1. Haskoning Australia Determining Circulation of the Great Barrier Reef Lagoon Using ADCP Data http://econews.com.au/ AiAiA – Gold Coast 2015 Heiko Loehr & Evan Watterson

2. OVERVIEW Intro: Great Barrier Reef (GBR) Lagoon ADCP Field Measurements Data Analysis Ocean Circulation in GBR Application of Results Excursion: Tropical Cyclones

3. GBR Lagoon 3

4. GBR Lagoon: Ocean Currents 4 South Equatorial Current

5. NCJ GBR Lagoon: Ocean Currents 5 Source: Andutta et al., 2013 South Equatorial Current NCJ – North Caledonia Jet NQC – North Queensland Current EAC – East Australian Current

6. GBR Lagoon: Study Site 6 Study Site Site 1 Site 2

7. GBR Lagoon: MetOcean 7

8. 8 Semi-diurnal tides Spring range: ~2m Neap range: ~0.8m Waves:

9. Field Measurements Two sites 9 months: Dec 2013 to Oct 2014 9 Site 1 Lat: -19°41.692’ Lon: 148°07.255’ Site 2 Lat: -19°48.000’ Lon: 148°18.000’ Instrument 600 kHZ ADCP (TRDI workhorse) & Nortek AWAC 600 kHZ ADCP TRDI Sentinel V Depth (m) 37 m CD43m CD Vertical resolution (bin size) 2m Current measurement intervals 10 minutes

10. Data Analysis Decomposition of measured current signal: 10

11. Data Analysis Decomposition of measured current signal: 11 Near Surface Mid-Water Near Bottom

12. Data Analysis 12

13. Data Analysis 13

14. Data Analysis 14

15. Data Analysis 15 Northerly wind

16. ADCP residual peak ~2.5x model Data Analysis 16 Northerly wind

17. Data Analysis 17 Northerly wind ADCP residual peak ~2.5x model South-Eastward ADCP residual

18. Data Analysis 18 Northerly wind South-Easterly wind

19. Data Analysis 19 Northerly wind SEC EAC Geostrophic Velocity Sealevel Anomaly Source: Integrated Marine Observing System

20. Data Analysis 20 Geostrophic Velocity Sealevel Anomaly SEC NQC EAC South-Easterly wind Source: Integrated Marine Observing System

21. Data Analysis 21 December-February February-April April-May M2 Constituent S2 Constituent

22. Data Analysis 22 December-February February-April April-May M2 Constituent S2 Constituent Directional variability of tidal currents Evidence of other drivers?

23. Data Validation 23 Source: Integrated Marine Observing System Study area Year: 2011 & Further Offshore!

24. Application 24 Hydrodynamic/ Sediment Transport Modelling of GBR Lagoon Tide + Wind only boundary conditions Good fit! Bad fit! Current Speed (m/s) Current Direction (degN) Blue – ADCP data Red – Model data

25. Blue – ADCP data Red – Model data Application 25 Tide + Wind + Ocean Current boundary conditions Good fit!

26. Application 26 Tide + Ocean Current boundary conditions Suspended Sediment Modelling

27. Excursion: Tropical Cyclones 27 Source: BoM

28. Excursion: Tropical Cyclones 28 TC Dylan

29. Excursion: Tropical Cyclones 29 B C Current Residual Echo Intensity Current Speed

30. Excursion: Tropical Cyclones 30 B C Current Residual Acoustic Backscatter Current Speed Valuable data for future study!!!

31. WWF.org.au Thank you 31 Any questions? Any questions? Heiko.Loehr@RHDHV.com

32. Literature Andutta, Fernando P., Ridd, Peter V. and Wolanski, E. (2013). The age and the flushing time of the great barrier reef waters, Continental Shelf Research, http://dx.doi.or /10.1016/j.csr.2012.11.016http://dx.doi.or CDM Smith (2013). Abbot Point Alternate Disposal Site Constraints Assessment. North Queensland Bulk Ports Corporation Choukroun, S., P. V. Ridd, R. Brinkman, and L. I. W. McKinna (2010). On the surface circulation in the western Coral Sea and residence times in the Great Barrier Reef, J. Geophys. Res., 115, C06013, doi:10.1029/2009JC005761 Codiga, D.L. (2011). Unified Tidal Analysis and Prediction Using the UTide Matlab Functions. Technical Report 2011- 01. Graduate School of Oceanography, University of Rhode Island, Narragansett, RI. 59pp. ftp://www.po.gso.uri.edu/ RHDHV (2014). Abbot Point DSAP Assessment, Numerical Modelling Report. Royal HaskoningDHV Vianna, M. L., Menezes, V. V. (2004) Subtidal Modulation of Tidal Currents on the Northeast Brazilian Shelf. Simpósio Brasileiro de Oceanografia, São Paulo, Brasil. Available from RDI http://www.rdinstruments.com Watterson, E. (2014). Operations Report, ADCP Current and Wave Monitoring, Abbot Point Dredge Disposal. Royal HaskoningDHV 32

33. Field Deployments 33

34. Stats 34

35. Stats pt2 35

36. Waves 36