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Review of the applications of Multiangle Imaging SpectroRadiometer to air quality research

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Science China Earth Sciences 2009年第1期52卷 132-144页

作者： Ralph A.KAHN jet propulsion laboratory California Institute of TechnologyPasadenaCA 91109USA

The Multiangle Imaging SpectroRadiometer(MISR) launched by NASA in late 1999 has a unique mul-tiangle design,which points nine cameras at fixed angles along the satellite flight track and collects reflected solar radiation *** design allows the retrieval of a rich dataset of particle abundance,shape and composition over both land and *** of its capabilities have not been seen by any currently operating satellite aerosol *** MISR is sensitive to fine particles,it provides a new data source to study the spatial and temporal characteristics of air quality over large geographical *** first briefly introduce the MISR instrument,the retrieval and structure of MISR aerosol data,and then review the applications of MISR aerosol data in various aspects of air quality research since its *** include the spatial distributions of particle pollution events such as dust storms,wild fires,and urban *** of the high quality of MISR aerosol data,they can be used as quantitative indicators of particle pollution *** review the current modeling studies of surface level particle ***,we introduce research results using MISR's advanced data such as the plume heights,and particle microphysical *** the discussion,we compare MISR research with current MODIS research to the best of our ability as MODIS data have been more extensively explored by the Chinese scientific ***,we summarize the advantages and disadvantages of MISR data related to its applications to the air quality *** the highly quantitative measurements and comprehensive aerosol information MISR can provide,we believe that it will provide great values to advance our understanding of the particle air pollution in China.

关键词： aerosol remote sensing MISR multiangle imaging aerosol optical thickness particulate matters PM2.5 PM10 air pollution

Molecular Oxygen Abundance in Galactic Massive Star Formation Regions Based on SWAS Observations

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Research in Astronomy and Astrophysics 2024年第9期24卷 83-98页

作者： Bing-Ru Wang Di Li Paul F.Goldsmith Jingwen Wu Chao-Wei Tsai Donghui Quan Xia Zhang Junzhi Wang Gary J.Melnick Jin-Zeng Li Gary A.Fuller Jinjin Xie National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Tsinghua University Beijing 100084China University of Chinese Academy of Sciences Beijing 100049China Research Center for Astronomical Computing Zhejiang LaboratoryHangzhou 311100China jet propulsion laboratory California Institute of TechnologyPasadenaCA 91109USA Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Guangxi Key laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China Center for Astrophysics Harvard&Smithsonian60 Garden StreetMS 66CambridgeMA 02138USA Jodrell Bank Center for Astrophysics Department of Physics&AstronomyUniversity of ManchesterOxford RoadManchesterM139PLUK I.Physikalisches Institut University of CologneZülpicher Str.7750937 KölnGermany

Molecular oxygen abundance is a key parameter in understanding the chemical network of the interstellar *** estimate the molecular oxygen column density and abundance for a sample of Galactic massive star formation regions based on observations from the Submillimiter Wave Astronomy Satellite(SWAS)*** obtained an averaged O_(2)spectrum based on this sample using the(SWAS)survey data(O_(2),487.249 GHz,N=3-1,J=3-2).No emission or absorption feature is seen around the supposed central velocity with a total integration time of t_(total)=8.67×10^(3)hr and an rms noise per channel of 1.45 m *** a kinetic temperature T_(kin)=30 K,we derive the 3σupper limit of the O_(2)column density to be 3.3×10^(15)cm^(-2),close to the lowest values reported in Galactic massive star formation regions in previous *** corresponding O_(2)abundance upper limit is6.7×10^(-8),lower than all previous results based on SWAS observations and is close to the lowest reported value in massive star formation *** a galactic scale,our statistical results confirm a generally low O_(2)abundance for Galactic massive star formation *** abundance is also lower than results reported in extragalactic sources.

关键词： ISM:molecules galaxies:abundances ISM:lines and bands Galaxy:abundances

SmallSat swarm gravimetry:Revealing the interior structure of asteroids and comets

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Astrodynamics 2021年第3期5卷 217-236页

作者： William Gordon Ledbetter Rohan Sood James Keane Jeffrey Stuart Astrodynamics and Space Research laboratory The University of AlabamaTuscaloosaAL 35487USA jet propulsion laboratory California Institute of TechnologyPasadenaCA 91109USA

A growing interest in small body exploration has motivated research into the rapid char-acterization of near-Earth objects to meet economic or scientific ***,knowledge of the internal density structure can aid with target selection and enables an understanding of prehistoric planetary formation to be *** this end,multi-layer extensions to the polyhedral gravity model are suggested,and an inversion technique is implemented to present their ***-orbit gravity gradiometry is simulated and employed in stochastic and deterministic algorithms,with results that imply robustness in both cases.

关键词： gravimetry asteroid exploration astrodynamics stochastic optimization

Why did life develop on the surface of the Earth in the Cambrian？

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Geoscience Frontiers 2016年第6期7卷 865-873页

作者： Carlo Doglioni Johannes Pignatti Max Coleman Department of Earth Sciences Sapienza University 00185 Rome Italy NASA jet propulsion laboratory California Institute of Technology Pasadena CA 91109 USA NASA Astrobiology Institute USA

Life was limited for most of Earth＇s history, remaining at a primitive stage and mostly marine until about 0.55 Ga. In the Paleozoic, life eventually exploded and colonized the continental realm. Why had there been such a long period of delayed evolution of life？ Early life was dominated by Archaea and Bacteria, which can survive ionizing radiation better than other organisms. The magnetic field preserves the atmosphere, which is the main shield of UV radiation. We explore the hypothesis that the Cambrian explosion of life could have been enabled by the increase of the magnetic field dipole intensity due to the solidification of the inner core, caused by the cooling of the Earth, and the concomitant decrease with time of the high-energy solar flux since the birth of the solar system. Therefore, the two phenomena could be responsible for the growth and thickening of the atmosphere and the development of land surface life.

关键词： Origin of lifeInner core solidificationSolar ionizing radiations

Towards intelligent geospatial data discovery:a machine learning framework for search ranking

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International Journal of Digital Earth 2018年第9期11卷 956-971页

作者： Yongyao Jiang Yun Li Chaowei Yang Fei Hu Edward MArmstrong Thomas Huang David Moroni Lewis J.McGibbney Christopher J.Finch NSF Spatiotemporal Innovation Center and Department of Geography and GeoInformation Science George Mason UniversityFairfaxVAUSA NASA jet propulsion laboratory California Institute of TechnologyPasadenaCAUSA

Current search engines in most geospatial data portals tend to induce users to focus on one single-data characteristic dimension(*** and release date).This approach largely fails to take account of users’multidimensional preferences for geospatial data,and hence may likely result in a less than optimal user experience in discovering the most applicable *** study reports a machine learning framework to address the ranking challenge,the fundamental obstacle in geospatial data discovery,by(1)identifying a number of ranking features of geospatial data to represent users’multidimensional preferences by considering semantics,user behavior,spatial similarity,and static dataset metadata attributes;(2)applying a machine learning method to automatically learn a ranking function;and(3)proposing a system architecture to combine existing search-oriented open source software,semantic knowledge base,ranking feature extraction,and machine learning *** show that the machine learning approach outperforms other methods,in terms of both precision at K and normalized discounted cumulative *** an early attempt of utilizing machine learning to improve the search ranking in the geospatial domain,we expect this work to set an example for further research and open the door towards intelligent geospatial data discovery.

关键词： Learning to rank semantic search user behavior search engine big data metadata data relevancy data portal

Erroneous use of Statistics behind Claims of a Major Solar Role in Recent Warming

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Research in Astronomy and Astrophysics 2022年第12期22卷 224-231页

作者： Mark T.Richardson Rasmus E.Benestad jet propulsion laboratory California Institute of TechnologyPasadenaCA 91109USA Department of Atmospheric Science Colorado State UniversityFt CollinsCO 90732USA Norwegian Meteorological Institute NO-0313 OsloNorway

In a study that attempted to relate solar and human activity to Earth's recent temperature change,Connolly et *** a basic error in the choice of statistical methods and so overreported the effect of the Sun.A major theme of their study was that there are many data sets of past solar activity,and some of these allegedly provide statistical evidence of“most of the recent global warming being due to changes in solar activity.”We avoid methods that are known to give inaccurate results and show that for 1970–2005 Northern Hemisphere land the corrected solar attribution fraction is-7%to+5%,compared with values of up to 64%reported in Connolly et *** higher values are entirely due to mistaken application of ***,we cannot test truly“recent”global warming since most of their solar data sets end before 2015,and two finish in the 1990s,but all tested post-1970 periods show similarly small solar *** solar-climate linkage is an area of fascinating and ongoing research with rigorous technical *** argue that instead of repeating errors,they should be acknowledged and corrected so that the debate can focus on areas of legitimate scientific uncertainty.

关键词： Earth (Sun:)solar-terrestrial relations Physical Data and Processes

Computational Research on Rotating Channel by a Modified Anisotropic Turbulence Model

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Journal of Thermal Science 2011年第5期20卷 385-393页

作者： Jianqin Zhu Zhi Tao Chaoqun Nie Institute of Engineering Thermophysics Chinese Academy of Science Beijing 100190 China National Key lab. on Aero-Engines School of Jet Propulsion Beihang University Beijing 100191.China

Based on the simplified format of the Reynolds stress equations, a fire-new rotational-modification method for the anisotropic turbulence model has been presented. A three-dimensional Navier-Stokes code with this new rotational modified k-ω turbulence models （β=0.1 and β=1） and the standard k-ω turbulence model have been used for the prediction of flow and heat transfer characteristics in a rotating smooth square channel. The Reynolds number Re based on the inlet velocity of the cooling air and hydraulic diameter is 6000 .The rotating speed are 300, 600, 900, 1200rpm respectively. The calculations results of using three turbulence models have been compared with the experimental data. The research results show that （1） the rotational modification coefficient Rf13 used in the new anisotropic k-ω model would increased/decreased the predictions of heat transfer on the trailing surface/leading surface compared to the standard k-ω model. And this tendency would be increased with the increased ft. （2） The simulation performance of the standard k-ω model was well on the leading surface. However, on the trailing surface it under-predicted the heat transfer at high rotating speed. （3） The calculation results of the new anisotropic k-ω model with β=0.1 proposed by the present paper agreed well with experimental data, both on the leading and trailing surfaces. Besides, compared to 1, 0.1 is a more appropriate magnitude of βat conditions in the present paper.

关键词： anisotropy turbulence model rotation heat transfer

Climate Patterns: Origin and Forcing

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American Journal of Climate Change 2021年第2期10卷 204-236页

作者： Alexander Ruzmaikin jet propulsion laboratory California Institute of Technology Pasadena USA

This brief review described spatial-time climate patterns generated by the dynamics and thermodynamics of the Earth’s climate system and methods of identifying these patterns. Specifically, it does discuss the following major climate patterns: El Ni?o-Southern Oscillation (ENSO), Cold Ocean-Warm Land (COWL) pattern, Northern and Southern Annular Patterns (NAM and SAM), Atlantic Multidecadal Oscillation (AMO) and Atlantic Meridional Overturning Circulation (AMOC), Pacific North-American Pattern (PNA) and Pacific Decadal Oscillation Pattern (PDO). In view of an extensive number of publications on some climate patterns, such as the ENSO, which discussed in many hundred of publications, this review is not intended to cover all the details of individual climate patterns but intends only to give a general overview of their structure, mechanisms of their formation and response to external forcing. It is assumed that the climate patterns can be treated as attractors of dynamical systems allowing us to extract and predict some specific features of the patterns such as the origin and evolution of the climate patterns and their role in climate change. Thus the knowledge of patterns allows the climate prediction on long time scales and understanding of how an external forcing affects the frequency of occurrence of climate patterns and their magnitude but not the spatial structure.

关键词： Spatial-Time Patters Dynamics Climate Change Climate Prediction

Toward Quantum-Inspired Model of Mind

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Journal of Quantum Information Science 2014年第1期4卷 22-43页

作者： Michail Zak jet propulsion laboratory California Institute of Technology Pasadena USA

This paper proposes a mathematical formalism for describing the machinery of human mind creativity. Since some functions of mind support discreteness of cognition, but others support its continuity, while time in physics is always continuous, an attempt to overcome the continuous/discrete duality of mind performance is implemented via utilization of special critical points: terminal attractors and repellers that act as autonomous biological clock. In this paper, attention is concentrated upon the discrete mode of the mind activity since the continuous mode was introduced and discussed in details in our previous publications. The fundamental novelty of the model is in its capability to move from disorder to order without external inputs in violation of the second law of thermodynamics;that suggests that this kind of dynamics requires extension of modern physics to include physics of life. Conceptually the discrete model links to its continuous version represented by a hypothetical particle of life that is briefly discussed prior to derivation of the discrete model. However, the discrete model should be considered as the next step in study of mind dynamics since it provides a bridge to mathematical origin of self-generated novelties in such brunches as mathematical logic and linguistic, i.e. the highest level activities of human mind. The proposed model deals with rules of mind activity rather than with its content.

关键词： Mind Creativity Terminal Singularities Biological Clock