Monthly and 3-hourly precipitation data from twentieth-century climate simulations by the newest generation of 18 coupled climate system models are analyzed and compared with available observations. The characteristics examined include the mean spatial patterns, intraseasonal-to-interannual and ENSO-related variability, convective versus stratiform precipitation ratio, precipitation frequency a...

[1] Atmospheric fronts are important for the day-to-day variability of weather in the midlatitudes, particularly during winter when extratropical storm-tracks are at their maximum intensity. Fronts are often associated with heavy rain, and strongly affect the local space-time distribution of rainfall. A recently developed objective front identification method that distinguishes between cold, wa...

It was once generally thought that stratiform precipitation was something occurring primarily, if not exclusively, in middle latitudes—in baroclinic cyclones and fronts. Early radar observations in the Tropics, however, showed large radar echoes composed of convective rain alongside stratiform precipitation, with the stratiform echoes covering great areas and accounting for a large portion of t...

Synoptic situations producing rainfall at four rawinsonde observatories at eastern Spain are classified as stratiform or convective depending on dynamic and thermodynamic instability indices. Two daily radiosonde and daily-accumulated precipitation data from four observatories in Eastern Spain are used: Madrid-Barajas (MB), Murcia (MU), Palma de Mallorca (PA) and Zaragoza (ZA). We calculated tw...

We analyzed lake-sediment cores from the Yucatan Peninsula, Mexico, to reconstruct the climate history of the region over the past 2600 years. Time series analysis of sediment proxies, which are sensitive to the changing ratio of evaporation to precipitation (oxygen isotopes and gypsum precipitation), reveal a recurrent pattern of drought with a dominant periodicity of 208 years. This cycle is ...

[1] High-resolution (0.1 0.1 ) geostationary satellite infrared radiances at 11 mm in combination with gridded (2.5 2.0 ) hourly surface precipitation observations are employed to document the spatial structure of the diurnal cycle of summertime deep convection and associated precipitation over North America. Comparison of the diurnal cycle pattern between the satellite retrieval and surface ob...

The theories of critical orogenic wedges and fluvial erosion are combined to explore the interactions between tectonics, erosion, and climate. A model framework is developed which allows the derivation of an exact analytical scaling relationship for how orogen width, height, and rock uplift rate vary as a function of accretionary flux and precipitation rate. Compared to a model with prescribed ...

a facile co-precipitation method for the synthesis of well-dispersed ndfeo3 nanocrystals is developed in the presence of octanoic acid as surfactant. co-precipitation can produce fine, high-purity, stoichiometric particles of single and multicomponent metal oxides. the product is characterized by fourier transform infrared spectroscopy (ft-ir), x-ray diffraction (xrd), scanning electron microsc...

In this paper, we investigate soil moisture, evapotranspiration and other major water balance components over six sites in the Sand Hills of Nebraska during a 6-year period (1998-2003) using a hydrological model. We simulate water budget components including root zone soil moisture and found that model predictions of soil moisture compare reasonably well with observations for these sites. In th...

Precise characterization of hydroclimate variability in Amazonia on various timescales is critical to understanding the link between climate change and biodiversity. Here we present absolute-dated speleothem oxygen isotope records that characterize hydroclimate variation in western and eastern Amazonia over the past 250 and 20 ka, respectively. Although our records demonstrate the coherent mill...