Search Results

You are looking at 21 - 30 of 36,463 items for :

  • Refine by Access: All Content x
Clear All
Chunmei Zhu and Dennis P. Lettenmaier

extremity of the much more pronounced NAMS phenomenon over northwestern Mexico). A key to understanding this predictability is datasets that support analyses of land–atmosphere interactions. The dataset described in this paper arises from this motivation. To date, data that will support land–atmosphere feedback studies within the NAMS region, particularly land surface states and fluxes such as soil moisture and turbulent heat fluxes, have been essentially nonexistent. This is a result mostly of the

Full access
Thara V. Prabha, Monique Y. Leclerc, Anandakumar Karipot, and David Y. Hollinger

1. Introduction Nocturnal respiratory release of carbon dioxide (CO 2 ) is an integral component of the ecosystem carbon balance. Several studies ( Goulden et al. 1996 ; Greco and Baldocchi 1996 ; Lindroth et al. 1998 ; Chen et al. 1999 ; Hollinger et al. 1999 ; Aubinet et al. 2000 ; Saleska et al. 2003 ) have reported an underestimation of CO 2 fluxes often associated with inadequate mixing in the stable boundary layer (SBL). Sporadic outbreaks of turbulence are also a common occurrence

Full access
John E. Walsh, William L. Chapman, and Diane H. Portis

-phase and ice-phase clouds; basic cloud microphysical properties; the relative importance of surface versus advective moisture fluxes in the formation of clouds; and the interactions among turbulence, radiation, and cloud microphysics in the evolution of the cloudy atmospheric boundary layer. While GCMs are the primary tool for projecting global climate change, validations with observed data, such as those produced by ARM, are only possible in a climatological sense. That is, direct day-by-day and hour

Full access
Chin-Hsuan Peng and Chun-Chieh Wu

Schubert 2009 ) and leading to the apparent import of absolute angular momentum under continuous diabatic heating inside the RMW (e.g., Smith and Montgomery 2015 ), which is favorable for further intensification of the vortex. As for the energy source of TC intensification, Riehl (1950) highlighted that sea surface heat fluxes play a crucial role in TC development. This concept was formally proposed in the context of the wind-induced surface heat exchange (WISHE) mechanism ( Emanuel 1986 , 1989

Restricted access
Tapio Schneider, Karen L. Smith, Paul A. O’Gorman, and Christopher C. Walker

1. Introduction Water vapor fields and fluxes in the troposphere are affected by processes on many scales. The specific humidity in the boundary layer is directly related to evaporation from the surface. From the boundary layer, water vapor is transported upward by large-scale eddies and, particularly in the deep Tropics, by convection. Transport and evaporation of condensate moistens the vicinity of moist-convective regions (see, e.g., Sun and Lindzen 1993 ; Emanuel and Pierrehumbert 1995

Full access
Carlos Domenech, Ernesto Lopez-Baeza, David P. Donovan, and Tobias Wehr

placed upon the retrieved cloud–aerosol profiles is consistent with a top-of-atmosphere (TOA) combined shortwave (SW) and longwave (LW) flux accuracy of 10 W m −2 for an instantaneous footprint of 10 × 10 km −2 ( EarthCARE Mission Advisory Group 2006 ). The scientific goals will be fulfilled by the payload of four instruments with precise collocated fields of view (FOV). The vertical atmospheric profiles will be acquired using a 353-nm high-spectral-resolution lidar (ATLID) and a cloud-profiling W

Full access
Vickal V. Kumar, Christian Jakob, Alain Protat, Christopher R. Williams, and Peter T. May

and Rajopadhyaya 1999 ). In general circulation models (GCMs) convection cannot be represented by modeling individual convective clouds. Instead, simple representations of the collective effects of a cumulus cloud ensemble existing in a model grid box are applied. Among the most widespread of these cumulus parameterization approaches is the so-called mass-flux approach [see Arakawa (2004) for an overview]. Here, the vertical transport by the cloud ensemble is directly related to the mass flux

Full access
Christopher J. Watts, Russell L. Scott, Jaime Garatuza-Payan, Julio C. Rodriguez, John H. Prueger, William P. Kustas, and Michael Douglas

-Arid Land-Surface-Atmosphere (SALSA) campaign over grassland and shrubland in the San Pedro catchment in 1997–98 ( Chehbouni et al. 2000 ). Neither of these campaigns was specifically designed to study the monsoon system. The intensive observation period (IOP) for NAME took place in the period July–September 2004 and a small network of flux stations ( Fig. 1 ) were set up in the core monsoon region in order to study the exchange of radiation, heat, and water vapor between the surface and the atmosphere

Full access
Natalia Tilinina, Alexander Gavrikov, and Sergey K. Gulev

1. Introduction Accurate estimation and identification of the mechanisms controlling air–sea heat fluxes in the mid- and subpolar latitudes are both critically important for diagnosing their role in ocean and atmospheric dynamics. In the North Atlantic, very high heat fluxes cause anomalous surface density fluxes, resulting in the surface transformation of water masses and associated deep convection of the Labrador and Greenland–Iceland–Norwegian (GIN) Seas ( Moore et al. 2014 ; Holdsworth and

Full access
G. Guo and J. A. Coakley Jr.

1. Introduction The National Aeronautics and Space Administration’s (NASA) Clouds and Earth Radiant Energy System (CERES) has, as one of its goals, estimating surface radiative fluxes ( Wielicki et al. 1996 ). Estimates from CERES rely on a mix of broadband radiances, which are obtained from the CERES radiometers on the Terra and Aqua satellites; high-spatial-resolution multispectral imagery, obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS); analyzed meteorological

Full access