Introduction Laser-induced breakdown spectroscopy (LIBS) is considered one of the most convenient and efficient analytical techniques for trace elemental analysis in gases, solids, and liquids. Both non-invasive and non-destructive, LIBS requires little-to-no sample preparation and can easily be performed either in the lab or in the field in hazardous industrial environments in real-time. Remot...

Hydride gases, such as phosphine and arsine, are important contaminants in process chemicals used in both the petrochemical and semiconductor industries. For example, the presence of phosphine, arsine, hydrogen sulfide and carbonyl sulfide in polymer grade ethylene or propylene can have a deleterious effect on catalysts used in the production of polypropylene plastics. Accurate data on the conc...

The ATMOS Fourier transform spectrometer was flown for a fourth time on the Space Shuttle as part of the ATLAS-3 instrument payload in November 1994. More than 190 sunrise and sunset occultation events provided measurements of more than 30 atmospheric trace gases at latitudes 3 49øN and 65 72øS, including observations both inside and outside the Antarctic polar vortex. The instrument configurat...

This paper uses satellite measurements and global model output to identify a recent shift in the latitudinal position of the stratospheric tropical pipe region and the subsequent impact on trend estimates throughout the stratosphere, especially in the extratropical regions where a north-south asymmetry has been found in the trends of mean age and a number of trace gases. This is an interesting ...

Lasers and laser spectroscopic techniques have been extensively used in several applications since their advent, and the subject has been reviewed extensively in the last several decades. This review is focused on three areas of laser spectroscopic applications in atmospheric and environmental sensing; namely laser-induced fluorescence (LIF), cavity ring-down spectroscopy (CRDS), and photolumin...

In [1] is presented a model of the semi-transparent atmosphere consisting of a stack of gauzes, representing the IR-active trace gases (molecules with three or more atoms). Results have been validated by comparing them with published results of K&T type of diagrams based on the two-way formulation. The one-way formulation does not show the huge absorption in the atmosphere nor the socalled back...

The thermal structure of the atmosphere has a relevant influence on the circulation mechanisms of air masses and on the distribution of trace gases. In this paper, a neural network algorithm aiming at the real-time retrieval of temperature profiles from the radiance measurements provided by the instrument GOME boarded on the ESA satellite ERS-2 will be illustrated, and the obtained results will...

The administration and storage of environmental characteristic spectral data are highly relevant in many fields of environmental study, such as measurement of trace gases in the atmosphere and air quality estimation. For this reason, a web-accessible database has been developed, offering ready access to the main parameters of molecular absorption spectral data. Web-based and friendly interfaces...

The development of compact spectroscopic gas sensors and their applications to environmental sensing will be described. These sensors employ mid-infrared difference-frequency generation (DFG) in periodically poled lithium niobate (PPLN) crystals pumped by two single-frequency solid state lasers such as diode lasers, diode-pumped solid state, and fiber lasers. Ultrasensitive, highly selective, a...

Municipal solid waste landfills are significant parts of anthropogenic greenhouse gas emissions. The emission of significant amount of landfill gas has generated considerable interest in quantifying such emissions. The chemical composition of the organic constituents and potential amount of landfill gas that can be derived from the waste were determined. The chemical formulae for the rapidly bi...