Oceanography The Official Magazine of
The Oceanography Society
Volume 28 Issue 01

View Issue TOC
Volume 28, No. 1
Pages 66 - 77

Variability in Near-Surface Salinity from Hours to Decades in the Eastern North Atlantic: The SPURS Region

Stephen C. Riser Jessica AndersonAndrey ShcherbinaEric D’Asaro
Article Abstract

We examine the variability of near-surface salinity in a 10° × 10° region of the eastern North Atlantic, the location of the first part of the Salinity Processes in the Upper-ocean Regional Study (SPURS-1). The data used were collected over a two-year period, largely by a group of two types of profiling floats equipped with sensors that record high-resolution temperature and salinity measurements in the upper few meters of the water column. By comparing the SPURS-1 measurements to observations in the area from previous decades, we examine variability at time scales ranging from a few hours (mostly consisting of rainfall-driven decreases in salinity) to diurnal cycles in temperature and salinity, seasonal variability and the annual cycle, and finally to decadal-scale changes. The relationship of near-surface salinity to the hydrological cycle suggests a continuous spectrum of variability in this cycle from hours to decades.


Riser, S.C., J. Anderson, A. Shcherbina, and E. D’Asaro. 2015. Variability in near-surface salinity from hours to decades in the eastern North Atlantic: The SPURS region. Oceanography 28(1):66–77, https://doi.org/10.5670/oceanog.2015.11.


Anderson, J., and S. Riser. 2014. Near-surface variability of temperature and salinity in the near-tropical ocean: Observations from profiling floats. Journal of Geophysical Research 119:7,433–7,448, https://doi.org/10.1002/2014JC010112.

D’Asaro, E. 2003. Performance of autonomous Lagrangian floats. Journal of Atmospheric and Oceanic Technology 20:896–911, https://doi.org/10.1175/1520-0426(2003)020<0896:POALF>2.0.CO;2.

Drushka, K., S. Gille, and J. Sprintall. 2014. The diurnal salinity cycle in the tropics. Journal of Geophysical Research 119:5,874–5,890, https://doi.org/10.1002/2014JC009924.

Durack, P., and S. Wijffels. 2010. Fifty-year trends in global ocean salinities and their relationship to broad-scale warming. Journal of Climate 23:4,342–4,362, https://doi.org/10.1175/2010JCLI3377.1.

Farrar, J.T., L. Rainville, A.J. Plueddemann, W.S. Kessler, C. Lee, B.A. Hodges, R.W. Schmitt, J.B. Edson, S.C. Riser, C.C. Eriksen, and D.M. Fratantoni. 2015. Salinity and temperature balances at the SPURS central mooring during fall and winter. Oceanography 28(1):56–65, https://doi.org/10.5670/oceanog.2015.06.

Fu, L.-L., D. Chelton, P.-Y. LeTraeon, and R. Morrow. 2010. Eddy dynamics from satellite altimetry. Oceanography 23(4):14–25, https://doi.org/10.5670/oceanog.2010.02.

Gentemann, C., C. Donlon, A. Stuart-Menteth, and F. Wentz. 2003. Diurnal signals in satellite sea surface temperature measurements. Geophysical Research Letters 30, 1140, https://doi.org/10.1029/2002GL016291.

Gray, A., and S. Riser. 2014. A global analysis of Sverdrup balance using absolute geostrophic velocities from Argo. Journal of Physical Oceanography 44:1,213–1,229, https://doi.org/10.1175/JPO-D-12-0206.1.

Riser, S.C., J. Nystuen, and A. Rogers. 2008. Monsoon effects in the Bay of Bengal inferred from profiling float-based measurements of wind speed and rainfall. Limnology and Oceanography 53:2,080–2,093, https://doi.org/10.4319/lo.2008.53.5_part_2.2080.

Roemmich, D., and J. Gilson. 2009. The 2004–2008 mean and annual cycle of temperature, salinity, and steric height in the global ocean from the Argo program. Progress in Oceanography 82:81–100, https://doi.org/10.1016/j.pocean.2009.03.004.

Schanze, J., R. Schmitt, and L. Yu. 2010. The global oceanic freshwater cycle: A state-of-the-art quantification. Journal of Marine Research 68:569–595, https://doi.org/10.1357/002224010794657164.

Soloviev, A., and R. Lukas. 2006. The Near-Surface Layer of the Ocean: Structure, Dynamics, and Applications. Springer, 572 pp.

Wunsch, C. 1972. The spectrum from two years to two minutes of temperature variability in the main thermocline at Bermuda. Deep Sea Research 19:577–593, https://doi.org/10.1016/0011-7471(72)90041-1.

Yang, J., S.C. Riser, J.A. Nystuen, W.E. Asher, and A.T. Jessup. 2015. Regional rainfall measurements using the Passive Aquatic Listener during the SPURS field campaign. Oceanography 28(1):124–133, https://doi.org/10.5670/oceanog.2015.10.