scholarly journals In Situ, Rotor-Based Drone Measurement of Wind Vector and Aerosol Concentration in Volcanic Areas

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 376
Author(s):  
Kansuke Sasaki ◽  
Minoru Inoue ◽  
Tomoya Shimura ◽  
Masato Iguchi

Unmanned aerial vehicles (UAVs), represented by rotor-based drones, are suitable for volcanic observations owing to the advantages of mobility and safety. In this study, vertical profiles of wind and aerosol concentrations at altitudes up to 1000 m around Mt. Sakurajima, one of the most active volcanoes in Japan, were measured in situ using a drone equipped with an ultrasonic anemometer and aerosol sensor. The drone-measured wind profiles were compared with Doppler LiDAR data and analysis values derived from a meteorological model. Drone-measured vertical profiles collected at a vertical speed of 1 m·s−1 (upward and downward) showed strong agreement with the LiDAR observations, as did the averaged values of hovering drone measurements. Obvious vertical wind shear was found by the drone in the vicinity of Mt. Sakurajima. An aerosol sensor was installed on the drone with the capability to measure fine (PM2.5) and coarse particles (PM10) simultaneously; in this manner, volcanic ash and aerosol pollutants around the volcano could be distinguished. Thus, it was proven that drones could be applied to investigate wind conditions and aerosols in situ, even at dangerous locations near active volcanoes.

2015 ◽  
Vol 15 (12) ◽  
pp. 7085-7102 ◽  
Author(s):  
N. L. Wagner ◽  
C. A. Brock ◽  
W. M. Angevine ◽  
A. Beyersdorf ◽  
P. Campuzano-Jost ◽  
...  

Abstract. Vertical profiles of submicron aerosol from in situ aircraft-based measurements were used to construct aggregate profiles of chemical, microphysical, and optical properties. These vertical profiles were collected over the southeastern United States (SEUS) during the summer of 2013 as part of two separate field studies: the Southeast Nexus (SENEX) study and the Study of Emissions and Atmospheric Composition, Clouds, and Climate Coupling by Regional Surveys (SEAC4RS). Shallow cumulus convection was observed during many profiles. These conditions enhance vertical transport of trace gases and aerosol and create a cloudy transition layer on top of the sub-cloud mixed layer. The trace gas and aerosol concentrations in the transition layer were modeled as a mixture with contributions from the mixed layer below and the free troposphere above. The amount of vertical mixing, or entrainment of air from the free troposphere, was quantified using the observed mixing ratio of carbon monoxide (CO). Although the median aerosol mass, extinction, and volume decreased with altitude in the transition layer, they were ~10 % larger than expected from vertical mixing alone. This enhancement was likely due to secondary aerosol formation in the transition layer. Although the transition layer enhancements of the particulate sulfate and organic aerosol (OA) were both similar in magnitude, only the enhancement of sulfate was statistically significant. The column integrated extinction, or aerosol optical depth (AOD), was calculated for each individual profile, and the transition layer enhancement of extinction typically contributed less than 10 % to the total AOD. Our measurements and analysis were motivated by two recent studies that have hypothesized an enhanced layer of secondary aerosol aloft to explain the summertime enhancement of AOD (2–3 times greater than winter) over the southeastern United States. The first study attributes the layer aloft to secondary organic aerosol (SOA) while the second study speculates that the layer aloft could be SOA or secondary particulate sulfate. In contrast to these hypotheses, the modest enhancement we observed in the transition layer was not dominated by OA and was not a large fraction of the summertime AOD.


2017 ◽  
Vol 68 (4) ◽  
pp. 873-878
Author(s):  
Alexandru Dandocsi ◽  
Anca Nemuc ◽  
Cristina Marin ◽  
Simona Andrei

An intensive measurement campaign was performed during September 2014 in southern Romania in two different locations: Magurele, Ilfov County and Turceni, Gorj County. This paper presents one case study with analysis of the aerosol properties from in-situ, passive remote sensing and active remote sensing measurements. A Multiwavelength Raman Lidar (RALI) provided one hour averaged vertical profiles of extinction and backscatter from the 532 nm and 1064 nm channels in Magurele. The UV scanning Lidar (MILI) provided one hour averaged backscattered and extinction vertical profiles for Turceni. Planetary Boundary Layer Height (PBLH) was calculated using the altitude of the maximum negative gradient of the range corrected signal. Mass concentrations for different aerosol species (organics, nitrate, sulphate, ammonium and chloride) were obtained from in-situ measurements using Aerosol Mass Spectrometer located in M�gurele and Aerosol Chemical Speciation Monitor (ACSM) located in Turceni.


Author(s):  
Abdullah Ali ◽  
Riris Adrianto ◽  
Miming Saepudin

One of the weather phenomena that potentially cause extreme weather conditions is the linear-shaped mesoscale convective systems, including squall lines. The phenomenon that can be categorized as a squall line is a convective cloud pair with the linear pattern of more than 100 km length and 6 hours lifetime. The new theory explained that the cloud system with the same morphology as squall line without longevity threshold. Such a cloud system is so-called Quasi-Linear Convective System (QLCS), which strongly influenced by the ambient dynamic processes, include horizontal and vertical wind profiles. This research is intended as a preliminary study for horizontal and vertical wind profiles of QLCS developed over the Western Java region utilizing Doppler weather radar. The following parameters were analyzed in this research, include direction pattern and spatial-temporal significance of wind speed, divergence profile, vertical wind shear (VWS) direction, and intensity profiles, and vertical velocity profile. The subjective and objective analysis was applied to explain the characteristics and effects of those parameters to the orientation of propagation, relative direction, and speed of the cloud system’s movement, and the lifetime of the system. Analysis results showed that the movement of the system was affected by wind direction and velocity patterns. The divergence profile combined with the vertical velocity profile represents the inflow which can supply water vapor for QLCS convective cloud cluster. Vertical wind shear that effect QLCS system is only its direction relative to the QLCS propagation, while the intensity didn’t have a significant effect.


2009 ◽  
Vol 24 (1) ◽  
pp. 223-244 ◽  
Author(s):  
Adam K. Baker ◽  
Matthew D. Parker ◽  
Matthew D. Eastin

Abstract Hurricane Ivan (2004) was a prolific producer of tornadoes as it made landfall on the U.S. Gulf Coast. Prior researchers have revealed that the tornadic cells within tropical cyclone (TC) rainbands are often supercellular in character. The present study investigates the utility of several common midlatitude, continental supercell and tornado diagnostic tools when applied to Hurricane Ivan’s tornado episode. The environment within Hurricane Ivan was favorable for storm rotation. While well offshore, the bands of Hurricane Ivan possessed embedded cells with mesocyclones of moderate intensity. A dual-Doppler analysis reveals that the updrafts of these cells were highly helical in the lower troposphere, suggesting significant ingestion of streamwise environmental vorticity. These coherent cells were long lived and could be tracked for multiple hours. As the supercells over the Gulf of Mexico approached the coast during Ivan’s landfall, rapid increases in midlevel vorticity and vertically integrated liquid (VIL) occurred. Based on compiled severe weather reports, these increases in storm intensity appear often to have immediately preceded tornadogenesis. The local environment for supercells in Ivan’s interior is evaluated through the use of 62 soundings from the operational land-based network and from research flights. There were substantial differences in the thermodynamic profiles and wind profiles at differing ranges from Ivan’s center, from quadrant to quadrant of Ivan’s circulation, and between land and sea. The most optimal environment for supercells and tornadoes occurred in the most interior section of Ivan’s right-front quadrant, with conditions being even more favorable over land than over the sea. For contrast, comparable values are presented for Hurricane Jeanne (2004), which was similar to Ivan in several respects, but was not a prolific tornado producer at landfall. Although both storms provided environments with comparable shallow—and deep—layer vertical wind shear, the Ivan environment had notably more CAPE, likely due to a prominent dry air intrusion. This increase in CAPE was reflected in substantial increases in common operational forecasting composite indices. The results suggest that the conventionally assessed ingredients for midlatitude continental supercells and tornadoes can be readily applied to discriminate among TC tornado episodes.


2021 ◽  
Author(s):  
Noel Baker ◽  
Michel Anciaux ◽  
Philippe Demoulin ◽  
Didier Fussen ◽  
Didier Pieroux ◽  
...  

<p>Led by the Belgian Institute for Space Aeronomy, the ESA-backed mission PICASSO (PICo-Satellite for Atmospheric and Space Science Observations) successfully launched its gold-plated satellite on an Arianespace Vega rocket in September 2020. PICASSO is a 3U CubeSat mission in collaboration with VTT Technical Research Center of Finland Ltd, AAC Clyde Space Ltd. (UK), and the CSL (Centre Spatial de Liège), Belgium. The commissioning of the two onboard scientific instruments is currently ongoing; once they are operational, PICASSO will be capable of providing scientific measurements of the Earth’s atmosphere. VISION, proposed by BISA and developed by VTT, will retrieve vertical profiles of ozone and temperature by observing the Earth's atmospheric limb during orbital Sun occultation; and SLP, developed by BISA, will measure in situ plasma density and electron temperature together with the spacecraft potential.</p><p>Serving as a groundbreaking proof-of-concept, the PICASSO mission has taught valuable lessons about the advantages of CubeSat technology as well as its many complexities and challenges. These lessons learned, along with preliminary measurements from the two instruments, will be presented and discussed.</p>


2021 ◽  
Author(s):  
Susan Kizer ◽  
David Flittner ◽  
Marilee Roell ◽  
Robert Damadeo ◽  
Carrie Roller ◽  
...  

<p>The Stratospheric Aerosol and Gas Experiment III (SAGE III) instrument installed on the International Space Station (ISS) has completed over three and a half years of data collection and production of science data products. The SAGE III/ISS is a solar and lunar occultation instrument that scans the light from the Sun and Moon through the limb of the Earth’s atmosphere to produce vertical profiles of aerosol, ozone, water vapor, and other trace gases. It continues the legacy of previous SAGE instruments dating back to the 1970s to provide data continuity of stratospheric constituents critical for assessing trends in the ozone layer. This presentation shows the validation results of comparing SAGE III/ISS ozone and water vapor vertical profiles from the newly released v5.2 science product with those of in situ and satellite data .</p>


2021 ◽  
Author(s):  
Manuela Lehner ◽  
Mathias W. Rotach

<p>The stable boundary layer is typically characterized by weak and sometimes intermittent turbulence, particularly under very stable conditions. In mountain valleys, nocturnal temperature inversions and cold-air pools form frequently under synoptically undisturbed and clear-sky conditions, which will dampen turbulence. On the other hand, thermally driven slope and valley winds form under the same conditions, which interact with each other and are both characterized by jet-like wind profiles, thus resulting in both horizontal and vertical wind shear, which creates a persistent source for turbulence production. Data will be presented from six flux towers in the Austrian Inn Valley, which are part of the i-Box measurement platform, designed to study near-surface turbulence in complex, mountainous terrain. The six sites are located within an approximately 6.5-km long section of the 2-3-km wide valley approximately 20 km east of Innsbruck. The data are analyzed to characterize the strength and intermittency of turbulence kinetic energy and turbulent fluxes across the valley and to determine whether the persistent wind shear associated with thermally driven flows is sufficient to generate continuous turbulence.</p>


2021 ◽  
Author(s):  
Pasquale Sellitto ◽  
Giuseppe Salerno ◽  
Simona Scollo ◽  
Alcide Giorgio di Sarra ◽  
Antonella Boselli ◽  
...  

<p>The EPL-RADIO (Etna Plume Lab - Radioactive Aerosols and other source parameters for better atmospheric Dispersion and Impact estimatiOns) and EPL-REFLECT (near-source estimations of Radiative EFfects of voLcanic aErosols for Climate and air quality sTudies) projects, funded by the EC Horizon2020 ENVRIplus and EUROVOLC Transnational Access to European Observatories programmes, aim to advance the understanding of Mount Etna as a persistent source of atmospheric aerosols and its impact on the  radiative budget at proximal to regional spatial scales. Research was tackled by carrying out three campaigns in the summers of 2016, 2017 and 2019 to observe the volcanic plume produced by passive degassing, proximally and distally from the summit craters, using a wide array of remote sensing and in situ instruments. Diverse data are collected to explore the link of inner degassing mechanisms to the characterisation of near-source aerosol physicochemical properties and subsequent impacts on the atmosphere, environment and regional climate system.</p><p>The results of the three campaigns have shown that the volcanic plume emitted by Mount Etna often mixes with aerosols of different origins generating a complex layered pattern. Frequent mineral dust transport events were observed by both LiDAR observations located at Serra La Nave (~7 km south-west from summit craters) and at a medium-term radiometric station, equipped with a Multi-Filter Rotating Shadowband Radiometer (MFRSR), and other instruments located at Milo (~10 km eastwards from the craters). LiDAR observations also allowed to study the coexistence of volcanic aerosols and biomass burning particles from local to more distal smoke plumes transports (like for the well-documented large fires from continental southern Italy in July 2017). In situ filter and optical particles counter measurements confirmed the presence of dust at Milo. The interaction/mixing among volcanic, wildfire, and dust aerosols occurs in an overall dynamical regime which appears to be dominated by sea breeze, which is strengthened by the presence of the dark volcanic lava flanks. Photolysis process also possibly play a role in determining the daily evolution of the aerosol plume.</p><p>The sources of these different aerosol types are studied in detail using Lagrangian trajectories and meteorological data. Off-line radiative transfer calculations, using EPL-RADIO/REFLECT observations as input data, are used to estimate the relative radiative impact of the different aerosol types with respect to the background passive-degassing aerosols coming from Mount Etna.</p>


2016 ◽  
Vol 9 (9) ◽  
pp. 4269-4278 ◽  
Author(s):  
Moritz Haarig ◽  
Ronny Engelmann ◽  
Albert Ansmann ◽  
Igor Veselovskii ◽  
David N. Whiteman ◽  
...  

Abstract. For the first time, vertical profiles of the 1064 nm particle extinction coefficient obtained from Raman lidar observations at 1058 nm (nitrogen and oxygen rotational Raman backscatter) are presented. We applied the new technique in the framework of test measurements and performed several cirrus observations of particle backscatter and extinction coefficients, and corresponding extinction-to-backscatter ratios at the wavelengths of 355, 532, and 1064 nm. The cirrus backscatter coefficients were found to be equal for all three wavelengths keeping the retrieval uncertainties in mind. The multiple-scattering-corrected cirrus extinction coefficients at 355 nm were on average about 20–30 % lower than the ones for 532 and 1064 nm. The cirrus-mean extinction-to-backscatter ratio (lidar ratio) was 31 ± 5 sr (355 nm), 36 ± 5 sr (532 nm), and 38 ± 5 sr (1064 nm) in this single study. We further discussed the requirements needed to obtain aerosol extinction profiles in the lower troposphere at 1064 nm with good accuracy (20 % relative uncertainty) and appropriate temporal and vertical resolution.


2020 ◽  
Vol 12 (9) ◽  
pp. 1532
Author(s):  
Seon Ki Park ◽  
Sojung Park

A flood-producing heavy rainfall event occurred at the mountainous coastal region in the northeast of South Korea on 5–6 August 2018, subsequent to extreme heat waves, through a quasi-stationary mesoscale convective system (MCS). We analyzed the storm environment via a multi-data approach using high-resolution (1-km) simulations from the Weather Research and Forecasting (WRF) and in situ/satellite/radar observations. The brightness temperature, from the Advanced Himawari Imager water vapor band, and the composite radar reflectivity were used to identify characteristics of the MCS and associated precipitations. The following factors affected this back-building MCS: low-level convergence by the Korea easterlies (Kor’easterlies), carrying moist air into the coast; strong vertical wind shear, making the updraft tilted and sustained; coastal fronts and back-building convection bands, formed through interactions among the Kor’easterlies, cold pool outflows, and orography; mid-level advection of cold air and positive relative vorticity, enhancing vertical convection and potential instability; and vigorous updraft releasing potential instability. The pre-storm synoptic environment provided favorable conditions for storm development such as high moisture and temperature over the coastal area and adjacent sea, and enhancement of the Kor’easterlies by expansion of a surface high pressure system. Upper-level north-northwesterly winds prompted the MCS to propagate south-southeastward along the coastline.


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