Inundation modeling and remote sensing in Cook Inlet with applications for morphology changes and Beluga whales movement

Tal Ezer Center for Coastal Physical Oceanography (CCPO) & Virginia Modeling, Analysis & Simulation Center (VMASC) Old Dominion University (ODU)

In collaboration with: Leo Oey, AOS, Princeton University (developed POM-WAD) Hua Liu, Geog. Dept., ODU (remote sensing)

Supported by: MMS (model development) NOAA/Fisheries (Belugas studies) ODU Office of Research (remote sensing) POM-WAD (POM with Wetting And Drying) scheme developed to works with 3D ocean circulation models including stratification, wind, rivers, eddies, deep-ocean circulation, Side view surface waves, data assimilation, etc. (Oey, 2005, 2006). Top view

Method: Solve full 3-D PE and impose blocking conditions based on D=H+

1. WETMASK = 0 for D  Hdry, = 1 otherwise.

2. Uij=0 if (Dij+Di-1,j)/2  Hdry

3. uijk=Uij if WETMASKij*WETMASKi-1,j =0 The WAD scheme has been tested for 1D and 2D idealized cases such as Tsunami Waves.

At landfall:  ≈ 10 m u ≈ 15 m/s Testing WAD in 3D POM-WAD Model: 1. Curvilinear grid (0.5-1 km) 2. Topography of mud-flat areas 3. Temp./Sal. stratification 4. Winds from local NOAA stations 5. Rivers runoff from USGS 6. Tidal forcing in south boundary

Sensitivity Studies: 1. with/without WAD 2. with/without rivers 3. with/without stratification

Applications: 1. Processes: rip tides, tidal bores, etc. 2. Beluga whale movement 3. Remote sensing: - evaluate model inundation - construct mudflat topography - study morphology changes References (http://www.ccpo.odu.edu/~tezer/Pub.html; http://aos.princeton.edu/WWWPUBLIC/PROFS/)

POM-WAD Inundation Model • Oey L-Y (2005) A wetting and drying scheme for POM. Ocean Modelling, 9: 133-150. • Oey LY (2006) An OGCM with movable land-sea boundaries. Ocean Modelling, 13: 176-195. • Saramul, S. and T. Ezer, Tidal-driven dynamics and mixing processes in a coastal ocean model with wetting and drying, Ocean Dynamics, doi:10.1007/s10236-009-0250-1, In Press, 2010. Cook Inlet Model • Oey, L.-Y., T. Ezer, C. Hu and F. Muller-Karger, Baroclinic tidal flows and inundation processes in Cook Inlet, Alaska: Numerical modeling and satellite observations, Ocean Dynamics, 57, 205-221, doi:10.1007/s10236-007-0103-8, 2007. Remote Sensing in CI • Ezer, T. and H. Liu, Combining remote sensing data and inundation modeling to map tidal mudflat regions and improve flood predictions: A proof of concept demonstration in Cook Inlet, Alaska. Geophys. Res. Let., 36, L04605, doi:10.29/2008GL036873, 2009. • Liu, H. and T. Ezer, Integration of Landsat imagery and an inundation model in flood assessment and predictions: A case study in Cook Inlet, Alaska, The 17th International Conference on Geoinformatics, Fairfax, VA, August 12-14, IEEE Xplore Publ., 2009. Beluga Whales in CI • Ezer, T., R. Hobbs and L.-Y. Oey, On the movement of beluga whales in Cook Inlet, Alaska: Simulations of tidal and environmental impacts using a hydrodynamic inundation model, Oceanography, Vol. 21, No. 4, 186-195, 2008. The amplification of the tides in the inlet are simulated quite well (no calibration/BC adjustment!) Anchorage

Nikiski

Seldovia

Kodiak Island mod

obs Upper Inlet Processes: Mud flats wetting/drying Tidal bores Knik Arm

Turnagain Arm The transition of the salinity front with the tides is very different in the two arms (implication for biol.?)

low tide high tide

slow draining during ebb tidal “bore” flood

m/s

Velocity and tide level in Turnagain Arm

ebb Central Cook Inlet: Strong tidal velocities over narrow channels cause “Rip-Tides” (drifter data from Mark Johnson, UAF)

EKE Model: Flood brings salty water from the Gulf of Alaska, ebb brings fresh water from the rivers in the upper inlet- the fronts cause “rip tides” in the central inlet.

High Tide Low Tide Model-data Comparison of salinity at different tidal stages shows a qualitative agreement, but some deficiencies (e.g., not enough freshwater river input  weaker salinity fronts)

Observed Model Vertical Velocity Model sensitivity tests show that river discharge is  With Rivers Discharge essential for the development of the Rip Tides

 No Rivers (only weak vertical stratification from climatology data)

 Homogeneous Water Ezer et al., Oceanography, Vol. 21, No. 4, December, 2008

Belugas in Cook Inlet are the most geographically and genetically isolated of the five Alaska stocks (Hobbs et al., O’Corry et al.)

Can Belugas location be predicted from Anchorage sea level? Satellite data may provide a way to evaluate the wetting and drying in the model

MODIS (MODerate resolution Imaging Spectroradiometer) data Model at low tide during low tide Anchorage Anchorage

15 km

MODIS images from the Terra (a) (b) & Aqua satellites (1:45 h apart) show the progress of exposing land during ebb.  Can we use more images to map the flooded regions? NOAA Navigation Charts: No topography resolution: t~10s, x~500m data for mudflats or upper Turnagain Arm!

resolution: t~16d, x~30-60m resolution: t~1-2d, x~250-500m

Water Level Prediction:

(x,y,t)=obs(t)A(x,y)cos[B(x,y)]+C(x,y)

obs=observed WL in Anchorage A, B, C = empirical parameters obtained from the statistics of the inundation model EBB

Shoreline and water level during one tidal cycle

FLOOD A1

A3 A5 A2 A4

A2 A4

A1 Water Level

A3 The inundated area of the mudflats can A5 be calculated from the satellite data Observing long-term morphological changes in the mudflats (all images taken ~2h after flood started in Anchorage) 3D CI topography derived from combining ~25 satellite images for inundated regions with model topography for deep regions Thank You