Fluctuation dissipation theorem in a general circulation model

2004 ◽  
Vol 31 (9) ◽  
pp. n/a-n/a ◽  
Author(s):  
I. Cionni ◽  
G. Visconti ◽  
F. Sassi
Keyword(s):  
General Circulation Model ◽  
General Circulation ◽  
Circulation Model ◽  
Fluctuation Dissipation ◽  
Fluctuation Dissipation Theorem

Climate Response of Linear and Quadratic Functionals Using the Fluctuation–Dissipation Theorem

2008 ◽  
Vol 65 (9) ◽  
pp. 2824-2841 ◽  
Author(s):  
Andrey Gritsun ◽  
Grant Branstator ◽  
Andrew Majda
Keyword(s):  
General Circulation ◽  
Atmospheric General Circulation Model ◽  
Circulation Model ◽  
Heat Fluxes ◽  
Heat Sources ◽  
State Variables ◽  
Fluctuation Dissipation ◽  
Fluctuation Dissipation Theorem ◽  
Low Pass ◽  
Momentum And Heat Fluxes

Abstract A generalization of the fluctuation–dissipation theorem (FDT) that allows generation of linear response operators that estimate the response of functionals of system state variables is tested for a system defined by an atmospheric general circulation model (AGCM). A sketch of the proof of this generalization is provided, followed by comparison of response estimates based on the theory and actual responses of the AGCM for various idealized anomalous equatorial heat sources. Tested response quantities include precipitation, variances of bandpass and low-pass streamfunction, and momentum and heat fluxes. The solutions from the FDT operators are very similar to the AGCM solutions in terms of structure while overestimating response amplitudes by about 20%. As an example of an application of such response operators, the FDT operator that estimates the response of bandpass upper-tropospheric streamfunction variance is used to find the most efficient means of disturbing the Atlantic storm tracks by tropical heating. The results of the study suggest that the generalized FDT is an attractive method for systematically studying response attributes of the climate system that are of interest to climate scientists and society.

Climate Response Using a Three-Dimensional Operator Based on the Fluctuation–Dissipation Theorem

2007 ◽  
Vol 64 (7) ◽  
pp. 2558-2575 ◽  
Author(s):  
Andrey Gritsun ◽  
Grant Branstator
Keyword(s):  
Influence Function ◽  
General Circulation ◽  
Three Dimensional ◽  
Circulation Model ◽  
Tropical Indian Ocean ◽  
The Arctic ◽  
External Forcing ◽  
Fluctuation Dissipation ◽  
Fluctuation Dissipation Theorem ◽  
Reduced Space

Abstract The fluctuation–dissipation theorem (FDT) states that for systems with certain properties it is possible to generate a linear operator that gives the response of the system to weak external forcing simply by using covariances and lag-covariances of fluctuations of the undisturbed system. This paper points out that the theorem can be shown to hold for systems with properties very close to the properties of the earth’s atmosphere. As a test of the theorem’s applicability to the atmosphere, a three-dimensional operator for steady responses to external forcing is constructed for data from an atmospheric general circulation model (AGCM). The response of this operator is then compared to the response of the AGCM for various heating functions. In most cases, the FDT-based operator gives three-dimensional responses that are very similar in structure and amplitude to the corresponding GCM responses. The operator is also able to give accurate estimates for the inverse problem in which one derives the forcing that will produce a given response in the AGCM. In the few cases where the operator is not accurate, it appears that the fact that the operator was constructed in a reduced space is at least partly responsible. As an example of the potential utility of a response operator with the accuracy found here, the FDT-based operator is applied to a problem that is difficult to solve with an AGCM. It is used to generate an influence function that shows how well heating at each point on the globe excites the AGCM’s Northern Hemisphere annular mode (NAM). Most of the regions highlighted by this influence function, including the Arctic and tropical Indian Ocean, are verified by AGCM solutions as being effective locations for stimulating the NAM.

scholarly journals The Response of a Simplified GCM to Axisymmetric Forcings: Applicability of the Fluctuation–Dissipation Theorem

2008 ◽  
Vol 65 (12) ◽  
pp. 3880-3898 ◽  
Author(s):  
Michael J. Ring ◽  
R. Alan Plumb
Keyword(s):  
General Circulation ◽  
Circulation Model ◽  
Quantitative Relationship ◽  
Model Atmosphere ◽  
Annular Mode ◽  
Annular Modes ◽  
Fluctuation Dissipation ◽  
Fluctuation Dissipation Theorem ◽  
Theoretical Predictions ◽  
The Tropics

Abstract Following on their previous work, in which they found the annular modes to be a preferred response of a simplified general circulation model atmosphere to a number of mechanical forcings, the authors now explore the quantitative relationship between forcing and response. In particular, the applicability of the fluctuation–dissipation theorem to this problem is investigated. First, the set of model trials is expanded by including runs in which the applied forcings are thermal rather than mechanical. For thermal forcings confined to the extratropics, “annular mode–like” responses, reminiscent of those found in earlier work, are found, but, as found in previous studies, the response is less like an annular mode when the forcing has significant amplitude in the tropics. Assuming small departures from the control climatology, and making a few further assumptions, the authors derive a theoretical relationship between forcing and response. This relationship is a statement of the fluctuation–dissipation theorem for this problem. The response of the model is found to be qualitatively consistent with the theoretical predictions. However, several aspects of the response diverge quantitatively from the theoretical expectation.

scholarly journals Practical Approximations to Seasonal Fluctuation–Dissipation Operators Given a Limited Sample

2016 ◽  
Vol 73 (6) ◽  
pp. 2529-2545 ◽  
Author(s):  
David Fuchs ◽  
Steven Sherwood
Keyword(s):  
General Circulation ◽  
Seasonal Fluctuation ◽  
Circulation Model ◽  
Small Sample ◽  
Prediction Errors ◽  
Limited Sample ◽  
State Response ◽  
Fluctuation Dissipation ◽  
Fluctuation Dissipation Theorem ◽  
Small Sample Sizes

Abstract This paper studies operators inspired by the fluctuation–dissipation theorem that consider the seasonality (nonstationarity) of the climate system under conditions of limited sample size relevant to application of the method to observational records. The approach is used to predict the steady-state response of an atmospheric general circulation model to localized temperature perturbations. A seasonal operator nominally requires a much larger data sample than a stationary operator; the authors study some strategies to overcome this. First, two methods for approximating the seasonality of the system are examined. Second, an alternative “transpose approach” to the standard dimension reduction is considered that is more efficient and accurate for small sample sizes and additionally enables the use of a kernel, which provides a convenient way to incorporate prior physical understanding into the operator. All operators show considerable skill in predicting seasonal responses for a variety of variables (temperature, winds, rainfall, and cloud cover) and better skill in predicting the annual-mean ones. A comparison of these predictions to ones done on the same system with temporally fixed boundary conditions shows unexpectedly that skill is, if anything, improved by the presence of a seasonal cycle. The authors suggest that the extra complexity due to a seasonal system is outweighed by the added information due to the seasonal forcing and the effect of seasonality in smoothing out prediction errors.

Fluctuation dissipation in a general circulation model

1993 ◽  
Vol 8 (6) ◽  
pp. 259-264 ◽  
Author(s):  
Gerald R North ◽  
Robert E Bell ◽  
James W Hardin
Keyword(s):  
General Circulation Model ◽  
General Circulation ◽  
Circulation Model ◽  
Fluctuation Dissipation

An eddy-permitting ocean-sea ice general circulation model (E3SMv0-HiLAT03): Description and evaluation

2019 ◽  
Author(s):  
Jiaxu Zhang ◽  
Wilbert Weijer ◽  
Mathew Einar Maltrud ◽  
Carmela Veneziani ◽  
Nicole Jeffery ◽  
...  
Keyword(s):  
Sea Ice ◽  
General Circulation Model ◽  
General Circulation ◽  
Circulation Model

Calculating the Natural Atmospheric Radiation Using the General Circulation Model of the Earth’s Lower and Middle Atmosphere

2020 ◽  
Vol 12 (5) ◽  
pp. 803-815
Author(s):  
B. N. Chetverushkin ◽  
I. V. Mingalev ◽  
E. A. Fedotova ◽  
K. G. Orlov ◽  
V. M. Chechetkin ◽  
...  
Keyword(s):  
General Circulation Model ◽  
General Circulation ◽  
Middle Atmosphere ◽  
Circulation Model ◽  
Atmospheric Radiation
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