All posts

This one had me nervous. We deployed our second array on February 15th, a terrifically calm day that went off without a hitch. A planned 20-day deployment is only now complete and has turned into a 53-day duration experiment. How did that happen? Well, turns out it was exceedingly challenging to find a time with co-operative weather such that the boat and dive team could operate.

Our team cannot operate safely when wind speeds are above 10 kts (5 m/s) or when waves are above 3 ft (1m), thresholds are indicated with a red dashed line. Notice there have not been many days recently where both conditions are met. I was then curious to know if this was “typical” for this time of year? Luckily NDBC buoys have long records of winds and waves.

So in retrospect, I guess I could have anticipated weather and scheduling related difficulties with this deployment period. I will be ready for this next year. Special shout-out to the field team and collaborators who were ready to step up at a moments notice to retrieve our gear while I was elsewhere this week.

If you are looking for a session and/or talks to see next week, check these out:

Monday, 02/19/24

2:00 – 3:00 pm CP13A: Nearshore Processes III Oral

“Modeled surf-zone eddies on a laboratory scale barred beach with varying wave period and directional spread” by Emma Shie Nuss (CP13A-05)
4:00 – 6:00 pm CP14B: Nearshore Processes IV Posters

“Spectral Wave Frictional Energy Dissipation Over Rocky Bathymetry” by Noah Clark (CP14B-1792)

Tuesday, 02/20/24

2:00 – 3:30 pm CP23B: Nearshore Processes VI Oral

“Modeling wave energy dissipation by bottom friction on rocky shores at the Monterey Peninsula, Central California” by Cesar Acevedo Ramirez (CP23B-02)
” Observations of Wave Dissipation by Bottom Friction on a Rough Rocky Shore” by Olavo Marques (CP23B-03)

2:00 – 3:30 pm CP23A: Coastal Ocean Modeling in Support of the Decisionmaking Process for Emergency Response, Resilience, Navigation, and the Blue Economy II Oral

“Pathways of cross-shelf exchange in a submarine canyon environment, Aotearoa New Zealand” by Phellipe Couto (CP23A-07)

Thursday, 02/22/24

4:00 – 6:00 pm CP44A: Buoyancy-Driven Flows in Estuaries and Continental Shelves IV Poster

“Developing a framework for the components of the baroclinic momentum balance on the inner shelf” by Andrea Rodriguez-Marin Freudmann (CP44A-1897)

4:00 – 6:00 pm CP44D: Mixing in Shelf Seas, the Nearshore, and Estuarine Environments I Poster
“Estimating Dissipation by Internal Waves from Moored Thermistor Chains” by Jacqueline McSweeney (CP44D-1951)

4:00 – 6:00 pm PI44A: Biophysical Interactions in the Southern Ocean Across Spatiotemporal Scales II Poster
“Episodic Summer Chlorophyll-a Blooms Driven by Along-Front Winds at Aotearoa’s Southeast Shelf Break Front” by Erik Johnson (PI44A-1723)

The ROXSI team just returned from a wonderful visit to the site of our next field experiment, the northwest shore of St. Thomas, USVI. Thank you to our great hosts from partner institution, UVI who showed us around the rugged volcanic coastline of the island by land and by sea. The variation in what can be consider a “rocky” coastline is truly remarkable. Surge channels and rocky caves, 30 degree cliff faces, sharp points, all within a couple kilometers! This is going to be a fascinating next couple of years.

Just before the weather turned, we were able to get out there and recover the array deployed for our first deployment on Frying Pan Shoals. The sea fuzz and muck were serious. Clean up and data download is gonna be a blast!

The Moana Project officially comes to a close this month. It has been a pleasure to work with the scientists and students to produce well-evaluated numerical products, collaborate with geneticists, chemists, and aquaculture specialists. We always hope that our work has impact! I was honored to visit and stay at the Whakatōhea Maori marae on the first hui, and was sorry to miss the final one. The Moana Project output, news and highlights are recorded here:

https://www.moanaproject.org/

and one more shout out to Dr. Mireya Montaño and the coastal Bay of Plenty model. Watch summer/winter particle releases and drifts:

As we head into the Fall, I want to give one more shout-out to the summer research students who came in and gave CEHG a boost! From designing and testing sampling plans, analysis of wave spectra, measuring currents from a jet ski, and teaching an AI to identify boat wakes, we learned a lot from you all in this short time. Hope to keep on seeing you around rocking those sweet T-shirts 😉

Erik Johnson has just published his first thesis chapter in JGR: Oceans! Erik analysed phytoplankton bloom events from southeast New Zealand and finds that the strength, duration, and location of the blooms in this area respond to the direction of episodic wind bursts because these winds alter ocean stratification. Check here for all the details:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022JC019609

Check out new work led by Dr. Rafael Santana of NIWA, published in Geoscientific Model Development,

https://gmd.copernicus.org/articles/16/3675/2023/

In this paper, Rafa looks at how assimilation of various ocean datasets can help (or hinder!) accurate simulation of the East Auckland Current region, one of the wilder Western Boundary Currents we have on our planet.

A completed bottom lander was successfully deployed and recovered(!) nearby ILM2 in Onslow Bay. We have been busy preparing and designing the lander and sampling scheme for this array, and I think we have converged on one. Thanks to all of the operations staff at CMS for their efforts on this. It will be exciting to see multiple landers in the water over the next 2 years. Stay tuned!

Big kudos to University of Otago PhD student, Erik Johnson, on submitting his PhD thesis! Erik has worked with satellite data, went on several RV Polaris cruises, and analyzed model output to tell a fascinating story of Otago shelfbreak episodic elevated primary productivity dynamics. Erik’s synthesis of event-to-weekly scale variability shows how local wind stress, when directed against the front (see image below) can stratify the water column and enhance productivity with a bloom strength as large as the seasonal cycle. Interestingly, the buoyancy advection is more consistent with small-scale submesoscale dynamics compared to Ekman transport. Congratulations, Erik!