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1.
Remote sensing instruments have been used to identify, track and in some cases quantify atmospheric constituents from space-borne platforms for nearly 30 years. These data have proven to be extremely useful for detecting hazardous ash and gas (principally SO2) clouds emitted by volcanoes and which have the potential to intersect global air routes. The remoteness of volcanoes, the sporadic timings of eruptions and the ability of the upper atmosphere winds to quickly spread ash and gas, make satellite remote sensing a key tool for developing hazard warning systems. It is easily recognized how powerful these tools are for hazard detection and yet there has not been a single instrument designed specifically for this use. Instead, researchers have had to make use of instruments and data designed for other purposes. In this article the satellite instruments, algorithms and techniques used for ash and gas detection are described from a historical perspective with a view to elucidating their value and shortcomings. Volcanic clouds residing in the mid- to upper-troposphere (heights above 5 km) have the greatest potential of intersecting air routes and can be dispersed over many 1,000s of kilometres by the prevailing winds. Global air traffic vulnerability to the threat posed by volcanic clouds is then considered from the perspectives of satellite remote sensing, the upper troposphere mean wind circulation, and current and forecast air traffic density based on an up-to-date aircraft emissions inventory. It is concluded that aviation in the Asia Pacific region will be increasingly vulnerable to volcanic cloud encounters because of the large number of active volcanoes in the region and the increasing growth rate of air traffic in that region. It is also noted that should high-speed civil transport (HSCT) aircraft become operational, there will be an increased risk to volcanic debris that is far from its source location. This vulnerability is highlighted using air traffic density maps based on NOx emissions and satellite SO2 observations of the spread of volcanic clouds.  相似文献   

2.
Olshansky  Robert  Xiao  Yu  Abramson  Daniel 《Natural Hazards》2020,101(1):1-38

Identifying the spatial extent of volcanic ash clouds in the atmosphere and forecasting their direction and speed of movement has important implications for the safety of the aviation industry, community preparedness and disaster response at ground level. Nine regional Volcanic Ash Advisory Centres were established worldwide to detect, track and forecast the movement of volcanic ash clouds and provide advice to en route aircraft and other aviation assets potentially exposed to the hazards of volcanic ash. In the absence of timely ground observations, an ability to promptly detect the presence and distribution of volcanic ash generated by an eruption and predict the spatial and temporal dispersion of the resulting volcanic cloud is critical. This process relies greatly on the heavily manual task of monitoring remotely sensed satellite imagery and estimating the eruption source parameters (e.g. mass loading and plume height) needed to run dispersion models. An approach for automating the quick and efficient processing of next generation satellite imagery (big data) as it is generated, for the presence of volcanic clouds, without any constraint on the meteorological conditions, (i.e. obscuration by meteorological cloud) would be an asset to efforts in this space. An automated statistics and physics-based algorithm, the Automated Probabilistic Eruption Surveillance algorithm is presented here for auto-detecting volcanic clouds in satellite imagery and distinguishing them from meteorological cloud in near real time. Coupled with a gravity current model of early cloud growth, which uses the area of the volcanic cloud as the basis for mass measurements, the mass flux of particles into the volcanic cloud is estimated as a function of time, thus quantitatively characterising the evolution of the eruption, and allowing for rapid estimation of source parameters used in volcanic ash transport and dispersion models.

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3.
Over the last 40 years, there have been numerous volcanic eruptions across the North Pacific (NOPAC) region that posed a potential threat to both local communities and transcontinental aircraft. The ability to detect these volcanic clouds using satellite remote sensing and predict their movement by dispersion modeling is a major component of hazard mitigation. The Puff volcanic ash transport and dispersion model, used by the Alaska Volcano Observatory, was used to illustrate the impact that these volcanic ash clouds have made across the NOPAC and entire Polar region over the past 40 years. Nearly, 400 separate ash clouds were analyzed that were either reported or detected to have reached above 6 km (20,000 ft) above sea level, an average of one ash cloud every 1.25 months. Particular events showed that ash clouds can be tracked from Alaska to Greenland (Crater Peak, Mount Spurr in 1992), from Kamchatka to Alaska (Kluvicheskoi Volcano in 1994), from Alaska to California (Mount Cleveland Volcano in 2001) and from multiple events within 1 day (Mount Augustine Volcano in 2006). This study showed the vast number of events that have impacted this Polar region and how tracking them is useful for hazard mitigation.  相似文献   

4.
基于FY-3A遥感数据的冰岛火山灰云识别   总被引：1，自引：0，他引：1  
赵谊  梁跃  马宝君  李永生  武晓军 《岩石学报》2014,30(12):3693-3700
2010年4月至5月期间冰岛艾雅法拉火山喷发造成了欧洲航空业史无前例的瘫痪以及巨大的经济损失,其严重影响再次显示,对火山灰云进行有效监测的重要性。火山灰云是由火山碎屑物及气体组成的混合物,火山碎屑物主要由直径小于2mm的岩石、矿物、火山玻璃碎片组成,火山灰云中的气体主要包括水汽、CO2、SO2、H2S、CH4、CO、HCL、HF、HBr、和NOx等。使用具有我国自主知识产权的FY-3A/VIRR数据,对此次艾雅法拉火山喷发的不同阶段选取具有典型风向变化的日期,采用分裂窗亮温差算法(SWTD)、RGB真彩色方法、中红外波段数据等进行火山灰云的识别,并将结果与冰岛地区的火山灰监测报告以及前人的研究结果进行对比研究,结果表明:火山喷发初期火山灰云中较高含量的水汽会补偿反面吸收的影响,妨碍分裂窗亮温差算法(SWTD)对火山灰云的识别,而中红外波段数据因对高温物体的敏感性,不受水汽的影响,对喷发初期较高温度的火山灰云识别效果较好;在喷发中期,火山灰云浓度较大时三种方法均表现良好,卫星图像中火山灰云的位置信息及漂移方向均非常清晰,且同气象条件相吻合,验证了识别方法的正确性。该项结果表明,具有我国自主知识产权的FY-3A数据能够达到监测火山灰云的目的,而如何更加清晰地界定火山灰云的边界位置以及更加准确的计算出火山灰云的浓度需要进一步的深入研究。  相似文献   

5.
Volcanic ash forecast during the June 2011 Cordón Caulle eruption   总被引：1，自引：0，他引：1  
We modelled the transport and deposition of ash from the June 2011 eruption from Cordón Caulle volcanic complex, Chile. The modelling strategy, currently under development at the Argentinean Naval Hydrographic Service and National Meteorological Service, couples the weather research and forecasting (WRF/ARW) meteorological model with the FALL3D ash dispersal model. The strategy uses volcanological inputs inferred from satellite imagery, eruption reports and preliminary grain-size data obtained during the first days of the eruption from an Argentinean ash sample collection network. In this sense, the results shown here can be regarded as a quasi-syn-eruptive forecast for the first 16 days of the eruption. Although this article describes the modelling process in the aftermath of the crisis, the strategy was implemented from the beginning of the eruption, and results were made available to the Buenos Aires Volcanic Ash Advisory Centers and other end users. The model predicts ash cloud trajectories, concentration of ash at relevant flight levels, expected deposit thickness and ash accumulation rates at relevant localities. Here, we validate the modelling strategy by comparing results with satellite retrievals and syn-eruptive ground deposit measurements. Results highlight the goodness of the combined WRF/ARW-FALL3D forecasting system and point out the usefulness of coupling both models for short-term forecast of volcanic ash clouds.  相似文献   

6.
长白山火山区是我国具有潜在喷发危险的活火山,在2002~2005年火山活动性增强出现了岩浆房扰动。利用卫星遥感技术具有观测范围大、观测时间长且连续的优势。因此,本文利用对流层污染探测仪（MOPITT）和大气红外探测仪（AIRS）高光谱遥感数据提取了2002~2005年长白山天池火山区CO总量、O3总量、水汽总量和地表温度异常信息,讨论了高光谱遥感气体地球化学异常信息与火山活动性之间的关系,并对2002~2005年长白山天池火山区火山活动性进行了研究。结果表明,高光谱遥感数据观测到的气体地球化学（CO、O3、水汽）异常与地震、形变监测结果以及地面流体（CO2、He、H2）观测结果相一致,表明MOPITT和AIRS高光谱遥感卫星观测到的气体异常变化较好地反映了2002~2005年大规模的深部岩浆局部扰动。在2002~2005年火山活动期间,CO总量、O3总量、水汽总量和地表温度均出现了显著异常且异常出现时段相应准偏差显著增大,反映了气体逸出量在时间上具有不均一性,可能与火山、地震活动过程中地应力的作用和变化有关。从气体异常持续的时间以及地面观测结果综合分析,2002~2005年岩浆房扰动并没有产生长时间的地幔物质流的上升和迁移。在火山活动性增强的时间段内,地表温度出现异常低值,这可能与太平洋板块俯冲过程中引起的断裂拉张增强有关。此外,火山活动过程中逸出的气体进入大气圈产生大气化学反应也会导致高光谱遥感所观测到的气体地球化学异常。研究结果为2002~2005年长白山火山活动性的研究提供了来自高光谱遥感数据的气体地球化学新证据,也对高光谱分辨率遥感数据在火山活动规律的研究以及火山监测中的应用具有一定意义。  相似文献   

7.
《Atmósfera》2014,27(2):193-214
For the first time, maps of surface concentration of nitrogen dioxide (NO2) are presented for the Colombian territory. NO2 surface concentrations for the year 2007 are inferred based on two sources of tropospheric NO2 column data: (1) a simulation using a three-dimensional global model (GEOS-Chem) and (2) measurements made by the ozone monitoring instrument (OMI) onboard the NASA Aura satellite. Results show monthly averages between 0.1 and 6 ppbv. We compare these inferred values to corrected ground measurements of NO2. We find correlation coefficients of up to 0.91 between the inferred data and the corrected observational data. A significant source of NO2 is biomass burning, which can be diagnosed by data of fire radiative power (FRP) from the Monitoring of Atmospheric Composition and Climate (MACC) reanalysis. We find a close relationship between high values of inferred NO2 surface concentrations and biomass burning for a large area which encompasses the departments of Caquetá, Meta, Guaviare, Vichada, and Putumayo.  相似文献   

8.
This retrospective study focuses on the fine silicate particles (<62 µm in diameter) produced in a large eruption that was otherwise well studied. Fine particles represent a potential hazard to aircraft, because as simple particles they have very low terminal velocities and could potentially stay aloft for weeks. New data were collected to describe the fine particle size distributions of distal fallout samples collected soon after eruption. Although, about half of the mass of silicate particles produced in this eruption of ~1 km3 dense rock equivalent magma were finer than 62 µm in diameter, and although these particles were in a stratospheric cloud after eruption, almost all of these fine particles fell to the ground near (<300 km) the volcano in a day or two. Particles falling out from 70 to 300 km from the volcano are mostly <62 µm in diameter. The most plausible explanation for rapid fallout is that the fine ash nucleates ice in the convective cloud and initiates a process of meteorological precipitation that efficiently removes fine silicates. These observations are similar to other eruptions and we conclude that ice formation in convective volcanic clouds is part of an effective fine ash removal process that affects all or most volcanic clouds. The existence of pyroclastic flows and surges in the El Chichón eruption increased the overall proportion of fine silicates, probably by milling larger glassy pyroclasts.  相似文献   

9.
There are over 100 active volcanoes in the North Pacific (NOPAC) region, most of which are located in sparsely populated areas. Dispersion models play an important role in forecasting the movement of volcanic ash clouds by complementing both remote sensing data and visual observations from the ground and aircraft. Puff is a three-dimensional dispersion model, primarily designed for forecasting volcanic ash dispersion, used by the Alaska Volcano Observatory and other agencies. Since early 2007, the model is in an automated mode to predict the movement of airborne volcanic ash at multiple elevated alert status volcanoes worldwide to provide immediate information when an eruption occurs. Twelve of the predictions are within the NOPAC region, nine more within the southern section of the Pacific ring of fire and the others are in Europe and the Caribbean. Model forecasts are made for initial ash plumes ranging from 4 to 20 km altitude above sea level and for a 24-h forecast period. This information is made available via the Puff model website. Model results can be displayed in Virtual Globes for three-dimensional visualization. Here, we show operational Puff predictions in two and three-dimensions in Google Earth®, both as iso-surfaces and particles, and study past eruptions to illustrate the capabilities that the Virtual Globes can provide. In addition, we show the opportunity that Google Maps® provides in displaying Puff operational predictions via an application programming web interface and how radiosonde data (vertical soundings) and numerical weather prediction vertical profiles can be displayed in Virtual Globes for assisting in estimating ash cloud heights.  相似文献   

10.
A critical factor in successfully monitoring and forecasting volcanic ash dispersion for aviation safety is the height reached by eruption clouds, which is affected by environmental factors, such as wind shear and atmospheric instability. Following earlier work using the Active Tracer High Resolution Atmospheric Model for strong Plinian eruptions, this study considered a range of eruption strengths in different atmospheres. The results suggest that relatively weak volcanic eruptions in the moist tropics can trigger deep convection that transports volcanic material to 15–20 km. For the same volcanic strength there can be ~9 km difference between eruption heights in moist tropical and dry subpolar environments (a larger height difference than previously suggested), which appears consistent with observations. These results suggest that eruption intensity should not be estimated from eruption height alone for tropospheric eruptions and also that the average height of volcanic eruptions may increase if the tropical atmospheric belt widens in a changing climate. Ash aggregation is promoted by hydrometeors (particularly liquid water), so the smaller modelled eruptions in moist atmospheres, which have a relatively small ash content for their height and water content, result in a relatively small proportion of fine ash in the dispersing cloud when compared to a dry atmosphere. This in turn makes the ash clouds much more difficult to detect using remote sensing than those in dry atmospheres. Overall, a weak eruption in the tropics is more likely to produce a plume above cruising levels for civil aviation, harder to detect and track, but with a lower concentration of fine ash than a mid-latitude or polar equivalent. There is currently no defined ‘acceptable’ concentration of ash for aircraft, but as these results suggest low-grade encounters in the tropics from undetected clouds are likely, it would be desirable to explore that issue.  相似文献   

11.
Volcanoes worldwide pose a major threat to humans at both local and global scales. The effective monitoring of volcanoes is essential to manage and reduce risk associated with the threat that they pose. The measurement of volcanic cloud composition can provide important clues to the underlying volcanic processes and can be indicative of impending eruption. Hazards posed by plumes to humans and animals are significant, as well as the potential climatic impacts and the threat to aircraft by the ingestion of volcanic ash all justify careful monitoring. Recent advances in instrument technology have allowed for high resolution monitoring of volcanic clouds from satellite-based instruments. There exists a suite of instruments with varying spatial, spectral and temporal resolutions, which when used in conjunction can provide detailed information about cloud properties. Such instruments have the capability to quantify sulphur dioxide, ash and aerosol content as well as the spatial and vertical distribution of species. Here we present an overview of the range of instruments useful for such monitoring, outline their functionality and describe the potential of future missions.  相似文献   

12.
The use of satellite data in combination with ground-based measurements can provide valuable information about atmospheric chemistry and air quality. In this study, ground-based Differential Optical Absorption Spectroscopy (DOAS) measurements of nitrogen dioxide (NO2) conducted in central Mexico are compared with the space-borne Ozone Monitoring Instrument (OMI) dataset of 2006-2011. Ground-based measurements exhibited large day-to-day variations and were on average three times higher than the space-borne derived average over the observation site. This difference is attributed to strong horizontal inhomogeneity of the lower layer of the measured NO2 columns, sampled over a large footprint from the satellite instrument. Also, a reduced sensitivity of the satellite observation near the surface, where the largest concentrations are expected, could be responsible for this large discrepancy. From the analyzed OMI dataset, distribution maps of NO2 above central Mexico were reconstructed, allowing to identify three main areas with increased NO2 column densities: The dominating metropolitan area of Mexico City, the heavily industrialized region of Tula to the north and the Cuernavaca valley to the south. In this analysis, seasonal variability of NO2 columns over central Mexico was detected, finding higher NO2 columns during the dry and cold season, followed by the dry and warm period, and finally the lowest NO2 columns were found during the rainy season. Pollution transport of this gas from Tula into Mexico City, as well as towards the Cuernavaca valley, is evident from this dataset.  相似文献   

13.
《Applied Geochemistry》1998,13(7):841-850
Increasing fumarolic activity at Popocatépetl volcano has been observed since 1992. On 21 December 1994, a series of eruptions at Popocatépetl volcano produced ash emissions that reached the city of Puebla located to the east of the volcano. Eruptive activity declined sharply from June 1995 until 5 March 1996 when ash emissions and fumarole flux increased to levels similar to those of December, 1994. Intermittent ash production has continued to 1997. Ash was sampled at more than 80 different locations around the volcano during the various eruptions. Gas produced during an eruption may be scavenged by the ash and leaching of the ash with water allows determination of the concentration of ions adsorbed from the volcanic gases. The leachates obtained from eruptions from December 1994 until 28 November 1996, were analyzed by potentiometry with selective electrodes for Cl− and F− and by ion chromatography for SO42−. Minor cations (Co2+, Pb2+, Zn2+, Cu2+, Mn2+, Sb2+, Ti4+, Cd2+, Tl3+) were determined in some samples by ICP-MS. The highest concentrations of Cl− and SO42− were obtained for the 21 December 1994 ash at the start of the eruptions with 19 550 ppm SO42− and 1028 ppm Cl− and for the emission which occurred on 5 March 1996, with 21 775 ppm SO42− and 1250 ppm Cl−. At both times a concentration decrease was observed, but with particular trends in each case. The composition of the ash leachates suggests that the two Popocatépetl eruptions in 1994 and 1996 began with phreatic and magmatic components. The increase in F− and the decrease in the Cl/F ratio may indicate a heating up of the volcanic system at the beginning of March, 1996, one week before the outpouring of lava in the bottom of the crater on 20 March 1996. The concentration trends for SO42−, Cl− and F− suggest that during the 1996 activity, the system attained higher temperatures than in 1994–1995.  相似文献   

14.
Chemical compositions of volcanic gases of several Japanese active volcanoes have been monitored from distant safe places since the beginning of the 1990s using an FT-IR spectral radiometer. For absorption measurements, an infrared light source behind volcanic gas emissions is necessary in a volcanic environment. In the early observations, infrared radiation from hot lava domes (Unzen volcano) and hot ground heated by high-temperature fumaroles (Usu, Aso, and Satsuma-Iwojima volcanoes) were used as infrared light sources. However, these sources were not available in many cases. This remote FT-IR method became more commonly applied to chemical monitoring of volcanic gases emitted from the summit or slopes of active volcanoes using scattered solar infrared light as infrared light sources (Sakurajima, Miyakejima, and Asama volcanoes). To date, eight species have been measured using this method: SO2, HCl, HF, CO, CO2, COS, SiF4, and H2O. The observations indicate that volcanic gases for each volcano have different chemical composition on a SO2–HCl–HF ternary diagram in spite of similar tectonic settings, suggesting that vapor/melt volume ratios during volcanic gas formation differ among volcanoes. During more than 15 years of monitoring, chemical changes in volcanic gases attributable to ascent of magma were observed only at Asama, where HCl/SO2 and HF/HCl ratios in the eruptive period were higher than those in non-eruptive period because of scrubbing of more soluble components in surface hydrothermal systems in the non-eruptive stage or solubility-controlled fractionation processes. Results show that these parameters are the most prospective ones among the various parameters measured using the remote FT-IR method to monitor volcanic activities.  相似文献   

15.
Over the past few decades, substantial progress has been made to overcome the technical difficulties of continuously measuring volcanic SO2 emissions. However, measurements of CO2 emissions still present many difficulties, partly due to the lack of instruments that can directly measure CO2 emissions and partly due to its strong atmospheric background. In order to overcome these difficulties, a commonly taken approach is to combine differential optical absorption spectroscopy (DOAS) by using NOVAC scan-DOAS instruments for continuous measurements of crateric SO2 emissions, and electrochemical/NDIR multi-component gas analyser system (multi-GAS) instruments for measuring CO2/SO2 ratios of excerpts of the volcanic plume. This study aims to quantify the representativeness of excerpts of CO2/SO2 ratios measured by Multi-GAS as a fraction of the whole plume composition, by comparison with simultaneously measured CO2/SO2 ratios using cross-crater Fourier transform infrared spectroscopy (FTIR). Two study cases are presented: Telica volcano (Nicaragua), with a homogenous plume, quiescent degassing from a deep source and ambient temperature, and Turrialba volcano (Costa Rica), which has a non-homogeneous plume from three main sources with different compositions and temperatures. Our comparison shows that in our “easier case” (Telica), FTIR and Multi-GAS CO2/SO2 ratios agree within a factor about 3 %. In our “complicated case” (Turrialba), Multi-GAS and FTIR yield CO2/SO2 ratios differing by approximately 13–25 % at most. These results suggest that a fair estimation of volcanic CO2 emissions can be provided by the combination of DOAS and Multi-GAS instruments for volcanoes with similar degassing conditions as Telica or Turrialba. Based on the results of this comparison, we report that by the time our measurements were made, Telica and Turrialba were emitting approximately 100 and 1,000 t day?1 of CO2, respectively.  相似文献   

16.
Sulfur dioxide measured at the Visitor’s Center of Hawai’i Volcanoes National Park, USA exhibits seasonal and diurnal patterns and is sensitive to rainfall, but the relationship between wind direction and SO2 is too inconsistent to support deterministic predictions of hourly SO2 based on hourly wind direction. Although SO2 at the Visitor Center has usually been below regulatory levels, high SO2 levels and adverse health effects remain a concern. This investigation identified patterns in hourly SO2 based on wind direction, time of day, month, and rainfall occurrence using 4 years of hourly data. Empirical probabilities were investigated using a Bayesian approach. Winds from the volcanic vents were rare, but when they did occur SO2 was elevated about half of the time. Conversely, half of the hours with elevated SO2 occurred when volcanic vents were not directly upwind. Episodes of elevated SO2 tended to occur during the months of November–March and between 8:00 a.m. and 5:00 p.m. Rainfall was associated with a marked reduction in SO2 (29–81% depending on wind direction). Individuals that wish to avoid exposure to volcanic fumes can take these patterns into account.  相似文献   

17.
The zenith sky scattered light spectra were carried out using zenith sky UV-visible spectrometer in clear and cloudy sky conditions during May-November 2000 over the tropical station Pune (18°32′N, 73°51′E). These scattered spectra are obtained in the spectral range 462–498 nm between 75° and 92° solar zenith angles (SZAs). The slant column densities (SCDs) as well as total column densities (TCDs) of NO2, O3, H2O and O4 are derived with different SZAs in clear and cloudy sky conditions. The large enhancements and reductions in TCDs of the above gases are observed in thick cumulonimbus (Cb) clouds and thin high cirrus (Ci) clouds, respectively, compared to clear sky conditions. The enhancements in TCDs of O3 appear to be due to photon diffusion, multiple Mie-scattering and multiple reflections between layered clouds or isolated patches of optically thick clouds. The reductions in TCDs due to optically thin clouds are noticed during the above period. The variations in TCDs of O3 measured under cloudy sky are discussed with total cloud cover (octas) of different types of clouds such as low clouds (C L ), medium clouds (C M ) and high clouds (C H ) during May-November 2000. The variations in TCDs of O3 measured in cloudy sky conditions are found to be well matched with cloud sensitive parameter colour index (CI) and found to be in good correlation. The TCDcloudy are derived using airmass factors (AMFs) computed without considering cloud cover and CI in radiative transfer (RT) model, whereas TCDmodel are derived using AMFs computed with considering cloud cover, cloud height and CI in RT model. The TCDmodel is the column density of illuminated cloudy effect. A good agreement is observed between TCDmodel, TCDDob and TCDGOME.  相似文献   

18.
More than 65 potentially active volcanoes on the Kamchatka Peninsula and the Kurile Islands pose a substantial threat to aircraft on the Northern Pacific (NOPAC), Russian Trans-East (RTE), and Pacific Organized Track System (PACOTS) air routes. The Kamchatka Volcanic Eruption Response Team (KVERT) monitors and reports on volcanic hazards to aviation for Kamchatka and the north Kuriles. KVERT scientists utilize real-time seismic data, daily satellite views of the region, real-time video, and pilot and field reports of activity to track and alert the aviation industry of hazardous activity. Most Kurile Island volcanoes are monitored by the Sakhalin Volcanic Eruption Response Team (SVERT) based in Yuzhno-Sakhalinsk. SVERT uses daily moderate resolution imaging spectroradiometer (MODIS) satellite images to look for volcanic activity along this 1,250-km chain of islands. Neither operation is staffed 24 h per day. In addition, the vast majority of Russian volcanoes are not monitored seismically in real-time. Other challenges include multiple time-zones and language differences that hamper communication among volcanologists and meteorologists in the US, Japan, and Russia who share the responsibility to issue official warnings. Rapid, consistent verification of explosive eruptions and determination of cloud heights remain significant technical challenges. Despite these difficulties, in more than a decade of frequent eruptive activity in Kamchatka and the northern Kuriles, no damaging encounters with volcanic ash from Russian eruptions have been recorded.  相似文献   

19.
《Comptes Rendus Geoscience》2015,347(3):145-152
Imaging spectroscopy at high resolution, in the infrared range, is a powerful tool for monitoring the behavior of minor species in planetary atmospheres and their evolution with latitude and longitude, season or local hour. Using the TEXES imaging spectrometer at the Infrared Telescope Facility (IRTF), this method has been applied for detecting and monitoring hydrogen peroxide and water vapor (using its proxy HDO) on Mars, then for monitoring sulfur dioxide and water (again using HDO) above the H2SO4 cloud deck (z = 65 km on Venus). Observations of Mars have shown that its atmosphere and climate are well reproduced by the Global Climatic Models. In contrast, strong spatio-temporal variations of SO2, observed above the Venus clouds, are not understood by the models. As a support of the forthcoming Juno space mission, a similar program has started on Jupiter to monitor its dynamics through 3-D maps of ammonia and phosphine.  相似文献   

20.
Metal roofing material is commonly used for residential and industrial roofs in volcanically active areas. Increased corrosion of metal roofing from chemically reactive volcanic ash following ash deposition post-eruption is a major concern due to decreasing the function and stability of roofs. Currently, assessment of ash-induced corrosion is anecdotal, and quantitative data are lacking. Here, we systematically evaluate the corrosive effects of volcanic ash, specifically ash leachates, on a variety of metal roofing materials (i.e. weathered steel, zinc, galvanized steel, and Colorsteel©) utilizing weathering chamber experiments and direct acid treatments. Weathering chamber tests were carried out for up to 30 days, and visual, chemical, and surface analyses did not definitively identify significant corrosion in any of the test roofing metal samples. Direct concentrated acid treatments with hydrochloric (HCl), sulphuric (H2SO4), and hydrofluoric (HF) acids demonstrate that roofing materials are chemically resilient. Our experimental results suggest that ash-leachate-related corrosion is a longer-term process (>1 month), potentially related to a multitude of factors including increased ash leachate concentrations, the dissolution of the glass matrix of the ash, moisture retention at the ash-surface boundary, and potential reactions involving photo-oxidation. Overall, corrosion is not a simple process related to the short-term release of acid and/or salt leachates from the ash surface, but a product of dynamic interactions involving ash and water at the surface of metal roofing material for extended periods.  相似文献   

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