J. Thomas Farrar

Research

SWOT

Surface Water and Ocean Topography satellite mission.

SWOT satellite mission image

Selected papers

Wang et al. (2025), SWOT mission validation of sea surface height measurements at sub-100 km scales (GRL). link

Kachelein et al. (2025), Sub-100 km ocean processes revealed by structure functions of SWOT sea surface height and in situ observing network (JGR). link

Fu et al. (2024), The Surface Water and Ocean Topography mission: A breakthrough in radar remote sensing of the ocean and land surface water (GRL). link

Wang et al. (2022), On the development of SWOT in-situ calibration/validation for short-wavelength ocean topography (JTECH). link

Chelton, Samelson, and Farrar (2022), Effects of uncorrelated measurement noise on SWOT estimates of SSH, velocity, and vorticity (JTECH). link

Morrow et al. (2019), Global observations of fine-scale ocean surface topography with the SWOT mission (Frontiers in Marine Science). link

S-MODE

S-MODE is a NASA Earth Venture Suborbital investigation that combines novel aircraft remote sensing techniques with coordinated measurements from ships and a fleet of uncrewed vehicles and other measurement platforms to study submesoscale ocean dynamics (scales less than about 10 km) and their contribution to vertical transport in the upper ocean. Oceanic fronts and the submesoscale instabilities that develop on them are thought to be important for vertical transport in the upper ocean, but these rapidly evolving features have been difficult to observe in detail. High-resolution computational models produce the features, but they need to be checked against observations. S-MODE addresses these challenges with coordinated sampling from three research aircraft, a research vessel, and dozens of uncrewed surface and subsurface platforms.

Text from Farrar et al. (2025), Bulletin of the American Meteorological Society: 10.1175/BAMS-D-23-0178.1 (AMS page).

S-MODE observing system schematic
S-MODE sea-surface temperature and current map

Selected papers

Farrar et al. (2025), S-MODE: the Sub-Mesoscale Ocean Dynamics Experiment (BAMS). link

Westbrook et al. (2024), Submesoscale Ocean Dynamics Experiment (S-MODE) data submission report (WHOI Technical Report). link

Tropical Dynamics

Figure credit: Farrar et al. (2021), Journal of Physical Oceanography. 10.1175/JPO-D-20-0048.1

Tropical dynamics figure from Farrar et al. 2021

Selected papers

Farrar, Durland, Jayne, and Price (2021), Long-distance radiation of Rossby waves from the equatorial current system (Journal of Physical Oceanography). link

Hasson et al. (2019), Intraseasonal variability of surface salinity in the eastern tropical Pacific associated with mesoscale eddies (Journal of Geophysical Research: Oceans).

Lee et al. (2018), Monitoring and interpreting the tropical oceans by satellite altimetry (Satellite Altimetry Over Ocean and Land Surfaces).

Greatbatch et al. (2018), Evidence for the maintenance of slowly varying equatorial currents by intraseasonal variability (Geophysical Research Letters).

Zuidema et al. (2016), Challenges and prospects for reducing coupled climate model SST biases in the eastern tropical Atlantic and Pacific Oceans (BAMS). link

Farrar and Durland (2012), Wavenumber-frequency spectra of inertia-gravity and mixed Rossby-gravity waves in the equatorial Pacific Ocean (Journal of Physical Oceanography).

Durland and Farrar (2012), The wavenumber-frequency content of resonantly excited equatorial waves (Journal of Physical Oceanography).

Farrar (2011), Barotropic Rossby waves radiating from tropical instability waves in the Pacific Ocean (Journal of Physical Oceanography).

Farrar (2008), Observations of the dispersion characteristics and meridional sea level structure of equatorial waves in the Pacific Ocean (Journal of Physical Oceanography).

Farrar and Weller (2006), Intraseasonal variability near 10 N in the eastern tropical Pacific Ocean (Journal of Geophysical Research). link

Air-Sea Interaction Measurements from Buoys

Buoy-based observing studies of upper-ocean and air-sea interaction processes. UOP SAFARI project page.

Selected papers

Riihimaki et al. (2024), Ocean surface radiation measurement best practices (Frontiers in Marine Science). link

Zippel et al. (2022), Parsing the kinetic energy budget of the ocean surface mixed layer (GRL). link

Joseph et al. (2022), Longwave radiation corrections for the OMNI Buoy Network (JTECH). link

Zippel et al. (2021), Moored turbulence measurements using pulse-coherent Doppler sonar (JTECH). link

Schlundt et al. (2020), Accuracy of wind observations from open-ocean buoys: correction for flow distortion (JTECH). link

Weller et al. (2019), Moored observations of surface meteorology and air-sea fluxes in the northern Bay of Bengal (Journal of Climate). link

Wijesekera et al. (2016), ASIRI: An ocean-atmosphere initiative for Bay of Bengal (BAMS). link

Schmitt et al. (2015), SPURS-2: Diagnosing the physics of a rainfall-dominated salinity minimum (Oceanography). link

Farrar et al. (2015), Salinity and temperature balances at the SPURS central mooring during fall and winter (Oceanography). link

Weller et al. (2016), Air-sea interaction in the Bay of Bengal (Oceanography). link

Air-Sea Interaction Measurements from Uncrewed Surface Vehicles

Uncrewed surface-vehicle observations of air-sea interaction and upper-ocean processes.

Wave Glider on ship deck

Selected papers

Bhuyan et al. (2026), Acoustic Doppler current profiler measurements from Saildrones with applications to submesoscale studies (JTECH). link

Grare, Lenain, and Farrar (2025), Observing ocean-atmosphere fluxes from autonomous surface vehicles (GRL). link

Hodges et al. (2023), Evaluation of ocean currents observed from autonomous surface vehicles (JTECH). link

Middleton et al. (2025), Observations of a splitting ocean cyclone resulting in subduction of surface waters (Science Advances). link

Zhang et al. (2019), Comparing air-sea flux measurements from a new unmanned surface vehicle and proven platforms during SPURS-2 (Oceanography). link

Rainville et al. (2019), Novel and flexible approach to access the open ocean: Uses of the Research Vessel Lady Amber during SPURS-2 (Oceanography). link