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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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NASA NTRS1985

Submarine Volcanic Eruptions and Potential Analogs for Venus

As part of an analysis program to better understand the diversity of volcanic processes on the terrestrial planets, an investigation of the volcanic landforms which exist on the Earth's ocean floor was initiated. In part, this analysis is focused toward gaining a better understanding of submarine volcanic landforms in their own right, but also it is hoped that these features may show similarities to volcanic landforms on Venus, due to the high ambient water (Earth) and atmospheric (Venus) pressures. A series of numerical modelling experiments was performed to investigate the relative importance of such attributes as water pressure and temperature on the eruption process, and to determine the rate of cooling and emplacement of lava flows in the submarine environment. Investigations to date show that the confining water pressure and the buoyancy effects of the surrounding water significantly affect the styles of volcanism on the ocean floor. In the case of Venusian volcanism, confining pressures will not be as great as that found at the ocean's abyssal plains, but nevertheless the general trend toward reducing magma vesiculation will hold true for Venus as well as the ocean floor. Furthermore, other analogs may also be found between submarine volcanism and Venusian activity.

Wilson, L.↗
NASA NTRS1989

Self-limiting physical and chemical effects in volcanic eruption clouds

One-dimensional aerosol microphysical and photochemical models are used to study the chemistry of stratospheric volcanic clouds. The results indicate that the aerosol microphysical processes of condensation and coagulation produce larger particles as the SO2 injection rate is increased. Larger particles have a smaller optical depth per unit mass and settle out of the stratosphere at a faster rate than smaller ones, restricting the total number of particles in the stratosphere. The microphysical processes moderate the impact of volcanic clouds on the earth's radiation budget and climate, suggesting that volcanic effects may be self limiting. It is noted that the injection of HCl into the stratosphere, which could lead to large ozone changes, is limited by a cold trap effect in which HCl and water vapor condense on ash particles in the rising volcanic plume and fall out as ice.

Pinto, Joseph P.↗
NASA NTRS2022

The 2019 Raikoke volcanic eruption -Part 2: Particle-phase dispersion and concurrent wildfire smoke emissions

Between 27 June and 14 July 2019 aerosol layers were observed by the United Kingdom (UK) Raman lidar network in the upper troposphere and lower stratosphere. The arrival of these aerosol layers in late June caused some concern within the London Volcanic Ash Advisory Centre (VAAC) as according to dispersion simulations the volcanic plume from the 21 June 2019 eruption of Raikoke was not expected over the UK until early July. Using dispersion simulations from the Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME), and supporting evidence from satellite and in situ aircraft observations, we show that the early arrival of the stratospheric layers was not due to aerosols from the explosive eruption of the Raikoke volcano but due to biomass burning smoke aerosols associated with intense forest fires in Alberta, Canada, that occurred 4 d prior to the Raikoke eruption. We use the observations and model simulations to describe the dispersion of both the volcanic and forest fire aerosol clouds and estimate that the initial Raikoke ash aerosol cloud contained around 15 Tg of volcanic ash and that the forest fires produced around 0.2 Tg of biomass burning aerosol. The operational monitoring of volcanic aerosol clouds is a vital capability in terms of aviation safety and the synergy of NAME dispersion simulations, and lidar data with depolarising capabilities allowed scientists at the Met Office to interpret the various aerosol layers over the UK and attribute the material to their sources. The use of NAME allowed the identification of the observed stratospheric layers that reached the UK on 27 June as biomass burning aerosol, characterised by a particle linear depolarisation ratio of 9 %, whereas with the lidar alone the latter could have been identified as the early arrival of a volcanic ash–sulfate mixed aerosol cloud. In the case under study, given the low concentration estimates, the exact identification of the aerosol layers would have made little substantive difference to the decision-making process within the London VAAC. However, our work shows how the use of dispersion modelling together with multiple observation sources enabled us to create a more complete description of atmospheric aerosol loading.

Martin J Osborne↗
NASA NTRS1983

A comparison of volcanic eruption processes on earth, moon, Mars, Io and Venus

The physical, chemical, and atmospheric characteristics of the silicate planets and satellites are surveyed in terms of their effects on the volcanic evolution of the surfaces of these bodies. The equations relating the parameters affecting magma ascent through the crust and eruption are analyzed, and three major types of eruption are characterized: effusive, steady explosive, and unsteady explosive. This analytical framework is then used to predict the nature of volcanic activity on each of the planets and satellites, and the predictions are compared with actual observations. Outstanding problems are discussed, with emphasis on the need for a general model of planetary interior dynamics applicable to bodies with varying degrees of interior viscosity, mantle activity, and lithospheric plate tectonics.

Wilson, L.↗
NASA NTRS1994

Volcanic Eruptions on Io: Heat Flow, Resurfacing, and Lava Composition

In this paper we consider the infrared outbursts on Io reported over the last 15 years and examine the implications for resurfacing rates and heat flow using a recent, well observed, eruption sequence. A large change was observed in Io's infrared emission on January 9, 1990 at several different wavelengths. We model this event as due to a large actively erupting lava flow. The flow increased its area at a rate of 1.5 x 10 5 m 2 s -1 and cooled from 1225 K to 555 K over about 2.6 hours. This event is consistent with other Io infrared outbursts and is used in this paper to estimate the more general characteristics of Ionian volcanism, resurfacing, and heat flow. The inferred eruption rate of 3 x 10 5 m 3 s -1 is very high, but is not unprecedented on the Earth.

Io↗
NASA NTRS2021

Evidence for Systematic Changes in the Stratospheric Aerosol Size Following Volcanic Eruptions of Diverse Magnitudes Using Space-Based Instruments

An analysis of multiwavelength stratospheric aerosol extinction coefficient data from the Stratospheric Aerosol and Gas Experiment II and III/ISS instruments is used to demonstrate a coherent relationship between the perturbation in extinction coefficient in an eruption’s main aerosol layer and an apparent change in aerosol size distribution that spans multiple orders of magnitude in the stratospheric impact of an volcanic event. The relationship is measurement-based and does not rely on assumptions about the aerosol size distribution. In this respect, it may be a unique tool to verify the performance of interactive aerosol models used in GCMs and ESMs and may suggest an avenue for improving aerosol extinction coefficient measurements from single channel observations such the Optical Spectrograph and Infrared Imager System. We note limitations on this analysis including that the presence of significant amounts of ash in the main aerosol layer may significantly modulate these results.

Larry Thomason↗
NASA NTRS2021

Evidence for the predictability of changes in the stratosphericaerosol size following volcanic eruptions of diverse magnitudesusing space-based instruments

An analysis of multiwavelength stratospheric aerosol extinction coefficient data from the Stratospheric Aerosol and Gas Experiment II and III/ISS instruments is used to demonstrate a coherent relationship between the perturbation in extinction coefficient in an eruption’s main aerosol layer and the wavelength dependence of that perturbation. This relationship spans multiple orders of magnitude in the aerosol extinction coefficient of stratospheric impact of volcanic events. The relationship is measurement-based and does not rely on assumptions about the aerosol size distribution. We note limitations on this analysis including that the presence of significant amounts of ash in the main sulfuric acid aerosol layer and other factors may significantly modulate these results. Despite these limitations, the findings suggest an avenue for improving aerosol extinction coefficient measurements from single-channel observations such as the Optical Spectrograph and Infrared Imager System as they rely on a prior assumptions about particle size. They may also represent a distinct avenue for the comparison of observations with interactive aerosol models used in global climate models and Earth system models.

Larry W Thomason↗
NASA NTRS1993

Observations of the loss of stratospheric NO2 following volcanic eruptions

Observations of stratospheric column amounts of nitrogen dioxide (NO2), nitric oxide (NO) and nitric acid (HNO3) have been made following major eruptions of the El Chichon and Mt. Pintatubo volcanoes. Midlatitude abundances of NO2 and NO were reduced by as much as 70% in the months following the appearance of the volcanic aerosols as compared to volcanically quite periods. There are heterogeneous reactions which could occur on the volcanic aerosols to convert NO2 into HNO3 but no commensurate increase in HNO3 column amounts was observed at the times of NO2 decrease.

Coffey, M. T.↗
NASA NTRS2019

A Recent Volcanic Eruption, Holuhraun, in the Central Highlands of Iceland as a Mars analog: The 2018 Field Campaign of FELDSPAR

In summer 2018, FELDSPAR conducted an analog sampling expedition to the Holuhraun volcanoin the central highlands of Iceland that erupted from August 2014 to February 2015. Holuhraun hassteep gradients within an otherwise relatively controlled region, and thus served as the primaryMars analog site for the 2018 FELDSPAR field campaign. Samples along gradients of mineralogyas measured via near-IR and visible reflectance spectroscopy, temperature as measured by an IRprobe, and physical location about the fissure (slope incline, directionality, height up the slope,etc.) were analyzed in-field with reflectance spectroscopy and X-ray fluorescence, in the field labfor adenosine trisphosphate (ATP) as an indicator of metabolic activity, and after return to thehome lab for both geochemical and geophysical parameters (moisture content, grain size, X-raydiffraction) and biochemical parameters (DNA content and speciation). This abstract representsthe first report on the 2018 field campaign with initial results and interpretation. This work is part ofField Exploration and Life Detection Sampling for Planetary Analogue Research (FELDSPAR), onFacebook @FELDSPAResearch.

Volcanic↗
NASA NTRS1975

An investigation of thermal anomalies in the Central American volcanic chain and evaluation of the utility of thermal anomaly monitoring in the prediction of volcanic eruptions

The author has identified the following significant results. Ground truth data collection proves that significant anomalies exist at 13 volcanoes within the test site of Central America. The dimensions and temperature contrast of these ten anomalies are large enough to be detected by the Skylab 192 instrument. The dimensions and intensity of thermal anomalies have changed at most of these volcanoes during the Skylab mission.

Stoiber, R. E.↗
NASA NTRS1978

Modeling lunar volcanic eruptions

Simple physical arguments are used to show that basaltic volcanos on different planetary bodies would fountain to the same height if the mole fraction of gas in the magma scaled with the acceleration of gravity. It is suggested that the actual eruption velocities and fountain heights are controlled by the velocities of sound in the two phase gas/liquid flows. These velocities are in turn determined by the gas contents in the magma. Predicted characteristics of Hawaiian volcanos are in excellent accord with observations. Assuming that the only gas in lunar volcano is the CO which would be produced if the observed Fe metal in lunar basalts resulted from graphite reduction, lunar volcanos would fountain vigorously, but not as spectacularly as their terrestrial counterparts. The volatile trace metals, halogens, and sulfur released would be transported over the entire moon by the transient atmosphere. Orange and black glass type pyroclastic materials would be transported in sufficient amounts to produce the observed dark mantle deposits.

Housley, R. M.↗
NASA NTRS1983

A two-dimensional model simulation of the EL Chichon volcanic eruption cloud

Using a two-dimensional model of sulfate photochemistry, transport, and aerosol microphysics, a 2-year period following the eruptions of El Chichon have been simulated. Present calculations suggest that the residence time of the cloud in the stratosphere exceeds 2 years. The model reproduces the observed optical depth, lidar backscatter, and infrared extinction coefficients, if about 10 megatonnes of SO2 are injected. The major deficiency of the model is a somewhat too rapid transport.

Capone, L. A.↗
NASA NTRS1985

Detection of volcanic eruptions from space by their sulfur dioxide clouds

The capabilities of the total ozone mapping spectrometer (TOMS) on the Nimbus 7 satellite for tracking volcano plumes are assessed. TOMS was installed on the sun-synchronous polar orbiting satellite to measure spatial variations in the global total ozone field. Radiance absorption coefficients of the atmosphere for four near-UV wavelengths from 312.5-380.0 are measured. Data from the El Chichon eruption in March-April 1982 revealed that SO2 was an absorbing species at 312.5 and 317.5 nm. The near-UV absorption level differences between SO2 and O3 permit discriminating the atmospheric densities of each species. An examination of the data base generated by TOMS since 1978 showed the perceptible tracks of all known major eruptions in the 1978-1982 time period. A constellation of three of the polar orbiting TOMS would be sufficient to provide near-real time alerts of plumes to warn aircraft of the hazards.

Krueger, A. J.↗