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Eleanor Blyth, John Gash, Amanda Lloyd, Matthew Pryor, Graham P. Weedon, and Jim Shuttleworth

to rainfall or river runoff, there are no publicly available global evaporation data. However, relevant surface exchange data are becoming available through the flux network (FLUXNET; Baldocchi et al. 2001 ). Many medium-term (5–10 years), ground-based observations of carbon dioxide and surface energy fluxes are now being made by FLUXNET at a network of locations across the world in different climate zones and over different ecosystems. Therefore, FLUXNET is arguably the most comprehensive

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Shuwen Zhang, Bangjun Cao, Weidong Zhang, Qian Cao, Yuan Liu, and Chongjian Qiu

1. Introduction Accurate estimates of the surface turbulent heat fluxes have always been the central and practical concern in atmospheric science and hydrometeorology, because the fluxes characterize the mass and energy exchanges between the surface and the atmosphere aloft and have a profound impact on the upper airflow. Besides, accurate estimates of the surface heat fluxes are imperative for accurately validating modeling of surface energy and mass balances ( Kalma et al. 2008 ). The

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Si Gao, Shunan Zhai, Long S. Chiu, and Dong Xia

), sea spray, and air–sea exchange coefficients], and internal dynamics (e.g., eyewall replacement and inner-core asymmetry) (e.g., Elsberry et al. 2013 ). Ocean-surface enthalpy fluxes are the major energy sources of TC formation and/or intensification (e.g., Ooyama 1969 ; Emanuel 1986 ; Craig and Gray 1996 ). In the absence of direct in situ measurements, two components of enthalpy fluxes, latent heat flux (LHF) and sensible heat flux (SHF), can be estimated respectively by using the following

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Christopher M. Godfrey and David J. Stensrud

1. Introduction Proper partitioning of the surface energy fluxes that drive the evolution of the planetary boundary layer (PBL) requires an accurate representation of land surface conditions in numerical weather prediction (NWP) models. Several key components of the land surface that significantly affect surface heat and moisture fluxes include soil temperature and moisture, fractional vegetation coverage ( σ f ), and green leaf area index (LAI). The lack of observational data for the accurate

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Carol Anne Clayson and Alec S. Bogdanoff

climatological energy and water budgets. Several researchers have estimated the change in fluxes due to the use of a diurnally varying SST, typically for very short time periods and limited areas. Schiller and Godfrey (2005) used a coupled one-dimensional ocean–atmosphere model at a mooring in the tropical Pacific Ocean during one week in November 1992, and found an average increase in fluxes of 10 W m −2 . A profiler deployed in the Gulf of California for a total of 976 profiles showed net heat flux

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James A. Mueller and Fabrice Veron

speed. Richter and Sullivan (2013) , however, found that the inertial impacts of sea spray dominate its stability effects. In addition to the potential reduction of the surface drag, Andreas and Emanuel (2001) suggested that reentrant spray enhances the enthalpy flux, although the reentrant spray could have a damping effect on the wave-induced stress at high wind speeds too. Andreas (2004) further postulated that the effective stress at high wind speeds could also be reduced by the vertical

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Alex M. Kowaleski and Jenni L. Evans

; Emanuel and Rotunno 2011 ), ocean–air moist entropy disequilibrium at the radius of maximum winds (RMW) and tropopause temperature matter most in determining maximum TC intensity (expressed as either maximum sustained wind speed or minimum central pressure). Within the PI framework a TC functions as a Carnot engine; moist entropy is acquired from surface latent and sensible heat fluxes under the eyewall and exported at the much colder tropopause. The maximum moist entropy increase and tropopause

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Andreas Münchow, Humfrey Melling, and Kelly K. Falkner

clear that factors affecting the global freshwater cycle have changed ( Dickson et al. 2002 , 2003 ; Munk 2003 ; Serreze et al. 2000 ; Curry et al. 2003 ) and that resulting signals are propagating through the North Atlantic ( Dickson et al. 1988 ; Belkin et al. 1998 ). Despite their potential impacts and global importance, freshwater fluxes from the Arctic to the North Atlantic are nearly unknown since direct observations are rare (e.g., Fram Strait: Schauer et al. 2004 ; Barents Sea

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G. O. Odhiambo and M. J. Savage

1. Introduction The 1998 Republic of South Africa National Water Act ( Republic of South Africa 1998 ) suggests a possible prescription for water allocation and charges for different land uses, making it even more crucial to consider how evaporation, which is one of the main components of the water balance, is to be measured or estimated routinely with reliable accuracy and precision ( Savage 2009 ). Reliable estimation of energy fluxes from a surface is also important for understanding

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Jonathan M. Winter and Elfatih A. B. Eltahir

1. Introduction Whether prescribed as an explicit climate sensitivity or calculated using multiple parameterizations, the response of the surface to changes in the atmosphere is uncertain. One uncertainty in particular, the sensitivity of latent heat flux to an increase in available energy, is especially salient as it directly impacts the effect of climate change on surface temperature. Climate change is likely to accelerate the hydrologic cycle, leading to increased global evapotranspiration

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