scholarly journals Ground-based FTIR retrievals of SF<sub>6</sub> at Réunion Island

2017 ◽  
Author(s):  
Minqiang Zhou ◽  
Bavo Langerock ◽  
Corinne Vigouroux ◽  
Pucai Wang ◽  
Christian Hermans ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
In Situ Measurements ◽  
Annual Growth Rate ◽  
Retrieval Strategy ◽  
Satellite Measurements ◽  
Individual Layer ◽  
Time Period ◽  
Independent Information ◽  
Air Column

Abstract. SF6 total columns are successfully retrieved from FTIR measurements (Saint Denis and Maïdo) at Réunion Island (21° S, 55° E) between 2004–2016 using the SFIT4 algorithm: the retrieval strategy and the error budget are presented. The FTIR SF6 retrieval has independent information in only one individual layer, covering the whole troposphere and the lower stratosphere. The trend of SF6 is analysed based on the FTIR retrieved dry air column-averaged mole fractions (XSF6) at Réunion Island, the in-situ measurements at America Samoa (SMO) and the collocated satellite measurements (MIPAS and ACE-FTS) in the southern tropics. The SF6 annual growth rate from FTIR retrievals is 0.265 ± 0.013 pptv/year for 2004–2016, which is slightly weaker than that from the SMO in-situ measurements (0.285 ± 0.002 pptv/year) for the same time period. The SF6 trend in the troposphere from MIPAS and ACE-FTS observations is also close to the ones from the FTIR retrievals and the SMO in-situ measurements.

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

2018 ◽  
Vol 11 (2) ◽  
pp. 651-662 ◽  
Author(s):  
Minqiang Zhou ◽  
Bavo Langerock ◽  
Corinne Vigouroux ◽  
Pucai Wang ◽  
Christian Hermans ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Atmospheric Chemistry ◽  
Michelson Interferometer ◽  
In Situ Measurements ◽  
Annual Growth Rate ◽  
Reunion Island ◽  
Individual Layer ◽  
Infrared Measurements ◽  
Réunion Island

Abstract. SF6 total columns were successfully retrieved from FTIR (Fourier transform infrared) measurements (Saint Denis and Maïdo) on Reunion Island (21∘ S, 55∘ E) between 2004 and 2016 using the SFIT4 algorithm: the retrieval strategy and the error budget were presented. The FTIR SF6 retrieval has independent information in only one individual layer, covering the whole of the troposphere and the lower stratosphere. The trend in SF6 was analysed based on the FTIR-retrieved dry-air column-averaged mole fractions (XSF6) on Reunion Island, the in situ measurements at America Samoa (SMO) and the collocated satellite measurements (Michelson Interferometer for Passive Atmospheric Sounding, MIPAS, and Atmospheric Chemistry Experiment Fourier Transform Spectrometer, ACE-FTS) in the southern tropics. The SF6 annual growth rate from FTIR retrievals is 0.265±0.013 pptv year−1 for 2004–2016, which is slightly weaker than that from the SMO in situ measurements (0.285±0.002 pptv year−1) for the same time period. The SF6 trend in the troposphere from MIPAS and ACE-FTS observations is also close to the ones from the FTIR retrievals and the SMO in situ measurements.

In situ measurements of hydrogen cyanide in the upper troposphere/lower stratosphere during Arctic spring 2000

2002 ◽  
Vol 107 (D5) ◽  
pp. SOL 47-1-SOL 47-6 ◽  
Author(s):  
A. A. Viggiano ◽  
D. E. Hunton ◽  
Thomas M. Miller ◽  
John O. Ballenthin
Keyword(s):  
Hydrogen Cyanide ◽  
Lower Stratosphere ◽  
In Situ Measurements ◽  
Upper Troposphere

scholarly journals Aerosols in the tropical and subtropical UT/LS: in-situ measurements of submicron particle abundance and volatility

2009 ◽  
Vol 9 (6) ◽  
pp. 24587-24628 ◽  
Author(s):  
S. Borrmann ◽  
D. Kunkel ◽  
R. Weigel ◽  
A. Minikin ◽  
T. Deshler ◽  
...  
Keyword(s):  
West Africa ◽  
Particle Number ◽  
Lower Stratosphere ◽  
In Situ Measurements ◽  
Submicron Particles ◽  
Volatile Fraction ◽  
Vertical Profiles ◽  
Number Density ◽  
Long Distance

Abstract. Processes occurring in the tropical upper troposphere and lower stratosphere (UT/LS) are of importance for the global climate, for the stratospheric dynamics and air chemistry, and they influence the global distribution of water vapour, trace gases and aerosols. The mechanisms underlying cloud formation and variability in the UT/LS are of scientific concern as these still are not adequately described and quantified by numerical models. Part of the reasons for this is the scarcity of detailed in-situ measurements in particular from the Tropical Transition Layer (TTL) within the UT/LS. In this contribution we provide measurements of particle number densities and the amounts of non-volatile particles in the submicron size range present in the UT/LS over Southern Brazil, West Africa, and Northern Australia. The data were collected in-situ on board of the Russian high altitude research aircraft M-55 "Geophysica" using the specialised COPAS (COndensation PArticle counting System) instrument during the TROCCINOX (Araçatuba, Brazil, February 2005), the SCOUT-O3 (Darwin, Australia, December 2005), and SCOUT-AMMA (Ouagadougou, Burkina Faso, August 2006) campaigns. The vertical profiles obtained are compared to those from previous measurements from the NASA DC-8 and NASA WB-57F over Costa Rica and other tropical locations between 1999 and 2007. The number density of the submicron particles as function of altitude was found to be remarkably constant (even back to 1987) over the tropical UT/LS altitude band such that a parameterisation suitable for models can be extracted from the measurements. At altitudes corresponding to potential temperatures above 430 K a slight increase of the number densities from 2005/2006 results from the data in comparison to the 1987 to 2007 measurements. The origins of this increase are unknown. By contrast the data from Northern hemispheric mid latitudes do not exhibit such an increase between 1999 and 2006. Vertical profiles of the non-volatile fraction of the submicron particles were also measured by a COPAS channel and are presented here. The resulting profiles of the non-volatile number density fraction show a pronounced maximum of 50% in the tropical TTL over Australia and West Africa. Below and above this fraction is much lower attaining values of 10% and smaller. In the lower stratosphere the fine particles mostly consist of sulphuric acid which is reflected in the low numbers of non-volatile residues measured by COPAS. Without detailed chemical composition measurements the reason for the increase of non-volatile particle fractions cannot yet be given. The long distance transfer flights to Brazil, Australia and West-Africa were executed during a time window of 17 months within a period of relative volcanic quiescence. Thus the data measured during these transfers represent a "snapshot picture" documenting the status of a significant part of the global UT/LS aerosol (with sizes below 1 μm) at low concentration levels 15 years after the last major (i.e., the 1991 Mount Pinatubo) eruption. The corresponding latitudinal distributions of the measured particle number densities are also presented in this paper in order to provide input on the UT/LS background aerosol for modelling purposes.

scholarly journals Long-term evolution and seasonal modulation of methanol above Jungfraujoch (46.5° N, 8.0° E): optimisation of the retrieval strategy, comparison with model simulations and independent observations

2014 ◽  
Vol 7 (5) ◽  
pp. 4659-4692 ◽  
Author(s):  
W. Bader ◽  
T. Stavrakou ◽  
J.-F. Muller ◽  
S. Reimann ◽  
C. D. Boone ◽  
...  
Keyword(s):  
Peak Amplitude ◽  
Systematic Bias ◽  
Retrieval Strategy ◽  
Model Simulations ◽  
Term Evolution ◽  
Time Period ◽  
Independent Observations ◽  
June July

Abstract. Methanol (CH3OH) is the second most abundant organic compound in the Earth's atmosphere after methane. In this work, we present the first long-term time series of methanol total, lower tropospheric and upper tropospheric-lower stratospheric partial columns derived from the analysis of high resolution Fourier transform infrared solar spectra recorded at the Jungfraujoch station (46.5° N, 3580 m a.s.l.). The retrieval of methanol is very challenging due to strong absorptions of ozone in the region of the selected υ8 band of CH3OH. Two wide spectral intervals have been defined and adjusted in order to maximize the information content. Methanol does not exhibit a significant trend over the 1995–2012 time period, but a strong seasonal modulation characterized by maximum values and variability in June–July, minimum columns in winter and a peak-to-peak amplitude of 130%. In situ measurements performed at the Jungfraujoch and ACE-FTS occultations give similar results for the methanol seasonal variation. The total and lower tropospheric columns are also compared with IMAGESv2 model simulations. There is no systematic bias between the observations and IMAGESv2 but the model underestimates the peak-to-peak amplitude of the seasonal modulations.

Ozone variability and trends in the UTLS derived from the IAGOS- CARIBIC observatory using JETPAC

2020 ◽  
Author(s):  
Harald Boenisch ◽  
Andreas Zahn ◽  
Luis Millan
Keyword(s):  
Water Vapour ◽  
Lower Stratosphere ◽  
In Situ Measurements ◽  
Research Infrastructure ◽  
European Research ◽  
Coordinate Systems ◽  
Upper Troposphere ◽  
Work In Progress

&lt;p&gt;The CARIBIC (Civil &amp;#160;Aircraft &amp;#160;for &amp;#160;the &amp;#160;Regular &amp;#160;Investigation &amp;#160;of the atmosphere Based on an&amp;#160;&lt;br&gt;Instrumented Container) project is part of the a European research infrastructure IAGOS (In-&lt;br&gt;Service Aircraft for a Global Observing System) making regular in-situ measurements of more&amp;#160;&lt;br&gt;than 100 atmospheric constituents, include ozone and water vapour, on-board of an in-service&amp;#160;&lt;br&gt;passenger &amp;#160;aircraft &amp;#160;operated &amp;#160;by &amp;#160;Lufthansa. &amp;#160;The &amp;#160;dataset &amp;#160;of &amp;#160;the &amp;#160;IAGOS-CARIBIC &amp;#160;is &amp;#160;therefore&amp;#160;&lt;br&gt;ideally suited as a testbed for the SPARC (Stratosphere-troposphere Processes And their Role&amp;#160;&lt;br&gt;in Climate) activity OCTAV-UTLS (Observed Composition Trends And Variability in the Upper&amp;#160;&lt;br&gt;Troposphere and Lower Stratosphere). One key aspect, shown here as work in progress, is to&amp;#160;&lt;br&gt;develop, define and apply common metrics for the comparison of different UTLS datasets&amp;#160;&lt;br&gt;using a variety of meteorological coordinate systems derived from reanalysis datasets. The&amp;#160;&lt;br&gt;focus here is on the variability of ozone in the upper troposphere and lower stratosphere&amp;#160;&lt;br&gt;(UTLS) on interannual and seasonal timescales and the observed trends. The in-situ ozone&amp;#160;&lt;br&gt;measurements by IAGOS-CARIBIC are analysed relative to different tropopause definitions&amp;#160;&lt;br&gt;and coordinate systems. All these meteorological information applied here are produced with&amp;#160;&lt;br&gt;the JETPAC tool &amp;#8210; Jet and Tropopause Products for Analysis and Characterization (Manney et&amp;#160;&lt;br&gt;al., 2011).&lt;/p&gt;

scholarly journals Validation of GOSAT and OCO-2 against In Situ Aircraft Measurements and Comparison with CarbonTracker and GEOS-Chem over Qinhuangdao, China

2021 ◽  
Vol 13 (5) ◽  
pp. 899
Author(s):  
Farhan Mustafa ◽  
Huijuan Wang ◽  
Lingbing Bu ◽  
Qin Wang ◽  
Muhammad Shahzaman ◽  
...  
Keyword(s):  
Vertical Structure ◽  
Co2 Concentration ◽  
In Situ Measurements ◽  
Vertical Profiles ◽  
Aircraft Measurements ◽  
Research Aircraft ◽  
Carbon Dioxide Co2 ◽  
Air Column ◽  
Good Agreement

Carbon dioxide (CO2) is the most important greenhouse gas and several satellites have been launched to monitor the atmospheric CO2 at regional and global scales. Evaluation of the measurements obtained from these satellites against accurate and precise instruments is crucial. In this work, aircraft measurements of CO2 were carried out over Qinhuangdao, China (39.9354°N, 119.6005°E), on 14, 16, and 19 March 2019 to validate the Greenhous gases Observing SATellite (GOSAT) and the Orbiting Carbon Observatory 2 (OCO-2) CO2 retrievals. The airborne in situ instruments were mounted on a research aircraft and the measurements were carried out between the altitudes of ~0.5 and 8.0 km to obtain the vertical profiles of CO2. The profiles captured a decrease in CO2 concentration from the surface to maximum altitude. Moreover, the vertical profiles from GEOS-Chem and the National Oceanic and Atmospheric Administration (NOAA) CarbonTracker were also compared with in situ and satellite datasets. The satellite and the model datasets captured the vertical structure of CO2 when compared with in situ measurements, which showed good agreement among the datasets. The dry-air column-averaged CO2 mole fractions (XCO2) retrieved from OCO-2 and GOSAT showed biases of 1.33 ppm (0.32%) and −1.70 ppm (−0.41%), respectively, relative to the XCO2 derived from in situ measurements.

scholarly journals Evaluation of ECMWF ERA-40 temperature and wind in the lower tropical stratosphere since 1988 from past long-duration balloon measurements

2007 ◽  
Vol 7 (13) ◽  
pp. 3399-3409 ◽  
Author(s):  
T. Christensen ◽  
B. M. Knudsen ◽  
J.-P. Pommereau ◽  
G. Letrenne ◽  
A. Hertzog ◽  
...  
Keyword(s):  
Wind Speed ◽  
Lower Stratosphere ◽  
Equatorial Region ◽  
Satellite Measurements ◽  
Operational Analysis ◽  
Long Duration ◽  
The Tropics ◽  
Recent Evaluation ◽  
Balloon Measurements

Abstract. The temperature and wind of the ECMWF ERA-40 reanalysis in the tropical lower stratosphere during the period 1988–2001 has been evaluated by comparison with independent in situ measurements of 21 IR Montgolfier and superpressure long-duration balloon flights performed by CNES from Pretoria (26° S) in South Africa in 1988–1989, Latacunga (1° S) in Ecuador in 1991–1998 and Bauru (22° S) in Brazil in 2000–2001. The ERA-40 temperature displays a bias varying progressively from +1.16 K in 1988–1989, to +0.26 K in 1994–1996 and −0.46 K after 1998, the latter being fully consistent with recent evaluations of ECMWF operational analysis from radio occultation and in situ long-duration balloon observations. The amplitude of the bias and its evolution are very similar to the results of a previous evaluation from radiosondes in 1991–2003, suggesting that the origin of the drift of ERA-40 might be mainly due to errors in the series of satellite measurements of MSU, replaced by AMSU in 1998, assimilated in the model. The ERA-40 zonal wind speed in the lower stratosphere appears slightly overestimated by 0.7–1.0 m/s on average in both the tropics and equatorial region, that is by 5–10% compared to the average 10–20 m/s wind speed. This bias, fully consistent with a recent evaluation of ECMWF operational analysis in 2004, is found constant during the whole 1988–2001 period, suggesting a shortfall in the variabililty of ERA-40 horizontal winds in the lower stratosphere in the tropics and the equatorial region. Finally calculated trajectories using ERA-40, frequently used for analysing field observations, are found in error compared to that of the balloons by ±500 km after 5 days and ±1000 km after 10 days.

In situ measurements of HNO3, NOy, NO, and O3 in the lower stratosphere and upper troposphere

2001 ◽  
Vol 35 (33) ◽  
pp. 5789-5797 ◽  
Author(s):  
J.A. Neuman ◽  
R.S. Gao ◽  
D.W. Fahey ◽  
J.C. Holecek ◽  
B.A. Ridley ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
In Situ Measurements ◽  
Upper Troposphere

scholarly journals Evaluation of ECMWF ERA-40 temperature and wind in the lower tropical stratosphere since 1988 from past long-duration balloon measurements

2007 ◽  
Vol 7 (2) ◽  
pp. 3423-3450 ◽  
Author(s):  
T. Christensen ◽  
B. M. Knudsen ◽  
J.-P. Pommereau ◽  
G. Letrenne ◽  
A. Hertzog ◽  
...  
Keyword(s):  
Wind Speed ◽  
Lower Stratosphere ◽  
Equatorial Region ◽  
Satellite Measurements ◽  
Operational Analysis ◽  
Long Duration ◽  
The Difference ◽  
The Tropics ◽  
Recent Evaluation

Abstract. The temperature and wind of the ECMWF ERA-40 reanalysis in the tropical lower stratosphere during the period 1988–2001 has been evaluated by comparison with independent in situ measurements of 21 IR Montgolfier and superpressure long-duration balloon flights performed by CNES from Pretoria (26° S) in South Africa in 1988–1989, Latacunga (1° S) in Ecuador in 1991–1998 and Bauru (22° S) in Brazil in 2000–2001. The ERA-40 temperature displays a bias varying progressively from +1.16 K in 1988–1989, to +0.26 K in 1994–1996 and −0.46 K after 1998, the latter being fully consistent with recent evaluations of ECMWF operational analysis from radio occultation and in situ long-duration balloon observations. The amplitude of the bias and its evolution are very similar to the results of a previous evaluation from radiosondes in 1991–2003, suggesting that the origin of the drift of ERA-40 might be mainly due to errors in the series of satellite measurements of MSU, replaced by AMSU in 1998, assimilated in the model. The ERA-40 zonal wind speed in the lower stratosphere appears slightly overestimated by 0.7–1.0 m/s on average in both the tropics and equatorial region, that is by 5–10% compared to the average 10–20 m/s wind speed. This bias, fully consistent with a recent evaluation of ECMWF operational analysis in 2004, is found constant during the whole 1988–2001 period, suggesting that the difference in that case might originate in the model. Finally calculated trajectories using ERA-40, frequently used for analysing field observations, are found in error compared to that of the balloons by ±500 km after 5 days and ±1000 km after 10 days.

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