scholarly journals Structural characterization of the equatorial F region plasma irregularities in the multifractal context

2019 ◽  
Author(s):  
Neelakshi Joshi ◽  
Reinaldo R. Rosa ◽  
Siomel Savio ◽  
Esfhan Alam Kherani ◽  
Francisco Carlos de Meneses ◽  
...  
Keyword(s):  
Ionospheric Plasma ◽  
Fluctuation Analysis ◽  
Multifractal Detrended Fluctuation Analysis ◽  
Plasma Irregularities ◽  
In Situ Data ◽  
F Region ◽  
Linear Algorithms ◽  
Multiplicative Cascade

Abstract. In the emerging ionosphere-space-weather paradigm, investigating dynamical properties of ionospheric plasma irregularities using advanced computational non-linear algorithms is providing new insights into their turbulent-like nature, for instance, the evidence of energy distribution via multiplicative cascade. In this study, we present multifractal analysis of the equatorial F region in situ data obtained from two different experiments performed at Alcântara (2.4° S; 44.4° W), Brazil to explore their scaling structures. First experiment observed several large-medium scale plasma bubbles whereas second experiment observed vertical uplift of the base of F region. Multifractal detrended fluctuation analysis and p-model fit is used to analyze the plasma density fluctuation time series. Result shows presence of multifractality with degree of multifractality 0.53–1.1 with 0.29 ≤ p ≤ 0.4 cascading probability for first experiment. Another experimental data also exhibits multifractality with degree of multifractality 0.27–0.33 with 0.42 ≤ p ≤ 0.44 cascading probability in the ionospheric plasma irregularities. Our results confirm the nonhomogeneous nature of plasma irregularities and characterize the underlying nonhomogeneous multiplicative cascade hypothesis in the ionospheric medium. Differences in terms of scaling and complexity in data belonging to different types of phenomena are also addressed.

scholarly journals Structural characterization of the equatorial F region plasma irregularities in the multifractal context

2020 ◽  
Vol 38 (2) ◽  
pp. 445-456
Author(s):  
Neelakshi Joshi ◽  
Reinaldo R. Rosa ◽  
Siomel Savio ◽  
Esfhan Alam Kherani ◽  
Francisco Carlos de Meneses ◽  
...  
Keyword(s):  
Large Scale ◽  
Ionospheric Plasma ◽  
Fluctuation Analysis ◽  
Multifractal Detrended Fluctuation Analysis ◽  
Plasma Irregularities ◽  
In Situ Data ◽  
F Region ◽  
Multiplicative Cascade

Abstract. In the emerging ionosphere–space–weather paradigm, investigating the dynamical properties of ionospheric plasma irregularities using advanced computational nonlinear algorithms provide new insights into their turbulent-seeming nature, for instance, the evidence of energy distribution via a multiplicative cascade. In this study, we present a multifractal analysis of the equatorial F region in situ data obtained from two different experiments performed at Alcântara (2.4∘ S, 44.4∘ W), Brazil, to explore their scaling structures. The first experiment observed several medium- to large-scale plasma bubbles whereas the second experiment observed vertical uplift of the base of the F region. The multifractal detrended fluctuation analysis and the p-model fit are used to analyze the plasma density fluctuation time series. The result shows the presence of multifractality with degree of multifractality 0.53–0.93 and 0.3≤p≤0.4 cascading probability for the first experiment. Other experimental data also exhibit multifractality with degree of multifractality 0.19–0.27 and 0.42≤p≤0.44 cascading probability in ionospheric plasma irregularities. Our results confirm the nonhomogeneous nature of plasma irregularities and characterize the underlying nonhomogeneous multiplicative cascade hypothesis in the ionospheric medium. Differences in terms of scaling and complexity in the data belonging to different types of phenomena are also addressed.

scholarly journals Characterization of Aura TES carbonyl sulfide retrievals over ocean

2014 ◽  
Vol 7 (1) ◽  
pp. 163-172 ◽  
Author(s):  
L. Kuai ◽  
J. Worden ◽  
S. S. Kulawik ◽  
S. A. Montzka ◽  
J. Liu
Keyword(s):  
Carbonyl Sulfide ◽  
Systematic Errors ◽  
Retrieval Algorithm ◽  
Aircraft Measurements ◽  
Random Errors ◽  
Mauna Loa ◽  
In Situ Data ◽  
Peak Sensitivity

Abstract. We present a description of the NASA Aura Tropospheric Emission Spectrometer (TES) carbonyl sulfide (OCS) retrieval algorithm for oceanic observations, along with evaluation of the biases and uncertainties using aircraft profiles from the HIPPO (HIAPER Pole-to-Pole Observations) campaign and data from the NOAA Mauna Loa site. In general, the OCS retrievals (1) have less than 1.0 degree of freedom for signals (DOFs), (2) are sensitive in the mid-troposphere with a peak sensitivity typically between 300 and 500 hPa, (3) but have much smaller systematic errors from temperature, CO2 and H2O calibrations relative to random errors from measurement noise. We estimate the monthly means from TES measurements averaged over multiple years so that random errors are reduced and useful information about OCS seasonal and latitudinal variability can be derived. With this averaging, TES OCS data are found to be consistent (within the calculated uncertainties) with NOAA ground observations and HIPPO aircraft measurements. TES OCS data also captures the seasonal and latitudinal variations observed by these in situ data.

scholarly journals Characterization of aura tropospheric emissions spectrometer carbonyl sulfide retrievals

2013 ◽  
Vol 6 (4) ◽  
pp. 6975-7003
Author(s):  
L. Kuai ◽  
J. Worden ◽  
S. S. Kulawik ◽  
S. A. Montzka ◽  
J. Liu
Keyword(s):  
Carbonyl Sulfide ◽  
Systematic Errors ◽  
Retrieval Algorithm ◽  
Aircraft Measurements ◽  
Random Errors ◽  
Mauna Loa ◽  
In Situ Data ◽  
Peak Sensitivity

Abstract. We present a description of the Tropospheric Emission Spectrometer (TES) carbonyl sulfide (OCS) retrieval algorithm, along with evaluation of the biases and uncertainties against aircraft profiles from the HIPPO campaign and data from the NOAA Mauna Loa site. In general, the OCS retrievals (1) have less than 1.0 degree of freedom for signals (DOFs), (2) are sensitive in the mid-troposphere with a peak sensitivity typically between 300 to 500 hPa, (3) but have much smaller systematic errors from temperature, CO2 and H2O calibrations relative to random errors from measurement noise. Here we estimate the monthly means from TES measurements averaged over multiple years so that random errors are reduced and useful information about OCS seasonal and latitudinal variability can be derived. With this averaging, TES OCS data are found to be consistent (within the calculated uncertainties) with NOAA ground observations and HIPPO aircraft measurements. TES OCS data also captures the seasonal and latitudinal variations observed by these in situ data.

scholarly journals Inside the hydro-physics processes at the plunge point location: an analysis by satellite and in situ data

2011 ◽  
Vol 8 (1) ◽  
pp. 1193-1223
Author(s):  
A. T. Assireu ◽  
E. Alcântara ◽  
E. M. L. M. Novo ◽  
F. Roland ◽  
F. S. Pacheco ◽  
...  
Keyword(s):  
Transition Zone ◽  
Landsat Tm ◽  
Density Currents ◽  
Wet Season ◽  
Satellite Measurements ◽  
Reservoir Water ◽  
In Situ Data ◽  
River Reservoir

Abstract. The plunge point locates the main point of mixing between river and the epilimnion reservoir water. The plunge point monitoring is essential to understand how it will be the behavior of density currents and its implications for reservoir. The applicability of satellite imagery products from different sensors (Landsat TM band 6 thermal signatures and visible channel) for characterization of the river-reservoir transition zone is presented in this study. We demonstrate the feasibility of the Landsat TM band imagery to discern the subsurface river plumes and the plunge point. The spatial variability of the plunge point evident in the hydrologic data illustrates the advantages of synoptic satellite measurements over in situ point measurements alone to detect the river-reservoir transition zone. It is indicated that the river flowing as underflow contributes to the thermal stability of the water column during wet season (summer-autumn). During the dry season, when the river-reservoir water temperature differences vanish and the river circulation is characterized by interflow-overflow, the river water inserts into the reservoir upper layers, affecting water quality. The results indicate good agreement between hydrologic and satellite data and that the jointly use of thermal and visible channel, operational monitoring of plunge point is feasible. The deduced information about the density current from this product could potentially be assimilated for numerical modeling and hence be of significant interest for environmental and climatological research.

scholarly journals Ionospheric Plasma Irregularities Based on In Situ Measurements From the Swarm Satellites

2020 ◽  
Vol 125 (7) ◽  
Author(s):  
Yaqi Jin ◽  
Chao Xiong ◽  
Lasse Clausen ◽  
Andres Spicher ◽  
Daria Kotova ◽  
...  
Keyword(s):  
Ionospheric Plasma ◽  
In Situ Measurements ◽  
Plasma Irregularities ◽  
Swarm Satellites

On the multifractality of plasma turbulence in the solar wind

2019 ◽  
Vol 15 (S354) ◽  
pp. 371-374
Author(s):  
Sebastián Echeverría ◽  
Pablo S. Moya ◽  
Denisse Pastén
Keyword(s):  
Solar Wind ◽  
Velocity Distribution ◽  
Distribution Functions ◽  
Fluctuation Analysis ◽  
Magnetic Fluctuations ◽  
Multifractal Detrended Fluctuation Analysis ◽  
Particle In Cell ◽  
Velocity Distribution Functions ◽  
Detrended Fluctuation

AbstractIn this work we have analyzed turbulent plasma in the kinetic scale by the characterization of magnetic fluctuations time series. Considering numerical Particle-In-Cell (PIC) simulations we apply a method known as MultiFractal Detrended Fluctuation Analysis (MFDFA) to study the fluctuations of solar-wind-like plasmas in thermodynamic equilibrium (represented by Maxwellian velocity distribution functions), and out of equilibrium plasma represented by Tsallis velocity distribution functions, characterized by the kappa (κ) parameter, to stablish relations between the fractality of magnetic fluctuation and the kappa parameter.

scholarly journals On developing a new ionospheric plasma index for Brazilian equatorial F region irregularities

2019 ◽  
Vol 37 (5) ◽  
pp. 807-818 ◽  
Author(s):  
Laysa Cristina Araujo Resende ◽  
Clezio Marcos Denardini ◽  
Giorgio Arlan Silva Picanço ◽  
Juliano Moro ◽  
Diego Barros ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Space Weather ◽  
Ionospheric Plasma ◽  
Monitoring Program ◽  
Plasma Irregularities ◽  
Plasma Drift ◽  
F Region ◽  
Maximum Value ◽  
Spread F

Abstract. F region vertical drifts (Vz) are the result of the interaction between ionospheric plasma with the zonal electric field and the Earth's magnetic field. Abrupt variations in Vz are strongly associated with the occurrence of plasma irregularities (spread F) during the nighttime periods. These irregularities are manifestations of space weather in the ionosphere's environment without necessarily requiring a solar burst. In this context, the Brazilian Space Weather Study and Monitoring Program (Embrace) of the National Institute for Space Research (INPE) has been developing different indexes to analyze these ionospheric irregularities in the Brazilian sector. Therefore, the main purpose of this work is to produce a new ionospheric scale based on the analysis of the ionospheric plasma drift velocity, named AV. It is based on the maximum value of Vz (Vzp), which in turn is calculated through its relationship with the virtual height parameter, h′F, measured by the Digisonde Portable Sounder (DPS-4D) installed in São Luís (2∘ S, 44∘ W; dip: −2.3∘). This index quantifies the time relationship between the Vz peak and the irregularity observed in the ionograms. Thus, in this study, we analyzed 7 years of data, between 2009 and 2015, divided by season in order to construct a standardized scale. The results show there is a delay of at least 15 min between the Vzp observation and the irregularity occurrence. Finally, we believe that this proposed index allows for evaluating the impacts of ionospheric phenomena in the space weather environment.

scholarly journals Ionospheric plasma irregularities studied with Swarm satellites

2018 ◽  
Vol 62 ◽  
pp. 01009
Author(s):  
Wojciech J. Miloch ◽  
Yaqi Jin ◽  
Chao Xiong ◽  
Guram Kervalishvili ◽  
Andres Spicher ◽  
...  
Keyword(s):  
Ionospheric Plasma ◽  
Ionospheric Irregularities ◽  
Global Studies ◽  
Gps Receiver ◽  
Magnetic Field Data ◽  
Plasma Irregularities ◽  
Swarm Satellites ◽  
The Magnetic Field ◽  
Level 2

To study and characterise the ionospheric plasma irregularities at all latitudes, one can employ in-situ measurements by satellites in polar orbits, such as the European Space Agency’s Swarm mission. Based on the Swarm data, we have developed the Ionospheric Plasma IRregularities (IPIR) product for a global characterisation of ionospheric irregularities along the satellite track at all latitudes. This new Level-2 data product combines complementary datasets from the Swarm satellites: the electron density from the electric field instrument, the GPS data from the onboard GPS receiver, and the magnetic field data from the onboard magnetometers. This can be used as a new tool for global studies of ionospheric irregularities and turbulence.

scholarly journals Intercomparison of polar ozone profiles by IASI/MetOp sounder with 2010 Concordiasi ozonesonde observations

2013 ◽  
Vol 6 (3) ◽  
pp. 613-620 ◽  
Author(s):  
J. Gazeaux ◽  
C. Clerbaux ◽  
M. George ◽  
J. Hadji-Lazaro ◽  
J. Kuttippurath ◽  
...  
Keyword(s):  
Positive Bias ◽  
Satellite Measurements ◽  
Recovery Processes ◽  
In Situ Data ◽  
Vertical Range ◽  
Polar Orbiting Satellite ◽  
Polar Ozone ◽  
Good Agreement

Abstract. Validation of ozone profiles measured from a nadir looking satellite instrument over Antarctica is a challenging task due to differences in their vertical sensitivity with ozonesonde measurements. In this paper, ozone observations provided by the Infrared Atmospheric Sounding Interferometer (IASI) instrument onboard the polar-orbiting satellite MetOp are compared with ozone profiles collected between August and October 2010 at McMurdo Station, Antarctica, during the Concordiasi measurement campaign. The main objective of the campaign was the satellite data validation. With this aim 20 zero-pressure sounding balloons carrying ozonesondes were launched during this period when the MetOp satellite was passing above McMurdo. This makes the dataset relevant for comparison, especially because the balloons covered the entire altitude range of IASI profiles. The validation methodology and the collocation criteria vary according to the availability of global positioning system auxiliary data with each electro-chemical cell ozonesonde observation. The relative mean difference is shown to depend on the vertical range investigated. The analysis shows a good agreement in the troposphere (below 10 km) and middle stratosphere (25–40 km), where the differences are lower than 10%. However a significant positive bias of about 10–26% is estimated in the lower stratosphere at 10–25 km, depending on altitude. The positive bias in the 10–25 km range is consistent with previously reported studies comparing in situ data with thermal infrared satellite measurements. This study allows for a better characterization of IASI-retrieved ozone over the polar region during ozone depletion/recovery processes.

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