Search Results

You are looking at 1 - 10 of 10,742 items for :

  • Marine boundary layer x
  • Refine by Access: All Content x
Clear All
Kirsty E. Hanley and Stephen E. Belcher

examined the role of ocean surface waves in shaping the wind profile in the marine atmospheric boundary layer. The focus has been the wave-driven wind regime, which observations suggest occurs when fast-moving swell propagates into regions of low geostrophic winds. The wave-induced stress decays over a shallow depth of the order 5 m, and so it might be thought that the waves have little influence in controlling the dynamics of the boundary layer. Using the classical Ekman model augmented with a term

Full access
Youichi Tanimoto, Shang-Ping Xie, Kohei Kai, Hideki Okajima, Hiroki Tokinaga, Toshiyuki Murayama, Masami Nonaka, and Hisashi Nakamura

surface wind curls ( Schneider and Miller 2001 ; Qiu 2003 ). Strong ocean advection and the deep winter mixed layer allow subsurface variability to affect SST ( Xie et al. 2000 ; Tomita et al. 2002 ) and surface heat flux ( Tanimoto et al. 2003 ). Strong SST gradients east of Japan maintain baroclinicity in the marine atmospheric boundary layers (MABL), which has been suggested as being important for atmospheric storm tracks ( Inatsu et al. 2003 ; Nakamura et al. 2004 ). While most studies of the

Full access
Peter P. Sullivan, James C. McWilliams, Jeffrey C. Weil, Edward G. Patton, and Harindra J. S. Fernando

layer currents. Air–sea coupling, accounting for a wavy interface ( Sullivan and McWilliams 2010 ) and ocean heterogeneity, is a broadband space–time process fundamentally rooted in the turbulent marine atmospheric boundary layer (MABL) and oceanic boundary layer (OBL) and remains an important research area for improving weather forecasts and climate predictions ( Small et al. 2008 ). Ocean submesoscale heterogeneity is subgrid in global models, and by necessity these models rely on single column

Restricted access
Virendra P. Ghate, Maria P. Cadeddu, Xue Zheng, and Ewan O’Connor

1. Introduction Marine boundary layer (MBL) stratocumulus clouds cover vast areas over eastern subtropical oceans and persist over very long periods ( Klein and Hartmann 1993 ). These clouds reflect much greater amount of solar radiation back to space as compared with the underlying ocean surface, while emitting longwave radiation similar to the ocean surface due to their high cloud-top temperatures. Hence these clouds have a net cooling effect on Earth’s surface and are an important component

Open access
Tao Luo, Renmin Yuan, Zhien Wang, and Damao Zhang

1. Introduction Sea salt is one of the largest natural contributors to the global aerosol loading and thus plays a significant role in the global climate ( Solomon et al. 2007 ). Sea salt dominates submicron and supermicron scatterers and total aerosol mass concentration in the marine boundary layer (MBL) ( Sievering et al. 2004 ). However, its radiative forcing is still poorly simulated in models ( Textor et al. 2006 ; Kinne et al. 2006 ). One important uncertainty is from the lack of a

Full access
Guang J. Zhang, Andrew M. Vogelmann, Michael P. Jensen, William D. Collins, and Edward P. Luke

1. Introduction Marine boundary layer (MBL) clouds have a strong shortwave cloud radiative forcing on the earth’s climate system ( Klein and Hartmann 1993 ). They form in the cold water regions off the west coast of major continents; via strong radiative cooling, they play an important role in modulating the sea surface temperatures (SSTs). However, their simulation in global climate models (GCMs) is among the most problematic, and few models can simulate the extent of these clouds ( Ma et al

Full access
Timothy A. Myers and Joel R. Norris

1. Introduction Low-level clouds have the largest net cloud radiative effect of all cloud types, acting to cool the planet via high albedo and a weak greenhouse effect ( Hartmann et al. 1992 ). The large and persistent decks of stratus and stratocumulus over eastern subtropical oceans are the primary contributors to this cooling effect. These clouds occur predominantly within a shallow, well-mixed marine boundary layer (MBL) over cool sea surface temperatures (SSTs) and under a strong

Full access
Jian Huang, Zhongshui Zou, Qingcun Zeng, Peiliang Li, Jinbao Song, Lin Wu, Jun A. Zhang, Shuiqing Li, and Pak-wai Chan

O (1). Similar to the AEM, the logarithmic variation in horizontal velocity variances with height as expressed in Eq . (1) can be obtained according to Eq . (4) . Hence, the k −1 law and logarithmic height dependence of the velocity variances are equivalent. c. Marine atmospheric boundary layer The turbulence in the marine ABL is more complex than that over a wall or a flat land surface due to the ocean surface waves ( Sun and French 2016 ). Studies (e.g., Hristov and Ruiz-Plancarte 2014

Restricted access
Richard J. Foreman and Stefan Emeis

1. Introduction Despite conflicting evidence in the past ( Garratt 1977 ), it is now accepted that the drag coefficient (defined below) in the marine atmospheric boundary layer (MABL) is an increasing function of the wind speed ( Sullivan and McWilliams 2010 ) for moderate wind speeds. At higher wind speeds, however, recent evidence suggests that the drag coefficient tends toward a constant value ( Donelan et al. 2004 ; Black et al. 2007 ). The exact equation that describes the relationship

Full access
Ramesh Vellore, Darko Koračin, Melanie Wetzel, Steven Chai, and Qing Wang

1. Introduction For more than a decade, there has been a great demand to understand the significance of predictability in numerical weather prediction models, as the predictability issues are related to the forecast skill. Because of the complex interactions of dynamical, radiative, and microphysical processes that occur on small spatial and temporal scales, realistic simulation of the cloud-capped marine boundary layer remains a potential challenge for most mesoscale models and even more so

Full access