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Rafail V. Abramov and Andrew J. Majda

satisfied a suitable fluctuation–dissipation theorem (FDT), then climate response to small external forcing could be calculated by estimating suitable statistics in the present climate. For the general FDT, see Deker and Haake (1975) , Risken (1989) , and Majda et al. (2005 , hereafter MAG05) . The topic of this paper is the use of a new algorithm ( Abramov and Majda 2007 , 2008 , hereafter AM07 , AM08 ) for calculating the FDT response to address the above issues in a prototype setting for the

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Chanh Q. Kieu and Da-Lin Zhang

approaches and realistic hurricane-like vortices. The objectives of this study are to a) extend the PV inversion algorithm of Wang and Zhang (2003 , hereafter WZ03) from one PV piece to multiple PV piece applications and then b) examine the dynamical effects of the above-mentioned axisymmetric PVAs on the intensity and structures of hurricane vortices using the piecewise PV inversion algorithm. This will be done by treating PV rings in the outer eyewall and the inner eyewall as well as the upper and

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Elizabeth E. Ebert and Michael J. Manton

rainfall estimates? How and why do estimates from different algorithms differ? Can satellite rainfall estimates be improved, and if so, how? In order to address these issues, several algorithm intercomparison projects have been conducted. The WetNet Precipitation Intercomparison Projects, PIP-1 and PIP-2, examined the abilities of various algorithms that use passive microwave data from the Special Sensor Microwave/Imager (SSM/I) onboard the Defense Meteorological Satellite Program (DMSP) polar orbiting

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Wesley Berg, William Olson, Ralph Ferraro, Steven J. Goodman, and Frank J. LaFontaine

to the launch of the first SSM/I in June of 1987, the United States Navy contracted the Hughes Aircraft Company to develop a number of geophysical retrieval algorithms from the microwave data gathered by the new sensor ( Hollinger et al. 1987 ). The original algorithms, referred to as the D-Matrix algorithms after the approach used for their development, suffered from a number of deficiencies but provided many insights into the information content and usefulness of the new microwave sensor. The

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Ralph R. Ferraro, Eric A. Smith, Wesley Berg, and George J. Huffman

, or mixed physical–empirical front-end algorithm, designed to discriminate the presence of rain from the background surface. The various rainfall intercomparison projects, including the Algorithm Intercomparison Projects (AIPs) sponsored by the Global Precipitation Climatology Project (GPCP) (see Arkin and Xie 1994 )and the National Aeronautic and Space Administration (NASA) WetNet Precipitation Intercomparison Projects (PIPs) (Barrett et al. 1994a), are revealing that the advantages of rainfall

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C. Kidd, D. Kniveton, and E. C. Barrett

1. Introduction The definition of statistical–empirical algorithms is not necessarily easy to determine. To envisage these algorithms as being a mere statistical relationship between two parameters (the passive microwave data and the ground truth data) would be too simplistic. Similarly, at the other extreme, rainfall retrievals using a physical model cannot solely rely upon radiative transfer theory. There is a full spectrum of algorithms that have evolved over several decades of research

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Xun Zhu

!5 DECEMBER 1994 Z H U 3593An Accurate and Efficient Radiation Algorithm for Middle Atmosphere Models XUN ZHUDepartment of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, Maryland(Manuscript received 6 August 1993, in final form 10 May 1994) ABSTRACT An accurate, efficient, and

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Matthieu Plu, Philippe Arbogast, and Alain Joly

. The first part of the present article opens with a brief presentation and a justification of the wavelet tools that are used: then it presents the extraction of the coherent field from a meteorological case study and the proposed algorithm to extract an individual coherent structure. The second part shows the application of the extraction on the upper-level precursor of an intense midlatitude storm and, using potential vorticity inversion, depicts the dynamics of the coherent structure that is

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Ayrton Zadra, Gilbert Brunet, and Jacques Derome

construct one such set. The purpose of this paper is therefore twofold: first, to describe a diagnostic algorithm based on the idea of normal mode decomposition and designed for studies of atmospheric variability; second, to illustrate the various features of the algorithm by applying it to a set of analyzed data. The algorithm is essentially a three-dimensional extension of the empirical normal mode (ENM) technique previously used by Brunet and Vautard (1996) in studies of two-dimensional shallow

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Peter M. Norris and Arlindo M. da Silva

polar orbiting satellites by Remote Sensing Systems (version 5) using the algorithm of Wentz (1997) . The data comes in daily files, one for each satellite, each containing CLWP mapped to a regular grid (0.25° × 0.25° resolution) complete with data gaps between orbits. Two maps exist per file, one of ascending orbit segments and the other of descending orbit segments. Data on each of the segment maps are overwritten at both the high latitudes where successive orbits cross and at the “seam” or

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