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The Orbiting Carbon Observatory-2 (OCO-2), launched on 2 July 2014, is a NASA mission designed to measure the column-averaged CO2 dry air mole fraction, XCO2. Towards that goal, it will collect spectra of reflected sun-light in narrow spectral ranges centered at 0.76, 1.6 and 2.0 µm with a resolving power (λ/△λ) of 20 000. These spectra will be used in an optimal estimation framework to retrieve XCO2. About 100 000 cloud free soundings of XCO2 each day will allow estimates of net CO2 fluxes on regional to continental scales to be determined. Here, we evaluate the OCO-2 spectrometer performance using pre-launch data acquired during instrument thermal vacuum tests in April 2012. A heliostat and a diffuser plate were used to feed direct sunlight into the OCO-2 instrument and spectra were recorded. These spectra were compared to those collected concurrently from a nearby high-resolution Fourier Transform Spectrometer that was part of the Total Carbon Column Observing Network (TCCON). Using the launch-ready OCO-2 calibration and spectroscopic parameters, we performed to tal column scaling fits to all spectral bands and compared these to TCCON results. On 20 April, we detected a CO2 plume from the Los Angeles basin at the JPL site with strongly enhanced short-term variability on the order of 1% (3-4 ppm). We also found good (<0.5 pppm) inter-footprint consistency in retrieved XCO2. The variations in spectral fitting residuals are consistent with signal-to-noise estimates from instrument calibration, while average residuals are systematic and mostly attributable to remaining errors in our knowledge of the CO2 and O2 spectroscopic parameters. A few remaining inconsistencies observed during TVAC may be attributable to the specific instrument setup on the ground and will be re-evaluated with in-orbit data, when the instrument is expected to be in a much more stable environment. [ABSTRACT FROM AUTHOR]

The Los Angeles basin is a significant anthropogenic source of major greenhouse gases (CO2 and CH4) and the pollutant CO, contributing significantly to regional and global climate change. We present a novel approach for monitoring the spatial and temporal distributions of greenhouse gases in the Los Angeles basin using a highresolution spectroscopic remote sensing technique. A new Fourier Transform Spectrometer called CLARS-FTS has been deployed since May 2010 at JPL's California Laboratory for Atmospheric Remote Sensing (CLARS) on Mt. Wilson, California for automated long-term measurements of greenhouse gases. The instrument design and performance of CLARS-FTS are presented. From its mountaintop location at an altitude of 1673 m, the instrument points at a programmed sequence of ground target locations in the Los Angeles basin, recording spectra of reflected near-IR solar radiation. Column-averaged dry-air mole fractions of greenhouse gases (XGHG) including XCO2, XCH4, and XCO are retrieved several times per day for each target. Spectra from a local Spectralon® scattering plate are also recorded to determine background (free tropospheric) column abundances above the site. Comparisons between measurements from LA basin targets and the Spectralon® plate provide estimates of the boundary layer partial column abundances of the measured species. Algorithms are described for transforming the measured interferograms into spectra, and for deriving column abundances from the spectra along with estimates of the measurement precision and accuracy. The CLARS GHG measurements provide a means to infer relative, and possibly absolute, GHG emissions. [ABSTRACT FROM AUTHOR]

The article discusses the Measurements of Humidity in the Atmosphere and Validation Experiment (MOHAVE), a campaign that was conducted at the Jet Propulsion Laboratory (JPL) Table Mountain Facility (TMF) in California on October 11-27 2009. The campaign has intended to validate water vapor measurements of atmospheric instruments and to examine the tropospheric humidity variability. It further explores the launch of 58 radiosondes and 20 Frost-Point hygrometer sondes during the campaign.

The article presents a study which evaluates the importance of Total Carbon Column Observing Network (TCCON) which was calibrated by World Meteorological Organization (WMO) in situ trace gas measurement scales. It states that the network is designed for aircraft campaigns for Stratosphere-Troposphere Analyses of Regional Transport 2008 (START-08) included a profile over the Lamont and Lauder sites. The global calibration factor of gas captures the TCCON data is also evaluated.

The article focuses on the measurements of CO2 operated by Fourier Transform Spectroscopic (FTS) solar observatory in Darwin, Northern Territory in August 2005. It states that the laboratory is component of Total Carbon Column Network that evaluates the atmospheric profusion of CO2 and other types of gases. It says that retrievals of CO2 were calibrated via aircraft profiles gathered during the Tropical Warm Pool-International Cloud Experiment (TWP-ICE) campaign.