aesop: assessing the effects of submesoscale ocean parameterizations

1

AESOP: Assessing the Effects of Submesoscale Ocean Parameterizations

Program Overview

Scott HarperCode 322, Physical Oceanography

Office of Naval [email protected]

2

AESOP: A Departmental Research Initiative

AESOP is a Code 32 “DRI” (all ONR money)

Programs within Code 32 pitch new DRI topics to management during an annual competition (the programs are taxed to provide the funding pool)

Typically three new topics are chosen each year

Represent a 6.1 (Basic Research) investment in a topic area of recognized naval interest

Recent initiatives have been of O(5 years) and O($7 mil)

Goal is to support focused efforts to make progress in difficult or emerging scientific areas

3

AESOP: Program Goals

Primary goal: define new methods and metrics to assess the submesoscale parameterizations used in basin and coastal ocean models, specifically with respect to their impact on synoptic model predictions

(For our purposes: sub-mesoscale ~ 100 m to 10 km)

The focus is on the actual representation and evolution of the ocean state in short-term (one week) model predictions, to determine how well the numerical parameterizations are capturing the unresolved physics in real time.

(Somewhat similar NSF’s ‘CPT’s, but for the real ocean)

4

AESOP: Formal Project Participants

ObservationsMike Gregg (APL/UW)Eric D’Asaro (APL/UW)James Girton (APL/UW)Shaun Johnston (Scripps)Jody Klymak (Scripps)Eric Kunze (UVic)Craig Lee (UW/APL)Rob Pinkel (Scripps)Dan Rudnick (Scripps)

ModelingJim McWilliams (UCLA)Enrique Curchister (LDEO/Columbia)Raffaele Ferrari (MIT)Oliver Fringer (Stanford)Ramsey Harcourt (APL/UW)Rich Hodur / Jim Doyle (NRL-MRY)Alexey Kaplan (LDEO/Columbia)Bill Large (NCAR)John Marshall (MIT)Jennifer MacKinnon (Scripps)Sutanu Sarkar (UCSD)Bob Street (Stanford)

5

AESOP: Schedule

Initial Kickoff Meeting, March 8-9, 2005

APL/UW, Seattle, WA

Field experiment: Monterey Bay area, August 2006

6

AESOP: Preliminary Observational Plans

Mike Gregg / Jack Miller

Explore and map diapycnal mixing, likely enhanced in this region by the interactions between the bathymetry and internal waves and tidal currents

A 14-day cruise is planned with:

– ship-mounted acoustic backscattering system

– bottom-mounted ADCPs– towed microstructure

profilers

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.



7


Jody Klymak / Rob Pinkel

Quantify the strength of the internal tide, rate of energy conversion to smaller scales, and energy pathways and rates of the dissipation mechanisms

R/P FLIP will be moored for one

month near the 1500m isobath (the generation site for the on-shore internal tide), equipped with two Doppler sonars and two rapidly profiling CTD’s





8


Shaun Johnston / Dan Rudnick

Provide hydrography and microstructure measurements of the upper 400m at 3km/6m resolution, and current profiles down to 600m at 6-20m resolution

R/V Roger Revelle will be requested for a one month cruise, towing a SeaSoar with CTD, fluorometer, and transmissometer





9


James Girton / Eric Kunze

Examine the IW energy and momentum fluxes on the continental slope (500m-2000m), the energy transfer to higher wave numbers, and structure of the bottom boundary layer

Ship time required for the XCP and and vertical microstructure surveys extending from the shelf out across the shelf break.



10


Eric D’Asaro / Craig Lee

Examine the horizontal and vertical mixing in regions of strong lateral variability (where the dynamics are truly three dimensional)

A combined program of three neutrally buoyant Lagrangian drifters deployed in a region of large horizontal gradients, with a towed Triaxus survey constantly crossing over the location of the drifters for several days





11

AESOP: Preliminary Modeling Plans

Jim McWilliams / Bob Street / Oliver Fringer





Nesting of non-hydrostatic SUNTANS code within the ROMS framework, to address the non-hydrostatic effects of the IW and internal tide generation and dissipation on the shelf (in conjunction with the NLIWI DRI)

Sutanu Sarkar

Comparison and coupling of ROMS with Fine Resolution LES code (FRLES), using momentum and buoyancy fluxes to compare against the collected observational data set

12


John Marshall / Raf Ferrari

Exploring the super-parameterization technique in the non-hydrostatic MITgcm code

Alexey Kaplan / Bill LargeEnrique Curchister

Running ROMS model at different resolutions and filtering the contribution of various mixing parameterizations to explore the impact of resolution



13


Jen MacKinnon

LES modeling to explore wave-wave interactions on the shelf, to guide the observational program and provide additional insight into energy conversion

Ramsey Harcourt

Running LES models of regions with large lateral gradients, using the Lagrangian and Triaxus observations of D’Asaro and Lee, to determine if the budgets can be closed locally





14

AESOP: Project Summary

Some products we hope to generate:

• new methods for assessing parameterizations

• new knowledge about submesoscale ocean processes

• a data set of sufficient temporal and spatial resolution to be used for future parameterization studies

• insight into the relative importance of different processes at various resolutions

• information on how current parameterizations affect ocean predictions

• new metrics to evaluate ocean models and their predictions

15

Logistics Summary

AESOP will try to work with all programs to share whatever data can be provided in real-time

Need to coordinate with ASAP to get the ocean forecasts (required for the Lagrangian float deployment and Triaxus survey), and with all projects operating in the region to gather observations for use in hindcasts and diagnostics

There are going to be a lot of assets in the water, and coordination will be required for the UNOLS requests (the AWACS/SWA06 experiment is taking place on the east coast at roughly the same time)

aesop: assessing the effects of submesoscale ocean parameterizations

Documents

iw energy

energy pathways

energy transfer

new topics

microstructure measurements

rate of energy conversion

ocean state

pitch new dri topics