Physical controls on the seasonal migration of the North Pacific transition zone chlorophyll front

Thumbnail Image



Journal Title

Journal ISSN

Volume Title

Repository Usage Stats


Citation Stats


The large seasonal migration of the transition zone chlorophyll front (TZCF) is of interest because a number of marine fauna, both commercial and endangered, appear to track it. Herein we examine the physical dynamics driving this seasonal migration of the TZCF. Vertical processes, traditionally viewed as controlling the dynamical supply of nutrients to surface waters, prove insufficient to explain seasonal variations in nutrient supply to the transition zone. Instead, we find that the horizontal Ekman transport of nutrients from higher latitudes drives the TZCF's southward migration. The estimated horizontal transport of nitrate supports up to 40% of new primary productivity in the region annually and nearly all of new primary productivity in the winter. The significance of horizontal advection to the North Pacific transition zone supports revising the paradigm that nutrients are supplied to surface waters from below. © 2010 by the American Geophysical Union.






Published Version (Please cite this version)


Publication Info

Ayers, JM, and MS Lozier (2010). Physical controls on the seasonal migration of the North Pacific transition zone chlorophyll front. Journal of Geophysical Research: Oceans, 115(5). p. C05001. 10.1029/2009JC005596 Retrieved from

This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.



M. Susan Lozier

Ronie-Richele Garcia-Johnson Emerita Professor of Earth and Ocean Sciences

Susan Lozier is a physical oceanographer with interests in large-scale ocean circulation. Upon completion of her PhD at the University of Washington, she was a postdoctoral scholar at Woods Hole Oceanographic Institution. She has been a member of the Duke faculty since 1992. Professor Lozier was the recipient of an NSF Early Career Award in 1996, was awarded a Bass Chair for Excellence in Research and Teaching in 2000, received a Duke University Award for Excellence in Mentoring in 2007, was named an American Meteorological Society Fellow in 2008, a Distinguished Professor in 2012, a Fellow of the American Geophysical Union in 2014 where she has been elected as president elect. She begins her two-year term as president-elect on Jan. 1, 2019, and then will serve a two-year term as AGU president beginning in 2021. She was named a Fellow of the American Association for the Advancement of Science in 2015. She currently serves as the past-president of The Oceanography Society and is the international lead for the OSNAP (Overturning in the Subpolar North Atlantic Program) observing system.

Unless otherwise indicated, scholarly articles published by Duke faculty members are made available here with a CC-BY-NC (Creative Commons Attribution Non-Commercial) license, as enabled by the Duke Open Access Policy. If you wish to use the materials in ways not already permitted under CC-BY-NC, please consult the copyright owner. Other materials are made available here through the author’s grant of a non-exclusive license to make their work openly accessible.