An integrated catchment and coastal

forecasting system for the Great Barrier Reef

Brassington, Tuteja, Stuart, TreleavenColberg, Sandery, Sakov, Freeman, Sakova, Allen, Laugesen,

Brinkman, Tonin, Beaman, Wilkin

ACOMO, Canberra, Oct 2016

Mechanical stress

Thermal stress

Water quality stress

pH stress

Multiple and integrated stress

NTCAusWAVE

NTCAusWAVE eReefs

Coastal ocean prediction system – design decisions

PHYSICAL OCEANOGRAPHY – first system• Physical ocean – feasible/mature (apply methodologies from BLUElink)• Adoption of ROMS (non-trivial decision)• BGC – maturing/R&D challenge (CSIRO making good progress)• River discharge volume• River nutrients modelled by passive tracers/Lagrange particles

500m

4km

SST

• ROMS-FC: • 4km: 512x128x30 ~2,000,000

• ROMS-HR:• 500m: 4327x1565x25 ~ 170,000,000

Simulations:1. Hindcast (2006 -2011)2. Nature run (2009-2011)3. Reanalysis EnOI/ EnKF

(2006 -2011)

Swaines

Palm Passage

Elusive Reef

• Bathymetry – blended product• GBR 100 (Rob Beaman, JCU)• GA Plus 250m (James Daniell)• GA 250m (Whitewell)

Model configuration

Hindcast simulations

Himawari-8 night-time composite9 Jan 2016

Modelled circulation

Yongala

Palm passage

Capricorn channel

Elusive reef

OB

SO

BS

MO

DE

LM

OD

EL

OB

SO

BS

MO

DE

LM

OD

EL

ROMS-HR +CFSR vs QIMOS/AIMS moorings

PHYSICAL OCEANOGRAPHY – first system• Physical ocean – feasible/mature (apply methodologies from BLUElink)• Adoption of ROMS (non-trivial decision)• BGC – immature/R&D challenge (CSIRO making good progress)• River nutrients modelled by passive tracers/Lagrange particles

OBSERVING SYSTEM• Real-time observations (deep water) - feasible• Lagoon observations – limited (R/T) require enhancement (Himawari-8, TGs)

Coastal ocean prediction system – design decisions

Observations – real-time and delayed

Himarwari-8

PHYSICAL OCEANOGRAPHY – first system• Physical ocean – feasible/mature (apply methodologies from BLUElink)• Adoption of ROMS (non-trivial decision)• BGC – immature/R&D challenge (CSIRO making good progress)• River nutrients modelled by passive tracers/Lagrange particles

OBSERVING SYSTEM• Real-time observations (deep water) - feasible• Lagoon observations – limited (R/T) require enhancement (Himawari-8, TGs)• Predictability transition (forced shallow chaotic shelf break)

Coastal ocean prediction system – design decisions

Is the GBR well mixed?

Is the GBR well mixed ?

Sandery et al., 10 yr GBR reanalysisMonthly correlation SST to BT

PHYSICAL OCEANOGRAPHY – first system• Physical ocean – feasible/mature (apply methodologies from BLUElink)• Adoption of ROMS (non-trivial decision)• BGC – immature/R&D challenge (CSIRO making good progress)• River nutrients modelled by passive tracers/Lagrange particles

OBSERVING SYSTEM• Real-time observations (deep water) - feasible• Lagoon observations – limited (R/T) require enhancement• Predictability transition (forced shallow chaotic shelf break)

DATA ASSIMILATION/ENSEMBLE FORECASTING• Ensemble KF vs Ensemble OI (not exploiting ROMS adjoint capability)

• Sample atmospheric forecast uncertainty• Sample river discharge uncertainty

FORCING SYSTEM• BRAN/OceanMAPS + TIDES• ACCESS-R + Ensemble perturbations• RIVER DISCHARGE (VOLUME + LOADS)

Coastal ocean prediction system – design decisions

Coastal ocean – reanalysis

IMOS ABOM GHRSST AVHRR L3S night time analysis

Daily mean from 3-day forecast with overlay of unassimilated super observations

21 May 2009

Coastal ocean – reanalysis

IMOS SRS ocean colour centred 3 day composite image from Aqua

satellite

Daily mean from 3-day forecast with overlay of unassimilated super observations

Catchment monitoring

Great Barrier Reef Catchment Loads Monitoring Program (Australian and Queensland Govt.)

eReefs catchment forecasts will use near real time rainfall and water level stations

25 eReefs catchments~ 25 water quality monitoring locations

across the Reef catchments

Catchment modeling

Water forecasts for most catchments meet performance benchmark (1st

stage – whole of catchment, daily)

Fitzroy at Rockhampton

Measured TSS (mg L-1

)

0 200 400 600 800 1000 1200 1400

Estim

ate

d T

SS

(m

g L

-1)

0

500

1000

1500

Mean prediction

1 to 1

5%

95%

Multivariate regression model for 7 water quality constituents (TSS, DIN, PN, DIP, PP, DON and DOP)

Reasonably good performance except for very few outliers

Catchment system

eReefs

Catchment

Modelling

System

Daily forecasts (25)

ROMS

SHOC/RECOM

Operation-ready

registered user website

Derived web products

Water quality forecasts

Web and Data Services

BGC

Select

“best”

forecastHourly forecasts

(ungauged areas)

Hourly forecasts

(7 catchments)

Catchment forecast services (daily updates)

Water quantity forecast Water quality forecast

Verification: water quantityVerification: water quality (annual load)

ROMS-FC

ROMS-HR

Yellow: Catchment locationsRed: River mouth locations

• Methodology• Explicit modelling of estuaries • (1) Aim to preserve river volume• Balance between model stability and (1)

River channels

Coastal ocean – river plumes

Upper: Modelled surface passive tracer (left) and associated age (right) are shown.

Lower: Surface salinity (left) and SST (right) during flooding period.

• Movement over reef northward. Further to the east southward movement within the EAC.

• River plumes tend to turn left hence moving northward over the southern hemisphere

• During this event, 2 westerly wind burst occur that advect the plume to the east

eReefs Marine Water Quality DashboardIndicator: Chlorophyll-a concentration (Chl)

Date: W08 2009 (16/02/2009 - 22/02/2009)

100 km

Bright Earth e-Atlas Basemap v1.0 (AIMS, GBRMPA, JCU, DSITIA, GA, UCSD, NASA, OSM, ESRI) CC BY

Print - Map http://www.bom.gov.au/marinewaterquality/

1 of 2 2/02/16 12:05 PM

eReefs Marine Water Quality DashboardIndicator: Chlorophyll-a concentration (Chl)

Date: W09 2009 (23/02/2009 - 01/03/2009)

100 km

Bright Earth e-Atlas Basemap v1.0 (AIMS, GBRMPA, JCU, DSITIA, GA, UCSD, NASA, OSM, ESRI) CC BY

Print - Map http://www.bom.gov.au/marinewaterquality/

1 of 2 2/02/16 12:05 PM

Burdekin river plume - 2009

16 F

EB

-22 F

EB

23 F

EB

-1 M

AR

Burdekin flood 2009

Integrated system – next steps

DEC 2017

JUN 2017

DEC 2016

Release of GBR Nature run Release of GBR reanalysis 1.0 => Draft paperHimawari-8 merged L2P data + Quality control

GBR reanalysis 2.0 [ROMS(4km)+EnKF]Forecast system [ROMS(4km)+EnKF+ACCESS]

Hindcast trial - ROMS(4km)+EnKF+ACCESSProbabilistic river tracer concentration mapsRiver particle density maps