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Gerald G. Mace and Sally Benson

-term data also makes the statistics relevant for evaluation of similar quantities derived from general circulation models because the statistics would be representative of regional conditions and not just the specific point at which the data were collected. This long time series also allows us to better quantify the uncertainty of the derived cloud radiative forcing by comparing fluxes at the surface and TOA. 2. Methodology and validation The primary purpose of the ACRF is to provide continuous

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Andrew S. Delman, Julie L. McClean, Janet Sprintall, Lynne D. Talley, Elena Yulaeva, and Steven R. Jayne

field campaigns ( Waterman et al. 2011 ). The extension of spatial and temporal coverage offered by ocean general circulation models (OGCMs) provides an opportunity to study the along-jet and cross-jet variations in eddy forcing. Eddy forcing likely varies with longitude along the KE jet axis, influenced by bathymetric ridges underlying the jet ( Fig. 1 ) as well as position relative to the maximum in EKE at 146°E. Quasigeostrophic models of idealized western boundary current extensions (e

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Heather Dawn Reeves, Yuh-Lang Lin, and Richard Rotunno

, Yuba River, Bear River, Butte Creek, and Eastern Tehama watersheds. An understanding of the underlying dynamical causes for this maximum is important because rainfall runoff from these watersheds ultimately drains into the Sacramento River, which flows through Sacramento, a city with a rather high flood threat and large population. The causes for the precipitation maximum at PNF are explored in this paper. As will be demonstrated, dynamical causes are case dependent, but two important forcings have

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Thomas Spengler and Joseph Egger

P is precipitation rate and E the evaporation rate (kg s −1 m −2 ) at the surface. Acknowledgments We thank P. Knippertz and A. Fink for some clarifying remarks on an earlier version of this comment. REFERENCES Knippertz , P. , and A. H. Fink , 2008 : Dry-season precipitation in tropical West Africa and its relation to forcing from the extratropics. Mon. Wea. Rev. , 136 , 3579 – 3596 . Kong , K-Y. , 2006 : Understanding the genesis of Hurricane Vince through the surface pressure

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Rafail V. Abramov and Andrew J. Majda

1. Introduction The low-frequency response to changes in external forcing for various components of the climate system is a central problem of contemporary climate change science. In particular, in the atmosphere the response of the low-frequency teleconnection patterns such as the Arctic Oscillation (AO), the North Atlantic Oscillation (NAO), and the Pacific–North America pattern (PNA), which steer the storm tracks, is a fundamental issue. Leith (1975) suggested that if the climate system

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Yuko M. Okumura, Clara Deser, Aixue Hu, Axel Timmermann, and Shang-Ping Xie

/Paleoclimate Modeling Intercomparison Project (CMIP/PMIP) ( Stouffer et al. 2006 ). In response to a 1 Sv (Sv ≡ 10 6 m 3 s −1 ) freshwater forcing in the subarctic North Atlantic, the AMOC slows down rapidly in all of the models and associated climatic anomalies exhibit a large degree of similarity, especially in the Atlantic basin: a north–south dipole pattern of surface temperature anomalies and southward displacement of the ITCZ. While a change in oceanic heat transport is fundamental for this interhemispheric

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Vassilis P. Papadopoulos, Yasser Abualnaja, Simon A. Josey, Amy Bower, Dionysios E. Raitsos, Harilaos Kontoyiannis, and Ibrahim Hoteit

potentially lead to fewer convection events because of positive surface buoyancy. The knowledge of the air–sea heat flux regime over the Red Sea is poor and limited to the estimation of the entire basin annual heat budget. Two studies carried out by Tragou et al. (1999) and Sofianos et al. (2002) , using different methodological approaches, result in a basin net heat loss between 8 and 11 W m −2 . However, the spatiotemporal characteristics of the surface heat exchange and the atmospheric forcing that

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Li Shi, Oscar Alves, Harry H. Hendon, Guomin Wang, and David Anderson

do not need to impose artificial MJO forcing in our methodology because the POAMA model naturally generates MJO activity. A brief description of the experimental set up, the coupled model, and the ensemble generation method are described in section 2 . Some basic features of ensemble results are examined in section 3 , and the impact of the MJO on the spread of the ensemble is explored in detail in section 4 . Finally, a discussion and summary are presented in section 5 . 2. Description of

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Leon D. Rotstayn and Joyce E. Penner

1. Introduction The concept of radiative forcing is useful as a first-order estimate of the potential climatic importance of various forcing mechanisms. It refers to the change in net radiative flux that results from a change in an atmospheric gas, aerosol, or other radiatively active property, such as land surface type. The Intergovernmental Panel on Climate Change (IPCC; Houghton et al. 1996 ; Penner et al. 1999 ) for example, uses the concept to compare the relative climatic importance of

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Orli Lachmy and Nili Harnik

and McIntyre 1985 ) that suggest that in the nonlinear limit a CL can undergo cycles of absorption, reflection, and overreflection, settling at the end on a fully reflective state. However, these studies focus on the CL dynamics alone. To understand how the CL will affect the wave–mean flow equilibration, an understanding of the CL dynamics needs to be combined with other factors of the dynamics of the full system and their interplay. The equilibrated state also depends on the radiative forcing

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