scholarly journals Attribution and evolution of ozone from Asian wild fires using satellite and aircraft measurements during the ARCTAS campaign

2012 ◽  
Vol 12 (1) ◽  
pp. 169-188 ◽  
Author(s):  
R. Dupont ◽  
B. Pierce ◽  
J. Worden ◽  
J. Hair ◽  
M. Fenn ◽  
...  
Keyword(s):  
Lower Troposphere ◽  
Dynamical Evolution ◽  
Mixing Ratios ◽  
In Situ Data ◽  
Photochemical Production ◽  
The Pacific ◽  
Western Asia ◽  
Quality Modeling ◽  
Low Sensitivity

Abstract. We use ozone and carbon monoxide measurements from the Tropospheric Emission Spectrometer (TES), model estimates of Ozone, CO, and ozone pre-cursors from the Real-time Air Quality Modeling System (RAQMS), and data from the NASA DC8 aircraft to characterize the source and dynamical evolution of ozone and CO in Asian wildfire plumes during the spring ARCTAS campaign 2008. On the 19 April, NASA DC8 O3 and aerosol Differential Absorption Lidar (DIAL) observed two biomass burning plumes originating from North-Western Asia (Kazakhstan) and South-Eastern Asia (Thailand) that advected eastward over the Pacific reaching North America in 10 to 12 days. Using both TES observations and RAQMS chemical analyses, we track the wildfire plumes from their source to the ARCTAS DC8 platform. In addition to photochemical production due to ozone pre-cursors, we find that exchange between the stratosphere and the troposphere is a major factor influencing O3 concentrations for both plumes. For example, the Kazakhstan and Siberian plumes at 55 degrees North is a region of significant springtime stratospheric/tropospheric exchange. Stratospheric air influences the Thailand plume after it is lofted to high altitudes via the Himalayas. Using comparisons of the model to the aircraft and satellite measurements, we estimate that the Kazakhstan plume is responsible for increases of O3 and CO mixing ratios by approximately 6.4 ppbv and 38 ppbv in the lower troposphere (height of 2 to 6 km), and the Thailand plume is responsible for increases of O3 and CO mixing ratios of approximately 11 ppbv and 71 ppbv in the upper troposphere (height of 8 to 12 km) respectively. However, there are significant sources of uncertainty in these estimates that point to the need for future improvements in both model and satellite observations. For example, it is challenging to characterize the fraction of air parcels from the stratosphere versus those from the fire because of the low sensitivity of the TES CO estimates used to mark stratospheric air versus air parcels affected by the smoke plume. Model transport uncertainties, such as too much dispersion, results in a broad plume structure from the Kazakhstan fires that is approximately 2 km lower than the plume observed by aircraft. Consequently, the model and TES data do not capture the photochemical production of ozone in the Kazakhstan plume that is apparent in the aircraft in situ data. However, ozone and CO distributions from TES and RAQMS model estimates of the Thailand plume are within the uncertainties of the TES data. Therefore, the RAQMS model is better able to characterize the emissions from this fire, the mixing of ozone from the stratosphere to the plume, and the photochemical production and transport of ozone and ozone pre-cursors as the plume moves across the Pacific.

scholarly journals Reconstructing ozone chemistry from Asian wild fires using models, satellite and aircraft measurements during the ARCTAS campaign

2010 ◽  
Vol 10 (11) ◽  
pp. 26751-26812 ◽  
Author(s):  
R. Dupont ◽  
B. Pierce ◽  
J. Worden ◽  
J. Hair ◽  
M. Fenn ◽  
...  
Keyword(s):  
Full Range ◽  
Lower Troposphere ◽  
Dynamical Evolution ◽  
Ozone Production ◽  
Fire Emissions ◽  
Mixing Ratios ◽  
The Pacific ◽  
Western Asia ◽  
Platform Comparison ◽  
Low Sensitivity

Abstract. We use ozone (O3) and carbon monoxide (CO) satellite measurements from the Tropospheric Emission Spectrometer (TES), simulations from the Real-time Air Quality Modeling System (RAQMS) and aircraft data from the NASA DC8 aircraft to characterize the chemical and dynamical evolution of Asian wildfire plumes during the spring ARCTAS campaign 2008. On the 19 April, NASA DC8 O3 and aerosol Differential Absorption Lidar (DIAL) observed two biomass burning plumes originating from North-Western Asia (Kazakhstan) and South-Eastern Asia (Thailand) that advected eastward over the Pacific reaching North America in 10 to 12 days. Using both TES observations and RAQMS chemical analyses, we track the wildfire plumes from their source to the ARCTAS DC8 platform. Comparison between satellite O3 and CO measurements and model results show consistency when the TES averaging kernel and constraint vector are applied to the model. However, RAQMS CO simulations suggest that TES observations do not capture the full range of CO variability in the plume due to low sensitivity. In both plumes, exchanges between the stratosphere and the troposphere tend to be a major factor influencing O3 concentrations. However, fire emissions of ozone precursors increase photochemical ozone production, particularly in the Thailand wildfire plume. Analysis shows that the Kazakhstan plume is responsible for increases of O3 and CO mixing ratios up to 6.4 ppbv and 38 ppbv in the lower troposphere, and the Thailand plume is responsible for increases of O3 and CO mixing ratios up to 11 ppbv and 71 ppbv in the upper troposphere.

scholarly journals Estimate of bias in Aura TES HDO/H<sub>2</sub>O profiles from comparison of TES and in situ HDO/H<sub>2</sub>O measurements at the Mauna Loa observatory

2011 ◽  
Vol 11 (9) ◽  
pp. 4491-4503 ◽  
Author(s):  
J. Worden ◽  
D. Noone ◽  
J. Galewsky ◽  
A. Bailey ◽  
K. Bowman ◽  
...  
Keyword(s):  
Bias Correction ◽  
Trace Gases ◽  
Lower Troposphere ◽  
Vertical Profiles ◽  
Thermal Contrast ◽  
Near Surface ◽  
Mauna Loa ◽  
In Situ Data ◽  
Infrared Radiances

Abstract. The Aura satellite Tropospheric Emission Spectrometer (TES) instrument is capable of measuring the HDO/H2O ratio in the lower troposphere using thermal infrared radiances between 1200 and 1350 cm−1. However, direct validation of these measurements is challenging due to a lack of in situ measured vertical profiles of the HDO/H2O ratio that are spatially and temporally co-located with the TES observations. From 11 October through 5 November 2008, we undertook a campaign to measure HDO and H2O at the Mauna Loa observatory in Hawaii for comparison with TES observations. The Mauna Loa observatory is situated at 3.1 km above sea level or approximately 680 hPa, which is approximately the altitude where the TES HDO/H2O observations show the most sensitivity. Another advantage of comparing in situ data from this site to estimates derived from thermal IR radiances is that the volcanic rock is heated by sunlight during the day, thus providing significant thermal contrast between the surface and atmosphere; this thermal contrast increases the sensitivity to near surface estimates of tropospheric trace gases. The objective of this inter-comparison is to better characterize a bias in the TES HDO data, which had been previously estimated to be approximately 5 % too high for a column integrated value between 850 hPa and 500 hPa. We estimate that the TES HDO profiles should be corrected downwards by approximately 4.8 % and 6.3 % for Versions 3 and 4 of the data respectively. These corrections must account for the vertical sensitivity of the TES HDO estimates. We estimate that the precision of this bias correction is approximately 1.9 %. The accuracy is driven by the corrections applied to the in situ HDO and H2O measurements using flask data taken during the inter-comparison campaign and is estimated to be less than 1 %. Future comparisons of TES data to accurate vertical profiles of in situ measurements are needed to refine this bias estimate.

scholarly journals Tunable diode laser in-situ CH<sub>4</sub> measurements aboard the CARIBIC passenger aircraft: instrument performance assessment

2014 ◽  
Vol 7 (3) ◽  
pp. 743-755 ◽  
Author(s):  
C. Dyroff ◽  
A. Zahn ◽  
S. Sanati ◽  
E. Christner ◽  
A. Rauthe-Schöch ◽  
...  
Keyword(s):  
Lower Troposphere ◽  
Correlation Study ◽  
Tunable Diode Laser ◽  
Long Distance ◽  
Airborne Measurements ◽  
Mixing Ratios ◽  
Flight Level ◽  
Passenger Aircraft ◽  
The Tropics

Abstract. A laser spectrometer for automated monthly measurements of methane (CH4) mixing ratios aboard the CARIBIC passenger aircraft is presented. The instrument is based on a commercial Fast Greenhouse Gas Analyser (FGGA, Los Gatos Res.), which was adapted to meet the requirements imposed by unattended airborne operation. It was characterised in the laboratory with respect to instrument stability, precision, cross sensitivity to H2O, and accuracy. For airborne operation, a calibration strategy is described that utilises CH4 measurements obtained from flask samples taken during the same flights. The precision of airborne measurements is 2 ppb for 10 s averages. The accuracy at aircraft cruising altitude is 3.85 ppb. During aircraft ascent and descent, where no flask samples were obtained, instrumental drifts can be less accurately determined and the uncertainty is estimated to be 12.4 ppb. A linear humidity bias correction was applied to the CH4 measurements, which was most important in the lower troposphere. On average, the correction bias was around 6.5 ppb at an altitude of 2 km, and negligible at cruising flight level. Observations from 103 long-distance flights are presented that span a large part of the northern hemispheric upper troposphere and lowermost stratosphere (UT/LMS), with occasional crossing of the tropics on flights to southern Africa. These accurate data mark the largest UT/LMS in-situ CH4 dataset worldwide. An example of a tracer-tracer correlation study with ozone is given, highlighting the possibility for accurate cross-tropopause transport analyses.

scholarly journals A framework for comparing remotely sensed and in-situ CO<sub>2</sub> concentrations

2008 ◽  
Vol 8 (1) ◽  
pp. 1549-1588 ◽  
Author(s):  
R. Macatangay ◽  
T. Warneke ◽  
C. Gerbig ◽  
S. Körner ◽  
R. Ahmadov ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Transport Model ◽  
Remotely Sensed ◽  
Infrared Spectrometry ◽  
Remotely Sensed Data ◽  
Solar Absorption ◽  
Mixing Ratios ◽  
In Situ Data ◽  
Global Calibration

Abstract. A framework that allows validating CO2 column averaged volume mixing ratios (VMRs) retrieved from ground-based solar absorption measurements using Fourier transform infrared spectrometry (FTS) against measurements made in-situ (such as from aircrafts and tall towers) has been developed. Since in-situ measurements are done frequently and at high accuracy on the global calibration scale, linking this scale with FTS total column retrievals ultimately provides a calibration scale for remote sensing. FTS, tower and aircraft data were analyzed from measurements during the CarboEurope Regional Experiment Strategy (CERES) from May to June 2005 in Biscarrosse, France. Carbon dioxide VMRs from the MetAir Dimona aircraft, the TM3 global transport model and Observations of the Middle Stratosphere (OMS) balloon based experiments were combined and integrated to compare with FTS measurements. The comparison agrees fairly well with differences resulting from the spatial variability of CO2 around the FTS as measured by the aircraft. Additionally, the Stochastic Time Inverted Lagrangian Transport (STILT) model served as a "transfer standard" between the in-situ data measured at a co-located tower and the remotely sensed data from the FTS. The variability of carbon dioxide VMRs was modeled well by STILT with differences coming partly from uncertainties in the spatial variation of carbon dioxide.

scholarly journals Global carbon monoxide products from combined AIRS, TES and MLS measurements on A-train satellites

2013 ◽  
Vol 13 (6) ◽  
pp. 15409-15441
Author(s):  
J. X. Warner ◽  
R. Yang ◽  
Z. Wei ◽  
F. Carminati ◽  
A. Tangborn ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Data Fusion ◽  
Lower Troposphere ◽  
Atmospheric Infrared Sounder ◽  
Upper Troposphere ◽  
In Situ Data ◽  
Diode Laser Spectrometer ◽  
Spatial Coverage ◽  
Transport Experiment

Abstract. This study tests a novel methodology to add value to satellite datasets. This methodology, data fusion, is similar to data assimilation, except that the background model-based field is replaced by a satellite dataset, in this case AIRS (Atmospheric Infrared Sounder) carbon monoxide (CO) measurements. The observational information comes from CO measurements with lower spatial coverage than AIRS, namely, from TES (Tropospheric Emission Spectrometer) and MLS (Microwave Limb Sounder). We show that combining these datasets with data fusion uses the higher spectral resolution of TES to extend AIRS CO observational sensitivity to the lower troposphere, a region especially important for air quality studies. We also show that combined CO measurements from AIRS and MLS provide enhanced information in the UTLS (upper troposphere/lower stratosphere) region compared to each product individually. The combined AIRS/TES and AIRS/MLS CO products are validated against DACOM (differential absorption mid-IR diode laser spectrometer) in situ CO measurements from the INTEX-B (Intercontinental Chemical Transport Experiment: MILAGRO and Pacific phases) field campaign and in situ data from HIPPO (HIAPER Pole-to-Pole Observations) flights. The data fusion results show improved sensitivities in the lower and upper troposphere (20–30% and above 20%, respectively) as compared with AIRS-only retrievals, and improved coverage compared with TES and MLS CO data.

scholarly journals TransCom N<sub>2</sub>O model inter-comparison – Part 1: Assessing the influence of transport and surface fluxes on tropospheric N<sub>2</sub>O variability

2014 ◽  
Vol 14 (2) ◽  
pp. 2307-2362 ◽  
Author(s):  
R. L. Thompson ◽  
P. K. Patra ◽  
K. Ishijima ◽  
E. Saikawa ◽  
M. Corazza ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Seasonal Cycle ◽  
Large Scale ◽  
Atmospheric Transport ◽  
Lower Troposphere ◽  
Vertical Gradient ◽  
Surface Fluxes ◽  
Meridional Transport ◽  
Mixing Ratios

Abstract. We present a comparison of chemistry-transport models (TransCom-N2O) to examine the importance of atmospheric transport and surface fluxes on the variability of N2O mixing ratios in the troposphere. Six different models and two model variants participated in the inter-comparison and simulations were made for the period 2006 to 2009. In addition to N2O, simulations of CFC-12 and SF6 were made by a subset of four of the models to provide information on the models proficiency in stratosphere-troposphere exchange (STE) and meridional transport, respectively. The same prior emissions were used by all models to restrict differences among models to transport and chemistry alone. Four different N2O flux scenarios totalling between 14 and 17 Tg N yr−1 (for 2005) globally were also compared. The modelled N2O mixing ratios were assessed against observations from in-situ stations, discrete air sampling networks, and aircraft. All models adequately captured the large-scale patterns of N2O and the vertical gradient from the troposphere to the stratosphere and most models also adequately captured the N2O tropospheric growth rate. However, all models underestimated the inter-hemispheric N2O gradient by at least 0.33 ppb (equivalent to 1.5 Tg N), which, even after accounting for an overestimate of emissions in the Southern Ocean of circa 1.0 Tg N, points to a likely underestimate of the Northern Hemisphere source by up to 0.5 Tg N and/or an overestimate of STE in the Northern Hemisphere. Comparison with aircraft data reveal that the models overestimate the amplitude of the N2O seasonal cycle at Hawaii (21° N, 158° W) below circa 6000 m, suggesting an overestimate of the importance of stratosphere to troposphere transport in the lower troposphere at this latitude. In the Northern Hemisphere, most of the models that provided CFC-12 simulations captured the phase of the CFC-12, seasonal cycle, indicating a reasonable representation of the timing of STE. However, for N2O all models simulated a too early minimum by 2 to 3 months owing to errors in the seasonal cycle in the prior soil emissions, which is still not adequately represented by terrestrial biosphere models. In the Southern Hemisphere, most models failed to capture the N2O and CFC-12 seasonality at Cape Grim, Tasmania, and all failed at the South Pole, whereas for SF6, all models could capture the seasonality at all sites, suggesting that there are large errors in modeled vertical transport in high southern latitudes.

Study on Stratospheric Carbonyl Sulfide Transport and Chemistry using ‘Age of Air’

2021 ◽  
Author(s):  
Chenxi Qiu ◽  
Felix Ploeger ◽  
Jens-Uwe Grooß ◽  
Marc von Hobe
Keyword(s):  
Atmospheric Chemistry ◽  
Michelson Interferometer ◽  
Carbonyl Sulfide ◽  
Polar Vortex ◽  
Lagrangian Model ◽  
Latitude Range ◽  
Mixing Ratios ◽  
Enhanced Absorption ◽  
In Situ Data

&lt;p&gt;Carbonyl sulfide (OCS or COS) is the longest lived and the most abundant reduced sulfur gas in the atmosphere. As chemical loss of OCS in the troposphere is slow, it can reach the stratosphere, where it is &amp;#160;photochemically oxidized and converted to stratospheric sulfate aerosol, being the largest source thereof in times of volcanic quiescence. Chemistry transport models show that OCS conversion occurs mainly in the &amp;#8216;tropical pipe&amp;#8217; region, while along the lower branch of Brewer-Dobson circulation (BDC), OCS is passively transported without significant chemical loss. The OCS depleted air is transported along the upper branch of BDC and descends again at high latitudes. Using the distinct characteristics of &amp;#160;&amp;#8216;age of air&amp;#8217; in the upper and lower branches of the BDC, this picture of OCS transport and especially the role of the &amp;#8216;tropical pipe&amp;#8217; as the main region of OCS conversion can be supported by looking at the relationship between age spectra and OCS mixing ratios.&lt;/p&gt;&lt;p&gt;In this study, we will investigate the relation of OCS mixing ratios and mean age of air as well as mass fractions of air with different transit times using satellite-based measurements from MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) and ACE-FTS (Atmospheric Chemistry Experiment - infrared Fourier Transform Spectrometer), and age spectra of air from CLaMS (Chemical Lagrangian Model of the Stratosphere).&lt;/p&gt;&lt;p&gt;In addition to satellite data analysis, we will investigate the distribution of OCS in the UTLS (upper troposphere and lower stratosphere) region and its relation to the age spectra using high-resolution in-situ observations of OCS. This unique dataset was obtained during the SOUTHTRAC mission in autumn 2019 by AMICA (Airborne Mid-Infrared Cavity enhanced Absorption spectrometer) on board the HALO (High Altitude Long Range) research aircraft. Flights from the main &amp;#160;campaign base in R&amp;#237;o Grande, Argentina (53.8S, 67.7W) covered a wide latitude range from 48&amp;#176; N to 70&amp;#176; S, even reaching the southern polar vortex where aged air masses having descended from high altitudes are typically found.&lt;/p&gt;&lt;p&gt;Our analysis of both satellite and in-situ data generally supports the established picture of OCS conversion in the &amp;#8216;tropical pipe&amp;#8217;.&lt;/p&gt;

scholarly journals Tunable diode laser in-situ CH<sub>4</sub> measurements aboard the CARIBIC passenger aircraft: instrument performance assessment

2013 ◽  
Vol 6 (5) ◽  
pp. 9225-9261 ◽  
Author(s):  
C. Dyroff ◽  
A. Zahn ◽  
S. Sanati ◽  
E. Christner ◽  
A. Rauthe-Schöch ◽  
...  
Keyword(s):  
Lower Troposphere ◽  
Correlation Study ◽  
Tunable Diode Laser ◽  
Long Distance ◽  
Airborne Measurements ◽  
Mixing Ratios ◽  
Laboratory Characterization ◽  
Passenger Aircraft ◽  
The Tropics

Abstract. A laser spectrometer for automated monthly measurements of methane (CH4) mixing ratios aboard the CARIBIC passenger aircraft is presented. The instrument is based on a commercial Fast Greenhouse Gas Analyzer (FGGA, Los Gatos Res.), which was adapted to meet the requirements imposed by unattended airborne employment. The modified instrument is described. A laboratory characterization was performed to determine the instrument stability, precision, cross sensitivity to H2O, and accuracy. For airborne operation a calibration strategy is described, that utilizes CH4 measurements obtained from flask samples taken during the same flights. The precision of airborne measurements is 2 ppbv for 10 s averages. The accuracy at aircraft cruising altitude is 3.85 ppbv. During aircraft ascent and descent, where no flask samples were obtained, instrumental drifts can be less accurately considered and the uncertainty is estimated to be 12.4 ppbv. A linear humidity bias correction was applied to the CH4 measurements, which was most important in the lower troposphere. On average, the correction bias was around 6.5 ppbv at an altitude of 2 km, and negligible at cruising flight level. Observations from 103 long-distance flights are presented that span a large part of the northern hemispheric upper troposphere and lowermost stratosphere (UT/LMS), with occasional crossing of the tropics on flights to southern Africa. These accurate data mark the largest UT/LMS in-situ CH4 dataset worldwide. An example of a tracer-tracer correlation study with ozone is given, highlighting the possibility for accurate cross-tropopause transport analyses.

scholarly journals Reinitializing Sea Surface Temperature in the Ensemble Intermediate Coupled Model for Improved Forecasts

Axioms ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 189
Author(s):  
Sittisak Injan ◽  
Angkool Wangwongchai ◽  
Usa Humphries ◽  
Amir Khan ◽  
Abdullahi Yusuf
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Southern Oscillation ◽  
Coupled Model ◽  
Sea Surface ◽  
In Situ Data ◽  
The Pacific ◽  
Intermediate Coupled Model ◽  
Sea Surface Temperature Anomalies

The Ensemble Intermediate Coupled Model (EICM) is a model used for studying the El Niño-Southern Oscillation (ENSO) phenomenon in the Pacific Ocean, which is anomalies in the Sea Surface Temperature (SST) are observed. This research aims to implement Cressman to improve SST forecasts. The simulation considers two cases in this work: the control case and the Cressman initialized case. These cases are simulations using different inputs where the two inputs differ in terms of their resolution and data source. The Cressman method is used to initialize the model with an analysis product based on satellite data and in situ data such as ships, buoys, and Argo floats, with a resolution of 0.25 × 0.25 degrees. The results of this inclusion are the Cressman Initialized Ensemble Intermediate Coupled Model (CIEICM). Forecasting of the sea surface temperature anomalies was conducted using both the EICM and the CIEICM. The results show that the calculation of SST field from the CIEICM was more accurate than that from the EICM. The forecast using the CIEICM initialization with the higher-resolution satellite-based analysis at a 6-month lead time improved the root mean square deviation to 0.794 from 0.808 and the correlation coefficient to 0.630 from 0.611, compared the control model that was directly initialized with the low-resolution in-situ-based analysis.

scholarly journals Enhancements of the refractory submicron aerosol fraction in the Arctic polar vortex: feature or exception?

2014 ◽  
Vol 14 (7) ◽  
pp. 9849-9901
Author(s):  
R. Weigel ◽  
C. M. Volk ◽  
K. Kandler ◽  
E. Hösen ◽  
G. Günther ◽  
...  
Keyword(s):  
Total Mass ◽  
Lower Stratosphere ◽  
Heat Exposure ◽  
Dynamical Evolution ◽  
The Arctic ◽  
Late Winter ◽  
Air Masses ◽  
Submicron Aerosol ◽  
Mixing Ratios

Abstract. In situ measurements with a 4-channel stratospheric condensation particle counter (CPC) were conducted at up to 20 km altitude on board the aircraft M-55 Geophysica from Kiruna, Sweden, in January through March (EUPLEX 2003; RECONCILE 2010) and in December (ESSenCe, 2011). During all campaigns air masses from the upper stratosphere and mesosphere were subsiding inside the Arctic winter vortex, thus transporting refractory aerosol into the lower stratosphere (Θ<500 K) by vertical dispersion. The strength and extent of this downward transport varied between the years depending on the dynamical evolution of the vortex. Inside the vortex and at altitudes of potential temperatures Θ ≥ 450 K as many as eight of eleven particles per cm3 contained refractory material, thermally stable residuals with diameters from 10 nm to a few μm which endure heat exposure of 250 °C. Particle mixing ratios (up to 150 refractory particles per milligram of air) and fractions of non-volatile particles (up to 75% of totally detected particles) reach highest values in air masses with lowest content of nitrous oxide (N2O, down to 70 nmol mol−1). This indicates that refractory aerosol originates from the upper stratosphere or the mesosphere. From mixing ratios of the long lived tracer N2O (simultaneously measured in situ) an empirical index was derived which serves to differentiate air masses according to their origin from inside the vortex, the vortex edge region, and outside the vortex. Previously, observed high fractions of refractory submicron aerosol in the 2003 Arctic vortex were ascribed to unusually strong subsidence during that winter. Measurements under perturbed vortex conditions in 2010 and during early winter in December 2011, however, revealed similarly high values. Thus, the abundance of refractory aerosol at high levels appears to be a feature rather than the exception for the Arctic vortices. During December, the import from aloft into the lower stratosphere appears to be developing; thereafter the abundance of refractory aerosol inside the vortex reaches its highest levels until March. A measurement-based estimate of the total mass of refractory aerosol inside the vortex is provided for each campaign. Based on the derived increase of particle mass in the lower stratospheric vortex (100–67 hPa pressure altitude) on the order of 32 × 106 kg between early and late winter and assuming a mesospheric origin, we estimate the total mass of mesospheric particles deposited in the Arctic vortex and compare it to the expected atmospheric influx of meteoritic material (110 ± 55 × 103 kg per day). Such estimates at present still hold considerable uncertainties which are discussed in detail. Nevertheless, the results strongly suggest that the Arctic vortex easily achieves the drainage of all meteoric material deposited on the upper atmosphere.

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