D. L. Albritton's research while affiliated with National Oceanic and Atmospheric Administration and other places

Publications (164)

Article
The flowing afterglow technique has been used to study the electron detachment reactionsThe rates of these reactions are sufficiently fast to make them important processes in D region ionospheric chemistry.
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Climate change can be driven by changes in the atmospheric concentrations of a number of radiatively active gases and aerosols. We have clear evidence that human activities have affected concentrations, distributions and life cycles of these gases. These matters, discussed in this chapter, were assessed at greater length in IPCC WGI report ""Radiat...
Article
The mobilities of H+ and D+ ions in He have been measured over a range of ratios of electric field strength E to helium number density N with a selected-ion flow-drift tube. It is found that, at E/N greater than about 40Td (1 Td=10-17V cm2), the apparent mobilities exhibit an unusual increase with increasing E/N that is attributed to the breakdown...
Book
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The Climate Change 2001 volumes of the Third Assessment Report of the IPCC provide the most comprehensive assessment of climate change since its second report, Climate Change 1995. This Synthesis Report gives a comprehensive summary of the main points of the three separate volumes of the Report: The Scientific Basis; Impacts, Adaptation, and Vulner...
Article
Full-text available
The Third Assessment Report of Working Group I of the Intergovernmental Panel on Climate Change (IPCC) builds upon past assessments and incorporates new results from the past five years of research on climate change 1. Many hundreds of scientists 2 from many countries participated in its preparation and review.
Chapter
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Climate Change 2001: The Scientific Basis is the most comprehensive and up-to-date scientific assessment of past, present and future climate change. The report: • Analyses an enormous body of observations of all parts of the climate system. • Catalogues increasing concentrations of atmospheric greenhouse gases. • Assesses our understanding of the p...
Technical Report
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The objective of the Symposium on the Global Atmospheric Effects of Aviation was to bring international scientific, technology, and policy leaders together to review the status of all relevant atmospheric research, for discussion of potential mitigation measures, and to consider what policy-relevant information may be available to decision makers i...
Article
The atmospheric abundance of methyl chloroform, CH{sub 3}CCl{sub 3}, a compound of only anthropogenic origin, is actually decreasing because of emission reductions in compliance with the United Nations Montreal Protocol and its subsequent amendments. This observation, reported by Prinn and co-workers elsewhere in this issue, is based on data from s...
Article
Net global warming potentials and instantaneous radiative forcing values that include the cooling from halocarbon-induced ozone destruction have been calculated for 14 of the most significant halocarbons. These calculations were performed by incorporating knowledge of direct global warming potentials with an evaluation of the relationship between t...
Article
Assessments of long-term ozone depletion by CFCs have relied on their relative effects as quantified by ozone depletion potentials (ODPs). These long-term ODPs, based on steady-state atmospheric impacts, are not appropriate for making shorter-term (decade-scale) forecasts. Time-dependent ODPs, derived using an empirical approach, show that some of...
Article
The field of atmospheric chemistry is data-limited, primarily because of the challenge of measuring the key chemical constituents in the global environment. Several recent advances, however, in rugged, portable, remotesensing, ground-based instrumentation and accurate, fast-response airborne instrumentation have provided powerful tools for the unde...
Article
The document represents an attempt to put together, in one place, a summary of the present state of knowledge concerning those processes that affect air concentrations of acidic and acidifying pollutants, during their transport, from emission to deposition. It is not intended to be an all-encompassing review of the entire breadth of each of the con...
Article
This paper provides the rationale, objectives, approach, and a brief description of the instrumentation included in the second airborne Chemical Instrumentation Test and Evaluation (CITE 2) mission conducted on NASA's Electra aircraft. CITE 2 intercompared data from instruments measuring NO2, HNO3, and PAN in the troposphere. This study, conducted...
Article
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Measurements of NO, NO2, O3, and CO are presented from 13 aircraft flights made over the eastern Pacific Ocean and the continental United States in August and September 1986 during the NASA GTE/CITE 2 program. Measurements of NO by three different groups (two different techniques) and of NO2 by three different groups (three different techniques) ar...
Article
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During August and September 1986, 11 aircraft flights were made over the eastern Pacific Ocean and continental United States. The suite of observations included simultaneous measurements of peroxyacetyl nitrate (PAN) and active nitrogen (NOx = NO + NO2). At altitudes of 4.5–6.1 km in the middle free troposphere, PAN was usually 5–6 times NOx in mar...
Article
Several trace sulfur gases that can have a significant influence on atmospheric chemistry are emitted from biological systems. In order to begin to address biological questions on the mechnisms of production of such gases, laboratory-scale experiments have been developed that reproduce such emissions under controlled conditions. Using a flux chambe...
Article
Calibration gas standards for H2S, CH3SH, CS2 and SO2, independently prepared by two separate research groups from the University of Idaho Department of Chemistry and the NOAA Aeronomy Laboratory, were directly intercompared using a gas chromatographic-flame photometric measurement procedure for all four species and a fluorimetric measurement proce...
Article
The mobilities in dry air of the positive ions NO+, NO+2, and O+2 and the negative ions O−, O−2, O−3, Cl−, NO−2, NO−3, NO−3 (HNO3), and NO−3 (HNO3)2 were measured at room temperature in a flow-drift tube apparatus. The measurements are reported as a function of E/N in the range 3–250 Td (1 Td = 10−17 V cm2). The results are compared with previously...
Article
Sulfur fluxes from bare soils, naturally vegetated surfaces and from several agricultural crops were measured at two mid-continent sites (Ames, Iowa and Celeryville, Ohio) and from one salt water marsh site (Cedar Island, North Carolina) during a field program conducted jointly by the NOAA Aeronomy Laboratory, Washington State University Laboratory...
Article
Simultaneous in situ measurements of NO, NO2, and O3 were obtained from balloon flights near 50 deg N in August and December 1982. NO(x)(NO + NO2) was reduced by a factor of 10 in the 21- to 28-km region in winter. Both NO and NO2 exhibited very sharp vertical gradients in the vicinity of 29 km. NO, for example, increased by nearly 20 times over on...
Article
A three-stage dynamic dilution system has been developed capable of generating calibration standards below 100 pptv using gravimetrically calibrated permeation tubes as a trace species source. Multistage dilution permits the use of equivalent one-step diluent flows approaching 1000 std 1 min −1. An allfluorocarbon flow path facilitates the handling...
Article
The mixing ratios for ozone and NOx (NO+NO2) have been measured at a rural site in the United States. From the seasonal and diurnal trends in the ozone mixing ratio over a wide range of NOx levels, we have drawn certain conclusions concerning the ozone level expected at this site in the absence of local photochemical production of ozone associated...
Article
In July of 1983, ambient measurements of nitric oxide (NO) were obtained at Wallops Island, VA, during the NASA GTE/CITE ground-based instrument intercomparison field study. The instrument, which was designed for measurements in the remote troposphere from an aircraft platform, is briefly described. Ten days of ambient air observations showed broad...
Article
The concentrations of HNO3 and NO3- particulates have been measured simultaneously with NO and NO2 concentrations at a nonurban field site in the Colorado mountains during a 5-year period. Seasonal and diurnal trends of these species are presented. Correlations of HNO3 and NO3- levels with each other and with NOx (NO+NO2) levels elucidate atmospher...
Article
The photostationary state (PSS) involving NO, NO2, and O3 has been studied at a site located in the Colorado mountains. During the daytime in summer the concentration of NO2 relative to the concentration of NO is greater than expected from the PSS. These results indicate that an additional oxidant OX other than O3 is converting NO to NO2. The level...
Article
Balloon-borne instrumentation carried on three separate flights into the stratosphere furnished data for estimates of the total stratospheric NOY (odd nitrogen species) content. The NOY content is of interest because nitrogen species control the O3 content of the stratosphere. The NO content was measured by sampling the chemiluminescence produced b...
Article
The anthropogenic hydrocarbons , , , benzene and toluene were measured at a rural site in the Rocky Mountains. The Denver metropolitan area appears to be the major local source of these compounds. These compounds are removed from the atmosphere almost solely by reaction with hydroxyl radicals. Under favorable circumstances, it is possible to relate...
Article
Monoterpene hydrocarbons were measured during the night at a rural site in the Rocky Mountains. The compounds positively identified and quantified were ..cap alpha..-pinene, camphene, ..beta..-pinene, ..delta..³-carene, and d-limonene. The average sum of the mixing ratios of the five compounds measured during the nighttime between July and Oct., 1...
Article
Data collected over a one year period at Niwot Ridge, a rural site located in the Colorado mountains, are presented. The concentrations of NO, NO2 and O3 have been measured as well as solar UV intensity and supporting meteorological parameters. The ratio of the concentration of NO to the concentration of NO2 reflects the photolysis of NO2 balanced...
Article
Measurements of the aromatic hydrocarbons (benzene, toluene, ethylbenzene and ortho(o)-xylene) at Niwot Ridge, Colorado have shown distinct correlations between the ratios of the concentrations of these compounds and the degree of direct urban influence. The major atmospheric removal mechanism of aromatic hydrocarbons is reaction with the hydroxyl...
Article
Measurements have been made of NOx (NO+NO2) at a site located in the Colorado mountains. These measurements revealed periods of exceptionally low NOx mixing ratios. During these episodes, the NOx mixing ratio dropped below 20 parts per trillion by volume for extended periods. These episodes are characterized by synoptic meteorological conditions in...
Article
The sampling of monoterpene hydrocarbons with Tenax-GC porous polymer has been examined in laboratory and field experiments. Numerous Tenax-GC artifact compounds, including benzene, toluene, n-heptane, n-octane, n-nonane, straight-chain aldehydes, benzaldehyde and acetophenone, were found to be produced on exposure to ozone. The destruction of mono...
Article
The photodissociation rate of NO2 by sunlight, jNO2, has been measured as a function of solar zenith angle, χ, at a nonurban field site in the Colorado mountains under a variety of sky conditions. These results indicate that jNO2χ = [0.01305 exp (− 0.360 secχ)] ± 7% s−1, for summertime, clear skies, small aerosol loadings, low-albedo background and...
Article
A portable permeation tube based system has been developed for the field calibration of nitric acid vapor collection on Nylon filters during actual atmospheric sampling. Extensive testing has been undertaken to determine the effects of: transfer line materials, the uptake of nitric acid on the filter holder apparatus, the linearity of dilution of t...
Article
The O− transfer reactions of O3− and CO3− with NO and SO2 were measured as a function of temperature in the range 170–605 K in a variable-temperature flowing afterglow system and as a function of center-of-mass kinetic energy in the range 0.04–2 eV in a flow-drift tube system. The rate constant in each case showed a marked energy dependence. The ra...
Article
Full-text available
The seasonal and diurnal variations of ozone mixing ratios have been observed at Niwot Ridge. Colorado. The ozone mixing ratios have been correlated with the NO x (NO+NO2) mixing ratios measured concurrently at the site. The seasonal and diurnal variations in O3 can be reasonably well understood by considering photochemistry and transport. In the w...
Article
Measurements of atmospheric monoterpene hydrocarbons were made at a site in the Colorado mountains. The research was undertaken to examine the influence of the compounds on the photochemistry of the troposphere. A sampling technique was developed using Tenax GC porous polymer traps with analysis by capillary gas chromatography and detection by flam...
Article
The A2Σ+ → X2Π band system of OT was observed for the first time. Fourteen bands with 0 ≤ v′ ≤ 4 and 0 ≤ v″ ≤ 3 were photographed at high resolution and rotationally assigned. Fitted values of 18 effective parameters of the model Hamiltonians used to describe individual vibrational levels of the two states are determined by least-squares from the d...
Article
Venturi inlets allow the injection of mass-selected ions into a flowing-afterglow apparatus for measurements of reaction rate constants. Diagnostic measurements for several inlets have been made in a flowing-afterglow apparatus and in a rarefied wind-tunnel. In the former, the venturi effect of each inlet was measured. In the latter, a visualizatio...
Article
A recently measured value of the dipole moment of H2SO4 necessitates a recalculation of stratospheric negative ion reaction rate constants with H2SO4. The measured reaction rate constants were normalized to a theoretical limit which depends on this dipole moment. The revised values are increased by the factor 2.7. Deduced values of stratospheric va...
Article
It is shown that the quality of the fit of frequencies for the (4, 4) band of the b4Σg−-a4Πu transition of O2+, obtained in an ion-beam experiment, can be significantly improved by the inclusion of a fine structure term of the form LzSz3 in the effective Hamiltonian for the a4Πu state, where Lz and Sz are respectively the components of the total or...
Article
The rate constant for the reaction N++NO was measured for center‐of‐mass collision energies from thermal to 2.5 eV. The measurements were made in a flow–drift tube apparatus in which the N+ ions were made by secondary reactions in the flow tube or were injected into the flow tube from a separate source. The measured rates were found to be in good a...
Article
Loss processes which remove Si+ ions selectively relative to other meteor-derived atomic ions in the E- and D-regions of the ionosphere have been identified and measured in the laboratory. The major Si+ loss in the E-region is the reaction Si+ + H2O → HSiO+ + H (1) with a rate constant 2.3 ± 0.9 × 10−10 cm3s−1 at 300 K. The corresponding reactions...
Article
The ion mobility of N+ ions in helium and argon is measured. The N+ ions were formed in a low‐pressure, electron impact source containing N2.
Article
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All of our previously published atmospheric N2O mixing ratio data must be divided by 1.07 to correct for an error that we have recently discovered in our 1975 N2O primary standard. This problem was uncovered during intercomparison of our electron-capture, gas-chromatographic measurement technique for N2O with a newly developed infrared absorption t...
Chapter
Water vapor plays a central role in the ion chemistry of the atmosphere below 80 km. The hydronium ions H 3 O + ·nH 2 O, are among the most stable atmospheric positive ions. The paths that convert O 2 + and NO + to hydronium ions are well understood. Water vapor also plays an important role in determining the composition of the sodium-ion clusters...
Article
Several association and switching reactions involving clusters of Na(+) ions with stratospheric neutral molecules have been examined at temperatures not greater than 420 K with a flow-tube apparatus. These measurements indicate that sodium compounds, NaX, that react with the H3O(+)-nH2O ions in the stratosphere will convert these ions into the clus...
Article
The branching ratios for the reactions of N(+) ions with O2 to form O2(+), NO(+) and O(+), which are responsible for the major loss of ionospheric N(+) ions, are determined as a function of kinetic energy in the collision energy range 0.06 to 1.8 eV. Measurements of product ion concentrations obtained following the addition of O2 to a N(+)-He gas m...
Article
The reactions of metastable O+* ions with N2 and O2 have been examined in a selected-ion flow-drift tube over the relative kinetic energy range from thermal to 0.2 eV. The rate constants are found to be (8.5±3.4)×10−10 and (8.1±3.2)×10−10 cm3 s−1, respectively, at these energies. These values are essentially equal to the gas-kinetic limiting va...
Article
The cross-section for the charge-transfer reaction of O− with O2 is determined in the relative kinetic energy range from 1 eV (threshold) to about 3 eV, using a combination of experimental and theoretical ion-swarm techniques. Reaction rate constants are measured in a helium-buffered flow-drift tube in the range 50 ≤ E/N ≤ 110 Td, where E is the DC...
Article
The rate constants of several H 2O + reactions have been measured as a function of relative kinetic energy in a flow-drift tube. The reactions were found to proceed in a variety of ways — charge transfer, proton transfer, and H-atom abstraction — and to have only moderate kinetic-energy dependences.
Article
Full-text available
The rate coefficients and product ions have been determined for reactions involving C(+), CH(+), CH2(+), CH3(+), CH5(+), C2(+), C2H(+), C2H2(+), D(+), OH(+), and H2O(+) ions with N and O atoms and NO molecules at 300 K. The values obtained for the rate coefficients are generally substantial fractions of the collision-limiting values, indicating tha...
Article
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A new photofragment spectrometer employing coaxial tunable single-mode laser and velocity-tuned fast-ion beams has been used to measure transition energies in the O2+b4Σg− ← a4Πu First Negative system to an accuracy and precision that are an order of magnitude better than was previously possible in Doppler-limited emission spectroscopy. The techniq...
Article
Gas-phase ion-molecule reactions involving H2SO4 and a variety of positiive and negative atmospheric ions have been studied by using a flowing afterglow apparatus. These ions include NO3-.nHNO3(n=0, 1, 2,) and H3O+.nH2O(n=0, 1, 2, 3). All of the negative ions studied react rapidly with H2SO4 to form HSO-4.nHNO3. These reactions establish a lower li...
Article
Full-text available
A new photofragment spectrometer employing coaxial tunable single-mode laser and velocity-tuned fast-ion beams has been used to measure transition energies in the O2+ b4Sigmag-
Article
The mixing ratios of CFCl3, CF2Cl2, and N2O have been measured as a function of altitude from 6 to 37 km above sea level by using a balloon-borne grab-sampling system. The 24 flights were made during the period July 1976 to March 1979 from Wyoming, Panama, Brazil, and Antarctica. These data are reported here both numerically and graphically, the la...
Article
The ion mibilities of atomic ions C+, S+ and F− in helium have been measured. The mobilities may be used to deduce the ion-atom interaction potential at collision energies than previously possible (AIP)
Article
Rate constants for the reactions of NO+(a3Σ+) ions with SO2, CO2, CH4, Ar, N2, H2, D2, and O2 have been measured for relative kinetic enegeies 0.04–2.5 eV in a flow-drift tube. Most of these reactions are fast and show little kinetic energy dependence. The reaction with Ar is slightly endothermic and its rate constant increases substantially with i...
Article
It is well known that NO+ ions constitute about 45% of the product ions of the ionospherically important reaction of N+ ions with O2. However, NO+ ions in both the ground X 1Sigma+ state and the metastable a 3Sigma+ state are energetically possible. The present study uses a selected-ion flow tube to determine the percentage of NO+(a 3Sigma+) produc...
Article
The reaction of Ar+ with NO to yield the possible ground‐state NO+(X1Σ+) and metastable‐state NO+(a 3Σ+) product ions has been studied near 300 K in a flow‐drift tube using helium and argon buffer gases separately. The ’’apparent’’ rate constant obtained in the argon buffer is an order of magnitude smaller than the rate constant obtained in the hel...
Article
Full-text available
In recent years, high‐resolution photoelectron spectroscopy and ab initio calculations have considerably revised and enlarged the understanding of the electronic structure of the NO+ ion. Based on these results, new potential energy curves for the electronic states of NO+ below 24 eV have been constructed and are given here. RKR potentials were cal...
Article
The reactions of S+ with O, and NO are studied in a helium-buffered flow-drift tube, at relative kinetic energies from 0.04 - 2ev. The significance of these reactions in interpreting the 32 and 34 e/m ion signals observed at 70-90 km in the ionosphere is discussed. (AIP)
Article
The reaction rate constants are measured for the destruction of Kr2+, Xe2+, C2+ with Nl, Ar, Kr, Xe, H2, N2, O2 at 300 °K. The reactions were carried out in a ion flow tube. (AIP)
Article
The rate constants for the reaction of O2+ ions with CH4 have been measured at relative kinetic energies of 0.04-1.2 eV. (AIP)
Article
The rate constants for the reactions of O(++) ions with several molecules and atoms have been measured. For reaction with N2 the rate constant was found to be (1.6 + or - 0.6) x 10 to the -9th cu cm/sec, which agrees very well with an earlier laboratory study but which is considerably larger than the upper limit deduced from satellite observations.
Article
Samples of stratospheric air were obtained at altitudes up to about 35 km from balloon flights carried out at 4 deg S (Brazil), 78 deg S (Antarctica), and 41 deg N (two flights, Wyoming) in 1978. The samples obtained were analyzed for methane using a gas chromatograph with flame ionization detection. The two Wyoming profiles and the Antarctica prof...
Article
This paper is a supplement to and extension of “Transport Properties of Gaseous Ions over a Wide Energy Range,” by H. W. Ellis, R. Y. Pai, E. W. McDaniel, E. A. Mason, and L. A. Viehland, Atomic Data and Nuclear Data Tables17, 177–210 (1976). The previous paper presented a compilation of experimental ionic mobility data available in February 1976....
Article
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Article
The rate constants for several ion–molecule reactions involving chlorine‐containing ions or molecules have been measured at 300 K with a flowing afterglow apparatus. These include the reaction of O− with CCl4, several negative ions with HCl, ClO− with several neutrals, and Cl− with O3. These reactions are used to place limits on the electron affini...
Article
The rate constants for the reaction of N+4 with O2, CO2, H2, and D2 have been studied as a function of mean relative kinetic energy in a flow‐drift tube using a nitrogen buffer gas. The N+2/N+4 equilibrium, which would otherwise deleteriously effect such a study, was suppressed by adding a trace of H2 as a purge gas that preferentially reacted with...