Search Results

You are looking at 11 - 20 of 43 items for :

  • Climate Implications of Frontal Scale Air–Sea Interaction x
  • All content x
Clear All
Ryusuke Masunaga, Hisashi Nakamura, Takafumi Miyasaka, Kazuaki Nishii, and Bo Qiu

region, turbulent sensible heat flux (SHF) and latent heat flux (LHF) from the ocean surface are enhanced into a cool dry continental air mass carried by the prevailing monsoonal northerlies (e.g., Kwon et al. 2010 ), especially along the KE because of locally augmented air–sea temperature differences (e.g., Taguchi et al. 2009 ; Tanimoto et al. 2011 ). It has been argued that sharp meridional contrasts in SHF across SST fronts act to restore near-surface baroclinicity efficiently, contributing to

Full access
Ryusuke Masunaga, Hisashi Nakamura, Takafumi Miyasaka, Kazuaki Nishii, and Youichi Tanimoto

sensible heat flux (SHF) and latent heat flux (LHF) from the ocean are enhanced in the cold season, because of large air–sea difference in temperature and humidity under dry, cold continental air advected by the prevailing monsoonal northerlies (e.g., Taguchi et al. 2009 ; Kwon et al. 2010 ). Despite a huge amount of heat release into the atmosphere, SST remains relatively high in winter along the KE owing to its advective effect. It has been argued that surface baroclinicity is restored through

Full access
Dimitry Smirnov, Matthew Newman, Michael A. Alexander, Young-Oh Kwon, and Claude Frankignoul

of the KOE most SST variability is atmosphere driven. A key outstanding question is the extent to which these ocean-driven SST anomalies impact the atmosphere, beyond the basic thermodynamic air–sea coupling via turbulent boundary layer heat flux exchange that operates throughout the extratropics ( Barsugli and Battisti 1998 ; Frankignoul et al. 1998 ; Lee et al. 2008 ). The answer to this question is key to the relevance of large-scale extratropical coupled air–sea modes and could have

Full access
A. Foussard, G. Lapeyre, and R. Plougonven

typical diameter of 100 km) that populate the World Ocean ( Chelton et al. 2011 ). Observational and numerical studies have shown that these structures affect the atmospheric boundary layer (e.g., Bourras et al. 2004 ; Lambaerts et al. 2013 ; Chelton et al. 2004 ; Frenger et al. 2013 ). This occurs through air–sea heat fluxes modulated by oceanic eddies ( Bourras et al. 2004 ; Villas Bôas et al. 2015 ), with a response of atmospheric stability to SST anomalies ( O’Neill 2012 ), and through wind

Full access
Akira Kuwano-Yoshida and Shoshiro Minobe

response over the Kuroshio and Oyashio Extensions (KOE) using a regional atmospheric model. They suggested that the storm-track response is different between winter and spring. In spring, the surface heat flux gradient is prominent over the SST front, resulting in enhanced storm-track activity, although in winter, the cold and dry air advection associated with the Asian winter monsoon induces large heat fluxes on both the cold and warm sides of the SST front, resulting in a weaker atmospheric response

Full access
Bunmei Taguchi and Niklas Schneider

the propagation of sea level and heat content anomalies. Surface Ekman pumping primarily excites equivalent barotropic mode Rossby waves that propagate westward largely independent of the wind-driven gyres (e.g., non-Doppler shift mode; Pedlosky 1996 ; Liu 1999 ). In contrast, surface buoyancy fluxes excite second and higher baroclinic mode (hereafter simply called higher baroclinic modes) Rossby waves that are strongly affected by the gyres and have eastward ray paths in the Kuroshio Extension

Full access
Ayumu Miyamoto, Hisashi Nakamura, and Takafumi Miyasaka

storm track along which migratory cyclones and anticyclones recurrently develop ( Nakamura and Shimpo 2004 ; Nakamura et al. 2008 ; Nonaka et al. 2009 ; Hotta and Nakamura 2011 ). Subweekly fluctuations in surface winds associated with cyclones and anticyclones act to relax the surface air temperature gradient around the SST front, yielding cross-frontal gradient of surface sensible heat flux (SHF) ( Nonaka et al. 2009 ; Hotta and Nakamura 2011 ). In fact, subweekly fluctuations in surface

Open access
Satoru Okajima, Hisashi Nakamura, Kazuaki Nishii, Takafumi Miyasaka, and Akira Kuwano-Yoshida

response shown below may be underestimated slightly. Atmospheric variables, including sea level pressure (SLP), geopotential height, air temperature, wind velocity, and turbulent heat fluxes, are obtained from the Japanese 25-yr Reanalysis Project (JRA-25; Onogi et al. 2007 ) for the period 1982–2011. In addition, precipitation data based on the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP; Xie and Arkin 1997 ) are used. These data are available on a 2.5° × 2.5° grid. b

Full access
Kazutoshi Sato, Atsuyoshi Manda, Qoosaku Moteki, Kensuke K. Komatsu, Koto Ogata, Hatsumi Nishikawa, Miki Oshika, Yuriko Otomi, Shiori Kunoki, Hisao Kanehara, Takashi Aoshima, Kenichi Shimizu, Jun Uchida, Masako Shimoda, Mitsuharu Yagi, Shoshiro Minobe, and Yoshihiro Tachibana

Sea, on both climatological and synoptic time scales. This relationship implies that surface heat fluxes in the East China Sea affect BFZ seasonal migration. In addition, Kuwano-Yoshida et al. (2013) demonstrated by a suite of numerical experiments using global climate models that surface evaporation from the warm ocean is important for maintenance of the quasi-stationary BFZ. The Kuroshio, one of the most prominent ocean currents in the world, flows along the shelf edge in the East China Sea (e

Full access
Benoît Vannière, Arnaud Czaja, Helen Dacre, and Tim Woollings

atmosphere. Sanders and Gyakum (1980) showed that explosive cyclogenesis occurs over a wide range of SSTs but, preferentially, near the strongest gradients. Giordani and Caniaux (2001) proposed the first detailed sensitivity analysis of how the Gulf Stream and its SST gradient affect, through surface turbulent fluxes and therefore the atmospheric boundary layer, frontogenesis and cyclogenesis. A strong sensitivity of an extratropical cyclone to prescribed SST anomalies was also demonstrated over the

Full access