Optical extinction properties of volcanic stratospheric aerosol derived from ground-based lidar and Sun photometer measurements

1998 ◽  
Vol 103 (D12) ◽  
pp. 13893-13902 ◽  
Author(s):  
Fernando Congeduti ◽  
John DeLuisi ◽  
Thomas DeFoor ◽  
Larry Thomason
Keyword(s):  
Stratospheric Aerosol ◽  
Optical Extinction ◽  
Sun Photometer ◽  
Ground Based Lidar

scholarly journals Estimating surface visibility at Hong Kong from ground-based LIDAR, sun photometer and operational MODIS products

2013 ◽  
Vol 63 (9) ◽  
pp. 1098-1110 ◽  
Author(s):  
Muhammad I. Shahzad ◽  
Janet E. Nichol ◽  
Jun Wang ◽  
James R. Campbell ◽  
Pak W. Chan
Keyword(s):  
Hong Kong ◽  
Sun Photometer ◽  
Ground Based Lidar

scholarly journals Interactions of meteoric smoke particles with sulphuric acid in the Earth's stratosphere

2012 ◽  
Vol 12 (1) ◽  
pp. 1553-1584
Author(s):  
R. W. Saunders ◽  
S. Dhomse ◽  
W. S. Tian ◽  
M. P. Chipperfield ◽  
J. M. C. Plane
Keyword(s):  
Sulphuric Acid ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Magnesium Silicate ◽  
Stratospheric Aerosol ◽  
Solution Viscosity ◽  
Time Resolved ◽  
Optical Extinction ◽  
Smoke Particles ◽  
Meteoric Smoke

Abstract. Nano-sized meteoric smoke particles (MSPs) with iron-magnesium silicate compositions, formed in the upper mesosphere as a result of meteoric ablation, may remove sulphuric acid from the gas-phase above 40 km and may also affect the composition and behaviour of supercooled H2SO4-H2O droplets in the global stratospheric aerosol (Junge) layer. This study describes a time-resolved spectroscopic analysis of the evolution of the ferric (Fe3+) ion originating from amorphous ferrous (Fe2+)-based silicate powders dissolved in varying Wt % sulphuric acid (30–75%) solutions over a temperature range of 223–295 K. Complete dissolution of the particles was observed under all conditions. The first-order rate coefficient for dissolution decreases at higher Wt % and lower temperature, which is consistent with the increased solution viscosity limiting diffusion of H2SO4 to the particle surfaces. Dissolution under stratospheric conditions should take less than a week, and is much faster than the dissolution of crystalline Fe2+ compounds. The chemistry climate model UMSLIMCAT (based on the UKMO Unified Model) was then used to study the transport of MSPs through the middle atmosphere. A series of model experiments were performed with different uptake coefficients. Setting the concentration of 1.5 nm radius MSPs at 80 km to 3000 cm−3 (based on rocket-borne charged particle measurements), the model matches the reported Wt % Fe values of 0.5–1.0 in Junge layer sulphate particles, and the MSP optical extinction between 40 and 75 km measured by a satellite-borne spectrometer, if the global meteoric input rate is about 20 t d−1. The model indicates that an uptake coefficient ≥0.01 is required to account for the observed two orders of magnitude depletion of H2SO4 vapour above 40 km.

scholarly journals Geophysical validation of SCIAMACHY Limb Ozone Profiles

2005 ◽  
Vol 5 (4) ◽  
pp. 4893-4928 ◽  
Author(s):  
E. J. Brinksma ◽  
A. Bracher ◽  
D. E. Lolkema ◽  
A. J. Segers ◽  
I. S. Boyd ◽  
...  
Keyword(s):  
Stratospheric Aerosol ◽  
Average Difference ◽  
Profile Data ◽  
Pointing Errors ◽  
Ozone Profile ◽  
Ground Based Lidar ◽  
Constant Altitude ◽  
The University ◽  
Zigzag Shape

Abstract. We discuss the quality of the two available SCIAMACHY limb ozone profile products. They were retrieved with the University of Bremen IFE's algorithm version 1.61 (hereafter IFE), and the official ESA offline algorithm (hereafter OL) versions 2.4 and 2.5. The ozone profiles were compared to a suite of correlative measurements from ground-based lidar and microwave, sondes, SAGE II and SAGE III (Stratospheric Aerosol and Gas Experiment). To correct for the expected Envisat pointing errors, which have not been corrected implicitly in either of the algorithms, we applied a constant altitude shift of −1.5 km to the SCIAMACHY ozone profiles. The IFE ozone profile data between 16 and 40 km are biased low by 3–6%. The average difference profiles show a characteristic zigzag shape with a wavelength of approximately 8 km. The standard deviation of the differences is typically 10% between 20 and 35 km. We show that more than 20% of the SCIAMACHY official ESA offline (OL) ozone profiles version 2.4 and 2.5 have unrealistic ozone values, most of these are north of 15° S. The remaining OL profiles compare well to correlative instruments above 24 km. Between 20 and 24 km, they underestimate ozone by 15±5%.

scholarly journals Error budget analysis of SCIAMACHY limb ozone profile retrievals using the SCIATRAN model

2013 ◽  
Vol 6 (10) ◽  
pp. 2825-2837 ◽  
Author(s):  
N. Rahpoe ◽  
C. von Savigny ◽  
M. Weber ◽  
A.V. Rozanov ◽  
H. Bovensmann ◽  
...  
Keyword(s):  
Systematic Errors ◽  
Stratospheric Aerosol ◽  
Transfer Model ◽  
Parameter Uncertainties ◽  
Optical Extinction ◽  
Budget Analysis ◽  
Error Characterization ◽  
Aerosol Optical Extinction ◽  
Scanning Imaging ◽  
Instrument Intercomparison

Abstract. A comprehensive error characterization of SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY) limb ozone profiles has been established based upon SCIATRAN transfer model simulations. The study was carried out in order to evaluate the possible impact of parameter uncertainties, e.g. in albedo, stratospheric aerosol optical extinction, temperature, pressure, pointing, and ozone absorption cross section on the limb ozone retrieval. Together with the a posteriori covariance matrix available from the retrieval, total random and systematic errors are defined for SCIAMACHY ozone profiles. Main error sources are the pointing errors, errors in the knowledge of stratospheric aerosol parameters, and cloud interference. Systematic errors are of the order of 7%, while the random error amounts to 10–15% for most of the stratosphere. These numbers can be used for the interpretation of instrument intercomparison and validation of the SCIAMACHY V 2.5 limb ozone profiles in a rigorous manner.

scholarly journals Contrails to Cirrus—Morphology, Microphysics, and Radiative Properties

2006 ◽  
Vol 45 (1) ◽  
pp. 5-19 ◽  
Author(s):  
David Atlas ◽  
Zhien Wang ◽  
David P. Duda
Keyword(s):  
Satellite Image ◽  
Radiative Properties ◽  
Time Of Arrival ◽  
Regional Warming ◽  
Optical Extinction ◽  
Essentially Normal ◽  
Minimum Age ◽  
Ground Based Lidar ◽  
Time Of Travel ◽  
Ice Water

Abstract This work is two pronged, discussing 1) the morphology of contrails and their transition to cirrus uncinus, and 2) their microphysical and radiative properties. It is based upon the fortuitous occurrence of an unusual set of essentially parallel contrails and the unanticipated availability of nearly simultaneous observations by photography, satellite, automated ground-based lidar, and a newly available database of aircraft flight tracks. The contrails, oriented from the northeast to southwest, are carried to the southeast with a component of the wind so that they are spread from the northwest to southeast. Convective turrets form along each contrail to form the cirrus uncinus with fallstreaks of ice crystals that are oriented essentially normal to the contrail length. Each contrail is observed sequentially by the lidar and tracked backward to the time and position of the originating aircraft track with the appropriate component of the wind. The correlation coefficient between predicted and actual time of arrival at the lidar is 0.99, so that one may identify both visually and satellite-observed contrails exactly. Contrails generated earlier in the westernmost flight corridor occasionally arrive simultaneously with those formed later closer to the lidar to produce broader cirrus fallstreaks and overlapping contrails on the satellite image. The minimum age of a contrail is >2 h and corresponds to the longest time of travel to the lidar. The lag between the initial formation of the contrail and its first detectability by Moderate-Resolution Imaging Spectroradiometer (MODIS) is ≈33 min, thus accounting for the distance between the aircraft track and the first detectable contrail by satellite. The lidar also provides particle fall speeds and estimated sizes, optical extinction coefficients, optical thickness (τ = 0.35), and ice water path (IWP = 8.1 g m−2). These values correspond to the lower range of those found for midlatitude cirrus by Heymsfield et al. The ice water per meter of length along the cloud lines is 103–104 times that released by typical jet aircraft. The synthesis of these findings with those of prior investigators provides confidence in the present results. Various authors find that contrail-generated cirrus such as reported here contribute to net regional warming.

scholarly journals Australian Lidar Measurements of Aerosol Layers Associated with the 2015 Calbuco Eruption

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 124
Author(s):  
Andrew R. Klekociuk ◽  
David J. Ottaway ◽  
Andrew D. MacKinnon ◽  
Iain M. Reid ◽  
Liam V. Twigger ◽  
...  
Keyword(s):  
Vertical Motion ◽  
Stratospheric Aerosol ◽  
Spatial Inhomogeneity ◽  
Volcanic Plume ◽  
Orthogonal Polarization ◽  
Aerosol Layer ◽  
Lidar Measurements ◽  
The Mean ◽  
Volcanic Aerosols ◽  
Ground Based Lidar

The Calbuco volcano in southern Chile (41.3° S, 72.6° W) underwent three separate eruptions on 22–23 April 2015. Following the eruptions, distinct layers of enhanced lidar backscatter at 532 nm were observed in the lower stratosphere above Buckland Park, South Australia (34.6° S, 138.5° E), and Kingston, Tasmania (43.0° S, 147.3° E), during a small set of observations in April–May 2015. Using atmospheric trajectory modelling and measurements from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) space-borne lidar and the Ozone Mapping Profiler Suite (OMPS) instrument on the Suomi National Polar-orbiting Partnership (NPP) satellite, we show that these layers were associated with the Calbuco eruptions. Buckland Park measurements on 30 April and 3 May detected discrete aerosol layers at and slightly above the tropopause, where the relative humidity was well below saturation. Stratospheric aerosol layers likely associated with the eruptions were observed at Kingston on 17 and 22 May in narrow discrete layers accompanied by weaker and more vertically extended backscatter. The measurements on 22 May provided a mean value of the particle linear depolarisation ratio within the main observed volcanic aerosol layer of 18.0 ± 3.0%, which was consistent with contemporaneous CALIOP measurements. The depolarisation measurements indicated that this layer consisted of a filament dominated by ash backscatter residing above a main region having likely more sulfate backscatter. Layer-average optical depths were estimated from the measurements. The mean lidar ratio for the volcanic aerosols on 22 May of 86 ± 37 sr is consistent with but generally higher than the mean for ground-based measurements for other volcanic events. The inferred optical depth for the main volcanic layer on 17 May was consistent with a value obtained from OMPS measurements, but a large difference on 22 May likely reflected the spatial inhomogeneity of the volcanic plume. Short-lived enhancements of backscatter near the tropopause of 17 May likely represented the formation cirrus that was aided by the presence of associated volcanic aerosols. We also provide evidence that gravity waves potentially influenced the layers, particularly in regard to the vertical motion observed in the strong layer on 22 May. Overall, these observations provide additional information on the dispersal and characteristics of the Calbuco aerosol plumes at higher southern latitudes than previously reported for ground-based lidar measurements.

scholarly journals Variability and evolution of the midlatitude stratospheric aerosol budget from 22 years of ground-based lidar and satellite observations

2017 ◽  
Vol 17 (3) ◽  
pp. 1829-1845 ◽  
Author(s):  
Sergey M. Khaykin ◽  
Sophie Godin-Beekmann ◽  
Philippe Keckhut ◽  
Alain Hauchecorne ◽  
Julien Jumelet ◽  
...  
Keyword(s):  
Asian Monsoon ◽  
Infrared Imaging ◽  
Imaging System ◽  
Late Summer ◽  
Stratospheric Aerosol ◽  
Atmospheric Composition ◽  
Orthogonal Polarization ◽  
Asian Monsoon Region ◽  
Lidar Measurements ◽  
Ground Based Lidar

Abstract. The article presents new high-quality continuous stratospheric aerosol observations spanning 1994–2015 at the French Observatoire de Haute-Provence (OHP, 44° N, 6° E) obtained by two independent, regularly maintained lidar systems operating within the Network for Detection of Atmospheric Composition Change (NDACC). Lidar series are compared with global-coverage observations by Stratospheric Aerosol and Gas Experiment (SAGE II), Global Ozone Monitoring by Occultation of Stars (GOMOS), Optical Spectrograph and InfraRed Imaging System (OSIRIS), Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), and Ozone Mapping Profiling Suite (OMPS) satellite instruments, altogether covering the time span of OHP lidar measurements. Local OHP and zonal-mean satellite series of stratospheric aerosol optical depth are in excellent agreement, allowing for accurate characterization of stratospheric aerosol evolution and variability at northern midlatitudes during the last 2 decades. The combination of local and global observations is used for a careful separation between volcanically perturbed and quiescent periods. While the volcanic signatures dominate the stratospheric aerosol record, the background aerosol abundance is found to be modulated remotely by the poleward transport of convectively cleansed air from the deep tropics and aerosol-laden air from the Asian monsoon region. The annual cycle of background aerosol at midlatitudes, featuring a minimum during late spring and a maximum during late summer, correlates with that of water vapor from the Aura Microwave Limb Sounder (MLS). Observations covering two volcanically quiescent periods over the last 2 decades provide an indication of a growth in the nonvolcanic component of stratospheric aerosol. A statistically significant factor of 2 increase in nonvolcanic aerosol since 1998, seasonally restricted to late summer and fall, is associated with the influence of the Asian monsoon and growing pollution therein.

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