Alexander Ruzmaikin - Academia.edu (original) (raw)

Papers by Alexander Ruzmaikin

Research paper thumbnail of Modes of natural and forced climate variability in 6 years of AIRS and AMSU data

2009 IEEE International Geoscience and Remote Sensing Symposium, 2009

We use the Atmospheric Infrared Sounder (AIRS) and Advance Microwave Sounding Unit (AMSU) data ob... more We use the Atmospheric Infrared Sounder (AIRS) and Advance Microwave Sounding Unit (AMSU) data obtained on Aqua spacecraft to study mid-tropospheric temperature variability in 2002-2008. The AIRS and AMSU deliver accurate, simultaneous measurements of the state of the atmosphere twice per day. We investigate the temperature variability at the surface and in a broad layer centered on 400 hPa in a zonally averaged N region over the ocean. Taking into account the nonlinear and non-stationary behavior of the temperature we use the data analysis adaptive to the data, the Empirical Mode Decomposition, to separate the atmosphere response to the CO increase from the modes of natural climate variability. Our tentative conclusions are as follows: (1) the AIRS record shows a phase shift relative to CO and a trend in accord with the increase of CO ; (2) the simultaneous AMSU record is in agreement with the cooling of the tropical ocean that may be caused in part by the decline in solar activity.

Research paper thumbnail of Clustering of atmospheric data by the deterministic annealing

Journal of Atmospheric and Solar-Terrestrial Physics, 2014

ABSTRACT The Deterministic Annealing (DA) clustering method, which determines the cluster centers... more ABSTRACT The Deterministic Annealing (DA) clustering method, which determines the cluster centers, their sizes, and probability with which data are associated with each cluster, is tested using artificial data and applied to atmospheric satellite data. It is also shown how the method can be advantageously used to characterize data outliers. The method is based on the optimization of a cost function that depends both on the averaged distance of data points to cluster centers and the Shannon entropy of the data. The cost function uses two independent parameters in a close analog to the Gibbs' thermodynamics (with the averaged distance similar to the internal energy) allowing a sufficient control of the formation of new clusters as "phase transitions" by changing the clustering parameter similar to the thermodynamical temperature. The satellite data used are a temperature-water vapor data set and the positions of deep convective clouds obtained from the measurements of the Atmospheric InfraRed Sounder (AIRS) on the Aqua satellite. The clustering of these data is demonstrated for the 2D case (at fixed pressure level) and for the 3D case at multiple pressure levels indicating potential applications to investigation of distributions of atmospheric profiles. Published by Elsevier Ltd.

Research paper thumbnail of Fractal flux tubes of the solar magnetic field

Lecture Notes in Physics, 1991

ABSTRACT

Research paper thumbnail of Trends in tropical circulation over the pacific during the last decade

2012 IEEE International Geoscience and Remote Sensing Symposium, 2012

ABSTRACT The Aqua spacecraft decadal time span generated a vast volume of data that can be used f... more ABSTRACT The Aqua spacecraft decadal time span generated a vast volume of data that can be used for climate change studies. Here we use these data to investigate the tropical circulation response to global warming during the last decade. We use the Atmospheric Infrared Sounder (AIRS), Advance Microwave Sounding Unit (AMSU) and the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) data obtained on Aqua spacecraft to determine the trends in the surface and mid-troposphere temperatures, as well as trends in cloudiness, Outgoing Longwave Radiation (OLR) and precipitation over the West and East Pacific in 2002-2011. The Aqua instruments deliver accurate, simultaneous measurements of the state of the atmosphere twice per day. We find that the tropical (Walker) circulation over Pacific Ocean has been accelerating during this last decade.

Research paper thumbnail of S18: Solar Variabilit y Effects U p on the Lower Atmos p here and Climate Or g anizers: Chair p erson: J. Austin Frida y , October 6; Room 1 Chair p erson

Research paper thumbnail of Nonuniform large-scale magnetic field and global structure of the universe

Research paper thumbnail of The interpretation of rotation measures of extragalactic radio sources

Astronomy and Astrophysics

Research paper thumbnail of A Magnetohydrodynamic dynamo model of the solar cycle

Research paper thumbnail of A nonlinear magnetohydrodynamic model of the solar dynamo

Research paper thumbnail of The Magnetic Field in Mirror-Invariant Turbulence

Research paper thumbnail of Galactic magnetic field parameters determined from Faraday rotation of radio sources

Research paper thumbnail of A method for determining the large-scale magnetic field in the solar corona

A method is developed for determining the magnetic field in the solar corona from observations of... more A method is developed for determining the magnetic field in the solar corona from observations of the Faraday rotation of many discrete radio sources projected against the corona. With this method the averaged characteristics of the coronal magnetic field and electron density can be obtained by using Tikhonov's (1963) method to solve a Fredholm integral equation of the first kind. The observations required to implement the proposed method are discussed, and a simple estimate of the expected solution is examined. A list of 42 extragalactic radio sources and pulsars which 'pass through' the corona at an angular distance of no more than 5 deg from the center of the sun is given.

Research paper thumbnail of Faraday rotation in galaxies, and absorption lines in quasars

Research paper thumbnail of The Turbulent Dynamo in Astrophysics

Research paper thumbnail of A disk dynamo

Research paper thumbnail of Magnetic field of a conducting fluid in two-dimensional motion

Zhurnal Eksperimental'noi i Teroreticheskoi Fiziki

The paper considers magnetic field development in a conducting fluid with one component of the ve... more The paper considers magnetic field development in a conducting fluid with one component of the velocity equal to zero; the other velocity components, the conductivity, and the magnetic field are assumed to be dependent on all three coordinates. Under these conditions a significant extension of the antidynamo theorem of plane motion (Zeldovich, 1956) is demonstrated. This result makes it possible to classify dynamo solutions in relation to the magnetic Reynolds number.

Research paper thumbnail of The calculation of Faraday rotation measures of cosmic radio sources

Astronomy and Astrophysics

Research paper thumbnail of The Turbulent Dynamo in a Disk

Research paper thumbnail of The Role of Differential Rotation in the Solar Dynamo

Research paper thumbnail of Steady-state magnetic field in a periodic flow

Research paper thumbnail of Modes of natural and forced climate variability in 6 years of AIRS and AMSU data

2009 IEEE International Geoscience and Remote Sensing Symposium, 2009

We use the Atmospheric Infrared Sounder (AIRS) and Advance Microwave Sounding Unit (AMSU) data ob... more We use the Atmospheric Infrared Sounder (AIRS) and Advance Microwave Sounding Unit (AMSU) data obtained on Aqua spacecraft to study mid-tropospheric temperature variability in 2002-2008. The AIRS and AMSU deliver accurate, simultaneous measurements of the state of the atmosphere twice per day. We investigate the temperature variability at the surface and in a broad layer centered on 400 hPa in a zonally averaged N region over the ocean. Taking into account the nonlinear and non-stationary behavior of the temperature we use the data analysis adaptive to the data, the Empirical Mode Decomposition, to separate the atmosphere response to the CO increase from the modes of natural climate variability. Our tentative conclusions are as follows: (1) the AIRS record shows a phase shift relative to CO and a trend in accord with the increase of CO ; (2) the simultaneous AMSU record is in agreement with the cooling of the tropical ocean that may be caused in part by the decline in solar activity.

Research paper thumbnail of Clustering of atmospheric data by the deterministic annealing

Journal of Atmospheric and Solar-Terrestrial Physics, 2014

ABSTRACT The Deterministic Annealing (DA) clustering method, which determines the cluster centers... more ABSTRACT The Deterministic Annealing (DA) clustering method, which determines the cluster centers, their sizes, and probability with which data are associated with each cluster, is tested using artificial data and applied to atmospheric satellite data. It is also shown how the method can be advantageously used to characterize data outliers. The method is based on the optimization of a cost function that depends both on the averaged distance of data points to cluster centers and the Shannon entropy of the data. The cost function uses two independent parameters in a close analog to the Gibbs' thermodynamics (with the averaged distance similar to the internal energy) allowing a sufficient control of the formation of new clusters as "phase transitions" by changing the clustering parameter similar to the thermodynamical temperature. The satellite data used are a temperature-water vapor data set and the positions of deep convective clouds obtained from the measurements of the Atmospheric InfraRed Sounder (AIRS) on the Aqua satellite. The clustering of these data is demonstrated for the 2D case (at fixed pressure level) and for the 3D case at multiple pressure levels indicating potential applications to investigation of distributions of atmospheric profiles. Published by Elsevier Ltd.

Research paper thumbnail of Fractal flux tubes of the solar magnetic field

Lecture Notes in Physics, 1991

ABSTRACT

Research paper thumbnail of Trends in tropical circulation over the pacific during the last decade

2012 IEEE International Geoscience and Remote Sensing Symposium, 2012

ABSTRACT The Aqua spacecraft decadal time span generated a vast volume of data that can be used f... more ABSTRACT The Aqua spacecraft decadal time span generated a vast volume of data that can be used for climate change studies. Here we use these data to investigate the tropical circulation response to global warming during the last decade. We use the Atmospheric Infrared Sounder (AIRS), Advance Microwave Sounding Unit (AMSU) and the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) data obtained on Aqua spacecraft to determine the trends in the surface and mid-troposphere temperatures, as well as trends in cloudiness, Outgoing Longwave Radiation (OLR) and precipitation over the West and East Pacific in 2002-2011. The Aqua instruments deliver accurate, simultaneous measurements of the state of the atmosphere twice per day. We find that the tropical (Walker) circulation over Pacific Ocean has been accelerating during this last decade.

Research paper thumbnail of S18: Solar Variabilit y Effects U p on the Lower Atmos p here and Climate Or g anizers: Chair p erson: J. Austin Frida y , October 6; Room 1 Chair p erson

Research paper thumbnail of Nonuniform large-scale magnetic field and global structure of the universe

Research paper thumbnail of The interpretation of rotation measures of extragalactic radio sources

Astronomy and Astrophysics

Research paper thumbnail of A Magnetohydrodynamic dynamo model of the solar cycle

Research paper thumbnail of A nonlinear magnetohydrodynamic model of the solar dynamo

Research paper thumbnail of The Magnetic Field in Mirror-Invariant Turbulence

Research paper thumbnail of Galactic magnetic field parameters determined from Faraday rotation of radio sources

Research paper thumbnail of A method for determining the large-scale magnetic field in the solar corona

A method is developed for determining the magnetic field in the solar corona from observations of... more A method is developed for determining the magnetic field in the solar corona from observations of the Faraday rotation of many discrete radio sources projected against the corona. With this method the averaged characteristics of the coronal magnetic field and electron density can be obtained by using Tikhonov's (1963) method to solve a Fredholm integral equation of the first kind. The observations required to implement the proposed method are discussed, and a simple estimate of the expected solution is examined. A list of 42 extragalactic radio sources and pulsars which 'pass through' the corona at an angular distance of no more than 5 deg from the center of the sun is given.

Research paper thumbnail of Faraday rotation in galaxies, and absorption lines in quasars

Research paper thumbnail of The Turbulent Dynamo in Astrophysics

Research paper thumbnail of A disk dynamo

Research paper thumbnail of Magnetic field of a conducting fluid in two-dimensional motion

Zhurnal Eksperimental'noi i Teroreticheskoi Fiziki

The paper considers magnetic field development in a conducting fluid with one component of the ve... more The paper considers magnetic field development in a conducting fluid with one component of the velocity equal to zero; the other velocity components, the conductivity, and the magnetic field are assumed to be dependent on all three coordinates. Under these conditions a significant extension of the antidynamo theorem of plane motion (Zeldovich, 1956) is demonstrated. This result makes it possible to classify dynamo solutions in relation to the magnetic Reynolds number.

Research paper thumbnail of The calculation of Faraday rotation measures of cosmic radio sources

Astronomy and Astrophysics

Research paper thumbnail of The Turbulent Dynamo in a Disk

Research paper thumbnail of The Role of Differential Rotation in the Solar Dynamo

Research paper thumbnail of Steady-state magnetic field in a periodic flow