ROMS Modelling in Australia: current status, plans and aspirations:

Transcription

1 ROMS Modelling in Australia: current status, plans and aspirations: John F Middleton, Moninya Roughan, Chari Pattiaratchi, Greg Ivey, Ryan Lowe, Jessica Benthuysen. and teams : John Luick, Charles James, Mark Doubell, Helen Phillips, Helen MacDonald, Mark Baird, John Wilkin, Sarath Wijeratne, Jones, Brinkman, Wake, McConocie Regions and Applications Generic Problem Aspirations Recommendations

2 1) South-East ROMS - NSW, 2) Southern Australian Regional Ocean Model - SARDI, 3) High Resolution Spencer Gulf Model (hydrodynamic, waves, particles, NPZD - SARDI) 4) Kimberley (internal tides) Ivey 5) Pilbara (internal tides) Ivey 6) Cyclone impacts Ivey 7) Ningaloo upwelling Lowe 8), 9) and 10) Pattiaratchi. 11) WA/SA very large scale model (dashed) - Pattiaratchi

3 Internal tides on NWS: Modelling of Kimberley shelf region (ROMS): Greg Ivey Rayson, Ivey, Pattiaratchi, Jones, Brinkman (2011). Journal of Geophysical Research Oceans, C01016, doi: /2009jc005881

4 Shelf modelling around the NW Cape: Nested modelling of Ningaloo Pilbara region (ROMS) Ryan Lowe Xu, Lowe, Ivey, Pattiaratchi, Jones, Brinkman (2012). Journal of Geophysical Research Oceans, in revision.

5 The Leeuwin Current: the roles of topographic trapping, mixing, and advection in a buoyancy driven eastern boundary current Jessica Benthuysen and team. What processes contribute to the poleward current s shelfbreak intensification? Alongshore geostrophic current. (cm/s) Meridional current (cm/s) Shelf water ρ u Ekman +8 cm/s -29 cm/s 29.5 o S

6 ROMS: West and southern Australia model- Chari and team Project: Ocean-shelf exchange with an emphasis on the roles of waves, tides, eddies and cross-shelf flows on carbon exchange (funded through ANNiMS) Winter snap-shot of temperature & Salinity Curvilinear-orthogonal grid, 2-4 km and 30 sigma layers Forcing: wind, air pressure, air sea fluxes (heat and freshwater) and tides. Open boundaries: monthly salinity and temperature climatology, monthly mean sea levels.

7 Example features Ningaloo and Shark Bay- Sporadic upwelling Bonny summer upwelling Satellite Satellite ROMS ROMS ROMS ROMS Dense water formation and cascading, WA shelf Temp Sigma-t Sal v- vel Temp Sigma-t Sal v- vel Summer Winter

8 Southern Australian Regional Ocean Model (SAROM) Johns Middleton, Luick and team Validation: against SST, historical and SAIMOS Mooring and CTD data ( ) right Applications to date: Studies of Spencer Gulf a) Dynamics and Speddies (Teixeira) b) OBC for High Res Spencer Gulf Model

9 SAROM Climatological forcing: SG dynamics and Speddies (Teixeira)

10 Larval TRANs prawn larval dispersal (Doubell) Fennel NPZD carrying capacity in SG (Doubell& James). SWAN Wave model detritus re suspension for NPZD (James) (mmol/m 3 ) Swimming Percentage settled after 45 days = 48 % +, non settled, settled SAROM Applications

11 SEA ROMS (Sth East Australian ROMS) Moninya Roughan and team Fennel Biological Model Physical Model Oct 2009 simulation of the formation of an EAC Cold core eddy. Initial Conds SynTS + CARS The physical model has a 5 day spinup. Biological model is initialised after this biological output is examined from day 7. NO3, NH4, Phytoplankton, Zooplankton, small and large detritus Initial nitrate concentrations from CARS Oct average with some adjustment to account for mixed layer depth to match that of the physical model. All other variables initialized with a small seeding population. BCs Northern boundary, nudged back to initial conditions, East and South are radiative. H. Macdonald PhD Research unpublished Team: Macdonald, Roughan, Baird, Wilkin

12 Day 16 Day 17 Day 18 Model SST Obs SST Zooplankton Phytoplankton Nitrate N P Z H. Macdonald PhD Research unpublished

13 Generic Problems The Models: ROMS is well supported through various web sites, has lots of bolt on routines (eg SWAN NPZD). Implementation can be challenging. Australian user group would help along with annual ROMS meetings Meteorological Forcing: BOM LAPS, ACCESS good quality but spatial and temporal gaps and no easy access via web. Can this be improved? NCAR/NCEP and ECMRF web sites are easily accessible and provided 4 times per day but coarse resolution. (. (1.9 o X 1.9 o and 0.75º x 0.75º ). NOAA/NCDC provides a blended 6 hourly 0.25 o Sea Surface Wind product.

14 Generic problems (cont.) Boundary Forcing: ROMS can be embedded in global models such as Bluelink and HYCOM care is needed to ensure exact balances of mass transports result. Errors in Bluelink/HYCOm will result in errors in child (nested) model.

15 Generic problems (cont.) Initial Conditions: CARS provides temperature and salinity data interpolated onto a (1/4 o X 1/4 o ) grid, at a year of weekly interval averages. The data set was last updated in 2008 and needs to be updated using the IMOS data collected since then and allowance made for ENSO and non ENSO years which can be important on the western and southern shelves.

16 Generic problems (cont.) CARS needs updating IMOS task? Alternatively SynTS can be used for model initialisation and for time varying boundary forcing from the surface to 2000m depth Skill gaps modelling : NPZD, assimilation, embedding child models inside parents share experiencs /advances Skill gaps physics: correct siting of backward b.c. s in regional models;

17 Aspirations where would we like to go? Proposed Research (unfunded as yet) UNSW: Investigate Predictability of the EAC given Strong constraint 4D VAR Data Assimilation. Strong uptake of IMOS data streams. SARDI/CSIRO: Great Australian Bight SARDI/MISA: Whole of ecosystem Spencer Gulf &Gulf St Vincent Development of local models to be informed by Australian efforts as a whole.

18 Recommendations? Annual Aust. ROMS meeting (tag on to other eg AMSA/AMOS Use of Bluelink/HYCOM MARVL Met data: Can BoM improve access to ACCESS? CARS needs updating to include all data Skill gaps (NPZD, assimilation): annual meeting will help Physics,Not to forget ROMS = Regional Oceanography Mathematical Solutions

19 Recommendations (cont.) Development of a ROMS/IMOS toolbox for model display/validation? eg.,matlab streamline vector plot software

20 Coupled SWAN ROMS Model of Spencer Gulf 30 Day Simulation of SWAN (stand alone) and Coupled SWAN ROMS. Wavewatch III forcing of SWAN on Southern and Western boundaries ACCESS Wind forcing of both SWAN and ROMS model. Significant Wave Height and Direction Similar Coupled model shows increased significant wave height, especially along Eastern side and near top of Spencer Gulf.