scholarly journals Decadal changes in the physical mechanisms of the seasonal cycle of summertime precipitation variability in Korea

2012 ◽  
Vol 117 (D7) ◽  
pp. n/a-n/a ◽  
Author(s):  
Joon-Woo Roh ◽  
Kwang-Yul Kim ◽  
Jong-Ghap Jhun
Keyword(s):  
Seasonal Cycle ◽  
Precipitation Variability ◽  
Physical Mechanisms

scholarly journals The Seasonal Cycle of Blocking and Associated Physical Mechanisms in the Australian Region and Relationship with Rainfall

2013 ◽  
Vol 141 (12) ◽  
pp. 4534-4553 ◽  
Author(s):  
M. J. Pook ◽  
J. S. Risbey ◽  
P. C. McIntosh ◽  
C. C. Ummenhofer ◽  
A. G. Marshall ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Seasonal Cycle ◽  
Seasonal Temperature ◽  
Ocean Fronts ◽  
Temperature Changes ◽  
Physical Mechanisms ◽  
Australian Region ◽  
Continental Antarctica ◽  
Positive Correlations ◽  
Blocking Index

Abstract The seasonal cycle of blocking in the Australian region is shown to be associated with major seasonal temperature changes over continental Antarctica (approximately 15°–35°C) and Australia (about 8°–17°C) and with minor changes over the surrounding oceans (below 5°C). These changes are superimposed on a favorable background state for blocking in the region resulting from a conjunction of physical influences. These include the geographical configuration and topography of the Australian and Antarctic continents and the positive west to east gradient of sea surface temperature in the Indo-Australian sector of the Southern Ocean. Blocking is represented by a blocking index (BI) developed by the Australian Bureau of Meteorology. The BI has a marked seasonal cycle that reflects seasonal changes in the strength of the westerly winds in the midtroposphere at selected latitudes. Significant correlations between the BI at Australian longitudes and rainfall have been demonstrated in southern and central Australia for the austral autumn, winter, and spring. Patchy positive correlations are evident in the south during summer but significant negative correlations are apparent in the central tropical north. By decomposing the rainfall into its contributions from identifiable synoptic types during the April–October growing season, it is shown that the high correlation between blocking and rainfall in southern Australia is explained by the component of rainfall associated with cutoff lows. These systems form the cyclonic components of blocking dipoles. In contrast, there is no significant correlation between the BI and rainfall from Southern Ocean fronts.

scholarly journals Seasonal cycle of precipitation variability in South America on intraseasonal timescales

2017 ◽  
Vol 51 (5-6) ◽  
pp. 1991-2001 ◽  
Author(s):  
Carolina S. Vera ◽  
Mariano S. Alvarez ◽  
Paula L. M. Gonzalez ◽  
Brant Liebmann ◽  
George N. Kiladis
Keyword(s):  
South America ◽  
Seasonal Cycle ◽  
Precipitation Variability

scholarly journals Beach Morphodynamic Response to a Submerged Reef

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 340 ◽  
Author(s):  
Douglas Duarte Nemes ◽  
Francisco Fabián Criado-Sudau ◽  
Marcos Nicolás Gallo
Keyword(s):  
Wave Energy ◽  
Wave Breaking ◽  
Seasonal Cycle ◽  
High Energy ◽  
Morphological Features ◽  
Energy Conditions ◽  
Vector System ◽  
Coastal Processes ◽  
Physical Mechanisms ◽  
Physical Functions

To develop beach engineering, the submerged structure’s primary physical functions have to be understood. This study focuses on submerged structures in order to understand the strategy of reduced wave energy, stabilizing the shoreline and not generating erosion or adversely modifying coastal processes. Important developments have been made since the 1990s, taking into account the functions of recreational amenity. However, non-dimensional models cannot explain the physical mechanisms that generate accretion or erosion morphological features in the lee of the submerged structure. The present study aims to collaborate with the understanding of the mechanism of beach response to a submerged structure. For this, 26 surveys were made using topographic, Lagrangian, and Eulerian hydrodynamic measures during one seasonal cycle of a beach system from Rio de Janeiro (Brazil) with a natural submerged reef or rocky bank V-shape in the plan. This beach system is energetic and intermediate when referring to wave energy conditions and beach states, respectively. The wave breaking vector system on the rocky bank’s geometry was examined in the intermediate and dissipative beach morphodynamic organization. The variability of the wave breaking vector system determines the establishment, deformation, and erosion features in the lee of the structure. During high-energy waves, the submerged structure’s hydrodynamic and morphodynamic processes are transparent. When the submerged structure combines with the dissipative beach state, the surfing wave conditions are improved. These results provide the dimensional and positional references for an engineering proposal for a beach system.

Human influence on the seasonal cycle of tropospheric temperature

Science ◽  
2018 ◽  
Vol 361 (6399) ◽  
pp. eaas8806 ◽  
Author(s):  
Benjamin D. Santer ◽  
Stephen Po-Chedley ◽  
Mark D. Zelinka ◽  
Ivana Cvijanovic ◽  
Céline Bonfils ◽  
...  
Keyword(s):  
Seasonal Cycle ◽  
Large Scale ◽  
Climate Models ◽  
Scientific Evidence ◽  
Tropospheric Temperature ◽  
Geographical Patterns ◽  
Physical Mechanisms ◽  
Statistical Confidence ◽  
Earth’S Climate ◽  
The Tropics

We provide scientific evidence that a human-caused signal in the seasonal cycle of tropospheric temperature has emerged from the background noise of natural variability. Satellite data and the anthropogenic “fingerprint” predicted by climate models show common large-scale changes in geographical patterns of seasonal cycle amplitude. These common features include increases in amplitude at mid-latitudes in both hemispheres, amplitude decreases at high latitudes in the Southern Hemisphere, and small changes in the tropics. Simple physical mechanisms explain these features. The model fingerprint of seasonal cycle changes is identifiable with high statistical confidence in five out of six satellite temperature datasets. Our results suggest that attribution studies with the changing seasonal cycle provide powerful evidence for a significant human effect on Earth’s climate.

Strain analysis with nanometer resolution using a conventional transmission electron microsopy technique: electron diffraction contrast imaging revisited

1995 ◽  
Vol 53 ◽  
pp. 168-169
Author(s):  
Koenraad G F Janssens ◽  
Omer Van der Biest ◽  
Jan Vanhellemont ◽  
Herman E Maes ◽  
Robert Hull
Keyword(s):  
Electron Diffraction ◽  
Strain Field ◽  
Elastic Strain ◽  
Strain Analysis ◽  
Local Strain ◽  
Contrast Imaging ◽  
Strain Characterization ◽  
Physical Mechanisms ◽  
Diffraction Contrast ◽  
Transmission Electron

There is a growing need for elastic strain characterization techniques with submicrometer resolution in several engineering technologies. In advanced material science and engineering the quantitative knowledge of elastic strain, e.g. at small particles or fibers in reinforced composite materials, can lead to a better understanding of the underlying physical mechanisms and thus to an optimization of material production processes. In advanced semiconductor processing and technology, the current size of micro-electronic devices requires an increasing effort in the analysis and characterization of localized strain. More than 30 years have passed since electron diffraction contrast imaging (EDCI) was used for the first time to analyse the local strain field in and around small coherent precipitates1. In later stages the same technique was used to identify straight dislocations by simulating the EDCI contrast resulting from the strain field of a dislocation and comparing it with experimental observations. Since then the technique was developed further by a small number of researchers, most of whom programmed their own dedicated algorithms to solve the problem of EDCI image simulation for the particular problem they were studying at the time.

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