Ground-based FTIR retrievals of SF&amp;lt;sub&amp;gt;6&amp;lt;/sub&amp;gt; on Reunion Island

Zhou, Minqiang; Langerock, Bavo; Vigouroux, Corinne; Wang, Pucai; Hermans, Christian; Stiller, G. P.; Walker, Kaley A.; Dutton, G. S.; Mahieu, Emmanuel; Mazière, Martine De

doi:10.5194/amt-11-651-2018

Cited by 10 publications

(3 citation statements)

References 38 publications

(47 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While this method is very convenient as it does not require an assumption of normality, it, however, fails at preserving the potential autocorrelation and heteroskedasticity of the residuals as they are resampled fully at random. Other studies (e.g., Prignon et al, 2019;Vigouroux et al, 2018;Zhou et al, 2018) applied the method of Santer et al (2000) to correct for autocorrelation when calculating the standard errors of the trend estimates. However, explicitly correcting for autocorrelation in this way creates additional estimation uncertainty which is not taken into account by this method.…”

Section: Trend Methodsmentioning

confidence: 99%

Stratospheric Fluorine as a Tracer of Circulation Changes: Comparison Between Infrared Remote‐Sensing Observations and Simulations With Five Modern Reanalyses

et al. 2021

Self Cite

View full text Add to dashboard Cite

Using multidecadal time series of ground-based and satellite Fourier transform infrared measurements of inorganic fluorine (i.e., total fluorine resident in stratospheric fluorine reservoirs), we investigate stratospheric circulation changes over the past 20 years. The representation of these changes in five modern reanalyses is further analyzed through chemical-transport model (CTM) simulations. From the observations but also from all reanalyses, we show that the inorganic fluorine is accumulating less rapidly in the Southern Hemisphere than in the Northern Hemisphere during the 21st century. Comparisons with a study evaluating the age-of-air of these reanalyses using the same CTM allow us to link this hemispheric asymmetry to changes in the Brewer-Dobson circulation (BDC), with the ageof-air of the Southern Hemisphere getting younger relative to that of the Northern Hemisphere. Large differences in simulated total columns and absolute trend values are, nevertheless, depicted between our simulations driven by the five reanalyses. Superimposed on this multidecadal change, we, furthermore, confirm a 5-7-year variability of the BDC that was first described in a recent study analyzing long-term time series of hydrogen chloride (HCl) and nitric acid (HNO 3 ). It is important to stress that our results, based on observations and meteorological reanalyses, are in contrast with the projections of chemistryclimate models in response to the coupled increase of greenhouse gases and decrease of ozone-depleting substances, calling for further investigations and the continuation of long-term observations. Plain Language SummaryThe overturning circulation of the stratosphere is projected to change in response to increases in greenhouse gases and decreases in ozone-depleting substances, with the Southern Hemisphere branch expected to get weaker relative to the Northern Hemisphere. Here, we use 30-year time series of observations and simulations of a long-lived tracer to investigate stratospheric circulation changes. The observations analyzed are from ground-based and satellite instruments. We compare them with simulations that use a chemical-transport model driven by winds from meteorological reanalyses of 1990-2019. A reanalysis assimilates meteorological measurements into a forecast model to simulate the best possible representation of the atmospheric state. All five simulations, which use different reanalyses, agree with the observational analysis showing that the analyzed tracer is accumulating less rapidly in the Southern Hemisphere than in the Northern Hemisphere through 2019. This hemispheric asymmetry is attributed to changes in the stratospheric transport circulation, with the Southern Hemisphere branch getting stronger relative to the Northern Hemisphere. Our results support the conclusions of a recent observational study but do not support circulation changes projected by chemistry-climate models. This study highlights the crucial importance of long-term observation time series.

show abstract

Section: Trend Methodsmentioning

confidence: 99%

Stratospheric Fluorine as a Tracer of Circulation Changes: Comparison Between Infrared Remote‐Sensing Observations and Simulations With Five Modern Reanalyses

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…The ACE focus regions are mainly in the Arctic and high latitude regions, and the observation data in the tropical and subtropical regions are little [38]. To obtain more comparable satellite data, we chose the satellite data of ±5 • latitudes and ±10 • longitudes (27-37 • N and 107-127 • E) centered on the Hefei station, and the FTIR data with a satellite transit time of ±2 days to compare the HCFC-22 vertical profiles from 2017-2022.…”

Section: Ace (Atmospheric Chemistry Experience) Satellite Datamentioning

confidence: 99%

Detection of Atmospheric Hydrofluorocarbon-22 with Ground-Based Remote High-Resolution Fourier Transform Spectroscopy over Hefei and an Estimation of Emissions in the Yangtze River Delta

Zeng,

Wang,

Shan

et al. 2023

Remote Sensing

View full text Add to dashboard Cite

Under the control of the Montreal Protocol and its amendments, hydrofluorocarbons (HCFCs) are used as temporary substitutes for ozone-depleting substances, such as chlorofluorocarbons, and are regulated for consumption and production. China plans to phase out HCFCs by 2030, and HCFC-22 (CHClF2) is currently the most abundant HCFC in the atmosphere. This study measures the vertical profiles and total columns of atmospheric HCFC-22 from January 2017 to December 2022, based on the mid-infrared solar spectra recorded by the ground-based high-resolution Fourier transform infrared (FTIR) spectrometer at the Hefei remote sensing station. The HCFC-22 total columns over Hefei increased from 2017–2018 and gradually decreased in 2018–2022, with an annual variation rate of 5.98% and −1.02% ± 0.02%, respectively. Compared with the ACE-FTS satellite independent dataset, the FTIR data indicate good consistency with the ACE-FTS data at a 5–25 km altitude, with an average relative difference of −4.38 ± 0.83% between the vertical profiles. HCFC-22 emissions in the Yangtze River Delta from 2017 to 2022 are estimated, derived from measured total columns combined with the Lagrangian transport model and the Bayesian inversion technique. In the Yangtze River Delta, HCFC-22 emissions were high in 2017, with a value of 33.3 ± 16.8 kt, and decreased from 2018 to 2022, with a minimum of 27.3 ± 13.6 kt in 2022 during the observations.

show abstract

“…Table 2 provides the retrieval settings adopted for each window. As already indicated, the SFIT-4 algorithm implements the OEM of Rodgers (2000), and the various contributions to the uncertainty budget are computed following the equations and formalism presented in previous papers, for example, in section 2.2 of Zhou et al (2018).…”

Section: Information Content and Uncertainty Budgetmentioning

confidence: 99%

First retrievals of peroxyacetyl nitrate (PAN) from ground-based FTIR solar spectra recorded at remote sites, comparison with model and satellite data

Mahieu

Fischer

Franco

et al. 2021

Elementa: Science of the Anthropocene

Self Cite

View full text Add to dashboard Cite

Peroxyacetyl nitrate (PAN) is the main tropospheric reservoir of NOx (NO + NO2). Its lifetime can reach several months in the upper cold troposphere. This enables the long-range transport of NOx radicals, under the form of PAN, far from the regions of emission. The subsequent release of NOx through the PAN thermal decomposition leads to the efficient formation of tropospheric ozone (O3), with important consequences for tropospheric oxidative capacity and air quality. The chemical properties of PAN have stimulated the progressive development of remote-sensing products by the satellite community, and recent additions open the prospect for the production of decadal and near-global time series. These products will provide new constraints on the distribution and evolution of this key trace gas in the Earth’s atmosphere, but they will also require reliable measurements for validation and characterization of performance. We present an approach that has been developed to retrieve PAN total columns from ground-based high-resolution solar absorption Fourier transform infrared (FTIR) spectra. This strategy is applied to observations recorded at remote FTIR stations of the Network for the Detection of Atmospheric Composition Change (NDACC). The resulting data sets are compared with total column time series derived from IASI (Infrared Atmospheric Sounding Interferometer) satellite observations and to a global chemical transport model. The results are discussed in terms of their overall consistency, mutual agreement, and seasonal cycles. Noticeable is the fact that the FTIR data point to substantial deficiencies in the global model simulation over high latitudes, a poorly sampled region, with an underestimation of the PAN columns during spring, at the peak of the seasonal cycle. Finally, we suggest avenues for development that should make it possible to limit intra- or intersite biases and extend the retrieval of PAN to other NDACC stations that are more affected by water vapor interferences.

show abstract

Ground-based FTIR retrievals of SF<sub>6</sub> on Reunion Island

Cited by 10 publications

References 38 publications

Stratospheric Fluorine as a Tracer of Circulation Changes: Comparison Between Infrared Remote‐Sensing Observations and Simulations With Five Modern Reanalyses

Stratospheric Fluorine as a Tracer of Circulation Changes: Comparison Between Infrared Remote‐Sensing Observations and Simulations With Five Modern Reanalyses

Detection of Atmospheric Hydrofluorocarbon-22 with Ground-Based Remote High-Resolution Fourier Transform Spectroscopy over Hefei and an Estimation of Emissions in the Yangtze River Delta

First retrievals of peroxyacetyl nitrate (PAN) from ground-based FTIR solar spectra recorded at remote sites, comparison with model and satellite data

Contact Info

Product

Resources

About