The atmospheric mean energetic level and external forcing

1991 ◽  
Vol 35 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Dagmar Novotná ◽  
Vojtěch Vítek
Keyword(s):  
External Forcing ◽  
Energetic Level

scholarly journals On Time Scales of Intrinsic Oscillations in the Climate System

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 459
Author(s):  
Anastasios A. Tsonis ◽  
Geli Wang ◽  
Wenxu Lu ◽  
Sergey Kravtsov ◽  
Christopher Essex ◽  
...  
Keyword(s):  
Low Frequency ◽  
Milankovitch Cycles ◽  
Data Sets ◽  
External Forcing ◽  
Natural Oscillations ◽  
Climatic Oscillations ◽  
Slow Feature Analysis ◽  
Limited Length ◽  
Past Data ◽  
Cumulative Evidence

Proxy temperature data records featuring local time series, regional averages from areas all around the globe, as well as global averages, are analyzed using the Slow Feature Analysis (SFA) method. As explained in the paper, SFA is much more effective than the traditional Fourier analysis in identifying slow-varying (low-frequency) signals in data sets of a limited length. We find the existence of a striking gap from ~1000 to about ~20,000 years, which separates intrinsic climatic oscillations with periods ranging from ~ 60 years to ~1000 years, from the longer time-scale periodicities (20,000 yr +) involving external forcing associated with Milankovitch cycles. The absence of natural oscillations with periods within the gap is consistent with cumulative evidence based on past data analyses, as well as with earlier theoretical and modeling studies.

A Method to Improve the Modal Convergence for Structures With External Forcing

1987 ◽  
Vol 54 (4) ◽  
pp. 904-909 ◽  
Author(s):  
Keqin Gu ◽  
Benson H. Tongue
Keyword(s):  
Spatial Distribution ◽  
Free Vibration ◽  
Convergence Rate ◽  
Traditional Approach ◽  
Vibration Modes ◽  
External Forcing ◽  
Slow Convergence ◽  
Assumed Mode Method ◽  
Mode Method ◽  
Assumed Mode

The traditional approach of using free vibration modes in the assumed mode method often leads to an extremely slow convergence rate, especially when discete interactive forces are involved. By introducing a number of forced modes, significant improvements can be achieved. These forced modes are intrinsic to the structure and the spatial distribution of forces. The motion of the structure can be described exactly by these forced modes and a few free vibration modes provided that certain conditions are satisfied. The forced modes can be viewed as an extension of static modes. The development of a forced mode formulation is outlined and a numerical example is presented.

Internal and external forcing of sea level variability in the Black Sea

2015 ◽  
Vol 45 (9-10) ◽  
pp. 2633-2646 ◽  
Author(s):  
Denis L. Volkov ◽  
Felix W. Landerer
Keyword(s):  
Sea Level ◽  
Black Sea ◽  
The Black Sea ◽  
External Forcing ◽  
Sea Level Variability

Equatorial Rossby Solitary Wave Under the External Forcing

2005 ◽  
Vol 43 (1) ◽  
pp. 45-48 ◽  
Author(s):  
Fu Zun-Tao ◽  
Liu Shi-Kuo ◽  
Liu Shi-Da
Keyword(s):  
Solitary Wave ◽  
External Forcing

scholarly journals Evaluating the Uncertainty Induced by the Virtual Salt Flux Assumption in Climate Simulations and Future Projections

2010 ◽  
Vol 23 (1) ◽  
pp. 80-96 ◽  
Author(s):  
Jianjun Yin ◽  
Ronald J. Stouffer ◽  
Michael J. Spelman ◽  
Stephen M. Griffies
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Ocean Model ◽  
Salt Flux ◽  
Freshwater Flux ◽  
Unexpected Result ◽  
Geophysical Fluid Dynamics Laboratory ◽  
External Forcing ◽  
Future Evolution ◽  
Near Term

Abstract The unphysical virtual salt flux (VSF) formulation widely used in the ocean component of climate models has the potential to cause systematic and significant biases in modeling the climate system and projecting its future evolution. Here a freshwater flux (FWF) and a virtual salt flux version of the Geophysical Fluid Dynamics Laboratory Climate Model version 2.1 (GFDL CM2.1) are used to evaluate and quantify the uncertainties induced by the VSF formulation. Both unforced and forced runs with the two model versions are performed and compared in detail. It is found that the differences between the two versions are generally small or statistically insignificant in the unforced control runs and in the runs with a small external forcing. In response to a large external forcing, however, some biases in the VSF version become significant, especially the responses of regional salinity and global sea level. However, many fundamental aspects of the responses differ only quantitatively between the two versions. An unexpected result is the distinctly different ENSO responses. Under a strong external freshwater forcing, the great enhancement of the ENSO variability simulated by the FWF version does not occur in the VSF version and is caused by the overexpansion of the top model layer. In summary, the principle assumption behind using virtual salt flux is not seriously violated and the VSF model has the ability to simulate the current climate and project near-term climate evolution. For some special studies such as a large hosing experiment, however, both the VSF formulation and the use of the FWF in the geopotential coordinate ocean model could have some deficiencies and one should be cautious to avoid them.

scholarly journals The main features of seasonal variability in the external forcing and dynamics of a deep mountain lake (Redó, Pyrenees)

2000 ◽  
Vol 59 (1s) ◽  
Author(s):  
Marc VENTURA ◽  
Lluis CAMARERO ◽  
Teresa BUCHACA ◽  
Frederic BARTUMEUS ◽  
David M. LIVINGSTONE ◽  
...  
Keyword(s):  
Seasonal Variability ◽  
Mountain Lake ◽  
External Forcing

scholarly journals Quantitative characteristics of the carcasses of Moxotó and Canindé goats fed diets with two different energy levels

2010 ◽  
Vol 39 (7) ◽  
pp. 1565-1570 ◽  
Author(s):  
Ana Cristina Chacon Lisboa ◽  
Dermeval Araújo Furtado ◽  
Ariosvaldo Nunes de Medeiros ◽  
Roberto Germano Costa ◽  
Rita de Cássia do Egypto Queiroga ◽  
...  
Keyword(s):  
Body Weight ◽  
Energy Level ◽  
Energy Levels ◽  
Experimental Period ◽  
Carcass Yield ◽  
Final Weight ◽  
Quantitative Characteristics ◽  
Energetic Level ◽  
Average Body ◽  
Average Body Weight

The objective of this work was to evaluate the quantitative characteristics of carcasses of Moxotó and Canindé goats finished in feedlots and fed diets of two levels of energy. It was used 40 castrated young goats, 20 from Moxotó breed and 20 from Canindé breed, each one with an average body weight of 15.2 kg. The animals were fed with diets containing 2.20 and 2.71 (Mcal/kg DM). The experimental period lasted 86 days. There was no difference among the barometric measures of Moxotó and Canindé kids. Canindé goats showed higher final weight, higher weight after fasting and higher hot and cold carcass weights when compared to the Moxotó animals. Animals that consumed diets with higher energy level had higher final weight and conformation as well as higher carcass yield. Considering the percentage values of the commercial meat cuts, no difference among treatments was observed. The diet was the factor that most influenced the non-constituent components of the carcass of Moxotó and Canindé goats. In general, animals belonging to the Canindé breed presented higher quantitative characteristics than the Moxotó breed. Supply of diets with higher energetic level (2.71 Mcal/kg DM) for goats from Moxotó and Canindé breeds, in feedlots, favors the production of carcass with higher yields and heavier commercial meat cuts.

Sign in / Sign up

Export Citation Format

Share Document