Search Results

You are looking at 1 - 10 of 19 items for :

  • Boundary currents x
  • CLIVAR - Western Boundary Currents x
  • All content x
Clear All
Kathryn A. Kelly, R. Justin Small, R. M. Samelson, Bo Qiu, Terrence M. Joyce, Young-Oh Kwon, and Meghan F. Cronin

1. Introduction In the strong Northern Hemisphere midlatitude western boundary current (WBC) systems—the Gulf Stream (GS) in the North Atlantic and the Kuroshio Extension (KE) in the North Pacific—there is a complex interaction between dynamics and thermodynamics and between the atmosphere and ocean ( Fig. 1 ). A precipitous drop in the meridional transport of heat in the Northern Hemisphere ocean occurs where these warm WBCs separate from the coast and flow into the ocean interior ( Trenberth

Full access
Shoshiro Minobe, Masato Miyashita, Akira Kuwano-Yoshida, Hiroki Tokinaga, and Shang-Ping Xie

currents in response to changes in surface wind speed, surface air temperature, and surface humidity (e.g., Namias 1959 ; Bjerknes 1964 ; Cayan 1992 ). Exceptions occur in regions of western boundary currents, such as the Gulf Stream and the Kuroshio, where SST anomalies are controlled by advection, resulting in a source of heat flux anomalies ( Dong et al. 2007 ; Tanimoto et al. 2003 ). There is observational evidence that the midlatitude ocean, especially western boundary currents, influences the

Full access
Terrence M. Joyce, Young-Oh Kwon, and Lisan Yu

2007 ) and are reflected in our results, which also derive from scatterometer wind measurements, although we have used the OAFlux winds at 1° × 1° resolution. A clear maximum of mean vorticity develops over the GS downstream of Cape Hatteras and the maximum positive vorticity follows the SST front of the GS much closer than that for the KE. This positive mean vorticity signature has been ascribed as being due to the ocean currents being reflected in the atmosphere boundary layer stress measurements

Full access
Haiming Xu, Hiroki Tokinaga, and Shang-Ping Xie

1. Introduction The Kuroshio Extension, the western boundary current of the North Pacific subtropical gyre, flows northeastward along the continental slope of the East China Sea, turns east through Tokara Strait, and proceeds eastward along the southern coast of Japan until it separates from the coast and enters the Pacific basin. It is well known that the Kuroshio south of Japan exhibits remarkable bimodal behavior between the large meander (LM) and the nonlarge meander (NLM) paths ( Taft 1972

Full access
Jeffrey Shaman, R. M. Samelson, and Eric Skyllingstad

wintertime air–sea fluxes that the heat advection supports, provide a second potentially important regional influence on the midlatitude atmosphere, as well as on the properties of North Atlantic mode water; this is true also of other western boundary currents in other ocean basins ( Kelly et al. 2010 ). Not only does North Atlantic mode water outcrop and form along the southern edge of the Gulf Stream, but the strong SST gradient across the Gulf Stream creates low-level baroclinicity in the troposphere

Full access
Young-Oh Kwon, Michael A. Alexander, Nicholas A. Bond, Claude Frankignoul, Hisashi Nakamura, Bo Qiu, and Lu Anne Thompson

1. Introduction Atmosphere–ocean interactions are exceptionally strong over western boundary currents and their eastward extensions (hereafter collectively WBCs): for example, the largest mean and variance at interannual and longer time scales of the net surface heat flux (Q net ) over the global ocean occurs in WBC regions ( Wallace and Hobbs 2006 ). Poleward heat transports by the ocean and atmosphere are comparable in the tropics, until the ocean transfers ~70% of its heat transport to the

Full access
Lu Anne Thompson and Young-Oh Kwon

changes in wind stress curl has been successfully modeled both in full ocean general circulation models ( Seager et al. 2001 ) and in simplified models ( Qiu 2003 ), the western boundary current systems remain difficult to model, particularly when the models do not resolve the mesoscale eddy field. Most coupled climate models are run with a low-resolution (∼1°) ocean component with low Reynolds’ number. The lack of eddy mixing and an eddy-driven recirculation gyre results in large biases in the KE and

Full access
James F. Booth, Lu Anne Thompson, Jérôme Patoux, Kathryn A. Kelly, and Suzanne Dickinson

) found that yearly anomalies of the time-filtered surface storm tracks in the Northern Hemisphere Pacific and Atlantic Oceans shift coherently with yearly anomalies in the western boundary currents (WBCs) location in the respective basins. Using 22 winters, they examined correlations between the surface storm tracks and the latent and sensible heat fluxes and the WBC variability. They found that there was significant change in the storm-track variability in concert with the changes in the Gulf Stream

Full access
Claude Frankignoul, Nathalie Sennéchael, Young-Oh Kwon, and Michael A. Alexander

be rather persistent because of SST anomaly reemergence, sustained forcing from the tropics, and low-frequency changes in oceanic heat advection. The extratropical SST variability is large near the strong SST gradients along the oceanic fronts associated with western boundary currents and their extensions (hereafter WBCs), especially at decadal time scales ( Nakamura et al. 1997 ; Nakamura and Kazmin 2003 ; Kwon et al. 2010a ), when the changes in the oceanic circulation are particularly

Full access
Masanori Konda, Hiroshi Ichikawa, Hiroyuki Tomita, and Meghan F. Cronin

evaporative heat release in the KE region on the midlatitude climate ( Liu and Wu 2004 ; Frankignoul and Sennéchael 2007 ). Local air–sea interaction analyses have generally focused on either the phase relationship between the sensible (SHF) and the latent heat flux (LHF) and the SST on monthly time scales ( Liu and Gautier 1990 ; Konda et al. 1996 ; Murakami and Kawamura 2001 ; Bond and Cronin 2008 ), or the effects of the SST on the stability of the atmospheric boundary layer (ABL) ( Nonaka and Xie

Full access