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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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At least 73 records · Page 4
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NASA NTRS2016

The Teaching of Anthropogenic Climate Change and Earth Science via Technology-Enabled Inquiry Education

A gap has existed between the tools and processes of scientists working on anthropogenic global climate change (AGCC) and the technologies and curricula available to educators teaching the subject through student inquiry. Designing realistic scientific inquiry into AGCC poses a challenge because research on it relies on complex computer models, globally distributed data sets, and complex laboratory and data collection procedures. Here we examine efforts by the scientific community and educational researchers to design new curricula and technology that close this gap and impart robust AGCC and Earth Science understanding. We find technology-based teaching shows promise in promoting robust AGCC understandings if associated curricula address mitigating factors such as time constraints in incorporating technology and the need to support teachers implementing AGCC and Earth Science inquiry. We recommend the scientific community continue to collaborate with educational researchers to focus on developing those inquiry technologies and curricula that use realistic scientific processes from AGCC research and/or the methods for determining how human society should respond to global change.

technology↗
NASA NTRS2017

University-Level Teaching of Anthropogenic Global Climate Change (AGCC) via Student Inquiry

This paper reviews university-level efforts to improve understanding of anthropogenic global climate change (AGCC) through curricula that enable student scientific inquiry. We examined 152 refereed publications and proceedings from academic conferences and selected 26 cases of inquiry learning that overcome specific challenges to AGCC teaching. This review identifies both the strengths and weaknesses of each of these case studies. It is the first to go beyond examining the impact of specific inquiry instructional approaches to offer a synthesis of cases. We find that inquiry teaching can succeed by concretising scientific processes, providing access to global data and evidence, imparting critical and higher order thinking about AGCC science policy and contextualising learning with places and scientific facts. We recommend educational researchers and scientists collaborate to create and refine curricula that utilise geospatial technologies, climate models and communication technologies to bring students into contact with scientists, climate data and authentic AGCC research processes. Many available science education technologies and curricula also require further research to maximise trade-offs between implementation and training costs and their educational value.

university level↗
NASA NTRS2023

Anthropogenic Aerosols Delay the Emergence of GHGs-Forced Wetting of South Asian Rainy Seasons Under a Fossil-Fuel Intensive Pathway

With continued fossil-fuel dependence, anthropogenic aerosols over South Asia are projected to increase until the mid-21st century along with greenhouse gases (GHGs). Using the Community Earth System Model (CESM1) Large Ensemble, we quantify the influence of aerosols and GHGs on South Asian seasonal precipitation patterns over the 21st century under a very high-emissions (RCP 8.5) trajectory. We find that increasing local aerosol concentrations could continue to suppress precipitation over South Asia in the near-term, delaying the emergence of precipitation increases in response to GHGs by several decades in the monsoon season and a decade in the post-monsoon season. Emergence of this wetting signal is expected in both seasons by the mid-21st century. Our results demonstrate that the trajectory of local aerosols together with GHGs will shape near-future precipitation patterns over South Asia. Therefore, constraining precipitation response to different trajectories of both forcers is critical for informing near-term adaptation efforts.

anthropogenic aerosols↗
NASA NTRS1974

Anthropogenic desertification by high-albedo pollution Observations and modeling

ERTS-1 MSS albedo data of Western Negev, Sinai and the Gaza strip are presented. A sharp contrast in albedo exists across the Negev-Sinai and Negev-Gaza strip borders. Anthropogenic desertification has occurred on the Arab side due to overgrazing and Bedouin agriculture, whereas natural vegetation grows much more abundantly on the Israeli side.

Otterman, J.↗
NASA NTRS1978

The effect of anthropogenic carbon monoxide on the methane budget of the troposphere

Photochemical model calculations indicate that significant perturbations in tropospheric OH, CH4, and related compounds may occur in the coming decades due to increased anthropogenic emissions of CO and NO(x). The magnitude and direction of the perturbation depends on future emission rates of CO and NO(x) and also on the efficiency with which urban NO(x) is transported to the ambient atmosphere. If CO and NO(x) emissions increase at comparable rates, the CO effect on OH will dominate and OH will decrease while CH4 increases. The effects of a variation in tropospheric OH, halocarbons, and other compounds include a perturbation to stratospheric ozone and the atmosphere's thermal equilibrium.

Chameides, W. L.↗
NASA NTRS1985

Tropospheric ozone - Seasonal behavior, trends, and anthropogenic influence

In the present analysis of tropospheric ozone data, attention is given to spatial and temporal variations. Two modes of seasonal behavior are noted for surface ozone at mid-latitudes: a broad summer maximum within a few hundred km of industrial/urban areas in Europe and the U.S., and a minimum in summer or autumn in sparcely populated regions that are remote from industrial activity. These and limited historical data indicate that summertime concentrations of ozone near the surface in the rural areas of Europe and the U.S. may have increased between 20 and 100 percent since the 1940s. It is suggested that the summer maximum in ozone and other observed trends are due to photochemical production associated with anthropogenic emissions of NO(x), hydrocarbons, and CO from fossil fuel combustion.

Logan, J. A.↗
NASA NTRS1985

A model investigation of the impact of increases in anthropogenic NOx emissions between 1967 and 1980 on tropospheric ozone

The impact of anthropogenic NOx emission on tropospheric ozone has been investigated. Two statistical models were used for estimating annual global emissions of NOx and for driving the trend in the emission for the years 1966-1980. Both models show a steady increase in the NOx emission, except for two brief periods of leveling off: after 1973 and after 1978. The impact was estimated by calculating the rates of emissions as functions of latitude, longitude, and year, with a one-dimensional (latitudinal) model, which included coupled tropospheric photochemistry and diffusive meridional transport. Steady-state photochemical calculations with prescribed NOx emissions appropriate for 1966 and 1980 indicate an ozone increase of 8-11 percent in the Northern Hemisphere, a result compatible with the rise in ozone suggested by the observations.

Dignon, J.↗
NASA NTRS1988

Ozone reduction in the 1980's - A model simulation of anthropogenic and solar perturbations

An interpretation of global ozone changes deduced from satellite data obtained since 1979 is presented, based on two-dimensional model simulations. The study shows that a depletion in total ozone of the order of 2 percent and a reduction in ozone density near 40 km of 7 to 12 percent over the 1979-1986 period are consistent with the observed increase in trace gas densities (chlorofluorocarbons, methane, nitrous oxide, carbon dioxide) and the simultaneous decrease in solar activity during this period. The model also suggests that ozone variations of solar and anthropogenic origins between 1979 and 1986 were of similar magnitude but that the ozone response to trace gas emissions increases substantially with latitude while the solar signal in ozone is present lower in the atmosphere and is nearly independent of latitude.

Brasseur, Guy↗
NASA NTRS1990

Influence of anthropogenic CCN on stratus microphysics

Analysis of the airborne measurements of CCN from the FIRE marine stratocumulus project of 1987 shows that continental aerosol was pervasive in air immediately above widespread stratus decks more than 500 km from the coast of California. Indications are that a large portion of the CCN component of the continental aerosol is anthropogenic. An important issue concerning continental CCN production is the question of the ratio of manmade CCN to natural particle production processes. The measurements certainly indicate that southern California air pollution or at the least continental aerosol is manifested in the cloud and above cloud aerosol.

Hudson, James G.↗
NASA NTRS1992

Natural versus anthropogenic factors affecting low-level cloud albedo over the North Atlantic

Cloud albedo plays a key role in regulating earth's climate. Cloud albedo depends on column-integrated liquid water content and the density of cloud condensation nuclei, which consists primarily of submicrometer-sized aerosol sulfate particles. A comparison of two independent satellite data sets suggests that, although anthropogenic sulfate emissions may enhance cloud albedo immediately adjacent to the east coast of the United States, over the central North Atlantic Ocean the variability in albedo can be largely accounted for by natural marine and atmospheric processes that probably have remained relatively constant since the beginning of the industrial revolution.

Falkowski, Paul G.↗
NASA NTRS1993

Possible effects of anthropogenically-increased CO2 on the dynamics of climate - Implications for ice age cycles

A dynamical model, developed to account for the observed major variations of global ice mass and atmospheric CO2 during the late Cenozoic, is used to provide a quantitative demonstration of the possibility that the anthropogenically-forced increase of atmospheric CO2, if maintained over a long period of time (perhaps by tectonic forcing), could displace the climatic system from an unstable regime of oscillating ice ages into a more stable regime representative of the pre-Pleistocene. This stable regime is characterized by orbitally-forced oscillations that are of much weaker amplitude than prevailed during the Pleistocene.

Saltzman, Barry↗
NASA NTRS1999

Increasing CO2 Coupled with Other Anthropogenic Perturbations: Effects on Ozone and Other Trace Gases

The GSFC 2D interactive chemistry-radiation-dynamics model has been used to study the effects on stratospheric trace gases of past and future CO2 increases coupled with changes in CFC'S, methane, and nitrous oxide. Previous simulations with the GSFC model showed that the stratospheric cooling calculated to result from doubling atmospheric CO2 would lead, in the absence of a growth of other anthropogenic gases, to a decrease in upper stratospheric NO(y) of roughly 15%. This work has been extended to simulate changes in stratospheric chemistry and dynamics occurring between the years 1960 and 2050. The simulations have been carried out with and without changes in CO2. In the low latitude upper stratosphere ozone is predicted to be 10% greater in 2050 than in 1990 when increased CO2 is included, compared with an increase of only 2% without the inclusion of CO2. In the low latitude lower stratosphere, ozone is predicted to decrease by about 1% between 1990 and 2050 when CO2 changes are taken into account, in contrast to an approximate 3% increase when they are not. The simulated behavior of water vapor is another example of the coupled responses. Between 1990 and 2050 low latitude water vapor is predicted to increase by 4% and 2% in the upper and lower stratosphere, respectively, without the inclusion of CO2 increases. with the inclusion of CO2 changes, the water vapor increases are predicted to be roughly 12% and 8%, for the upper and lower stratosphere, respectively.

Rosenfield, J. E.↗
NASA NTRS2000

Coupling Satellite and Ground-Based Instruments to Map Climate Forcing by Anthropogenic Aerosols

Climate forcing by anthropogenic aerosols is a significant but highly uncertain factor in global climate change. Only satellites can offer the global coverage essential to reducing this uncertainty; however, satellite measurements must be coupled with correlative, in situ measurements both to constrain the aerosol optical properties required in satellite retrieval algorithms and to provide chemical identification of aerosol sources. This grant funded the first two years of a three-year project which seeks to develop methodologies for combining spaceborne lidar with in-situ aerosol data sets to improve estimates of direct aerosol climate forcing. Progress under this two-year grant consisted in the development and deployment of a new in-situ capability for measuring aerosol 180' backscatter and the extinction-to-backscatter ratio. This new measurement capacity allows definitive lidar/in-situ comparisons and improves our ability to interpret lidar data in terms of climatically relevant quantities such as the extinction coefficient and optical depth. Measurements were made along the coast of Washington State, in Central Illinois, over the Indian Ocean, and in the Central Pacific. Thus, this research, combined with previous measurements by others, is rapidly building toward a global data set of extinction-to-backscatter ratio for key aerosol types. Such information will be critical to interpreting lidar data from the upcoming PICASSO-CENA, or P-C, satellite mission. Another aspect of this project is to investigate innovative ways to couple the lidar-satellite signal with targeted in-situ measurements toward a direct determination of aerosol forcing. This aspect is progressing in collaboration with NASA Langley's P-C lidar simulator and radiative transfer modeling by the University of Lille, France.

Charlson, Robert J.↗
NASA NTRS2000

Coupling Satellite and Ground-Based Instruments to Map Climate Forcing by Anthropogenic Aerosol

Climate forcing by anthropogenic aerosols is a significant but highly uncertain factor in global climate change. Only satellites can offer the global coverage essential to reducing this uncertainty; however, satellite measurements must be coupled with correlative, in situ measurements both to constrain the aerosol optical properties required in satellite retrieval algorithms and to provide chemical identification of aerosol sources. This grant funded the third year of a three-year project which seeks to develop methodologies for combining spaceborne lidar with in-situ aerosol data sets to improve estimates of direct aerosol climate forcing. Progress under this one-year grant consisted in analysis and publication of field studies using a new in-situ capability for measuring aerosol 180 deg backscatter and the extinction-to-backscatter ratio. This new measurement capacity allows definitive lidar/in-situ comparisons and improves our ability to interpret lidar data in terms of climatically relevant quantities such as the extinction coefficient and optical depth. Analyzed data consisted of measurements made along the coast of Washington State, in Central Illinois, over the Indian Ocean, and in the Central Pacific. Thus, this research, combined with previous measurements by others, is rapidly building toward a global data set of extinction-to-backscatter ratio for key aerosol types. Such information will be critical to interpreting lidar data from the upcoming PICASSO-CENA, or P-C, satellite mission. Another aspect of this project is to investigate innovative ways to couple the lidar-satellite signal with target in-situ measurements toward a direct determination of aerosol forcing. This aspect is progressing in collaboration with NASA Langley's P-C lidar simulator.

Charlson, Robert J.↗
NASA NTRS2009

Detecting Anthropogenic Impacts on Lightning: Is There an Obvious Signal?

Bell et al. inferred the presence of increased (decreased) summer rainfall and storm heights over the southern tier (off the east coast) of the continental U.S. (CONUS) during the midweek. Amongst other data sources, the Bell et al. study employed Tropical Rainfall Measurement Mission (TRMM) passive microwave and precipitation radar data to reach these conclusions. Importantly, to explain the midweek increases in rainfall and storm echo top heights Bell et al. invoked the presence of anthropogenic influences via increased aerosol loading present in the middle of the work week. Conversely, Schultz et al. argue against the Bell et al. findings, noting that no significant trend in rainfall (amount or occurrence) can be detected in rain gauge data collected from 219 surface observing stations over a 42 year period. Based on previously suggested impacts of enhanced aerosol concentrations on precipitation microphysics and in particular, the ice phase, the results of Bell et al. suggest that in addition to the rainfall signal there may be a detectable response in lightning frequency (to the extent that the aerosol hypothesis invoked is valid). This study examines TRMM Lightning Imaging Sensor observations to detect both daily increases and decreases of lightning over the CONUS and neighboring ocean regions and further examines the possibility (through observations) of systematic direct impacts on lightning activity associated with large city locations.

Petersen, Walter A.↗
NASA NTRS2010

Solar Cycle and Anthropogenic Forcing of Surface-Air Temperature at Armagh Observatory, Northern Ireland

A comparison of 10-yr moving average (yma) values of Armagh Observatory (Northern Ireland) surface-air temperatures with selected solar cycle indices (sunspot number (SSN) and the Aa geomagnetic index (Aa)), sea-surface temperatures in the Nino 3.4 region, and Mauna Loa carbon dioxide (CO2) (MLCO2) atmospheric concentration measurements reveals a strong correlation (r = 0.686) between the Armagh temperatures and Aa, especially, prior to about 1980 (r = 0.762 over the interval of 1873-1980). For the more recent interval 1963-2003, the strongest correlation (r = 0.877) is between Armagh temperatures and MLCO2 measurements. A bivariate fit using both Aa and Mauna Loa values results in a very strong fit (r = 0.948) for the interval 1963-2003, and a trivariate fit using Aa, SSN, and Mauna Loa values results in a slightly stronger fit (r = 0.952). Atmospheric CO2 concentration now appears to be the stronger driver of Armagh surface-air temperatures. An increase of 2 C above the long-term mean (9.2 C) at Armagh seems inevitable unless unabated increases in anthropogenic atmospheric gases can be curtailed. The present growth in 10-yma Armagh temperatures is about 0.05 C per yr since 1982. The present growth in MLCO2 is about 0.002 ppmv, based on an exponential fit using 10-yma values, although the growth appears to be steepening, thus, increasing the likelihood of deleterious effects attributed to global warming.

Wilson, Robert M.↗
NASA NTRS2014

Impacts of Intercontinental Transport of Anthropogenic Fine Particulate Matter on Human Mortality

Fine particulate matter with diameter of 2.5 microns or less (PM2.5) is associated with premature mortality and can travel long distances, impacting air quality and health on intercontinental scales. We estimate the mortality impacts of 20 % anthropogenic primary PM2.5 and PM2.5 precursor emission reductions in each of four major industrial regions (North America, Europe, East Asia, and South Asia) using an ensemble of global chemical transport model simulations coordinated by the Task Force on Hemispheric Transport of Air Pollution and epidemiologically-derived concentration-response functions. We estimate that while 93-97 % of avoided deaths from reducing emissions in all four regions occur within the source region, 3-7 % (11,500; 95 % confidence interval, 8,800-14,200) occur outside the source region from concentrations transported between continents. Approximately 17 and 13 % of global deaths avoided by reducing North America and Europe emissions occur extraregionally, owing to large downwind populations, compared with 4 and 2 % for South and East Asia. The coarse resolution global models used here may underestimate intraregional health benefits occurring on local scales, affecting these relative contributions of extraregional versus intraregional health benefits. Compared with a previous study of 20 % ozone precursor emission reductions, we find that despite greater transport efficiency for ozone, absolute mortality impacts of intercontinental PM2.5 transport are comparable or greater for neighboring source-receptor pairs, due to the stronger effect of PM2.5 on mortality. However, uncertainties in modeling and concentration-response relationships are large for both estimates.

human health↗
NASA NTRS2012

Mixing of Dust and NH3 Observed Globally over Anthropogenic Dust Sources

The global distribution of dust column burden derived from MODIS Deep Blue aerosol products is compared to NH3 column burden retrieved from IASI infrared spectra. We found similarities in their spatial distributions, in particular their hot spots are often collocated over croplands and to a lesser extent pastures. Globally, we found 22% of dust burden collocated with NH3, with only 1% difference between land-use databases. This confirms the importance of anthropogenic dust from agriculture. Regionally, the Indian subcontinent has the highest amount of dust mixed with NH3 (26 %), mostly over cropland and during the pre-monsoon season. North Africa represents 50% of total dust burden but accounts for only 4% of mixed dust, which is found over croplands and pastures in Sahel and the coastal region of the Mediterranean. In order to evaluate the radiative effect of this mixing on dust optical properties, we derive the mass extinction efficiency for various mixtures of dust and NH3, using AERONET sunphotometers data. We found that for dusty days the coarse mode mass extinction efficiency decreases from 0.62 to 0.48 square meters per gram as NH3 burden increases from 0 to 40 milligrams per square meter. The fine mode extinction efficiency, ranging from 4 to 16 square mters per gram, does not appear to depend on NH3 concentration or relative humidity but rather on mineralogical composition and mixing with other aerosols. Our results imply that a significant amount of dust is already mixed with ammonium salt before its long range transport. This in turn will affect dust lifetime, and its interactions with radiation and cloud properties

dust sources↗