scholarly journals Airborne lidar observations of the 2010 Eyjafjallajökull volcanic ash plume

2011 ◽  
Vol 116 ◽  
Author(s):  
Franco Marenco ◽  
Ben Johnson ◽  
Kate Turnbull ◽  
Stuart Newman ◽  
Jim Haywood ◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Airborne Lidar ◽  
Ash Plume ◽  
Lidar Observations

scholarly journals Airborne observations of the Eyjafjalla volcano ash cloud over Europe during air space closure in April and May 2010

2011 ◽  
Vol 11 (5) ◽  
pp. 2245-2279 ◽  
Author(s):  
U. Schumann ◽  
B. Weinzierl ◽  
O. Reitebuch ◽  
H. Schlager ◽  
A. Minikin ◽  
...  
Keyword(s):  
Mass Concentration ◽  
Volcanic Ash ◽  
Particle Density ◽  
Airborne Lidar ◽  
Particle Sedimentation ◽  
Space Closure ◽  
Ash Plume ◽  
Ground Based Lidar ◽  
Ash Cloud ◽  
Mass Concentrations

Abstract. Airborne lidar and in-situ measurements of aerosols and trace gases were performed in volcanic ash plumes over Europe between Southern Germany and Iceland with the Falcon aircraft during the eruption period of the Eyjafjalla volcano between 19 April and 18 May 2010. Flight planning and measurement analyses were supported by a refined Meteosat ash product and trajectory model analysis. The volcanic ash plume was observed with lidar directly over the volcano and up to a distance of 2700 km downwind, and up to 120 h plume ages. Aged ash layers were between a few 100 m to 3 km deep, occurred between 1 and 7 km altitude, and were typically 100 to 300 km wide. Particles collected by impactors had diameters up to 20 μm diameter, with size and age dependent composition. Ash mass concentrations were derived from optical particle spectrometers for a particle density of 2.6 g cm−3 and various values of the refractive index (RI, real part: 1.59; 3 values for the imaginary part: 0, 0.004 and 0.008). The mass concentrations, effective diameters and related optical properties were compared with ground-based lidar observations. Theoretical considerations of particle sedimentation constrain the particle diameters to those obtained for the lower RI values. The ash mass concentration results have an uncertainty of a factor of two. The maximum ash mass concentration encountered during the 17 flights with 34 ash plume penetrations was below 1 mg m−3. The Falcon flew in ash clouds up to about 0.8 mg m−3 for a few minutes and in an ash cloud with approximately 0.2 mg m−3 mean-concentration for about one hour without engine damage. The ash plumes were rather dry and correlated with considerable CO and SO2 increases and O3 decreases. To first order, ash concentration and SO2 mixing ratio in the plumes decreased by a factor of two within less than a day. In fresh plumes, the SO2 and CO concentration increases were correlated with the ash mass concentration. The ash plumes were often visible slantwise as faint dark layers, even for concentrations below 0.1 mg m−3. The large abundance of volatile Aitken mode particles suggests previous nucleation of sulfuric acid droplets. The effective diameters range between 0.2 and 3 μm with considerable surface and volume contributions from the Aitken and coarse mode aerosol, respectively. The distal ash mass flux on 2 May was of the order of 500 (240–1600) kg s−1. The volcano induced about 10 (2.5–50) Tg of distal ash mass and about 3 (0.6–23) Tg of SO2 during the whole eruption period. The results of the Falcon flights were used to support the responsible agencies in their decisions concerning air traffic in the presence of volcanic ash.

scholarly journals Validation of ash optical depth and layer height retrieved from passive satellite sensors using EARLINET and airborne lidar data: the case of the Eyjafjallajökull eruption

2016 ◽  
Vol 16 (9) ◽  
pp. 5705-5720 ◽  
Author(s):  
Dimitris Balis ◽  
Maria-Elissavet Koukouli ◽  
Nikolaos Siomos ◽  
Spyridon Dimopoulos ◽  
Lucia Mona ◽  
...  
Keyword(s):  
Optical Depth ◽  
Volcanic Ash ◽  
Volcanic Eruptions ◽  
Airborne Lidar ◽  
Lidar Data ◽  
Data Sets ◽  
Layer Height ◽  
Satellite Retrievals ◽  
Ash Plume ◽  
Airborne Lidar Data

Abstract. The vulnerability of the European airspace to volcanic eruptions was brought to the attention of the public and the scientific community by the 2010 eruptions of the Icelandic volcano Eyjafjallajökull. As a consequence of this event, ash concentration thresholds replaced the “zero tolerance to ash” rule, drastically changing the requirements on satellite ash retrievals. In response to that, the ESA funded several projects aiming at creating an optimal end-to-end system for volcanic ash plume monitoring and prediction. Two of them, namely the SACS-2 and SMASH projects, developed and improved dedicated satellite-derived ash plume and sulfur dioxide level assessments. The validation of volcanic ash levels and height extracted from the GOME-2 and IASI instruments on board the MetOp-A satellite is presented in this work. EARLINET lidar measurements are compared to different satellite retrievals for two eruptive episodes in April and May 2010. Comparisons were also made between satellite retrievals and aircraft lidar data obtained with the UK's BAe-146-301 Atmospheric Research Aircraft (managed by the Facility for Airborne Atmospheric Measurements, FAAM) over the United Kingdom and the surrounding regions. The validation results are promising for most satellite products and are within the estimated uncertainties of each of the comparative data sets, but more collocation scenes would be desirable to perform a comprehensive statistical analysis. The satellite estimates and the validation data sets are better correlated for high ash optical depth values, with correlation coefficients greater than 0.8. The IASI retrievals show a better agreement concerning the ash optical depth and ash layer height when compared with the ground-based and airborne lidar data.

Lidar observations of the Eyjafjallajokull volcanic ash plume at Leipzig, Germany

2010 ◽  
Author(s):  
Matthias Tesche ◽  
Albert Ansmann ◽  
Anja Hiebsch ◽  
Ina Mattis ◽  
Jörg Schmidt ◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Ash Plume ◽  
Lidar Observations

scholarly journals Validation of ash optical depth and layer height retrieved from passive satellite sensors using EARLINET and airborne lidar data: The case of the Eyjafjallajökull eruption

2016 ◽  
Author(s):  
D. Balis ◽  
M. E. Koukouli ◽  
N. Siomos ◽  
S. Dimopoulos ◽  
L. Mona ◽  
...  
Keyword(s):  
Optical Depth ◽  
Volcanic Ash ◽  
Volcanic Eruptions ◽  
Airborne Lidar ◽  
Lidar Data ◽  
Atmospheric Measurements ◽  
Layer Height ◽  
Lidar Measurements ◽  
Satellite Retrievals ◽  
Ash Plume

Abstract. The vulnerability of the European airspace to volcanic eruptions was brought to the attention of the public and the scientific community by the 2010 eruptions of the Icelandic volcano Eyjafjallajökull. As a consequence of this event ash concentration thresholds replaced the ‘zero-tolerance to ash’ rule, drastically changing the requirements on satellite ash retrievals. In response to that, ESA funded several projects aiming at creating an optimal End-to-End System for Volcanic Ash Plume Monitoring and Prediction. Two of them, namely the SACS-2 and SMASH projects, developed and improved dedicated satellite-derived ash plume and sulphur dioxide level assessments. These estimates were extensively validated using ground-based and aircraft lidar measurements. The validation of volcanic ash levels and height extracted from the GOME-2 and IASI instruments on board the MetOp-A satellite is presented in this work. EARLINET lidar measurements are compared to different satellite retrievals for two eruptive episodes in April and May 2010. Comparisons were made between satellite retrievals and aircraft lidar data obtained with UK's BAe-146-301 Atmospheric Research Aircraft (managed by the Facility for Airborne Atmospheric Measurements, FAAM) over the United Kingdom and the surrounding regions. The validation results are promising for most satellite products and are within the estimated uncertainties of each of the comparative datasets, but more collocation scenes are needed to perform a comprehensive statistical analysis. The satellite estimates and the validation data sets are better correlated for high ash optical depth values, with correlation coefficients greater than 0.8. The IASI data show a better consistency concerning the ash optical depth and ash layer height when compared with the lidar data.

scholarly journals Convective boundary layer evolution to 4 km asl over High-alpine terrain: Airborne lidar observations in the Alps

2000 ◽  
Vol 27 (5) ◽  
pp. 689-692 ◽  
Author(s):  
S. Nyeki ◽  
M. Kalberer ◽  
I. Colbeck ◽  
S. De Wekker ◽  
M. Furger ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Convective Boundary Layer ◽  
Airborne Lidar ◽  
Convective Boundary ◽  
The Alps ◽  
Lidar Observations

scholarly journals Characterizing a New England Saltmarsh with NASA G-LiHT Airborne Lidar

2019 ◽  
Vol 11 (5) ◽  
pp. 509 ◽  
Author(s):  
Ian Paynter ◽  
Crystal Schaaf ◽  
Jennifer Bowen ◽  
Linda Deegan ◽  
Francesco Peri ◽  
...  
Keyword(s):  
New England ◽  
Spartina Alterniflora ◽  
Regional Scale ◽  
Satellite Observations ◽  
Airborne Lidar ◽  
Aerial Imagery ◽  
Lidar Data ◽  
Terrestrial Lidar ◽  
Airborne Lidar Data ◽  
Lidar Observations

Airborne lidar can observe saltmarshes on a regional scale, targeting phenological and tidal states to provide the information to more effectively utilize frequent multispectral satellite observations to monitor change. Airborne lidar observations from NASA Goddard Lidar Hyperspectral and Thermal (G-LiHT) of a well-studied region of saltmarsh (Plum Island, Massachusetts, United States) were acquired in multiple years (2014, 2015 and 2016). These airborne lidar data provide characterizations of important saltmarsh components, as well as specifications for effective surveys. The invasive Phragmites australis was observed to increase in extent from 8374 m2 in 2014, to 8882 m2 in 2015 (+6.1%), and again to 13,819 m2 in 2016 (+55.6%). Validation with terrestrial lidar supported this increase, but suggested the total extent was still underestimated. Estimates of Spartina alterniflora extent from airborne lidar were within 7% of those from terrestrial lidar, but overestimation of height of Spartina alterniflora was found to occur at the edges of creeks (+83.9%). Capturing algae was found to require observations within ±15° of nadir, and capturing creek structure required observations within ±10° of nadir. In addition, 90.33% of creeks and ditches were successfully captured in the airborne lidar data (8206.3 m out of 9084.3 m found in aerial imagery).

Lidar observations of volcanic aerosol over the UK since June 2019

2020 ◽  
Author(s):  
Geraint Vaughan ◽  
David Wareing ◽  
Hugo Ricketts
Keyword(s):  
Volcanic Ash ◽  
Stratospheric Aerosol ◽  
Aerosol Layer ◽  
Raman Lidar ◽  
Lidar System ◽  
Elastic Channel ◽  
Enhanced Sensitivity ◽  
Volcanic Cloud ◽  
The Uk ◽  
Lidar Observations

<p>On 22 June 2019, the Raikoke volcano in the Kuril Islands erupted, sending a plume of ask and sulphur dioxide into the stratosphere. A Raman lidar system at Capel Dewi, UK (52.4°N, 4.1°W) has been used to measure the extent and optical depth of the stratospheric aerosol layer following the eruption. The lidar was modified to give it much enhanced sensitivity in the elastic channel, allowing measurements up to 25 km, but the Raman channel is only sensitive to the troposphere. Therefore, backscatter ratio profiles were derived by comparison with aerosol-free profiles derived from nearby radiosondes, corrected for aerosol extinction. Small amounts of stratospheric aerosol were measured prior to the arrival of the volcanic cloud, probably from pyroconvection over Canada. Volcanic ash began to arrive as a thin layer at 14 km late on 3 July, extending over the following month to fill the stratosphere below around 19 km. Aerosol optical depths reached around 0.03 by mid-August and continued at this level for the remainder of the year. The location of peak backscatter varied considerably but was generally around 15 km. However, on one notable occasion on August 25, a layer around 300 m thick with peak lidar backscatter ratio around 1.5 was observed as high as 21 km.</p>

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