This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is composed of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, added line-shape formalisms, and validity. Moreover, molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth. Of considerable note, experimental IR cross-sections for almost 300 additional molecules important in different areas of atmospheric science have been added to the database. The compilation can be accessed through www.hitran.org. Most of the HITRAN data have now been cast into an underlying relational database structure that offers many advantages over the long-standing sequential text-based structure. The new structure empowers the user in many ways. It enables the incorporation of an extended set of fundamental parameters per transition, sophisticated line-shape formalisms, easy user-defined output formats, and very convenient searching, filtering, and plotting of data. A powerful application programming interface making use of structured query language (SQL) features for higher-level applications of HITRAN is also provided.

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The HITRAN 2008 molecular spectroscopic database

Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

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Climate Change 2007: The Physical Science Basis.

This chapter should be cited as: Myhre, G., D. Shindell, F.-M. Bréon, W. Collins, J. Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee, B. Mendoza, T. Nakajima, A. Robock, G. Stephens, T. Takemura and H. Zhang, 2013: Anthropogenic and Natural Radiative Forcing. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Coordinating Lead Authors: Gunnar Myhre (Norway), Drew Shindell (USA)

Anthropogenic and Natural Radiative Forcing

http://joenschem.com/yahoo_site_admin/assets/docs/atkinson2000r.93190106.pdf

Atmospheric chemistry of VOCs and NOx

Atmospheric degradation of volatile organic compounds

The primary quantum yields of OH(X 2Π),H(2S), and oxygen atoms [O(1D)+O(3P)] produced in the photodissociation of H2O2 at 193 and 222 nm have been measured at 298 K. At 193 nm, the primary quantum yields were observed to be 1.51±0.18, 0.16±0.04, and <0.02, for Φ(OH), Φ(H), and the sum of Φ(O) and Φ(O 1S), respectively. At 222 nm, the OH yield was Φ(OH)=2.02±0.35, the H atom yield was Φ(H)=0.024±0.012, and Φ(O) was <0.002. The errors quoted above are 2σ, precision plus estimated systematic errors. The OH product was directly monitored by pulsed laser‐induced fluorescence, and the atomic species were detected via cw resonance fluorescence. The OH quantum yields reported here were measured relative to known product quantum yields in the dissocation of H2O2 at 248 nm. H(2S) yields were measured relative to those in photolysis of HBr and HCl, (at 193 nm) or CH3SH (at 222 nm), whereas O atoms yields were measured relative to O3 photolysis at both wavelengths. The present results indicate unit dissociation of H2...

Photodissociation of H2O2 at 193 and 222 nm: Products and quantum yields

The absorption cross sections of BrONO2 between 200 and 500 nm were measured over the temperature range 298 to 220 K using a diode array spectrometer. The BrONO2 absorption cross sections are weakly dependent on temperature at wavelengths 450 nm; at 480 nm the cross section decreased by ∼35% in going from 298 K to 220 K. Our room temperature absorption cross sections are in good agreement with the measurements of Spencer and Rowland (1978) over the common wavelength range of the measurements, 200 to 390 nm. We show that wavelengths longer than 390 nm must be included in the calculation of the BrONO2 atmospheric photolysis rate. We also show that photolysis of BrONO2 could be a significant atmospheric loss process for odd oxygen (due to halogen chemistry) below about 25 km. The infrared absorption cross sections for the BrONO2 band centered at 803.3 cm−1 were also measured. The integrated band strength was (2.7±0.5) × 10−17 cm2 molecule−1 cm−1.

UV/visible and IR absorption cross sections of BrONO2

The atmospherically important reactions of both CH 3 S and CH 3 SOO were examined using the technique of pulsed laser photolysis/laser-induced fluorescence. Rate coefficients for the reactions CH 3 S+O 3 →products (1) and CH 3 S+NO 2 →CH 3 SO+NO (2) were measured to be k 1 (T)=(1.98±0.38) X 10 -12 exp[(290±40)/T] cm 3 molecule -1 s -1 and k 2 (T)=(2.06±0.44) X 10 -11 exp[(320±40)/T] cm 3 molecule -1 s -1

Reactions of methylthio and (methylthio)dioxy with ozone, nitrogen dioxide, and nitric oxide

The reactions of CH{sub 3}S + O{sub 3} {r_arrow} products (1), CH{sub 3}SO + O{sub 3} {r_arrow} products (2), and CH{sub 3}SS + O{sub 3} {r_arrow} (3) were investigated at 300 K in a discharge flow tube reactor coupled to a photoionization mass spectrometer. The measured value of {kappa}{sub 1} is (5.7 {plus_minus} 1.4) x 10{sup {minus}12} cm{sup 3} molecule {sup {minus}1} s{sup {minus}1} Torr He. The authors observed that OH was produced in this reaction or in subsequent steps and that complex branched chain reactions, which generate CH{sub 3}S from its precursor molecule, took place in the flow tube reactor. The authors found that CH{sub 3}SO was a product of reaction 1 and the branching ratio for this channel was 15 {plus_minus} 4%, between 0.7 and 2.2 Torr He, independent of pressure. A preliminary value of {kappa}{sub 2} = (6 {plus_minus} 3) x 10{sup {minus}13} cm{sup {minus}3} molecule{sup {minus}1} s{sup {minus}1} was measured. CH{sub 3}S was not a major product of reaction 2. These results suggest that the reaction with O{sub 3} is a major CH{sub 3}S removal process in the atmosphere. The rate coefficient for the reaction of CH{sub 3}SS with O{sub 3}(3) was measured to be {kappa}{submore » 3} = (4.6 {plus_minus} 1.1) x 10{sup {minus}13} cm{sup {minus}3} molecule{sup {minus}1}s{sup {minus}1}. 26 refs., 6 figs., 1 tab.« less

Kinetics and mechanisms of the reactions of methylthio, methylsulfinyl, and methyldithio radicals with ozone at 300 K and low pressures

Rate coefficients for the reaction of OH radical with HCl (k1) between 200 and 400 K, were measured to be 3.28 × 10-17 T1.66 exp [184/T] cm3 molecule-1 s-1 by producing OH via pulsed laser photolysis and detecting it via laser induced fluorescence. The rate coefficients for the reactions of OH with DCl (k2), OD with HCl (k3), and OD with DCl (k4) were also measured using the same method to be k2 = 2.9 × 10-12 exp [−728/T], k3 = 8.1 × 10-18 T1.85 exp [300/T], and k4 = 2.5 × 10-12 exp [−660/T] cm3 molecule-1 s-1. k1 − k4 were computed for 200 < T < 400 K using the variational transition theory, including tunneling corrections, to be k1 = 1.49 × 10-16 T1.35 exp [262/T], k2 = 9.04 × 10-20 T2.34 exp[429/T], k3 = 1.01 × 10-16 T1.4 exp[309/T], and k4 = 1.64 × 10-19 T2.27 exp [385/T]cm3 molecule-1 s-1, in reasonable agreement with experiments. They were also used to analyze the origin of the isotope effects. A two-dimensional chemical transport model calculation shows that our measured higher values of k1 at low ...

A. R. Ravishankara

Papers

Photodissociation of H2O2 at 193 and 222 nm: Products and quantum yields

UV/visible and IR absorption cross sections of BrONO2

Reactions of methylthio and (methylthio)dioxy with ozone, nitrogen dioxide, and nitric oxide

Kinetics and mechanisms of the reactions of methylthio, methylsulfinyl, and methyldithio radicals with ozone at 300 K and low pressures

Rate coefficients for the reactions of oh and od with hcl and dcl between 200 and 400 k