scholarly journals Retrieval of aerosol microphysical properties from AERONET photopolarimetric measurements: 1. Information content analysis

2015 ◽  
Vol 120 (14) ◽  
pp. 7059-7078 ◽  
Author(s):  
Xiaoguang Xu ◽  
Jun Wang
Keyword(s):  
Content Analysis ◽  
Information Content ◽  
Microphysical Properties

scholarly journals All-sky Information Content Analysis for Novel Passive Microwave Instruments in the Range from 23.8 GHz up to 874.4 GHz

2017 ◽  
Author(s):  
Verena Grützun ◽  
Stefan A. Buehler ◽  
Lukas Kluft ◽  
Jana Mendrok ◽  
Manfred Brath ◽  
...  
Keyword(s):  
Content Analysis ◽  
Information Content ◽  
Atmospheric Composition ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Submillimeter Wavelength ◽  
Great Ability ◽  
Microphysical Properties ◽  
Spatial Coverage ◽  
Cloud Ice

Abstract. We perform an all-sky information content analysis for channels in the millimeter/submillimeter wavelength with 24 channels in the region from 23.8 up to 874.4 GHz. Our set of channels corresponds to the instruments ISMAR and MARSS, which are available on the British FAAM research aircraft, and it is complemented by two precipitation channels at low frequencies from Deimos. The channels also cover ICI, which will be part of the MetOp-SG mission. We use simulated atmospheres from the ICON model as basis for the study and quantify the information content with the reduction of degrees of freedom (ΔDOF). The required Jacobians are calculated with the radiative transfer model ARTS. Specifically we focus on the dependence of the information content on the atmospheric composition. In general we find a high information content for the frozen hydrometeors, which mainly comes from the higher channels beyond 183.31 GHz (on average 4.99 for cloud ice and 4.84 for snow). Profile retrievals may be possible for the mass densities and some information about the microphysical properties, especially for cloud ice, can be gained. The information about the liquid hydrometeors comes from the lower channels and is comparably low (2.36 for liquid cloud water and 1.81 for rain). There is little information about the profile or the microphysical properties. The Jacobians for a specific cloud hydrometeor strongly depend on the atmospheric composition. Especially for the liquid hydrometeors they even change sign in some cases. However, the information content is robust. For liquid hydrometeors it slightly decreases in the presence of any frozen hydrometeor, for the frozen hydrometeors it slightly decreases in the presence of the respective other frozen hydrometeor. The overall results with regard to the frozen hydrometeors in principle also hold for the ICI sensor. This points to its great ability to observe ice clouds from space on a global scale with a good spatial coverage in unprecedented detail.

scholarly journals RETRIEVAL OF AEROSOL MICROPHYSICAL PROPERTIES BASED ON THE OPTIMAL ESTIMATION METHOD: INFORMATION CONTENT ANALYSIS FOR SATELLITE POLARIMETRIC REMOTE SENSING MEASUREMENTS

2018 ◽  
Vol XLII-3 ◽  
pp. 533-537 ◽  
Author(s):  
W. Z. Hou ◽  
Z. Q. Li ◽  
F. X. Zheng ◽  
L. L. Qie
Keyword(s):  
Content Analysis ◽  
Information Content ◽  
Estimation Method ◽  
Soil Surface ◽  
Optimal Estimation ◽  
Bare Soil ◽  
Transfer Model ◽  
Surface Reflectance ◽  
Microphysical Properties ◽  
Single Viewing

This paper evaluates the information content for the retrieval of key aerosol microphysical and surface properties for multispectral single-viewing satellite polarimetric measurements cantered at 410, 443, 555, 670, 865, 1610 and 2250 nm over bright land. To conduct the information content analysis, the synthetic data are simulated by the Unified Linearized Vector Radiative Transfer Model (UNLVTM) with the intensity and polarization together over bare soil surface for various scenarios. Following the optimal estimation theory, a principal component analysis method is employed to reconstruct the multispectral surface reflectance from 410 nm to 2250 nm, and then integrated with a linear one-parametric BPDF model to represent the contribution of polarized surface reflectance, thus further to decouple the surface-atmosphere contribution from the TOA measurements. Focusing on two different aerosol models with the aerosol optical depth equal to 0.8 at 550 nm, the total DFS and DFS component of each retrieval aerosol and surface parameter are analysed. The DFS results show that the key aerosol microphysical properties, such as the fine- and coarse-mode columnar volume concentration, the effective radius and the real part of complex refractive index at 550 nm, could be well retrieved with the surface parameters simultaneously over bare soil surface type. The findings of this study can provide the guidance to the inversion algorithm development over bright surface land by taking full use of the single-viewing satellite polarimetric measurements.

IMAGE OF THE REPUBLIC OF MORDOVIA IN THE MEDIA VOLGA FEDERAL DISTRICT (BASED ON CONTENT ANALYSIS OF NEWS PUBLICATIONS)

2020 ◽  
Vol 10 (4) ◽  
pp. 44-52
Author(s):  
LARISA ZAITSEVA ◽  
Keyword(s):  
Content Analysis ◽  
Information Content ◽  
Federal District ◽  
Information Space ◽  
Political News ◽  
Social Sphere ◽  
The Media ◽  
The Republic ◽  
Number Of Publications

The territorial image is formed both purposefully by the subjects of image-making, and spontaneously-based on the influence of information content published in various media. The purpose of the research is to analyze the image of the Republic of Mordovia in the information space of the Volga Federal district. The image of the territory formed by external target audiences by means of news materials is studied using the method of case study and content analysis of publications: “Volga news”, “Federal Press” news of the PFD, “Pravda PFD”. The authors conclude that modern reality is perceived through the prism of the information field created by mass media. The media creates images filled with certain data, facts, colored by emotions, on the basis of which representations, opinions, judgments, and assessments are subsequently formed. The media play a significant role in shaping the territorial image, especially for external target audiences who are not familiar with the region and do not have their own assessment knowledge and experience. Most of the information content about the Republic in the studied media is related to the main thematic blocks: politics, economy, social sphere, culture (art, sports). Moreover, if in the publications “Volga news” and “Pravda PFD” mention of the region prevails in the economic block, then in the publications “Federal Press” and “Nezavisimaya Gazeta” - in the political one. The Volga news publication significantly dominates the rest in terms of the number of publications about Mordovia. The content of publications is mostly positive and neutral related to the issues of economic development of the territory and the preparation and holding of the world football championship. Pravda PFD mentions the Republic in the context of news from neighboring territories, most of the publications date back to 2018, but here the context is related to the Republic's positions among the regions of the PFD in various ratings. The publication “Federal-Press” forms a generally reflective image of the territory, focusing on the negative aspects of regional life. “Nezavisimaya Gazeta”, giving priority to political news, maintains a neutral and reflective context of publications, paying attention to the key problems of the territory. Thus, the desired image of the region is counter-dictated to the image broadcast by the media through various information channels, so it is necessary to constantly monitor the information space and timely correction of the broadcast materials.

scholarly journals Assessing the credibility of COVID-19 vaccine mis/disinformation in online discussion

2021 ◽  
pp. 016555152110406
Author(s):  
Reijo Savolainen
Keyword(s):  
Content Analysis ◽  
Information Content ◽  
Online Discussion ◽  
Qualitative Content Analysis ◽  
Discussion Group

This study examines how the credibility of the content of mis- or disinformation, as well as the believability of authors creating such information is assessed in online discussion. More specifically, the investigation was focused on the credibility of mis- or disinformation about COVID-19 vaccines. To this end, a sample of 1887 messages posted to a Reddit discussion group was scrutinised by means of qualitative content analysis. The findings indicate that in the assessment of the author’s credibility, the most important criteria are his or her reputation, expertise and honesty in argumentation. In the judgement of the credibility of the content of mis/disinformation, objectivity of information and plausibility of arguments are highly important. The findings highlight that in the assessment of the credibility of mis/disinformation, the author’s qualities such as poor reputation, incompetency and dishonesty are particularly significant because they trigger expectancies about how the information content created by the author is judged.

scholarly journals Soil moisture retrieval from multi-instrument observations: Information content analysis and retrieval methodology

2013 ◽  
Vol 118 (10) ◽  
pp. 4847-4859 ◽  
Author(s):  
J. Kolassa ◽  
F. Aires ◽  
J. Polcher ◽  
C. Prigent ◽  
C. Jimenez ◽  
...  
Keyword(s):  
Content Analysis ◽  
Soil Moisture ◽  
Information Content

scholarly journals Understanding the aerosol information content in multi-spectral reflectance measurements using a synergetic retrieval algorithm

2010 ◽  
Vol 3 (6) ◽  
pp. 1589-1598 ◽  
Author(s):  
D. Martynenko ◽  
T. Holzer-Popp ◽  
H. Elbern ◽  
M. Schroedter-Homscheidt
Keyword(s):  
Content Analysis ◽  
Information Content ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Degrees Of Freedom ◽  
Surface Albedo ◽  
Water Soluble ◽  
Retrieval Algorithm ◽  
Aerosol Types ◽  
Reflectance Measurements

Abstract. An information content analysis for multi-wavelength SYNergetic AErosol Retrieval algorithm SYNAER was performed to quantify the number of independent pieces of information that can be retrieved. In particular, the capability of SYNAER to discern various aerosol types is assessed. This information content depends on the aerosol optical depth, the surface albedo spectrum and the observation geometry. The theoretical analysis is performed for a large number of scenarios with various geometries and surface albedo spectra for ocean, soil and vegetation. When the surface albedo spectrum and its accuracy is known under cloud-free conditions, reflectance measurements used in SYNAER is able to provide for 2–4° of freedom that can be attributed to retrieval parameters: aerosol optical depth, aerosol type and surface albedo. The focus of this work is placed on an information content analysis with emphasis to the aerosol type classification. This analysis is applied to synthetic reflectance measurements for 40 predefined aerosol mixtures of different basic components, given by sea salt, mineral dust, biomass burning and diesel aerosols, water soluble and water insoluble aerosols. The range of aerosol parameters considered through the 40 mixtures covers the natural variability of tropospheric aerosols. After the information content analysis performed in Holzer-Popp et al. (2008) there was a necessity to compare derived degrees of freedom with retrieved aerosol optical depth for different aerosol types, which is the main focus of this paper. The principle component analysis was used to determine the correspondence between degrees of freedom for signal in the retrieval and derived aerosol types. The main results of the analysis indicate correspondence between the major groups of the aerosol types, which are: water soluble aerosol, soot, mineral dust and sea salt and degrees of freedom in the algorithm and show the ability of the SYNAER to discern between this aerosol types. The results of the work will be further used for the development of the promising methodology of the construction error covariance matrices in the assimilation system.

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