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Reanalysis of NOAA H 2 observations: implications for the H 2 budget
Abstract. Hydrogen (H2) is a promising low-carbon alternative to fossil fuels for many applications. However, significant gaps in our understanding of the atmospheric H2 budget limit our ability to predict the impacts of greater H2 usage. Here we use NOAA H2 dry air mole fraction observations from air samples collected from ground-based and ship platforms during 2010–2019 to evaluate the representation of H2 in the NOAA GFDL-AM4.1 atmospheric chemistry-climate model. We find that the base model configuration captures the observed interhemispheric gradient well but underestimates the surface concentration of H2 by about 10 ppb. Additionally, the model fails to reproduce the 1–2 ppb yr−1 mean increase in surface H2 observed at background stations. We show that the cause is most likely an underestimation of current anthropogenic emissions, including potential leakages from H2-producing facilities. We also show that changes in soil moisture, soil temperature, and snow cover have most likely caused an increase in the magnitude of the soil sink, the most important removal mechanism for atmospheric H2, especially in the Northern Hemisphere. However, there remains uncertainty due to fundamental gaps in our understanding of H2 soil removal, such as the minimum moisture required for H2 soil uptake, for which we performed extensive sensitivity analyses. Finally, we show that the observed meridional gradient of the H2 mixing ratio and its seasonality can provide important constraints to test and refine parameterizations of the H2 soil sink.
Concentration to the ecliptic of night sky emission in the line h alpha and its radial velocities <o kontsetratsii izlucheniya nochnogo neba v linii h alpha k ekliptike i o luchevykh skorostyakh etoy linii<
Observations of nightglow emissions in hydrogen spectrum
Intensity measurements on spectra of gases of planetary interest - h sub 2, h sub o, and co sub 2.
Hydrogen quadrupole, water vapor and carbon dioxide spectral band intensities with reference to planetary atmosphere observations
Autoionization states of h- below the n equals 2 level of h
Resonances below inelastic threshold of electron hydrogen scattering examined by projection operator technique of Feshbach
Cross section for impact ionization of H /is/ atoms by H /is/ atoms near threshold
Cross section for impact ionization of hydrogen atoms by hydrogen atoms near ionization threshold
Low-energy atomic collisions. I - The Schroedinger equation for H super plus -H.
Low energy atomic collisions, considering Schroedinger equation for proton interchange
Rotational excitation of H sub 2 and D sub 2 by H impact.
Distorted wave calculation from rotational excitation of molecular hydrogen and molecular deuterium in thermal collisions with atomic hydrogen, presenting angular distributions, cross sections, etc
Measurement of charge-exchange cross sections for H super plus, H sub 2 super plus, and He super plus ions.
Charge exchange cross sections measurements for ion-molecule pairs of hydrogen, argon, krypton, helium and xenon
Partition functions and thermodynamic properties to high temperatures for H sub 3 and H sub 2 ions
Partition functions and thermodynamic properties to high temperatures for hydrogen triatomic and diatomic molecular ions
Direct mechanism of reaction CH sub 3 super plus plus x CH sub 4 yields C sub 2 H sub 5 super plus plus H sub 2.
Formation mechanism of positive ethyl ion and hydrogen molecule during interaction between positive methyl ion and methane molecule
Calculated Total Elastic Scattering Cross Sections for H(1S) plus H(1S) at Collision Energies Below 1 eV
Calculating scattering cross sections for prediction of atomic beam scattering
A Resonance Theory of Termolecular Recombination Kinetics - H plus h plus m Yields H2 plus m
RESONCE THEORY OF TERMOLECULAR RECOMBINATION kinetics
H-2, H-3, He-3 production in solar flares
The production of deuterium, tritium, and helium-3 from nuclear reactions of accelerated charged particles is evaluated with the ambient solar atmosphere. Updated cross sections and kinematics are used, calculations are extended to very low energies (approximates 0.1 MeV/nucleon), and the angular distribution of the secondary particles is calculated. The calculations are compared with data on accelerated isotopes from solar flares. In particular, the August 1972 events are considered for which both He-3 and nuclear gamma rays were observed. An explanation for He-3-rich events is provided in terms of the angular distributions of secondary isotopes, and the flux of 2.2 MeV gamma rays from such flares are also predicted.
Optical, infrared and radio studies of compact H II regions. II - The H alpha knot S88B
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Experimental and reduced dimensionality quantum rate coefficients for H2(D2) + CN yields H(D)CN + H(D)
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A potential energy surface for the process H2 + H2O yielding H + H + H2O - Ab initio calculations and analytical representation
Extensive ab initio calculations on the ground state potential energy surface of H2 + H2O were performed using a large contracted Gaussian basis set and a high level of correlation treatment. An analytical representation of the potential energy surface was then obtained which reproduces the calculated energies with an overall root-mean-square error of only 0.64 mEh. The analytic representation explicitly includes all nine internal degrees of freedom and is also well behaved as the H2 dissociates; it thus can be used to study collision-induced dissociation or recombination of H2. The strategy used to minimize the number of energy calculations is discussed, as well as other advantages of the present method for determining the analytical representation.
Miyun 232 MHz survey 1: Fields centered at: alpha:00(h)41(m), delta:41 deg 12 min and alpha: 07(h)00(m),delta:35 deg 00 min
A new meter-wave survey of sky region north of declination +30 deg is carried out with the Miyun 232 MHz Synthesis Radio Telescope (MSRT). The instrument, observation, and method of data reduction are briefly described. A preliminary catalog, first of a series, for two 8 deg. x 8 deg. regions centered respectively at 35 deg. is presented. On the average 4 - 5 sources per square degree are recorded with position accuracy of 5 sec. / S(Jy). BGPW scale is adopted for the flux density calibration. The accuracy of flux determination is limited by background fluctuation which is about 30 mJy. The catalog is complete for sources with flux larger than 0.25 Jy. The total number of sources listed in the paper amounts to 687. Several extended sources, sources with convex spectra, and one GPS source were found. Spectra of sources with flux larger than 0.5 Jy were also given.