Learning incorporates a broad range of complex procedures. Machine learning (ML) is subdivision artificial intelligence based on the biological process. The ML approach deals with design algorithms to learn from machine readable data. covers main domains such as data mining, difficult-to-program applications, and software applications. It collection variety (e.g. neural networks, support vector machines, self-organizing map, decision trees, random forests, case-based reasoning, genetic...

Abstract For the first time, method of four‐dimensional variational data assimilation is applied to analysis chemically active trace species. By combining observations with a numerical model analyse simultaneously several species over period few days, able exploit information which not available conventional techniques. Moreover, effective use can be made asynoptic even for have strong diurnal cycles. Synoptic analyses are produced. A Lagrangian approach adopted, allowing separation dynamics...

A model aircraft equipped with a custom laser-based, open-path methane sensor was deployed around natural gas compressor station to quantify the leak rate and its variability at in Barnett Shale. The open-path, laser-based provides fast (10 Hz) precise (0.1 ppmv) measurements of compact package while remote control nimble safe operation local source. Emission rates were measured from 22 flights over one-week period. Mean emission 14 ± 8 g CH4 s–1 (7.4 4.2 median) observed or approximately...

We demonstrate compact, low power, lightweight laser-based sensors for measuring trace gas species in the atmosphere designed specifically electronic unmanned aerial vehicle (UAV) platforms. The utilize non-intrusive optical sensing techniques to measure atmospheric greenhouse concentrations with unprecedented vertical and horizontal resolution (~1 m) within planetary boundary layer. are developed including carbon dioxide, water vapor methane atmosphere. Key innovations coupling of very...

With the increasing awareness of health impacts particulate matter, there is a growing need to comprehend spatial and temporal variations global abundance ground level airborne matter with diameter 2.5 microns or less (PM2.5). Here we use suite remote sensing meteorological data products together groundbased observations from 8,329 measurement sites in 55 countries taken 1997-2014 train machinelearning algorithm estimate daily distributions PM2.5 1997 present. In this first paper series,...

This paper presents a review of the main ozone destroying catalytic cycles operating in stratosphere. Particular attention is paid to kinetic aspects these such as rate limiting step and chain length. Although it an important parameter, length various seldom considered when are discussed. survey highlights that low stratosphere involving HO 2 halogens (notably bromine) particularly important. In approximate order effectiveness most loss polar lower BrO/CIO, /BrO, OH/HO cycles.

Carbon aerosols are produced by all combustion processes. This paper investigates some possible effects of heterogeneous reduction atmospheric constituents on carbon aerosols. Reduction HNO 3 , NO 2 and O may be an important effect increased air traffic that has not been considered to date. It is shown if heterogeneously reduced amorphous aerosols, then a significant, lower stratospheric ozone loss mechanism could exist. almost independent temperature does require the presence sunlight. The...

This paper reviews the current knowledge of gas phase bromine photochemistry and presents a budget study atmospheric species. The effectiveness ozone catalytic loss cycles involving is quantified by considering their chain length effectiveness. new variable defined as multiplied rate cycle's rate‐limiting step. enables fair comparison different species which have very concentrations. analysis clearly shows that below 25 km BrO/ClO BrO/HO 2 are among most important destruction cycles.

This paper considers the effect of heterogeneous bromine reactions on stratospheric photochemistry. We have considered both sulfate aerosols and polar clouds (PSCs). It is shown that hydrolysis BrONO 2 enhances HOBr concentration, which in turn OH HO concentrations, thereby reducing HCl lifetime concentration. The leads to a nighttime production HOBr, making major reservoir. photolysis gives rapid increase concentration at dawn, as was recently observed by Salawitch et al. [1994]. decrease...

Machine-learning approaches (neural networks and support vector machines) are used to explore the reasons for a persistent bias between aerosol optical depth (AOD) retrieved from MODerate resolution Imaging Spectroradiometer (MODIS) accurate ground-based Aerosol Robotic Network. While this falls within expected uncertainty of MODIS algorithms, there is room algorithm improvement. The results machine-learning suggest link AOD biases surface type. MODIS-derived may be showing dependence on...

With the increasing awareness of health impacts particulate matter, there is a growing need to comprehend spatial and temporal variations global abundance ground-level airborne matter (PM2.5). Here we use suite remote sensing meteorological data products together with ground based observations PM2.5 from 8,329 measurement sites in 55 countries taken between 1997 2014 train machine learning algorithm estimate daily distributions present. We demonstrate that new product can reliably represent...

Phytophthora megakarya (Pmeg) and palmivora (Ppal) are closely related species causing cacao black pod rot. Although Ppal is a cosmopolitan pathogen, the only known host of economic importance for Pmeg. Pmeg more virulent on than Ppal. We sequenced compared genomes identified virulence-related putative gene models (PGeneM) that may be responsible their differences in specificities virulence. have estimated genome sizes 126.88 151.23 Mb PGeneM numbers 42,036 44,327, respectively. The...

A Global Ocean Carbon Algorithm Database (GOCAD) has been developed from over 500 oceanographic field campaigns conducted worldwide the past 30 years including in situ reflectances and coincident satellite imagery, multi- hyperspectral Chromophoric Dissolved Organic Matter (CDOM) absorption coefficients 245-715 nm, CDOM spectral slopes eight visible ultraviolet wavebands, dissolved particulate organic carbon (DOC POC, respectively), inherent optical, physical, biogeochemical properties. From...

CMOS IC technology has become an affordable means for implementing capable systems operating at 300 GHz and above. circuits have been used to generate a signal up 1.3 THz detect both amplitude phase of signals 1.2 THz, ~10 THz. Additionally, transmitter receiver ~300 electronic smelling using rotational spectroscopy, 30-Gb/s 300-GHz QPSK data communication with -6-dBm output power, 820 imaging array fabricated in reported. These results, along the circuit performance literature, link...

Abstract In this research, we present data‐driven forecasting of ionospheric total electron content (TEC) using the Long‐Short Term Memory (LSTM) deep recurrent neural network method. The random forest machine learning method was used to perform a regression analysis and estimate variable importance input parameters. data are obtained from satellite ground based measurements characterizing solar‐terrestrial environment. We relative 34 different parameters, including solar flux, wind density,...

A three‐dimensional (3D) radiative‐dynamical‐chemical model has been developed and used to study the evolution of trace gases in Arctic lower stratosphere during winter 1989–1990. series 10‐day integrations were performed throughout this period. The includes a comprehensive scheme gas phase chemical reactions as well parameterization heterogeneous occurring on polar stratospheric cloud (PSC) surfaces. An important element 3D is transport scheme. In species achieved by non diffusive method...

We present an analysis of chlorine chemistry in the Arctic stratosphere during winter 1991/92 and assess its potential implications for ozone depletion. In accordance with observations total organic chlorine, ClONO 2 HCl, box model results indicate following: (1) An almost complete activation cold period. (2) A possible contribution from heterogeneous reaction HOCl + HCl gas‐phase CH 3 O ClO to conversion active chlorine. (3) strong buildup following PSC disappearance which remains main...

Abstract This paper describes a simple, but effective, procedure for producing three‐dimensional tracer fields and general diagnostics based on an equivalent PV latitude–potential‐temperature coordinate system. The generated by this method are shown to agree quantitatively with independently measured profiles total columns. Using initialization makes short model simulations of around week or so much more realistic. It can be used assimilate non‐global measurements, such as sonde...

We have analyzed thirteen years (1993 to 2005) of HALOE and over two EOS MLS observations (September 2004 December 2006) for QBO annual cycle trace variations in tropical H 2 O, HCl, ozone, N CO, HF, CH 4 . use these results develop the theory explaining both Brewer‐Dobson circulation (BDC) driven fluctuations gases. For BDC drive part tropopause forcing through temperature as has been shown previously. amplify CO at recently by Randel et al (2007). In cases, signal is carried upward mean...

Abstract The long term Advanced Very High Resolution Radiometer (AVHRR)‐Normalized Difference Vegetation Index (NDVI) record provides a critical historical perspective on vegetation dynamics necessary for global change research. Despite the proliferation of new sources global, moderate resolution datasets, remote sensing community is still struggling to create datasets derived from multiple sensors that allow simultaneous use spectral time series analysis. To overcome non‐stationary aspect...

With the exception of acetone it is not generally recognized how important atmospheric carbonyls and alkyl radicals are in lower stratosphere upper troposphere. Carbonyl compounds crucial intermediate species for autocatalytic production OH. For example, troposphere calculated based on data assimilation analysis Atmospheric Trace Molecule Spectroscopy Experiment (ATMOS) that CH 3 due to degradation contributes around 40% overall , a key initiation step HO x production, with contribution...

This paper considers the nature of carbonaceous surfaces, means by which they are activated, some functional groups that support, and reaction mechanisms may be involved. Because strong affinity surfaces for organic species because ease with compounds in a high oxidation state can oxidize surface, it is highly likely aerosols interacting chemically range ways have, as yet, not been fully characterized but significantly affect oxidizing capacity our atmosphere. If HONO formed on surface then...