OASIS - The Zappa Lab

Observatory for Air-Sea Interaction Studies
Lamont-Doherty Earth Observatory

Led by Prof. Christopher J Zappa, the Observatory for Air-Sea Interaction Studies (OASIS) is affiliated with the Lamont-Doherty Earth Observatory (LDEO) within the Columbia Climate School, Columbia University. OASIS conducts observational research focused on the oceanic and atmospheric boundary layers. This includes ocean waves and wave breaking, air-sea CO₂ exchange, near-surface ocean and atmospheric turbulence, and boundary-layer processes of heat, mass, and momentum transport. The group develops and deploys instruments including infrared, multispectral, and polarimetric cameras, as well as turbulence sensors, on fixed and mobile platforms such as ships, ocean towers, moorings, drifting buoys, and uncrewed airborne systems (UAS). The study areas range from laboratory wind-wave tanks, to rivers and estuaries, to shelf seas and polynyas, to the open ocean, from the poles to the equator.

Updates

Research Projects

Selected Publications

Lab Members & Participation Guide

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Research Highlights

Air-Sea Interaction & Wave-Related Processes
As wind blows over the ocean, waves form, grow, interact with each other, and eventually break. The presence of waves on the sea surface impacts the exchange of energy, momentum, heat, and gases. In particular, small-scale gravity-capillary waves (meter to millimeter scale waves) have an outsized impact on ocean-atmosphere interactions. However, detailed observations of these waves are scarce. We use a variety of methods to measure these waves and the turbulent flow above and below the sea surface, including polarimetric and infrared imagery, LiDAR, sonic anemometry, and pulse-coherent acoustic doppler current profilers (ADCPs).

Project Website

Upper Ocean Processes
A number of globally relevant phenomena modify the structure of the surface ocean over vertical scales of meters, affecting ocean–atmosphere coupling. Because these near-surface processes have limited vertical scales and occur intermittently in time, they are challenging to represent accurately in both fundamental physical theory and computational modeling. Their effects must also be accounted for when making in-situ and remote sensing measurements of the ocean surface. We conduct observational process studies of these phenomena, acquiring comprehensive in-situ measurements of the near-surface ocean and atmosphere. We leverage these novel datasets to interrogate physical theory and state-of-the-art models, ultimately advancing fundamental understanding of the ocean and improving representations of air–sea coupling in weather and climate forecasting.

Antarctic Oceanography
In 2017 aboard the R/V Araon, we deployed a mooring equipped with instruments to measure temperature, salinity, wave characteristics, ice thickness, and vertical current velocities in Terra Nova Bay, Ross Sea in order to understand the formation and vertical mixing of High Salinity Shelf Water (HSSW), an important constituent of the Antarctic Bottom Water that drives global ocean circulation.

Ikaaġvik Sikukun
Bridging the scientific and indigenous communities: Sea Ice Change in Arctic Alaska.

Project Website

The Sea Surface Microlayer Universe
A multi-disciplinary and multi-institutional effort to increase our understanding of the significance and role of the air-sea interface (sea surface microlayer, SML) as the boundary layer controlling atmosphere-ocean interactions. The first phase of this project took place in 2016 on the R/V Falkor in the Timor Sea. The second phase is ongoing. The second phase took place in 2019 in Fiji.

Project Website

Selected Publications

Hogan, L., Zappa, C. J., Cifuentes-Lorenzen, A., Edson, J. B., O’Donnell, J., Ullman, D. S. (2025), Observations of Breaking Wave Dissipation and Their Relationship to Atmosphere-Ocean Energy Transfer, Journal of Geophysical Research: Oceans, e2024JC022130, doi: 10.1029/2024JC022130.

Witte, C. R., Zappa, C. J. (2025), The Response of Large Diurnal Warm Layers to Short-Term Variability in Solar and Wind Forcing: Observations and Physical Modeling, American Meteorological Society: Journal of Physical Oceanography, 55, 771–786, doi: 10.1175/JPO-D-24-0106.1.

Laxague, N. J. M., Zappa, C. J., Soumya, S., Wurl, O. (2024), The suppression of ocean waves by biogenic slicks, Nature Communications, 21:20240385, doi: 10.1098/rsif.2024.0385.

Miller, U. K., Zappa, C. J., Gordon, A. L., Yoon, S., Stevens, C., Lee, W. S. (2024), High Salinity Shelf Water production rates in Terra Nova Bay, Ross Sea from high-resolution salinity observations, Nature Communications, (2024)15:373, doi: 10.1038/s41467-023-43880-1.

Witte, C. R., C. J. Zappa, and J. B. Edson (2023), The Response of Ocean Skin Temperature to Rain: Observations and Implications for Parameterization of Rain-Induced Fluxes, Journal of Geophysical Research: Oceans, 128(1), e2022JC019146, doi:10.1029/2022JC019146.

Miller, U. K., C. J. Zappa, S. F. Zippel, J. T. Farrar, and R. A. Weller (2023), Scaling of Moored Surface Ocean Turbulence Measurements in the Southeast Pacific Ocean, Journal of Geophysical Research: Oceans, 128(1), e2022JC018901, doi:10.1029/2022JC018901.

Zippel, S. F., J. T. Farrar, C. J. Zappa, and A. J. Plueddemann (2022), Parsing the Kinetic Energy Budget of the Ocean Surface Mixed Layer, Geophysical Research Letters, 49(2), e2021GL095920, doi:10.1029/2021GL095920.

Witte, C. R., C. J. Zappa, A. R. Mahoney, J. Goodwin, C. Harris, R. E. Schaeffer, R. Schaeffer Sr, S. Betcher, D. D. W. Hauser, N. J. M. Laxague, J. M. Lindsay, A. Subramaniam, K. E. Turner, and A. Whiting (2021), The Winter Heat Budget of Sea Ice in Kotzebue Sound: Residual Ocean Heat and the Seasonal Roles of River Outflow, Journal of Geophysical Research: Oceans, 126(9), e2020JC016784, doi:10.1029/2020JC016784.

Laxague, N. J. M., and C. J. Zappa (2020), The impact of rain on ocean surface waves and currents, Geophysical Research Letters, 47(7), e2020GL087287, doi:10.1029/2020GL087287.

Zappa, C. J., S. M. Brown, N. J. M. Laxague, T. Dhakal, R. A. Harris, A. M. Farber, and A. Subramaniam (2020), Using ship-deployed high-endurance unmanned aerial vehicles for the study of ocean surface and atmospheric boundary layer processes, Frontiers in Marine Science, 6(777), doi:10.3389/fmars.2019.00777.

Laxague, N. J. M., and C. J. Zappa (2020), Observations of mean and wave orbital flows in the ocean’s upper centimetres, Journal of Fluid Mechanics, 887, A10, doi:10.1017/jfm.2019.1019.

Brumer, S. E., C. J. Zappa, B. W. Blomquist, C. W. Fairall, A. Cifuentes-Lorenzen, J. B. Edson, I. M. Brooks, and B. J. Huebert (2017), Wave-related Reynolds number parameterizations of CO2 and DMS transfer velocities, Geophysical Research Letters, 44(19), 9865-9875, doi:10.1002/2017GL074979.