Tina Geller, PhD student (INSTAAR/ATOC)

INSTAAR Seminar Series. Hybrid event, in person and via Zoom
Tina will give one of three grad student talks during the hour

Audience: All are welcome

Location: Online and in SEEL 303. 4001 Discovery Drive, Boulder, CO. Coffee, cookies, and PIZZA will be served.

Special note:  The SEEL building is usually locked. If you do not have access to the SEEL building, please enter through the SEEC-SEEL bridge located in the south side of SEEC (next to SEEC S249). Someone will hold the door there from 11:45 AM-noon.

After presentation: There will be time for informal discussion with the speaker after the presentation.

Abstract: Lagoons along the Alaskan Beaufort Sea coast are seasonally productive during ice-free months (i.e., the open water season) and support diverse food webs that include or sustain fish, migratory birds, polar bears, and whales. Nutrients are the base of these food webs, and their transport at the coast is modulated by highly variable lagoon circulation and inlet fluxes. To characterize open-water circulation in Beaufort Sea lagoons, a numerical model was implemented for a connected system of five lagoons that vary in river input and shelf connectivity. Specifically, the Regional Ocean Modeling System (ROMS) was implemented for July to October of 2019 for Arey, Kaktovik, Jago, Tapkaurak, and Oruktalik Lagoons. The model accounts for winds, rivers, shelf circulation, and tides. Preliminary results show that transport within the lagoons and lagoon-shelf fluxes vary in magnitude and direction, corresponding to shifts in winds and shelf currents. Additionally, from early to late summer, as river discharge decreases, the delay between freshwater entry and exit increases. The response of circulation to different forcings varies among the lagoons, however. Kaktovik Lagoon, with no direct shelf connection, has the smallest inlet fluxes and is shielded from large swings in salinity and temperature with river discharge. Jago, Tapkaurak, and Oruktalik Lagoons, located on the east side of the chain, have no physical barriers separating them, and therefore function as one lagoon that becomes fresher and warmer with river discharge but is quickly flushed with shelf water during a strong wind or current event. Arey Lagoon, on the west side of the chain, has the largest river influence and the largest inlet fluxes. These preliminary results suggest that nutrients will remain longer in more protected Beaufort Sea lagoons and will be exported to the shelf in greater amounts during time periods with high wind and strong offshore currents.