Planning float deployments from Denman voyage

[yuhang559]

Our DP24 brings 2 EM-APEX floats to the Denman voyage. One will have temperature microstructure on it. We are working out where to deploy them and the aim is to target a place where we are most confident of westward propagation.

To do list:

• [x] put a large number of floats in the model and look at their trajectories (done by Max).
• [ ] overlay sea ice information on the more northern trajectories
• [ ] water properties and velocities from the model along the trajectories/ even just in the region of the trajectories to inform ballasting of the floats
• [ ] separate the flow into mean and EKE during the months of deployment at different depth levels

[yuhang559]

Put a large number of floats in the model and look at their trajectories (done by Max): Max released 1000 floats in the red box (indicating the possible released area) and another 1000 floats in the blue box on March 1. These floats were then advected for 2 months with their positions saved every 1 hour.
The gif file of the float trajectories The floats are plotted at all depth. Interestingly, there are a couple of blue floats that make it into the Denman Glacier cavity, around day 20 and again for longer around day 37...

[yuhang559]

I am working on presenting the sea ice conditions along the trajectories of floats released from the red box (the potential released area). The left panel shows the sea ice concentration in March with floats released after 10 days and the right panel shows the sea ice concentration in April with floats released after 40 days. The magenta line indicates the 0.15 sea ice concentration threshold and the dashed line shading the regions covered by sea ice.

[LauraHeBo]

Thanks so much Max and Yuhang. This is very useful! THe trajectories are quite different between the two regions. Do you mind reminding me how the trajectories are tracked, please? Is it flow at the surface / mid-depth/ bottom ? I am thinking about the depth at which the floats will drift. I cannot remember what the value is, and whether these floats have an ice-avoidance algorithim. If they do, then, it is likely that the floats will spend less time near the surface, and the currents at the drift depth will be driving where the floats go (theoretically).

[MaxNikurashin]

Hi Laura,

These particles are at different depths and track the local velocities at their respective depths. In this particular release, I specified that the particles maintain their depth, so they are only advected by the horizontal velocities.

Cheers, Max