scholarly journals Wildfire smoke in the lower stratosphere identified by in situ CO observations

2020 ◽  
Vol 20 (22) ◽  
pp. 13985-14003
Author(s):  
Joram J. D. Hooghiem ◽  
Maria Elena Popa ◽  
Thomas Röckmann ◽  
Jens-Uwe Grooß ◽  
Ines Tritscher ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
Vertical Displacement ◽  
Isotopic Signature ◽  
Atmospheric Composition ◽  
Lagrangian Model ◽  
Back Trajectory ◽  
Orthogonal Polarization ◽  
Enhancement Ratio ◽  
Wildfire Smoke

Abstract. Wildfires emit large quantities of aerosols and trace gases, which occasionally reach the lower stratosphere. In August 2017, several pyro-cumulonimbus events injected a large amount of smoke into the stratosphere, observed by lidar and satellites. Satellite observations are in general the main method of detecting these events since in situ aircraft- or balloon-based measurements of atmospheric composition at higher altitudes are not made frequently enough. This work presents accidental balloon-borne trace gas observations of wildfire smoke in the lower stratosphere, identified by enhanced CO mole fractions at approximately 13.6 km. In addition to CO mole fractions, CO2 mole fractions and isotopic composition of CO (δ13C and δ18O) have been measured in air samples, from both the wildfire plume and background, collected using an AirCore and a lightweight stratospheric air sampler (LISA) flown on a weather balloon from Sodankylä (4–7 September 2017; 67.37∘ N, 26.63∘ E; 179 m a.m.s.l.), Finland. The greenhouse gas enhancement ratio (ΔCO:ΔCO2) and the isotopic signature based on δ13C(CO) and δ18O(CO) independently identify wildfire emissions as the source of the stratospheric CO enhancement. Back-trajectory analysis was performed with the Chemical Lagrangian Model of the Stratosphere (CLaMS), tracing the smoke's origin to wildfires in British Columbia with an injection date of 12 August 2017. The trajectories are corrected for vertical displacement due to heating of the wildfire aerosols, by observations made by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument. Knowledge of the age of the smoke allowed for a correction of the enhancement ratio, ΔCO:ΔCO2, for the chemical removal of CO by OH. The stable isotope observations were used to estimate the amount of tropospheric air in the plume at the time of observation to be about 45±21 %. Finally, the plume extended over 1 km in altitude, as inferred from the observations.

scholarly journals Wildfire smoke in the lower stratosphere identified by in situ CO observations

2020 ◽  
Author(s):  
Joram J. D. Hooghiem ◽  
Maria Elena Popa ◽  
Thomas Röckmann ◽  
Jens-Uwe Grooß ◽  
Ines Tritscher ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
Atmospheric Composition ◽  
Lagrangian Model ◽  
Trace Gas ◽  
Back Trajectory ◽  
Orthogonal Polarization ◽  
Enhancement Ratio ◽  
Wildfire Smoke ◽  
British Colombia

Abstract. Wildfires emit large quantities of aerosols and trace gases, which occasionally reach the lower stratosphere. In August 2017, several pyro-cumulonimbus events injected a large amount of smoke into the stratosphere, observed by lidar and satellites. Satellite observations are in general the main method of detecting these events since in situ aircraft- or balloon-based measurements of atmospheric composition at higher altitudes are not made frequent enough. This work presents accidental balloon-borne trace gas observations of wildfire smoke in the lower stratosphere, identified by enhanced CO mole fractions at approximately 13.6 km. In addition to CO mole fractions, CO2 mole fractions as well as isotopic composition of CO (δ13C and δ18O) have been measured in air samples collected using an AirCore and a LIghtweight Stratospheric Air sampler (LISA) flown on a weather balloon from Sodankylä (4–7 September 2017, 67.37° N, 26.63° E, 179 m a.s.l.), Finland. The greenhouse gas enhancement ratio (∆CO : ∆CO2) and the isotopic signature based on δ13C(CO) and δ18O(CO) independently identify wildfire emissions as the source of the stratospheric CO enhancement. Back-trajectory analysis, performed with the Chemical Lagrangian Model of the Stratosphere (CLaMS), corrected for vertical displacement, due to heating of the wildfire aerosols, by observations made by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument, trace the smoke’s origin to wildfires in British Colombia with an injection date of 12 August 2017. Knowledge of the age of the smoke allowed for a correction of the enhancement ratio, ∆CO : ∆CO2, for the chemical removal of CO by OH. The stable isotope observations were used to estimate the amount of tropospheric air in the plume at the time of observation to be about 34 ± 14 %. The in situ observations provide information on the trace gas chemistry of smoke plumes that reach the stratosphere, as well as the vertical extent of 1 km of the 2017 smoke plume.

scholarly journals Stratospheric aerosols from the Sarychev volcano eruption in the 2009 Arctic summer

2013 ◽  
Vol 13 (13) ◽  
pp. 6533-6552 ◽  
Author(s):  
F. Jégou ◽  
G. Berthet ◽  
C. Brogniez ◽  
J.-B. Renard ◽  
P. François ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
Imaging System ◽  
Stratospheric Aerosol ◽  
Atmospheric Composition ◽  
The Arctic ◽  
Orthogonal Polarization ◽  
Volcano Eruption ◽  
A Value ◽  
Sulphate Aerosols ◽  
Tropospheric Aerosol

Abstract. Aerosols from the Sarychev volcano eruption (Kuril Islands, northeast of Japan) were observed in the Arctic lower stratosphere a few days after the strongest SO2 injection which occurred on 15 and 16 June 2009. From the observations provided by the Infrared Atmospheric Sounding Interferometer (IASI) an estimated 0.9 Tg of sulphur dioxide was injected into the upper troposphere and lower stratosphere (UTLS). The resultant stratospheric sulphate aerosols were detected from satellites by the Optical Spectrograph and Infrared Imaging System (OSIRIS) limb sounder and by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and from the surface by the Network for the Detection of Atmospheric Composition Changes (NDACC) lidar deployed at OHP (Observatoire de Haute-Provence, France). By the first week of July the aerosol plume had spread out over the entire Arctic region. The Sarychev-induced stratospheric aerosol over the Kiruna region (north of Sweden) was measured by the Stratospheric and Tropospheric Aerosol Counter (STAC) during eight balloon flights planned in August and September 2009. During this balloon campaign the Micro Radiomètre Ballon (MicroRADIBAL) and the Spectroscopie d'Absorption Lunaire pour l'Observation des Minoritaires Ozone et NOx (SALOMON) remote-sensing instruments also observed these aerosols. Aerosol concentrations returned to near-background levels by spring 2010. The effective radius, the surface area density (SAD), the aerosol extinction, and the total sulphur mass from STAC in situ measurements are enhanced with mean values in the range 0.15–0.21 μm, 5.5–14.7 μm2 cm−3, 5.5–29.5 × 10−4 km−1, and 4.9–12.6 × 10−10 kg[S] kg−1[air], respectively, between 14 km and 18 km. The observed and modelled e-folding time of sulphate aerosols from the Sarychev eruption is around 70–80 days, a value much shorter than the 12–14 months calculated for aerosols from the 1991 eruption of Mt Pinatubo. The OSIRIS stratospheric aerosol optical depth (AOD) at 750 nm is enhanced by a factor of 6, with a value of 0.02 in late July compared to 0.0035 before the eruption. The HadGEM2 and MIMOSA model outputs indicate that aerosol layers in polar region up to 14–15 km are largely modulated by stratosphere–troposphere exchange processes. The spatial extent of the Sarychev plume is well represented in the HadGEM2 model with lower altitudes of the plume being controlled by upper tropospheric troughs which displace the plume downward and upper altitudes around 18–20 km, in agreement with lidar observations. Good consistency is found between the HadGEM2 sulphur mass density and the value inferred from the STAC observations, with a maximum located about 1 km above the tropopause ranging from 1 to 2 × 10−9 kg[S] kg−1[air], which is one order of magnitude higher than the background level.

Results from a comparison of HCN measurements and Lagrangian backtrajectory analyses in the Asian Summer Monsoon Anticyclone

2020 ◽  
Author(s):  
Yun Li ◽  
Bärbel Vogel ◽  
Felix Plöger ◽  
Silvia Bucci ◽  
Bernard Legras ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Lower Stratosphere ◽  
Asian Summer Monsoon ◽  
Atmospheric Composition ◽  
Convective Activity ◽  
Mixing Ratios ◽  
Research Aircraft ◽  
Asian Summer ◽  
Good Tracer

<p>The StratoClim aircraft field campaign took place from Kathmandu, Nepal, in summer 2017 in<br>order to study the atmospheric composition, chemistry, and dynamics in the Asian Summer<br>Monsoon Anticyclone (ASMA) which is known to transport surface emissions to the mid-latitude<br>lower stratosphere and the stratosphere worldwide. Hydrogen cyanide (HCN) which is primarily<br>emitted from biomass burning and has a UTLS lifetime on the order of 1-2 years is a good tracer for<br>biomass burning import into the lower and free stratosphere.<br>HCN in the ASM Upper Troposphere and Lower Stratosphere (UTLS) was measured in-situ<br>employing the Chemical-Ionization Time-of-Flight Mass Spectrometer FUNMASS on board the<br>high-altitude research aircraft M55-Geophysica. The observed HCN mixing ratios in and above the<br>ASMA exhibit interesting vertical and horizontal signatures around the tropopause as well as in the<br>LS probably resulting from convective activity or air mass origin (AMO). We here compare<br>measured HCN to Lagrangian simulations by the ClaMS and TRACZILLA models which employ<br>two different approaches to represent higher-reaching convective events. The simulations succeed to<br>track some of the observed HCN features back to convective activity or AMO. The quality of the<br>reproduction and further outcomes on the atmospheric relevance will be discussed in the<br>presentation.</p>

scholarly journals Midlatitude ClO during the maximum atmospheric chlorine burden: in situ balloon measurements and model simulations

2005 ◽  
Vol 5 (6) ◽  
pp. 1623-1638 ◽  
Author(s):  
B. Vogel ◽  
R. Müller ◽  
A. Engel ◽  
J.-U. Grooß ◽  
D. Toohey ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
Stratospheric Ozone ◽  
Lagrangian Model ◽  
Night Time ◽  
Model Simulations ◽  
Mixing Ratios ◽  
Chlorine Monoxide ◽  
Good Agreement ◽  
Balloon Measurements

Abstract. Chlorine monoxide (ClO) plays a key role in stratospheric ozone loss processes at midlatitudes. We present two balloon-borne in situ measurements of ClO conducted in northern hemisphere midlatitudes during the period of the maximum of total inorganic chlorine loading in the atmosphere. Both ClO measurements were conducted on board the TRIPLE balloon payload, launched in November 1996 in León, Spain, and in May 1999 in Aire sur l'Adour, France. For both flights a ClO daylight and night-time vertical profile was derived over an altitude range of approximately 15-35 km. ClO mixing ratios are compared to model simulations performed with the photochemical box model version of the Chemical Lagrangian Model of the Stratosphere (CLaMS). Simulations along 24-hour backward trajectories were performed to study the diurnal variation of ClO in the midlatitude lower stratosphere. Model simulations for the flight launched in Aire sur l'Adour 1999 show an excellent agreement with the ClO measurements. For the flight launched in León 1996, an overall good agreement is found, whereas the flight is characterized by a more complex dynamical situation due to a possible mixture of vortex and non-vortex air. We note that for both flights at solar zenith angles greater than 86°-87° simulated ClO mixing ratios are higher than observed ClO mixing ratios. However, the present findings indicate that no substantial uncertainties exist in midlatitude chlorine chemistry of the stratosphere.

scholarly journals Nitric acid trihydrate nucleation and denitrification in the Arctic stratosphere

2014 ◽  
Vol 14 (2) ◽  
pp. 1055-1073 ◽  
Author(s):  
J.-U. Grooß ◽  
I. Engel ◽  
S. Borrmann ◽  
W. Frey ◽  
G. Günther ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Nucleation Rate ◽  
Regional Scale ◽  
Lagrangian Model ◽  
The Arctic ◽  
Orthogonal Polarization ◽  
Rate Model ◽  
Formation Pathway ◽  
Improved Model

Abstract. Nitric acid trihydrate (NAT) particles in the polar stratosphere have been shown to be responsible for vertical redistribution of reactive nitrogen (NOy). Recent observations by Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP) aboard the CALIPSO satellite have been explained in terms of heterogeneous nucleation of NAT on foreign nuclei, revealing this to be an important formation pathway for the NAT particles. In state of the art global- or regional-scale models, heterogeneous NAT nucleation is currently simulated in a very coarse manner using a constant, saturation-independent nucleation rate. Here we present first simulations for the Arctic winter 2009/2010 applying a new saturation-dependent parametrisation of heterogeneous NAT nucleation rates within the Chemical Lagrangian Model of the Stratosphere (CLaMS). The simulation shows good agreement of chemical trace species with in situ and remote sensing observations. The simulated polar stratospheric cloud (PSC) optical properties agree much better with CALIOP observations than those simulated with a constant nucleation rate model. A comparison of the simulated particle size distributions with observations made using the Forward Scattering Spectrometer Probe (FSSP) aboard the high altitude research aircraft Geophysica, shows that the model reproduces the observed size distribution, except for the very largest particles above 15 μm diameter. The vertical NOy redistribution caused by the sedimentation of the NAT particles, in particular the denitrification and nitrification signals observed by the ACE-FTS satellite instrument and the in situ SIOUX instrument aboard the Geophysica, are reproduced by the improved model, and a small improvement with respect to the constant nucleation rate model is found.

scholarly journals NAT nucleation and denitrification in the Arctic stratosphere

2013 ◽  
Vol 13 (8) ◽  
pp. 22107-22150 ◽  
Author(s):  
J.-U. Grooß ◽  
I. Engel ◽  
S. Borrmann ◽  
W. Frey ◽  
G. Günther ◽  
...  
Keyword(s):  
Regional Scale ◽  
Lagrangian Model ◽  
The Arctic ◽  
Orthogonal Polarization ◽  
Rate Model ◽  
Formation Pathway ◽  
Trace Species ◽  
Constant Rate ◽  
Research Aircraft

Abstract. Nitric acid trihydrate (NAT) particles in the polar stratosphere have been shown to be responsible for vertical redistribution of reactive nitrogen (NOy). Recent observations by Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP) aboard the CALIPSO satellite have been explained in terms of heterogeneous nucleation of NAT on foreign nuclei, revealing it to be an important formation pathway for the NAT particles. In state of the art global or regional scale models, heterogeneous NAT nucleation is currently simulated in a very coarse manner using a constant, saturation-independent nucleation rate. Here we present first simulations for the Arctic winter 2009/2010 applying a new saturation-dependent parametrisation of heterogeneous NAT nucleation rates within the Chemical Lagrangian Model of the Stratosphere (CLaMS). The simulation shows good agreement of chemical trace species with in situ and remote sensing observations. The simulated PSC optical properties agree better with CALIOP observations than those simulated with a constant rate model. A comparison of the simulated particle size distributions with observations made using the Forward Scattering Spectrometer Probe (FSSP) aboard the high altitude research aircraft Geophysica, showed that the model reproduces the observed size distribution, except for the very largest particles above 15 μm diameter. The vertical NOy redistribution caused by the sedimentation of the NAT particles, in particular the denitrification and nitrification signals observed by the ACE-FTS satellite instrument and the in-situ SIOUX instrument aboard the Geophysica, are reproduced by the model, but the improvement of the new parametrisation with respect to the constant rate model remains small.

scholarly journals In Situ exploration of the giant planets

2021 ◽  
Author(s):  
O. Mousis ◽  
D. H. Atkinson ◽  
R. Ambrosi ◽  
S. Atreya ◽  
D. Banfield ◽  
...  
Keyword(s):  
Solar System ◽  
Giant Planets ◽  
Atmospheric Composition ◽  
Formation History ◽  
History Of ◽  
Composition Structure ◽  
Galileo Probe ◽  
Probe Measurements

AbstractRemote sensing observations suffer significant limitations when used to study the bulk atmospheric composition of the giant planets of our Solar System. This impacts our knowledge of the formation of these planets and the physics of their atmospheres. A remarkable example of the superiority of in situ probe measurements was illustrated by the exploration of Jupiter, where key measurements such as the determination of the noble gases’ abundances and the precise measurement of the helium mixing ratio were only made available through in situ measurements by the Galileo probe. Here we describe the main scientific goals to be addressed by the future in situ exploration of Saturn, Uranus, and Neptune, placing the Galileo probe exploration of Jupiter in a broader context. An atmospheric entry probe targeting the 10-bar level would yield insight into two broad themes: i) the formation history of the giant planets and that of the Solar System, and ii) the processes at play in planetary atmospheres. The probe would descend under parachute to measure composition, structure, and dynamics, with data returned to Earth using a Carrier Relay Spacecraft as a relay station. An atmospheric probe could represent a significant ESA contribution to a future NASA New Frontiers or flagship mission to be launched toward Saturn, Uranus, and/or Neptune.

scholarly journals Aircraft measurements of gravity waves in the upper troposphere and lower stratosphere during the START08 field experiment

2015 ◽  
Vol 15 (13) ◽  
pp. 7667-7684 ◽  
Author(s):  
Fuqing Zhang ◽  
Junhong Wei ◽  
Meng Zhang ◽  
K. P. Bowman ◽  
L. L. Pan ◽  
...  
Keyword(s):  
Power Law ◽  
Gravity Waves ◽  
Lower Stratosphere ◽  
Potential Temperature ◽  
Shear Instability ◽  
Aircraft Measurements ◽  
Upper Troposphere ◽  
Airborne Measurements ◽  
Wide Range

Abstract. This study analyzes in situ airborne measurements from the 2008 Stratosphere–Troposphere Analyses of Regional Transport (START08) experiment to characterize gravity waves in the extratropical upper troposphere and lower stratosphere (ExUTLS). The focus is on the second research flight (RF02), which took place on 21–22 April 2008. This was the first airborne mission dedicated to probing gravity waves associated with strong upper-tropospheric jet–front systems. Based on spectral and wavelet analyses of the in situ observations, along with a diagnosis of the polarization relationships, clear signals of mesoscale variations with wavelengths ~ 50–500 km are found in almost every segment of the 8 h flight, which took place mostly in the lower stratosphere. The aircraft sampled a wide range of background conditions including the region near the jet core, the jet exit and over the Rocky Mountains with clear evidence of vertically propagating gravity waves of along-track wavelength between 100 and 120 km. The power spectra of the horizontal velocity components and potential temperature for the scale approximately between ~ 8 and ~ 256 km display an approximate −5/3 power law in agreement with past studies on aircraft measurements, while the fluctuations roll over to a −3 power law for the scale approximately between ~ 0.5 and ~ 8 km (except when this part of the spectrum is activated, as recorded clearly by one of the flight segments). However, at least part of the high-frequency signals with sampled periods of ~ 20–~ 60 s and wavelengths of ~ 5–~ 15 km might be due to intrinsic observational errors in the aircraft measurements, even though the possibilities that these fluctuations may be due to other physical phenomena (e.g., nonlinear dynamics, shear instability and/or turbulence) cannot be completely ruled out.

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