Sinton bands - evidence for deuterated water on mars.
IR absorption spectra of Mars atmosphere may be due to deuterated water
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IR absorption spectra of Mars atmosphere may be due to deuterated water
It is proposed that a vapor explosion of a submerged pool of liquid sulfur will remove the crust overlying an area of about 50-km diam. Thermal radiation from the exposed liquid sulfur pool with a surface temperature of 600 K is then presumed to be responsible for the 5-micron outbursts that have been observed. The explosive volcanoes are expected to leave black sulfur calderas, which are, indeed, found on the surface. The 5-micron outburst observed by Sinton (1980), on June 11, 1979 (UT), is identified with a new caldera found on Voyager 2 photographs but which had not been present on Voyager 1 pictures.
New polarization measurements of Io were made with two different polarimeters at 3.8 and 4.8 microns. The measurements, at phase angles of about 2 deg, detect the polarization of reflected sunlight at both wavelengths. Only upper limits can be determined for the volcanic activity in 1986, but these limits show that there has been a remarkable decrease in activity, particularly of the Loki volcano, at these short wavelengths. The 1984 data (Goguen and Sinton (1985) are reanalyzed with the new model, which includes polarization of reflected sunlight. The large amount of thermal emission from the Loki volcano in 1984 produced a polarization that was dominant over that of reflected sunlight.
The International Jupiter Watch is a program for the encouragement and coordination of the study of temporal variations in the Jovian system. It consists of six discipline working groups concerned with: the Io torus under N. Schneider; the Jovian atmosphere under R. West; the magnetosphere and radio emissions under I. de Peter and M. Klein; aurora under J. Caldwell; the Galilean satellites under W. Sinton and J. Goguen; and laboratory measurement and theory under B. Lutz. To date the IJW has held two workshops and selected several Jupiter Watch periods for coordinated observations. The next Jupiter Watch workshop is tentatively scheduled for 1990 in association with the next COSPAR meeting.
The transmission curve of the Martian atmosphere derived by Opik is compared with transmission curves of an atmosphere containing various amounts of nitrogen dioxide. It is found that the amount of 6 x l0(exp 18) sq cm column NO2 (or even less) given by Sinton as an upper limit for the Martian NO2 content could adequately explain the phenomenon of the blue haze. This finding made it worthwhile to investigate the effect of the temperature and pressure sensitive equilibrium 2 NO2 reversibly yields N204 upon the total NO2 content and the altitude-number density distributions of NO2 and N204. Computations were carried out for surface temperatures of 273 K, 243 K, 213 K, and 183 K and for three different temperature distributions. The discussion of the results leads to the suggestion of several important new experiments.
Solar photovoltaics (PV) is entering a new era of multi-terawatt deployment, with 2 TW already in service and more than 75 TW predicted in many scenarios by 2050. This next era has been enabled by over five decades of cumulative advances in PV module cost reduction, performance and reliability. The current scale of deployment also introduces new needs, opportunities and challenges. In this Perspective we frame a path forwards based on learning, broadly defined as a combination of expansion of knowledge and advances through research and development, experience and collaboration. We discuss historical topics where learning has driven PV deployment until now, and emerging areas that are required to sustain high levels of future deployment. We expect progress to continue in terms of module price, performance and reliability, driven by advances in PV cell and module design, the emergence of tandem devices and increased focus on extending module lifetimes. Large-scale deployment also means large-scale sustainability and responsibility. We therefore posit that additional metrics, such as the impact on global CO2 emissions, resource consumption and design for reuse and recycling, will become increasingly important to the PV industry and provide opportunities for further learning.
IrO 2 is a commonly employed anode catalyst for CO 2 electrolysis in membrane electrode assembly (MEA) systems. However, under high current densities, its structural reconstruction leads to activity loss and stability degradation, limiting the industrial viability of CO 2 electrolysis. In this work, we demonstrated a confinement reconstruction strategy to precisely regulate the structural evolution during electrolysis. Ethylene glycol serves as a structural modulator, protecting the catalyst surface, suppressing soluble species formation, and promoting ordered structural evolution. Single-atom Ru acts as a stability enhancer, forming robust Ir–O–Ru bridging structures that facilitate an ordered transformation from a 4-fold [RuO 4 ]/[IrO 4 ] to a 6-fold symmetry [RuO 6 ]/[IrO 6 ] octahedral framework, thereby enhancing structural rigidity and long-term stability. As a result, in MEA-based CO 2 electrolysis, the catalyst achieves a stable operation at 200 mA cm –2 for 480 h, maintaining a CO selectivity above 80%. Theoretical calculations further elucidate that the enhanced stability originates from the suppression of oxygen vacancy formation, making the lattice-oxygen-mediated mechanism (LOM) potentially less favorable. This work provides insights into the structural evolution of the OER catalysts under high-current-density conditions, paving the way for large-scale CO 2 electrolysis commercialization.
Like Mario grabbing a super mushroom, PV modules just keep getting bigger! As they grow, so do the challenges of handling, installing, and testing them in the field. At NREL, we've embarked on our own New Hope - adapting to this size revolution across our tools, transportation, ergonomics, and field compatibility. Join us as we navigate this galactic expansion and keep PV testing at the cutting edge.
Mars IR spectra in 3-4 micron region attributed to terrestrial HDO molecules on basis of solar spectra and water vapor abundances
Solar spectra of far IR absorption of atmosphere above 4.2 km, using interferometer and cryogenic bolometer measurements
Photographs of Uranus in the 8870 A band of methane exhibit limb brightening and brightening at the south pole. The polar brightening is explained by an upper atmospheric haze in addition to Rayleigh scattering by the upper atmosphere. An estimate of the geometric albedo at this wavelength yields a value near 0.01.
The employment of a high-resolution Fourier Transform Spectrometer (FTS) is described for planetary and other astronomical spectroscopy in conjunction with the 88-inch telescope at Mauna Kea Observatory. The FTS system is designed for a broad range of uses, including double-beam laboratory spectroscopy, infrared gas chromatography, and nuclear magnetic resonance spectroscopy. The data system is well-suited to astronomical applications because of its great speed in acquiring and transforming data, and because of the enormous storage capability of the magnetic tape unit supplied with the system. The basic instrument is outlined 2nd some of the initial results from the first attempted use on the Mauna Kea 88-inch telescope are reported.
An image intensifying tube placed at the f/10 Cassegrain focus of an 88-in. reflector telescope was used together with a narrow filter centered at the 8870-A methane band to obtain near-infrared photographs of Uranus and its satellites. Good images of Uranus were obtained with a 1-min exposure, while the faintest satellite Miranda was well recorded in about one hour. The short-exposure photograph of Uranus shows that the limb is brighter than the center of the disk and brightest at the south pole. The explanation for the brightening of the limb and pole seems to be haze in the planet's upper atmosphere.
A number of anomalous or discordant observations of Io can be explained if this Jovian satellite has an atmosphere containing ammonia. Such an atmosphere will be frozen at the unilluminated pole during the solstices, but will evaporate at the equinoctial seasons. The ammonia atmosphere will explain (1) the posteclipse brightenings and their observed times of occurrence and nonoccurrence; (2) the observed departure from a two-layer model heating curve upon emergency from the eclipse; (3) the discordant temperatures obtained at 10 and 20 micrometers; and (4) discordant temperatures obtained at 10 and 20 micrometers during the total phase of an eclipse by Jupiter.
Observations of the S(1) line of the pressure-induced fundamental band of H2 in the spectra of Saturn and Jupiter are analyzed by comparing the observed line shape with predictions of both a reflecting-layer model and a homogeneous-scattering model of the atmospheres. Upper and lower limits are derived for the values of relative intensity that occur between 5000 and 5100 kaysers, the percent absorption due to H2 at 5100 kaysers is estimated, and it is established that methane and ammonia cannot account for the broad absorption attributed to hydrogen. The comparison with the model atmospheres shows that the reflecting-layer model appears to give the best fit to the Saturn line profile for temperatures near 150 K, while both models provide good fits to the Jupiter data, but for widely differing temperatures. Difficulties encountered in determining the true continuum level, especially for Jupiter, are discussed.
The relative rings-to-disk brightness (specific intensity) of Saturn at 39 microns was resolved using a 224-cm telescope, and the total flux of Saturn relative to Jupiter in the same bandpass was measured from the NASA Learjet Observatory. These two measurements, which were made with Saturn's rings near maximum inclination, determine the disk and average ring (A and B) brightness in terms of an absolute flux calibration of Jupiter in the same bandpass. While present uncertainties in Jupiter's absolute calibration make it impossible to compare existing measurements unambiguously, it is nevertheless possible to conclude the following: (1) observations between 20 and 40 microns are all compatible (within 2 sigmas) with a disk brightness temperature of 94 K and do not agree with the radiative equilibrium models of Trafton (1967); (2) the rings at large tilt contribute a flux component comparable to that of the planet itself for wavelengths not exceeding about 40 microns; and (3) there is a decrease of approximately 22% in the relative ring:disk brightness between effective wavelengths of 33.5 and 39 microns.
An investigation is conducted concerning the possibility that the rings about Uranus discovered during the occultation of star SAO 158687 might have been observed in earlier studies of the planet. It is concluded that in view of a very low estimate for the contrast of the rings seen against the disk, a detection of the rings by earlier visual observers is unlikely. It appears, however, that the Stratoscope II photographs recorded the projection of the rings on the disk of Uranus.