Showing papers by "Charles E. Miller published in 2004"
California Institute of Technology1, Goddard Space Flight Center2, University of Bremen3, National Institute of Water and Atmospheric Research4, Woods Hole Oceanographic Institution5, University of California, Berkeley6, Harvard University7, Haverford College8, Commonwealth Scientific and Industrial Research Organisation9, Colorado State University10, Climate Monitoring and Diagnostics Laboratory11, Goodrich Corporation12
TL;DR: The Orbiting Carbon Observatory (OCO) as mentioned in this paper is the first global, space-based measurements of atmospheric carbon dioxide (CO 2 ) with the precision, resolution and coverage needed to characterize CO 2 sources and sinks on regional scales.
539 citations
TL;DR: In this paper, high-resolution near-infrared spectra of carbon dioxide have been recorded using the McMath-Pierce Fourier transform spectrometer at the Kitt Peak National Solar Observatory.
110 citations
01 Dec 2004
TL;DR: This article collected the first space-based measurements of atmospheric CO2 with the precision, resolution, and coverage needed to characterize its sources and sinks on regional scales and quantify their variability over the seasonal cycle.
Abstract: Science objectives include: Collect the first space-based measurements of atmospheric CO2 with the precision, resolution, and coverage needed to characterize its sources and sinks on regional scales and quantify their variability over the seasonal cycle. Use independent data validation approaches to ensure high accuracy (1-2 ppm, 0.3% - 0.5%). Reliable climate predictions require an improved understanding of CO2 sinks. What human and natural processes are controlling atmospheric CO2? What are the relative roles of the oceans and land ecosystems in absorbing CO2?
67 citations
TL;DR: In this article, the authors used the McMath-Pierce Fourier transform spectrometer at the Kitt Peak National Solar Observatory (KPNSSO) to detect the line positions of the 16 O 13 C 16 O isotopologue.
40 citations
TL;DR: In this article, the authors measured near-IR and UV spectroscopy from 220 to 298 K and from 45 to 200 Torr, respectively, and determined the low-pressure and high-pressure limit rate constants for reaction 1 were determined to be k_o = (2.1 ± 0.1) × 10^(-31) × (T/300)^(-(3.1± 0.5)) cm^3 molecule^(-1) s.
Abstract: Rate coefficients for the reaction HO_2 + NO_2 + N_2 → HO_2NO_2 + N_2 (reaction 1) were measured using simultaneous near-IR and UV spectroscopy from 220 to 298 K and from 45 to 200 Torr. Using the data acquired in the present experiment, the low-pressure and high-pressure limit rate constants for reaction 1 were determined to be k_o = (2.1 ± 0.1) × 10^(-31) × (T/300)^(-(3.1±0.3)) cm^6 molecule^(-2) s^(-1) and k∞ = (2.4 ± 0.1) × 10^(-12) × (T/300))^(-(1.9±0.5)) cm^3 molecule^(-1) s^(-1), using the expressions for rate constants adopted by the NASA data evaluation panel (F_c = 0.6). The reaction rate was significantly enhanced in the presence of methanol due to a chaperone effect involving an HO_2·CH_3OH complex. Enhancement parameters for this process were quantified as a function of temperature. During the course of our studies, we observed an unexpected time-dependent UV absorption unaccounted for in previous examinations of reaction 1 that employed UV spectroscopy to monitor HO_2. We show that this absorption, which may have led to errors in those prior studies, is due to the process NO_2 + NO_2 ⇄ N_2O_4 (reaction 3). Using UV−visible spectroscopy, we determine k_(-3) to be (36 ± 10) s^(-1) at 231 K and 100 Torr using the NASA-recommended equilibrium constant for the dimerization of NO_2. This represents the first measurement of k_(-3) at T < 250 K.
31 citations
TL;DR: The small, positive inertial defect Delta=0.075667(60) amu A2 and lack of any observable torsional splittings in the spectrum indicate that cis-cis HOONO exists in a well-defined planar structure at room temperature.
Abstract: The pure rotational spectrum of cis-cis peroxynitrous acid, HOONO, has been observed. Over 220 transitions, sampling states up to J(')=67 and K-a(')=31, have been fitted with an rms uncertainty of 48.4 kHz. The experimentally determined rotational constants agree well with ab initio values for the cis-cis conformer, a five-membered ring formed by intramolecular hydrogen bonding. The small, positive inertial defect Delta=0.075667(60) amu A(2) and lack of any observable torsional splittings in the spectrum indicate that cis-cis HOONO exists in a well-defined planar structure at room temperature.
15 citations
TL;DR: In this paper, an analogous oxygen atom exchange reaction for the isoelectronic O(^1D) + N_2O system was proposed to explain the mass-independent isotopic fractionation (MIF) in atmospheric N 2 O.
Abstract: Recent experiments have shown that in the oxygen isotopic exchange reaction for O(^1D) + CO_2 the elastic channel is approximately 50% that of the inelastic channel [Perri et al., 2003]. We propose an analogous oxygen atom exchange reaction for the isoelectronic O(^1D) + N_2O system to explain the mass-independent isotopic fractionation (MIF) in atmospheric N_2O. We apply quantum chemical methods to compute the energetics of the potential energy surfaces on which the O(^1D) + N_2O reaction occurs. Preliminary modeling results indicate that oxygen isotopic exchange via O(^1D) + N_2O can account for the MIF oxygen anomaly if the oxygen atom isotopic exchange rate is 30–50% that of the total rate for the reactive channels.
13 citations
TL;DR: The proton affinity of peroxyacetic acid has been studied using ab initio methods as mentioned in this paper, and the most stable peroxyACetic acid structure forms a nearly planar five-membered ring in which the carbonyl oxygen...
Abstract: The proton affinity of peroxyacetic acid has been studied using ab initio methods. The most stable peroxyacetic acid structure forms a nearly planar five-membered ring in which the carbonyl oxygen ...
8 citations