strong, among the strongest measured, having about 10 times greater kinetic energy density than numerous low-energy sites, which is consistent with the strong barotropic tides of the area. The ratio of diurnal baroclinic to barotropic kinetic energy found in this area is unusually high., Funding for the use of RV OR1 was provided by the National Science Council of Taiwan. TFD was supported by the Office of Naval Research (ONR) Ocean Acoustics Program under grants N00014-05-1-0482 and N00014-11-1-0194. AEN was supported under ONR grant N00014- 08-1-0763, and GG under ONR grant N00014-07-01-0482. HCG and MJC were supported by ONR grants N00014-09-1-0392 and N00014-07-1-0650.

This paper represents a consensus on the state-of-the-art in wind retrieval using synthetic aperture radar (SAR), after the SEASAR 2012 workshop “Advances in SAR Oceanography” hosted by the European Space Agency (ESA) and the Norwegian Space Centre in Tromsø, Norway 18–22 June 2012. We document the recent advances of the methodologies, which are capitalizing on the improved capabilities of the modern generation of SAR sensors providing Doppler grid and multi-polarizations. The many applications of SAR wind retrieval have also benefitted from on the improved availability of wide swath modes (~500 km) with excellent coverage, giving much better overview of regional and mesoscale wind features. The accuracy of offshore wind retrieval is robust and generally in the order of 1.5 m/s in speed and 20° in direction, whereas the new methodologies steadily improve the performance for the more challenging conditions near cyclones and complex coastal topography.

This proposal consists of six individual self-contained projects. A common component of all tasks is the exploitation of satellite imagery. The six projects are listed as the following tasks: a) Task 1: To determine the characteristics of typhoons with satellite SAR imagery and to measure with in-situ sensors the air-sea fluxes during the passage of typhoons. b) Task 2: To complement the acquisition and analysis of conventional radar intensity images and other data by direct high-resolution imaging of surface current fields from space by along-track InSAR. c) Task 3: To measure surface signatures and Bragg modulations during the passage of soliton packets. d) Task 4: To improve the characterizations of the Philippine Archipelago Straits dynamics we propose to acquire satellite data, in particular synthetic aperture radar (SAR) imagery of features and processes present in these straits. e) Task 5: To determine the structure, the seasonal and annual variability of the cold dome over the outer continental shelf northeast of Taiwan and the position and variability of the Kuroshio Current, in particular excursions onto the continental shelf. f) Task 6: To explore innovative uses for commercial radar applications. the best solution., Prepared in collaboration with CSTARS, University of Miami, Miami, FL.

Author Posting. © American Geophysical Union, 2004. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 109 (2004): C03006, doi:10.1029/2002JC001468., In order to examine spatial and temporal variability of the shelfbreak front during peak stratification, repeated surveys using a towed undulating vehicle (SeaSoar) are used to describe the evolution of shelfbreak frontal structure during 26 July to 1 August 1996 south of New England. Spatial correlation (e-folding) scales for the upper 60 m of the water column were generally between 8 and 15 km for temperature, salinity, and velocity. Temporal correlation scales were about 1 day. The frontal variability was dominated by the passage of a westward propagating meander that had a wavelength of 40 km, a propagation speed of 0.11 m s−1, and an amplitude of 15 km (30 km from crest to trough). Along-front geostrophic velocities (referenced to a shipboard acoustic Doppler current profilers) were as large as 0.45 m s−1, although subject to significant along-front variations. The relative vorticity within the jet was large, with a maximum 0.6 of the local value of the Coriolis parameter. Seaward of the front, a small detached eddy consisting of shelf water was present with a diameter of approximately 15 km. Ageostrophic contributions to the velocity field are estimated to be as large as 0.3 m s−1 in regions of sharp curvature within the meander. These observations strongly suggest that during at least some time periods, shelfbreak exchange is nonlinear (large Rossby number) and dominated by features on a horizontal scale of order 10 km., This work was performed under grants N-00014-95-1-0575 and N-00014-98-1-0059. as part of the ONR Shelfbreak PRIMER Initiative. Some additional analysis and writing was done under ONR grants N-00014-00-1-0931 and N-00014-01-1-0247.

This proposal consists of six individual self-contained projects. A common component of all tasks is the exploitation of satellite imagery. The six projects are listed as the following tasks: Task 1 -- Air-Sea Interactions in Typhoon Conditions; Task 2 -- Satellite Observations of Surface Signatures and Properties of Internal Waves in Straits; Task 3 -- Satellite Observations, Surface Signatures, and Properties of Nonlinear Internal Waves; Task 4 -- Satellite Observations of Surface Signatures in the Philippine Sea; Task 5 -- Satellite Observations of Oceanographic Processes for Quantifying, Predicting, and Exploiting Uncertainty (QPE); and Task 6 -- Exploitation of Commercial Satellite Radars. The long-term goal of this project is to employ satellite SAR imagery to the quantitative analysis of typhoons, internal waves, ocean surface features, sea state prediction, and coastal dynamics. To achieve this, a variety of satellite SAR sensors with different imaging frequencies, multi-polarizations, and different beam modes are used to determine which combination of the above capabilities could provide the best solution.

The long-term goal of this project is to develop a typhoon Synthetic Aperture Radar (SAR) wind algorithm for C-Band that can be modified to be applied to X-Band and L-Band SAR data. We begin with a multi-pronged approach that will include up to three different SAR wind and wave algorithms to be validated with in-situ observations and accurate model predictions during typical hurricane and typhoon conditions. The next step will be to modify these algorithms to allow both SAR data from L-band and X-band systems. The specific scientific objectives of this study are as follows: (1) to determine how accurately C-band wind algorithms can measure the wind vector field in tropical cyclones, such as hurricanes and typhoons; (2) to determine how accurately C-band wave algorithms can measure the properties of directional wave field in tropical cyclones, such as hurricanes and typhoons; (3) to examine how these wind and wave algorithms could be extended to perform for SAR data from L-band and X-band systems; (4) to determine a test data set of ground truth based on in-situ and airborne observations as well as highly accurate model predictions; and (5) to develop performance metrics that provides error statistics. The new typhoon wind model and complementary sea state and waves algorithm will provide unprecedented information about the intensity and structure of typhoons and hurricanes.

The specific scientific objectives of this study, to be carried out in collaboration with the Tidal Flat investigators, are: a) To describe the geomorphologic changes using historical satellite imagery. b) To improve our understanding of the dynamics of tidal flats during various phases of the tidal cycle using satellite SAR image data. c) Support the on-going experimental measurement phases with new satellite data acquisitions. d) To determine how SAR signatures can be related to the sedimentary and geotechnical properties of the tidal flat. e) To generate high resolution wind maps for improved understanding of the wind forcing variability and turbulence over tidal flats. f) To provide spatial snapshots of the dynamics during the flooding and ebbing stages governing tidal flats. g) Radar imaging of the wave field and translation of the images into snapshots of ?elevation maps" of the surface using both satellite and ship or floating platform based sensors. h) Measurements of the wave field and the atmosphere above the wave field using ASIS buoys to generate data sets that could be compared to wave models and radar both in the spectral and phase-resolved domains, and leads to a better understanding how the wind profile, fluxes, coefficient of drag vary with respect to differing wind and wave conditions. i) Measurements of breaking using acoustic and microwave means as well as in-situ sensors locally.