The first remote-sensing measurements of HFC-32 in the Earth's atmosphere by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS)

Author(s):  
R. Dodangodage ◽  
P.F. Bernath ◽  
C.D. Boone ◽  
J. Crouse ◽  
J.J. Harrison
2015 ◽  
Vol 8 (10) ◽  
pp. 11171-11207
Author(s):  
E. M. Buzan ◽  
C. A. Beale ◽  
C. D. Boone ◽  
P. F. Bernath

Abstract. This paper presents an analysis of observations of methane and its two major isotopologues, CH3D and 13CH4 from the Atmospheric Chemistry Experiment (ACE) satellite between 2004 and 2013. Additionally, atmospheric methane chemistry is modeled using the Whole Atmospheric Community Climate Model (WACCM). ACE retrievals of methane extend from 6 km for all isotopologues to 75 km for 12CH4, 35 km for CH3D, and 50 km for 13CH4. While total methane concentrations retrieved from ACE agree well with the model, values of δD–CH4 and δ13C–CH4 show a bias toward higher δ compared to the model and balloon-based measurements. Calibrating δD and δ13C from ACE using WACCM in the troposphere gives improved agreement in δD in the stratosphere with the balloon measurements, but values of δ13C still disagree. A model analysis of methane's atmospheric sinks is also performed.


1972 ◽  
Vol 2 (2) ◽  
pp. 113-114
Author(s):  
K. Harwood

Spectrometers give information on the chemical composition and physical properties of celestial objects. The Earth’s atmosphere restricts the observable spectra to windows in the absorption. Most of these windows are less than one octave wide. To increase the amount of information gained, it is necessary to increase the resolution of the spectrometers. With the advent of balloons, rockets and spacecraft, it is possible to make observations free from atmospheric absorption and it is possible to gain more information by increasing the bandwidth of spectrometers. This paper describes an infra-red Fourier transform spectrometer. The interferometer has a bandwidth of over one decade, from 500 to 5,000 cm-1, with a maximum resolution of 10 cm-1. The resolution can be electronically controlled. There are no absorbing or refracting parts in the interferometer and the resolution is limited by mechanical considerations.


2013 ◽  
Vol 13 (14) ◽  
pp. 6921-6950 ◽  
Author(s):  
A. T. Brown ◽  
C. M. Volk ◽  
M. R. Schoeberl ◽  
C. D. Boone ◽  
P. F. Bernath

Abstract. Long lived halogen-containing compounds are important atmospheric constituents since they can act both as a source of chlorine radicals, which go on to catalyse ozone loss, and as powerful greenhouse gases. The long-term impact of these species on the ozone layer is dependent on their stratospheric lifetimes. Using observations from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) we present calculations of the stratospheric lifetimes of CFC-12, CCl4, CH4, CH3Cl and N2O. The lifetimes were calculated using the slope of the tracer–tracer correlation of these species with CFC-11 at the tropopause. The correlation slopes were corrected for the changing atmospheric concentrations of each species based on age of air and CFC-11 measurements from samples taken aboard the Geophysica aircraft – along with the effective linear trend of the volume mixing ratio (VMR) from tropical ground based AGAGE (Advanced Global Atmospheric Gases Experiment) sites. Stratospheric lifetimes were calculated using a CFC-11 lifetime of 45 yr. These calculations produced values of 113 + (−) 26 (18) yr (CFC-12), 35 + (−) 11 (7) yr (CCl4), 69 + (−) 65 (23) yr (CH3Cl), 123 + (−) 53 (28) yr (N2O) and 195 + (−) 75 (42) yr (CH4). The errors on these values are the weighted 1σ non-systematic errors. Systematic errors were estimated by recalculating lifetimes using VMRs which had been modified to reflect differences between ACE-FTS retrieved VMRs and those from other instruments. The results of these calculations, including systematic errors, were as follows: 113 + (−) 32 (20) for CFC-12, 123 + (−) 83 (35) for N2O, 195 + (−) 139 (57) for CH4, 35 + (−) 14 (8) for CCl4 and 69 + (−) 2119 (34) yr for CH3Cl. For CH3Cl & CH4 this represents the first calculation of the stratospheric lifetime using data from a space based instrument.


2009 ◽  
Vol 9 (20) ◽  
pp. 8039-8047 ◽  
Author(s):  
G. González Abad ◽  
P. F. Bernath ◽  
C. D. Boone ◽  
S. D. McLeod ◽  
G. L. Manney ◽  
...  

Abstract. We present the first near global upper tropospheric distribution of formic acid (HCOOH) observed from space using solar occultation measurements from the Fourier transform spectrometer (FTS) on board the Atmospheric Chemistry Experiment (ACE) satellite. Using a new set of spectroscopic line parameters recently published for formic acid by Vander Auwera et al. (2007) and Perrin and Vander Auwera (2007), we have retrieved the concentrations of HCOOH between 5 km and the tropopause for ACE-FTS observations from February 2004 to September 2007. We observe a significant seasonal dependence for the HCOOH concentrations related to vegetation growth and biomass burning. We estimate an emission ratio of 0.0051±0.0015 for HCOOH relative to CO for tropical South American fires using a selected set of data for September 2004. Results from the balloon-borne MkIV Fourier transform spectrometer are also presented and compared with the ACE measurements.


2006 ◽  
Vol 6 (8) ◽  
pp. 2355-2366 ◽  
Author(s):  
G. Dufour ◽  
R. Nassar ◽  
C. D. Boone ◽  
R. Skelton ◽  
K. A. Walker ◽  
...  

Abstract. From January to March 2005, the Atmospheric Chemistry Experiment high resolution Fourier transform spectrometer (ACE-FTS) on SCISAT-1 measured many of the changes occurring in the Arctic (50–80° N) lower stratosphere under very cold winter conditions. Here we focus on the partitioning between the inorganic chlorine reservoirs HCl and ClONO2 and their activation into ClO. The simultaneous measurement of these species by the ACE-FTS provides the data needed to follow chlorine activation during the Arctic winter and the recovery of the Cl-reservoir species ClONO2 and HCl. The time evolution of HCl, ClONO2 and ClO as well as the partitioning between the two reservoir molecules agrees well with previous observations and with our current understanding of chlorine activation during Arctic winter. The results of a chemical box model are also compared with the ACE-FTS measurements and are generally consistent with the measurements.


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