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During the first half of 2020, extreme heat persisted in Siberia; wildfires developed in the region as a result. Heat waves in this region have been linked with summertime stationary Rossby waves (Schubert et al. 2011; 2014), but specific mechanisms driving the 2020 event are unclear.
Contents include the following: Ca-, Al-Rich Inclusions and Ameoboid Olivine Aggregates: What We Know and Don t Know About Their Origin. Aluminium-26 and Oxygen Isotopic Distributions of Ca-Al-rich Inclusions from Acfer 214 CH Chondrite. The Trapping Efficiency of Helium in Fullerene and Its Implicatiion to the Planetary Science. Constraints on the Origin of Chondritic Components from Oxygen Isotopic Compositions. Role of Planetary Impacts in Thermal Processing of Chondrite Materials. Formation of the Melilite Mantle of the Type B1 CAIs: Flash Heating or Transport? The Iodine-Xenon System in Outer and Inner Portions of Chondrules from the Unnamed Antarctic LL3 Chondrite. Nucleosynthesis of Short-lived Radioactivities in Massive Stars. The Two-Fluid Analysis of the Kelvin-Helmholtz Instability in the Dust Layer of a Protoplanetary Disk: A Possible Path to the Planetesimal Formation Through the Gravitational Instability. Shock-Wave Heating Model for Chonodrule Formation: Heating Rate and Cooling Rate Constraints. Glycine Amide Hydrolysis with Water and OH Radical: A Comparative DFT Study. Micron-sized Sample Preparation for AFM and SEM. AFM, FE-SEM and Optical Imaging of a Shocked L/LL Chondrite: Implications for Martensite Formation and Wave Propagation. Infrared Spectroscopy of Chondrites and Their Components: A Link Between Meteoritics and Astronomy? Mid-Infrared Spectroscopy of CAI and Their Mineral Components. The Origin of Iron Isotope Fractionation in Chondrules, CAIs and Matrix from Allende (CV3) and Chainpur (LL3) Chondrites. Protoplanetary Disk Evolution: Early Results from Spitzer. Kinetics of Evaporation-Condensation in a Melt-Solid System and Its Role on the Chemical Composition and Evolution of Chondrules. Oxygen Isotope Exchange Recorded Within Anorthite Single Crystal in Vigarano CAI: Evidence for Remelting by High Temperature Process in the Solar Nebula. Chondrule Forming Shock Waves in Solar Nebula by X-Ray Flares. Organic Globules with Anormalous Nitrogen Isotopic Compositions in the Tagish Lake Meteorite: Products of Primitive Organic Reactions. Yet Another Chondrule Formation Scenario. CAIs are Not Supernova Condensates. Microcrystals and Amorphous Material in Comets and Primitive Meteorites: Keys to Understanding Processes in the Early Solar System. A Nearby Supernova Injected Short-lived Radionuclides into Our Protoplanetary Disk. REE+Y Systematics in CC and UOC Chondrules. Meteoritic Constraints on Temperatures, Pressures, Cooling Rates, Chemical Compositions, and Modes of Condensation in the Solar Nebula. The I-Xe Record of Long Equilibration in Chondrules from the Unnamed Antarctic Meteorite L3/LL3. Early Stellar Evolution.
Elevated temperatures resulting from the urban heat island (UHI) effect can have widespread impacts on human health, infrastructure, and ecosystems. These impacts can be exacerbated by changes in climate and extreme variation in regional temperature. By 2030, experts expect Cambridge, Massachusetts will experience warmer than average temperatures, more heat waves, and triple the number of abnormally warm days above 90°F per year. The NASA DEVELOP Program partnered with the City of Cambridge’s Community Development Department and the American Geophysical Union’s Thriving Earth Exchange to inform ongoing efforts aimed at reducing the impacts of urban heat in the city of Cambridge. The team used scenes obtained from High Resolution Orthoimagery and the National Agriculture Imagery Program in conjunction with building footprint data, to calculate rooftop albedo between 2008 and 2018. Using these results, maps displaying building-specific variation in albedo across Cambridge were created. A nighttime land surface temperature (LST) record for June, July, and August between 2003 and 2019 was constructed using the Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) nighttime LST product. Lastly, temperature anomalies were calculated for Cambridge using seasonally averaged nighttime LST values obtained from Aqua MODIS to display ‘hot spots’ for summers between 2004 and 2019. The results of this project were then incorporated into an interactive ArcGIS Dashboard. This work will allow end users to explore spatial and temporal trends in albedo, nighttime LST, and temperature anomalies to assess whether the City of Cambridge is successfully reducing the effects of UHIs.
A full-wave propagation model was developed that describes the propagation of gravity waves from the Earth's surface to the upper boundary, which can be placed anywhere between 150 and 500 km altitude. The model includes a realistic background atmosphere, and includes the effects of mean horizontal winds and their vertical shears, mean vertical temperature gradients, the eddy and molecular diffusion of heat and momentum, and the effects of ion-drag. This model solves five coupled second-order differential equations (continuity, momentum, and energy) in the vertical coordinate to derive the perturbation variables u', v', w' (horizontal and vertical velocity components), T' (temperature) and p' (pressure). The upper boundary can be automatically selected based on tests using the radiation condition at the upper boundary, wherein the height is increased until the wave is experiencing severe dissipation at the upper boundary, ensuring that substantial absorption occurs for any waves reflected from the upper boundary. The determination of wave amplitude is a key requirement of wave energetics. Therefore, the fullwave model has been applied to airglow observations in order to determine wave amplitudes as a function of altitude. This was accomplished by using the full-wave model output to drive a chemistry perturbation module that describes minor species perturbations and the resulting airglow perturbations. The full-wave output was multiplied by an altitude-independent factor such that the modeled and observed relative airglow intensity perturbations were equal. The effects of mean winds were included in these studies, and found to be the most important model input affecting the calculations (being more important than the choice of eddy diffusion profiles and chemical kinetic coefficients). In one study (Hickey et al., 1997a) these winds could not be well estimated from the measurements, whereas in the second study (Hickey et al.,1997b) the mean were well defined with a sodium wind-temperature lidar.
The Lunar and Planetary Science XXXVI, Part 22 is presented. The topics include: 1) Pressure Histories from Thin and Thick Shock-induced Melt Veins in Meteorites; 2) Nano-structured Minerals as Signature of Microbial Activity; 3) The Insoluble Carbonaceous Material of CM Chondrites as Possible Source of Discrete Organics During the Asteroidal Aqueous Phase; 4) Discovery of Abundant Presolar Silicates in Subgroups of Antarctic Micrometeorites; 5) Characteristics of a Seismometer for the LUNAR-A Penetrator; 6) Heating Experiments of the HaH 262 Eucrite and Implication for the Metamorphic History of Highly Metamorphosed Eucrites; 7) Measurements of Ejecta Velocity Distribution by a High-Speed Video Camera; 8) Petrological Comparison of Mongolian Jalanash Ureilite and Twelve Antarctic Ureilites; 9) Metallographic Cooling Rate of IVA Irons Revisited; 10) Inhomogeneous Temperature Distribution in Chondrules in Shock-Wave Heating Model; 11) Subsurface Weathering of Rocks and Soils at Gusev Crater; 12) Extinct Radioactivities in the Early Solar System and the Mean Age of the Galaxy; 13) Correlation of Rock Spectra with Quantitative Morphologic Indices: Evidence for a Single Rock Type at the Mars Pathfinder Landing Site; 14) Silicon Isotopic Ratios of Presolar Grains from Supernovae; 15) Current Status and Readiness on In-Situ Exploration of Asteroid Surface by MINERVA Rover in Hayabusa Mission; 16) Long Formation Period of Single CAI: Combination of O and Mg Isotope Distribution; 17) Supra-Canonical Initial 26Al/27Al Indicate a 105 Year Residence Time for CAIs in the Solar Proto-Planetary Disk; 18) Evolution of Mercury's Obliquity; 19) First Results from the Huygens Surface Science Package; 20) Polyhedral Serpentine Grains in CM Chondrites; 21) Mountainous Units in the Martian Gusev Highland Region: Volcanic, Tectonic, or Impact Related? 22) Petrography of Lunar Meteorite MET 01210, A New Basaltic Regolith Breccia; 23) Earth-Moon Impacts at ~300 Ma and ~500 Ma Ago; 24) Chemical and Isotopic Analyses of Apollo 16 Glasses: An Integrated Approach; 25) Measuring the Surfaces on Mars; 26) Melting in Martian Snowbanks; 27) The Effect of Ni on Fe-FeS Phase Relations: Implications for the Chemistry of the Martian Core; 28) Shorelines in the Western United States as Analogs for Hypothesized Shoreline Features on Mars; 29) Al and Ti Isotopic Ratios of Presolar SiC Grains of Type Z; 30) Physicochemical Conditions of Clinopyroxene Crystallization in the Parental Bodies of Ordinary Chondrites; 31) Metamorphosed CM and CI Carbonaceous Chondrites Could be from the Breakup of the Same Earth-crossing Asteroid; 32) Aqueous Alteration and Hydrogen Generation on Parent Bodies of Unequilibrated Ordinary Chondrites: Thermodynamic Modeling for the Semarkona Composition; and 33) Preliminary Analysis of Relative Abundances of Hydrothermal Alteration Products in the C1-N10, Y6-N19, and Yax-1_863.51 Impact Melt Samples, Chicxulub Structure, Mexico
The imaging telescope on board the Transition Region and Coronal Explorer (TRACE) spacecraft observed the decaying transversal oscillations of a long [(130 +/- 6) x 10(exp 6) meters], thin [diameter (2.0 +/- 0.36) x 10(exp 6) meters], bright coronal loop in the 171 angstrom Fe-IX emission line. The oscillations were excited by a solar flare in the adjacent active region. The decay time of the oscillations is 12.1 +/- 6.7 minutes for an oscillation with a frequency 3.90 +/- 0.13 millihertz The coronal dissipation coefficient is estimated to be eight to nine orders of magnitude larger than the theoretically predicted classical value. The larger dissipation coefficient may solve existing difficulties with wave heating and reconnection theories.
The 837 km New York City shoreline is lined by significant economic assets and dense population vulnerable to sea level rise and coastal flooding. After Hurricane Sandy in 2012, New York City developed a comprehensive plan to mitigate future climate risks, drawing upon the scientific expertise of the New York City Panel on Climate Change (NPCC), a special advisory group comprised of university and private-sector experts. This paper highlights current NPCC findings regarding sea level rise and coastal flooding, with some of the City's ongoing and planned responses. Twentieth century sea level rise in New York City (2.8 cm/decade) exceeded the global average (1.7 cm/decade), underscoring the enhanced regional risk to coastal hazards. NPCC (2015) projects future sea level rise at the Battery of 28 - 53 cm by the 2050s and 46 - 99 cm by the 2080s, relative to 2000 - 2004 (mid-range, 25th - 75th percentile). High-end SLR estimates (90th percentile) reach 76 cm by the 2050s, and 1.9 m by 2100. Combining these projections with updated FEMA flood return period curves, assuming static flood dynamics and storm behavior, flood heights for the 100-year storm (excluding waves) attain 3.9-4.5 m (mid-range), relative to the NAVD88 tidal datum, and 4.9 m (high end) by the 2080s, up from 3.4 m in the 2000s. Flood heights with a 1% annual chance of occurrence in the 2000s increase to 2.0 - 5.4% (mid-range) and 12.7% per year (high-end), by the 2080s. Guided by NPCC (2013, 2015) findings, New York City has embarked on a suite of initiatives to strengthen coastal defenses, employing various approaches tailored to specific neighborhood needs. NPCC continues its collaboration with the city to investigate vulnerability to extreme climate events, including heat waves, inland floods and coastal storms. Current research entails higher-resolution neighborhood-level coastal flood mapping, changes in storm characteristics, surge height interactions with sea level rise, and stronger engagement with stakeholders and community-based organizations.
Background: Climate change is projected to increase the frequency, intensity, and duration of heat waves while reducing cold extremes, yet few studies have examined the relationship between temperature and fetal health. Objectives: We estimate the impacts of extreme temperatures on birth weight and gestational age in Manhattan, a borough in New York City, and explore differences by socioeconomic status (SES). Methods: We combine average daily temperature from 1985 to 2010 with birth certificate data in Manhattan for the same time period. We then generate 33 downscaled climate model time series to project impacts on fetal health. Results: We find exposure to an extra day where average temperature 25 F and 85 F during pregnancy is associated with a 1.8 and 1.7 g (respectively) reduction in birth weight, but the impact varies by SES, particularly for extreme heat, where teen mothers seem most vulnerable. We find no meaningful, significant effect on gestational age. Using projections of temperature from these climate models, we project average net reductions in birth weight in the 2070- 2099 period of 4.6 g in the business-as-usual scenario. Conclusions: Results suggest that increasing heat events from climate change could adversely impact birth weight and vary by SES.
We examine satellite-based measurements of chlorophyll solar-induced fluorescence (SIF) over the region impacted by the Russian drought and heat wave of 2010. Like the popular Normalized Difference Vegetation Index (NDVI) that has been used for decades to measure photosynthetic capacity, SIF measurements are sensitive to the fraction of absorbed photosynthetically-active radiation (fPAR). However, in addition, SIF is sensitive to the fluorescence yield that is related to the photosynthetic yield. Both SIF and NDVI from satellite data show drought-related declines early in the growing season in 2010 as compared to other years between 2007 and 2013 for areas dominated by crops and grasslands. This suggests an early manifestation of the dry conditions on fPAR. We also simulated SIF using a global land surface model driven by observation-based meteorological fields. The model provides a reasonable simulation of the drought and heat impacts on SIF in terms of the timing and spatial extents of anomalies, but there are some differences between modeled and observed SIF. The model may potentially be improved through data assimilation or parameter estimation using satellite observations of SIF (as well as NDVI). The model simulations also offer the opportunity to examine separately the different components of the SIF signal and relationships with Gross Primary Productivity (GPP).
The potential role of ion-cyclotron waves in the electron heating process has been studied, using the HOTRAY code. It is demonstrated that ion-cyclotron waves can play an important role in both the energy transfer to plasmaspheric electrons and the subsequent downward heat conduction to SAR arc altitudes. In particular, such waves can experience enhanced path integrated amplification along the steep plasmapause density gradient. The latter tends to keep the wave normal angle small on several successive bounces across the equator, thus allowing cyclotron-resonant amplification leading to a total gain of up to 20 e-foldings. When the wave propagation vector becomes highly oblique, absorption occurs during Landau resonance with thermal plasmaspheric electrons, increasing the electron temperature in the direction parallel to the ambient field and leading directly to heat conduction into ionosphere.
Detailed theoretical studies of chromospheric inhomogeneities consider dynamics as well as radiative transfer of mass flow as a consequence of energy deposition. It is shown that pressure is exerted by the heating waves, especially in inhomogeneous structures, where they can be defracted. A dynamical model is formulated that depicts the inhomogeneous structure of the chromosphere-corona transition region through mass flow regimes.
Electron and ion plasma measurements on Solar Probe are important, especially to elucidate the role of coronal holes as sources of the solar wind and to resolve the long debated question of the importance of wave heating within 20 solar radii to the acceleration of the solar wind. Adaptable instruments are required to cover the large dynamic range of parameters between 1 AU and 4 solar radii. The baseline mission would be improved, in some respects, by the addition of a second spacecraft, following the first by a distance of several solar radii. A spinning spacecraft would be satisfactory, but not essential, for the present objectives. Attention should be paid to having the heat shield electrically conducting. An instrument for ion and electron (but no composition) measurements would have a mass of approximately 10 kg, require 8 w of power, and generate data at a maximum rate of approximately 2 kbits/sec.
The work reviews some investigations into the mass and energy flow in the solar chromosphere and corona; the objective of these investigations is the development of a physical model that will not only account for the physical conditions in the outer atmosphere of the sun, but can also be applied to the study of the outer atmospheres of other stars. Particular attention is given to mass and energy flow in regions with weak and strong magnetic fields, to observational evidence for wave heating and systematic mass flows, and to heating mechanisms. Consideration is given throughout to mechanisms of energy input and energy loss.
An investigation was conducted of the two reactions: Sc + F2 yields ScF(asterisk) + F and Y + Cl2 yields YCl(asterisk) + Cl. Experiments were designed for studying the reactions under the relatively high pressure conditions (5-20 torr) appropriate for chemical laser operation. A shock tube was used to provide a short duration flow through a supersonic nozzle array. Shock wave heating is used to dissociate the ScCl3 or YCl3 at temperatures of about 6000 K, before the gases are accelerated and expanded through the supersonic nozzle array. The expanded primary flow is then mixed with a secondary flow of F2 introduced through slots at the trailing edge of each nozzle blade. Graphs show the temporal behavior of the visible spontaneous emission over the range from 3000 to 9000 A for a typical test condition, a microdensitometer tracing of the visible emission over the range from 4000 to 7000 A, and the spontaneous emission from ScF(asterisk) obtained by computer image processing of intensity data.
It is noted that the imaging proportional of the Einstein Observatory has been used to search for X-ray emission from eight radio supernova remnants which are near three of the Cos-B unidentified gamma-ray sources: 2CG 311-01, CG 327-0, and CG 333+0. Emissions are observed from three of the remnants and upper limits on the remainder which are consistent with the luminosity expected from a simple blast-wave heated plasma model of the process. Thus none of the remnants are superluminous as might be expected if the pattern of the Crab Nebula were followed. It is thought that the remnant RCW 103 may be Vela-like. It is noted that another of the remnants, Kes 27, has centrally peaked X-ray emission which is unlike the shell-like emission seen for many remnants and which does not correlate well with its asymmetric radio emission.
The accumulation of observational material (ultraviolet spectroscopic measures, quantitative optical spectroscopy, and X-ray photometry) and its use in discerning the presence and character of mass loss across the cool half of the H-R diagram and establishing constraints on theoretical models are discussed. Analogies with closed and open solar magnetic structures are found. Two determinants of atmospheric wind structure, temperature and gravity, may suffice in a most superficial way to define the wind and atmospheric structure in a star, however it is apparent that there is still a missing parameter which may stem from magnetic activity and its particular configuration. Theories that appear successful in reproducing observed line profiles, wind temperatures, and terminal velocities incorporate Alfven wave heating and momentum deposition. Successive observations of an active binary (lambda and G8III-IV) and a supergiant star, alpha Aqr (G2 Ib) revealed that magnetic activity and perhaps mass loss occur on restricted regions of a stellar surface and that long-term structures are present in the wind. These phenomena are present in the solar atmosphere and wind and may be considered a general characteristic of stellar winds.
It is shown that the acoustic wave heating theory of stellar coronae explains neither Einstein Observatory coronae data nor previous UV and X-ray observations of the sun and other stars, on the evidence of data implying that magnetic fields, stellar rotation rates and convection zone parameters figure in the determination of coronal heating. Einstein Observatory results suggest that O-type star coronae are heated by the interaction of turbulent stellar winds with slowly-decaying primordial magnetic fields or by radiative instabilities in the flow. The apparent absence of coronae in Ap stars is due to the stability of atmospheres in which even weak convection is suppressed by the strong field. Dynamo action is implicated in some normal A-type stars and in F- and later-type dwarfs. Coronal characteristics of dMe and dM stars, close binaries, and K- and M-type giants are also considered.
A computationally efficient two-stream parameterization of IR cooling is developed for a middle atmosphere dynamics model. The parameterization combines the monochromatic feature of an emissivity formulation with the computational simplicity of a single spatial integral to evaluate the monochromatic transfer equation. Calculations show strong radiative control of the mesopause region and the need for substantial deceleration of the mean zonal winds. Calculated temperatures show good agreement in the summer hemisphere where planetary wave activity is negligible, but in the polar night of the winter hemisphere they are about 30 K too cold, which suggests planetary wave heating must make up the deficit. With observed ozone densities, globally averaged radiative equilibrium temperatures in the 65-75 km region are too cold and an additional heat source about 1 K/day is required.