Coherent Lagrangian Pathways from the Surface Ocean to Interior (CALYPSO) Departmental Research Initiative


The vertical movement of water from the surface to depth across the base of the mixed layer has implications for the transport of properties, gases, biogeochemistry, and the fate of drifting particles/objects. But, vertical velocities are very weak (about a thousand times smaller than horizontal velocities) and difficult to detect.  In order to determine that forecast systems can properly represent these motions we need to answer the following critical questions:

  • How are water and properties from the surface boundary layer exported to depth?
  • What coherent pathways act as conduits for exchange?
  • What dynamics shapes these pathways? What are the Lagrangian trajectories, what are the time and space scales of subduction and where does the water end up?
  • Can we predict these pathways in 3-Dimensions and what data are needed to aid or constrain predictive models?

Previous work in this area of study has been funded and published by ONR funded research on Coherent Dynamical Systems and the “3-D plus time” Multidisciplinary University Research Initiative (MURI) research initiative. These programs established the theoretical and mathematical basis for predicting coherent Lagrangian structures in the ocean. Confirmation of the predictive theory has only been accomplished in the horizontal dimension and the observational study and confirmation of predictive theories for 3-dimensions plus time have not yet been demonstrated.

Goal of the DRI

  • Establish an understanding and predictive capability of the three-dimensional coherent pathways by which water carrying tracers and drifting objects is transported from the surface ocean to depths below the mixed layer.
  • Design and implement an observational study to test the theories, hypothesis, and predictions of the 3-D, time evolving Lagrangian pathways.
  • Iteratively improve the predictive models with process, scale, and parameterizations gleaned from the observational and theoretical work.


Calypso aims to advance the state of science for:

  • Modeling vertical transport between the mixed layer and pycnocline on a range of scales, and including interactions between mesoscale dynamics and submesoscale processes.
  • Theoretical and dynamical understanding toward improved predictability. Using knowledge of the surface ocean dynamics (at mesoscales), gain predictability of Lagrangian subduction pathways from the surface to interior (at submesoscales).
  • Measurement capabilities for vertical velocity and three-dimensional trajectories. We envision a heterogeneous multi-platform experiment with the use of autonomy to enable cooperation and refine sampling strategies. A field experiment will be designed to measure vertical velocities and three-dimensional trajectories at the submesoscale (~1 km) within the context of a mesoscale (~100 km) oceanic front.

This study is anticipated to take place in the Southwest Mediterranean Sea, which harbors an unstable front between salty Mediterranean water and the relatively fresh Atlantic water entering through Gibraltar. This location was identified in pilot studies and provides an ocean laboratory with predictable frontal structures of the appropriate scale and energetics. We anticipate that the study will be in partnership with scientists from the Mediterranean Institute for Advanced Studies - Spanish National Research Council and the University of the Balearic Islands (IMEDEA (CSIC-UIB)) and the Balearic Islands Coastal Observing and Forecasting System (SOCIB Research Infrastructure), in Mallorca, Spain, who conducted a cutting edge experiment “AlborEx” in the region in 2014.

Request for Planning Letters

The first step in the DRI process is for prospective investigators to prepare planning letters. The purpose of the planning letters is to allow investigators to submit a short (three pages maximum) summary of their ideas on this topic for ONR to evaluate, provide technical feedback and indicate whether a full proposal would have a reasonable chance of success.

Important Dates

July 31, 2017: Last date to submit planning letters (submit by email)
August 31, 2017: Last date ONR will respond to all submitted planning letters and requests for proposals
October 30, 2017: Nominal due date for encouraged proposals
November 30, 2017: Earliest anticipated commencement of awards made with FY18 funding - dependent on USG budgetary process

All planning letters should be submitted by email to:

Dr. Terri Paluszkiewicz (

Please use the following naming convention in your email submission: CALYPSO planning letter from "Your Name" in your email subject line. If you do not receive a thank you note within 10 days, please follow-up with a resend. If you do not receive a response by August 31st, please send an inquiry by email.

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