A new climatology of aerosols in the middle and upper stratosphere by alternative analysis of GOMOS observations during 2002–2006

Salazar, V.; Renard, Jean‐Baptiste; Hauchecorne, Alain; Bekki, Slimane; Berthet, Gwenaël

doi:10.1080/01431161.2013.786196

Cited by 9 publications

(8 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Excluding the regions of local aerosol concentrations enhancements, the averaged retrieved values are in agreement with conventional satellite data for background conditions (e.g. SAGE and GO-MOS data, Neely et al, 2011;Salazar et al, 2013), typically of a few 10 −4 km −1 in the 20-25 km altitude range and a few 10 −5 km −1 at around 30 km. Of course, more flights will be necessary to be able to statistically compare the LOAC and satellite retrieved extinctions.…”

Section: Upper Tropospheric and Stratospheric Flightssupporting

confidence: 56%

LOAC: a small aerosol optical counter/sizer for ground-based and balloon measurements of the size distribution and nature of atmospheric particles – Part 2: First results from balloon and unmanned aerial vehicle flights

et al. 2016

Self Cite

View full text Add to dashboard Cite

Abstract. In the companion (Part I) paper, we have described and evaluated a new versatile optical particle counter/sizer named LOAC (Light Optical Aerosol Counter), based on scattering measurements at angles of 12 and 60 • . That allows for some typology identification of particles (droplets, carbonaceous, salts, and mineral dust) in addition to sizesegregated counting in a large diameter range from 0.2 µm up to possibly more than 100 µm depending on sampling conditions . Its capabilities overpass those of preceding optical particle counters (OPCs) allowing the characterization of all kind of aerosols from submicronicsized absorbing carbonaceous particles in polluted air to very coarse particles (> 10-20 µm in diameter) in desert dust plumes or fog and clouds. LOAC's light and compact design allows measurements under all kinds of balloons, on-board unmanned aerial vehicles (UAVs) and atPublished by Copernicus Publications on behalf of the European Geosciences Union. 3674J.-B. Renard et al.: LOAC: a counter/sizer for ground-based and balloon measurements -Part 2 ground level. We illustrate here the first LOAC airborne results obtained from a UAV and a variety of scientific balloons. The UAV was deployed in a peri-urban environment near Bordeaux in France. Balloon operations include (i) tethered balloons deployed in urban environments in Vienna (Austria) and Paris (France), (ii) pressurized balloons drifting in the lower troposphere over the western Mediterranean (during the Chemistry-Aerosol Mediterranean Experiment -ChArMEx campaigns), (iii) meteorological sounding balloons launched in the western Mediterranean region (ChArMEx) and from Aire-sur-l'Adour in south-western France (VOLTAIRE-LOAC campaign). More focus is put on measurements performed in the Mediterranean during (ChArMEx) and especially during African dust transport events to illustrate the original capability of balloon-borne LOAC to monitor in situ coarse mineral dust particles. In particular, LOAC has detected unexpected large particles in desert sand plumes.

show abstract

Section: Upper Tropospheric and Stratospheric Flightssupporting

confidence: 56%

LOAC: a small aerosol optical counter/sizer for ground-based and balloon measurements of the size distribution and nature of atmospheric particles – Part 2: First results from balloon and unmanned aerial vehicle flights

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although the aerosol is not well known at these altitudes, it can be expected that the natural variability is smaller there than below (see e.g. Salazar et al, 2013). Recent volcanic eruptions did not reach these heights directly, but aerosols are transported by the Brewer-Dobson circulation (BDC) up to above 30 km; see e.g.…”

Section: End-to-end Testsmentioning

confidence: 99%

UTLS water vapour from SCIAMACHY limb measurementsV3.01 (2002–2012)

et al. 2016

View full text Add to dashboard Cite

Abstract. The SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) aboard the Envisat satellite provided measurements from August 2002 until April 2012. SCIAMACHY measured the scattered or direct sunlight using different observation geometries. The limb viewing geometry allows the retrieval of water vapour at about 10-25 km height from the near-infrared spectral range (1353-1410 nm). These data cover the upper troposphere and lower stratosphere (UTLS), a region in the atmosphere which is of special interest for a variety of dynamical and chemical processes as well as for the radiative forcing. Here, the latest data version of water vapour (V3.01) from SCIAMACHY limb measurements is presented and validated by comparisons with data sets from other satellite and in situ measurements. Considering retrieval tests and the results of these comparisons, the V3.01 data are reliable from about 11 to 23 km and the best results are found in the middle of the profiles between about 14 and 20 km. Above 20 km in the extra tropics V3.01 is drier than all other data sets. Additionally, for altitudes above about 19 km, the vertical resolution of the retrieved profile is not sufficient to resolve signals with a short vertical structure like the tape recorder. Below 14 km, SCIAMACHY water vapour V3.01 is wetter than most collocated data sets, but the high variability of water vapour in the troposphere complicates the comparison. For 14-20 km height, the expected errors from the retrieval and simulations and the mean differences to collocated data sets are usually smaller than 10 % when the resolution of the SCIAMACHY data is taken into account. In general, the temporal changes agree well with collocated data sets except for the Northern Hemisphere extratropical stratosphere, where larger differences are observed. This indicates a possible drift in V3.01 most probably caused by the incomplete treatment of volcanic aerosols in the retrieval. In all other regions a good temporal stability is shown. In the tropical stratosphere an increase in water vapour is found between 2002 and 2012, which is in agreement with other satellite data sets for overlapping time periods.Published by Copernicus Publications on behalf of the European Geosciences Union.

show abstract

“…Optical instruments performing remote sensing measurements from the ground or from space with photometric, lidar, and extinction techniques (e.g. Shaw et al, 1973;Bitar et al, 2010;Winker et al, 2010;Salazar et al, 2013) provide indications on the size distribution and on the nature of the particles (liquid, carbon, minerals, ice, ...), generally assuming a priori hypotheses in the retrieval process. Complementarily, in situ optical measurements with optical particle counters can provide more accurate information on the local size distributions of the particles (Deshler et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

LOAC: a small aerosol optical counter/sizer for ground-based and balloon measurements of the size distribution and nature of atmospheric particles – Part 1: Principle of measurements and instrument evaluation

et al. 2016

Self Cite

View full text Add to dashboard Cite

Abstract. The study of aerosols in the troposphere and in the stratosphere is of major importance both for climate and air quality studies. Among the numerous instruments available, optical aerosol particles counters (OPCs) provide the size distribution in diameter range from about 100 nm to a few tens of µm. Most of them are very sensitive to the nature of aerosols, and this can result in significant biases in the retrieved size distribution. We describe here a new versatile optical particle/sizer counter named LOAC (Light Optical Aerosol Counter), which is light and compact enough to perform measurements not only at the surface but under all kinds of balloons in the troposphere and in the stratosphere. LOAC is an original OPC performing observations at two scattering angles. The first one is around 12 • , and is almost insensitive to the refractive index of the particles; the second one is around 60 • and is strongly sensitive to the refractive Published by Copernicus Publications on behalf of the European Geosciences Union. J.-B. Renard et al.: Size distribution and nature of atmospheric particlesindex of the particles. By combining measurement at the two angles, it is possible to retrieve the size distribution between 0.2 and 100 µm and to estimate the nature of the dominant particles (droplets, carbonaceous, salts and mineral particles) when the aerosol is relatively homogeneous. This typology is based on calibration charts obtained in the laboratory. The uncertainty for total concentrations measurements is ±20 % when concentrations are higher than 1 particle cm −3 (for a 10 min integration time). For lower concentrations, the uncertainty is up to about ±60 % for concentrations smaller than 10 −2 particle cm −3 . Also, the uncertainties in size calibration are ±0.025 µm for particles smaller than 0.6 µm, 5 % for particles in the 0.7-2 µm range, and 10 % for particles greater than 2 µm. The measurement accuracy of submicronic particles could be reduced in a strongly turbid case when concentration of particles > 3 µm exceeds a few particles cm −3 . Several campaigns of cross-comparison of LOAC with other particle counting instruments and remote sensing photometers have been conducted to validate both the size distribution derived by LOAC and the retrieved particle number density. The typology of the aerosols has been validated in well-defined conditions including urban pollution, desert dust episodes, sea spray, fog, and cloud. Comparison with reference aerosol mass monitoring instruments also shows that the LOAC measurements can be successfully converted to mass concentrations.

show abstract

A new climatology of aerosols in the middle and upper stratosphere by alternative analysis of GOMOS observations during 2002–2006

Cited by 9 publications

References 62 publications

LOAC: a small aerosol optical counter/sizer for ground-based and balloon measurements of the size distribution and nature of atmospheric particles – Part 2: First results from balloon and unmanned aerial vehicle flights

LOAC: a small aerosol optical counter/sizer for ground-based and balloon measurements of the size distribution and nature of atmospheric particles – Part 2: First results from balloon and unmanned aerial vehicle flights

UTLS water vapour from SCIAMACHY limb measurementsV3.01 (2002–2012)

LOAC: a small aerosol optical counter/sizer for ground-based and balloon measurements of the size distribution and nature of atmospheric particles – Part 1: Principle of measurements and instrument evaluation

Contact Info

Product

Resources

About