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Caitlin Whalen

Senior Oceanographer

Affiliate Assistant Professor, Oceanography





Research Interests

Small-scale oceanic processes as viewed from global and regional scales including diapycnal mixing, internal waves, submesoscale dynamics, air–sea interactions, and mesoscale–internal wave interactions


B.A. Physics, Reed College, 2008

Ph.D. Physical Oceanography, University of California at San Diego, 2015


2000-present and while at APL-UW

Abyssal heat budget in the southwest Pacific basin

Lele, R., and 8 others including C.B. Whalen, "Abyssal heat budget in the southwest Pacific basin," J. Phys. Oceanogr., 51, doi:10.1175/JPO-D-21-0045.1, 2021.

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1 Nov 2021

The abyssal Southwest Pacific Basin has warmed significantly between 1992–2017, consistent with warming along the bottom limb of the meridional overturning circulation seen throughout the global oceans. Here we present a framework for assessing the abyssal heat budget that includes the time-dependent unsteady effects of decadal warming and direct and indirect estimates of diapycnal mixing from microscale temperature measurements and finescale parameterizations. The unsteady terms estimated from the decadalwarming rate are shown to be within a factor of 3 of the steady state terms in the abyssal heat budget for the coldest portion of the water column and therefore, cannot be ignored. We show that a reduction in the lateral heat flux for the coldest temperature classes compensated by an increase in warmer waters advected into the basin has important implications for the heat balance and diffusive heat fluxes in the basin. Finally, vertical diffusive heat fluxes are estimated in different ways: using the newly available CTD-mounted microscale temperature measurements, a finescale strain parameterization, and a vertical kinetic energy parameterization from data along the P06 transect along 32.5°S. The unsteady-state abyssal heat budget for the basin shows closure within error estimates, demonstrating that (i) unsteady terms have become consequential for the heat balance in the isotherms closest to the ocean bottom and (ii) direct and indirect estimates from full depth GO-SHIP hydrographic transects averaged over similarly large spatial and temporal scales can capture the basin-averaged abyssal mixing needed to close the deep overturning circulation.

Decreased stratification in the abyssal southwest Pacific basin and implication for the energy budget

Zhang, H.J., C.B. Whalen, N. Kumar, and S.G. Purkey, "Decreased stratification in the abyssal southwest Pacific basin and implication for the energy budget," Geophys. Res. Lett., 48, doi:10.1029/2021GL094322, 2021.

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16 Oct 2021

The large scale circulation of the ocean is primarily driven by density differences. As dense, heavy water sinks, it fills the deep ocean basins and aids in pushing water around the globe, cycling around the world over many centuries. A key location where this happens is around Antarctica. The ice and cold winds cool the water, making it denser. This cooled water sinks, displacing the deep water and pushing it northwards. As Antarctica warms, this water carries the extra heat into the rest of the world, causing the deep ocean to rapidly warm. In the Southwest Pacific Basin, we find that this bottom intensified warming has caused a significant reduction in the stratification of the deepest layer over the past three decades. This change can disrupt the global ocean conveyor belt, impacting the transport of heat, carbon dioxide, nutrients, and other dissolved matter around the world.

New technological frontiers in ocean mixing

Frajka-Williams, E., J.A. Brearley, J.D. Nash, and C.B. Whalen, "New technological frontiers in ocean mixing," in Ocean Mixing: Drivers, Mechanisms and Impacts, M. Meredith and A. Naveira Garabato, eds., 345-361, doi:10.1016/B978-0-12-821512-8.00021-9 (Elsevier, 2022).

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17 Sep 2021

This chapter gives an overview of recent advances in in situ observations of ocean mixing. It starts by providing a brief history of measuring ocean mixing. It then describes adaptations of traditional measurements and methods to autonomous platforms, including profiling floats and autonomous underwater vehicles. For each approach, the method is described as well as its limitations. Evidence for successful application of each method is provided.

More Publications

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center