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C. W. Fairall, Taneil Uttal, Duane Hazen, Jeffrey Hare, Meghan F. Cronin, Nicholas Bond, and Dana E. Veron

). This paper complements two recent papers featuring analysis of the TAO buoy observations along 95° and 110°W: studies of the annual cycle of cloud radiative forcing at the surface ( Cronin et al. 2006a ) and the annual cycle of sensible and latent heat fluxes ( Cronin et al. 2006b ). The first paper found disagreements as large as 100 W m −2 between buoy radiative flux observations and NWP reanalysis values; the second paper found disagreements of the same order for latent heat flux. The

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Lauren E. Padilla, Geoffrey K. Vallis, and Clarence W. Rowley

1. Introduction The steady-state response of the global-mean, near-surface temperature to an increase in greenhouse gas concentrations (e.g., a doubling of CO 2 levels) is given, definitionally, by the equilibrium climate sensitivity (ECS), and this is evidently an unambiguous and convenient measure of the sensitivity of the climate system to external forcing. However, given the long time scales involved in bringing the ocean to equilibrium, the ECS may only be realized on a time scale of many

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Jonathan M. Winter and Elfatih A. B. Eltahir

. Each numerical experiment was initialized 1 April 1994 and allowed to spin up for 21 months. The domain was centered at 40°N, 95°W and spanned 100 points zonally, 60 points meridionally with a horizontal grid spacing of 60 km ( Fig. 2 ). The 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) dataset ( Uppala et al. 2005 ) was used to force the boundaries under the exponential relaxation of Davies and Turner (1977) . SSTs were prescribed using the National Oceanic

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Yi Song and Yongqiang Yu

1. Introduction Both atmospheric and oceanic circulations exhibit prominent fluctuations on decadal and multidecadal time scales. Despite rising concentrations of atmospheric greenhouse gases (GHGs), the global mean surface air temperature (SAT) has remained flat for the past 16 years (i.e., the recent warming hiatus; Easterling and Wehner 2009 ). This observation challenges the prevailing view that anthropogenic forcing leads to global warming. An interpretation regarding the hiatus is the

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Jian Yuan, Dennis L. Hartmann, and Robert Wood

called cloud radiative forcing (CRF), may respond to external influences on the climate system and thereby constitute a substantial climate feedback (e.g., Schneider 1972 ; Cess et al. 1996 ). The tropical climate system response to an external perturbation is an important outstanding problem, and cloud feedback still stands as a large source of uncertainty in predicting future climate ( Cess et al. 2001b ; Stephens 2005 ; Solomon et al. 2007 ). Clouds respond both to large-scale dynamical

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Timothy Andrews

1. Introduction Radiative forcings have long been used to quantify and rank the drivers of climate change (e.g., Hansen et al. 1997 ; Shine and Forster 1999 ). In climate models, radiative forcings can help us understand why different models differ in their simulations of the past and future. For example, Forster et al. (2013) found the intermodel spread in the global surface temperature change across phase 5 of the Coupled Model Intercomparison Project (CMIP5) ( Taylor et al. 2012

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Hiroki Ichikawa, Hirohiko Masunaga, Yoko Tsushima, and Hiroshi Kanzawa

1. Introduction The radiative effect of clouds, often called cloud radiative forcing (CRF), associated with convective activity largely controls the radiative balance–imbalance at the top of the atmosphere (TOA) over the tropics through the horizontal extension of high clouds that accompany deep convection ( Ramanathan and Collins 1991 ; Lindzen et al. 2001 ; Hartmann et al. 2001 ). The response of CRF associated with convective activity to an imposed climate perturbation is thus fundamental

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Amy H. Butler, David W. J. Thompson, and Ross Heikes

1. Introduction There is increasing evidence that anthropogenic forcing has driven and will drive several robust changes in the extratropical circulation. Among the most robust changes are poleward shifts in the extratropical storm tracks consistent with positive trends in the northern and southern annular modes of variability. Observations reveal robust positive trends in the southern annular mode (SAM) during austral spring/summer that are consistent with forcing by the Antarctic ozone hole

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Michael P. Meredith, Alberto C. Naveira Garabato, Andrew McC. Hogg, and Riccardo Farneti

help to evaluate changes in the overturning. In this paper, we investigate an ocean at (or close to) the eddy-saturated limit, and evaluate how the overturning circulation will behave at this limit. The overall response of the overturning circulation in the Southern Ocean to changes in wind stress forcing will depend on the differing responses of the Eulerian mean and eddy-induced components ( Fig. 1 ). The magnitude of the Eulerian mean overturning is reasonably expected to be linear with wind

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Jiapeng Miao, Tao Wang, Huijun Wang, Yali Zhu, and Jianqi Sun

. This is partly caused by suppressed ENSO-associated tropical Indo–western Pacific sea surface temperature (SST) variability, reduced EAWM interannual variability, and northward-retreating EAWM signals. The EAWM intensity is also regulated by the Arctic Oscillation (AO) on the interannual time scale ( Gong et al. 2001 ; Wu and Wang 2002 ). Furthermore, the Arctic amplification and sea ice loss may affect the EAWM ( Wang and Liu 2016 ; Zhou 2017 ). Both anthropogenic forcings [e.g., greenhouse

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