nasa-gesdisc/es-publications-researchareas huggingface dataset:
Explosive connections? Mass media, social media, and the geography of collective violence in African states (2015)

Growing evidence indicates that the diffusion of information and communication technologies (ICTs) can substantially alter the contours of collective violence in developing nations. However, empirical investigations of such effects have generally been hampered by an inability to systematically measure geographic variation in ICT penetration, across multiple technologies and multiple countries. In this article, I show that geo-referenced household surveys can be used to estimate subnational differences in the spatial reach of radio and cellular communications infrastructures in 24 African states. By combining these estimates with geo-referenced measures of the location of disaggregated events of collective violence, I show that there are important differences between centralized mass communication technologies  such as radios  that foster vertical linkages between state and society, and decentralized social communication technologies  such as cell phones  that foster horizontal linkages between the members of a society. The evidence demonstrates that the geographic reach of mass media penetration generates substantial pacifying effects, while the reach of social media penetration generates substantial increases in collective violence, especially in areas lacking access to mass media infrastructure. I argue that these findings are consistent with a theory of ICT effects which focuses on the strengthening and weakening of economies of scale in the marketplace of ideas.

Research areas: Habitat Conversion/Fragmentation
Observations of supermicron-sized aerosols originating from biomass burning in southern Central Africa (2021)

Abstract. During the 3 years of the ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) campaign, the NASA Orion P-3 was equipped with a 2D stereo (2D-S) probe that imaged particles with maximum dimension (D) ranging from 10 < D < 1280 m. The 2D-S recorded supermicron-sized aerosol particles (SAPs) outside of clouds within biomass burning plumes during flights over the southeastern Atlantic off Africa's coast. Numerous SAPs with 10 < D < 1520 m were observed in 2017 and 2018 at altitudes between 1230 and 4000 m, 1000 km from the coastline, mostly between 711 S. No SAPs were observed in 2016 as flights were conducted further south and further from the coastline. Number concentrations of refractory black carbon (rBC) measured by a single particle soot photometer ranged from 200 to 1200 cm3 when SAPs were observed. Transmission electron microscopy images of submicron particulates, collected on Holey carbon grid filters, revealed particles with potassium salts, black carbon (BC), and organics. Energy-dispersive X-ray spectroscopy spectra also detected potassium, a tracer for biomass burning. These measurements provided evidence that the submicron particles originated from biomass burning. NOAA Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) 3 d back trajectories show a source in northern Angola for times when large SAPs were observed. Fire Information for Resource Management System (FIRMS) Moderate Resolution Imaging Spectroradiometer (MODIS) 6 active fire maps showed extensive biomass burning at these locations. Given the back trajectories, the high number concentrations of rBC, and the presence of elemental tracers indicative of biomass burning, it is hypothesized that the SAPs imaged by the 2D-S are examples of BC aerosol, ash, or unburned plant material.

Research areas: Air Quality, Environmental Impacts
Large simulated radiative effects of smoke in the south-east Atlantic (2018)

Abstract. A 12001200 km2 area of the tropical South Atlantic Ocean near Ascension Island is studied with the HadGEM climate model at convection-permitting and global resolutions for a 10-day case study period in August 2016. During the simulation period, a plume of biomass burning smoke from Africa moves into the area and mixes into the clouds. At Ascension Island, this smoke episode was the strongest of the 2016 fire season.The region of interest is simulated at 4 km resolution, with no parameterised convection scheme. The simulations are driven by, and compared to, the global model. For the first time, the UK Chemistry and Aerosol model (UKCA) is included in a regional model with prognostic aerosol number concentrations advecting in from the global model at the boundaries of the region.Fire emissions increase the total aerosol burden by a factor of 3.7 and cloud droplet number concentrations by a factor of 3, which is consistent with MODIS observations. In the regional model, the inversion height is reduced by up to 200 m when smoke is included. The smoke also affects precipitation, to an extent which depends on the model microphysics. The microphysical and dynamical changes lead to an increase in liquid water path of 60 g m2 relative to a simulation without smoke aerosol, when averaged over the polluted period. This increase is uncertain, and smaller in the global model. It is mostly due to radiatively driven dynamical changes rather than precipitation suppression by aerosol.Over the 5-day polluted period, the smoke has substantial direct radiative effects of +11.4 W m2 in the regional model, a semi-direct effect of 30.5 W m2 and an indirect effect of 10.1 W m2. Our results show that the radiative effects are sensitive to the structure of the model (global versus regional) and the parameterization of rain autoconversion. Furthermore, we simulate a liquid water path that is biased high compared to satellite observations by 22 % on average, and this leads to high estimates of the domain-averaged aerosol direct effect and the effect of the aerosol on cloud albedo. With these caveats, we simulate a large net cooling across the region, of 27.6 W m2.

Research areas: Environmental Impacts
The increasing impact of weather on electricity supply and demand (2018)

Wind and solar power have experienced rapid cost declines and are being deployed at scale. However, their output variability remains a key problem for managing electricity systems, and the implications of multi-day to multi-year variability are still poorly understood. As other energy-using sectors are electrified, the shape and variability of electricity demand will also change. We develop an open framework for quantifying the impacts of weather on electricity supply and demand using the Renewables.ninja and DESSTINEE models. We demonstrate this using a case study of Britain using National Grid's Two Degrees scenario forwards to 2030. We find the British electricity system is rapidly moving into unprecedented territory, with peak demand rising above 70 GW due to electric heating, and intermittent renewable output exceeding demand as early as 2021. Hourly ramp-rates widen by 50% and year-to-year variability increases by 80%, showing why future power system studies must consider multiple years of data, and the influence of weather on both supply and demand. Our framework is globally applicable, and allows detailed scenarios of hourly electricity supply and demand to be explored using only limited input data such as annual quantities from government scenarios or broader energy systems models.

Research areas: Energy Production/Use
Constraining the relationships between aerosol height, aerosol optical depth and total column trace gas measurements using remote sensing and models (2020)

Abstract. Proper quantification of the aerosol vertical height is essential to constrain the atmospheric distribution and lifetime of aerosols, as well as their impact on the environment. We use globally distributed, daily averaged measurements of aerosol stereo heights of fire aerosols from the Multi-angle Imaging SpectroRadiometer (MISR) to understand the aerosol distribution. We also connect these results with a simple plume rise model and a new multi-linear regression model approach based on daily measurements of NO2 from OMI and CO from MOPITT to understand and model the global aerosol vertical height profile over biomass burning regions. First, plumes associated with the local dry-burning season at midlatitudes to high latitudes frequently have a substantial fraction lofted into the free troposphere and in some cases even the stratosphere. Second, plumes mainly associated with less-polluted regions in developing countries and heavily forested areas tend to stay closer to the ground, although they are not always uniformly distributed throughout the boundary layer. Third, plumes associated with more serious loadings of pollution (such as in Africa, Southeast Asia and northeast China) tend to have a substantial amount of smoke transported uniformly through the planetary boundary layer and up to around 3 km. Fourth, the regression model approach yields a better ability to reproduce the measured heights compared to the plume rise model approach. This improvement is based on a removal of the negative bias observed from the plume model approach, as well as a better ability to work under more heavily polluted conditions. However, over many regions, both approaches fail, requiring deeper work to understand the physical, chemical and dynamical reasons underlying the failure over these regions.

Research areas: Air Quality, Environmental Impacts
Copper distribution in European topsoils: An assessment based on LUCAS soil survey (2018)

Copper (Cu) distribution in soil is influenced by climatic, geological and pedological factors. Apart from geological sources and industrial pollution, other anthropogenic sources, related to the agricultural activity, may increase copper levels in soils, especially in permanent crops such as olive groves and vineyards. This study uses 21,682 soil samples from the LUCAS topsoil survey to investigate copper distribution in the soils of 25 European Union (EU) Member States. Generalized Linear Models (GLM) were used to investigate the factors driving copper distribution in EU soils. Regression analysis shows the importance of topsoil properties, land cover and climate in estimating Cu concentration. Meanwhile, a copper regression model confirms our hypothesis that different agricultural management practices have a relevant influence on Cu concentration. Besides the traditional use of copper as a fungicide for treatments in several permanent crops, the combined effect of soil properties such as high pH, soil organic carbon and clay, with humid and wet climatic conditions favours copper accumulation in soils of vineyards and tree crops. Compared to the overall average Cu concentration of 16.85 mg kg1, vineyards have the highest mean soil Cu concentration (49.26 mg kg1) of all land use categories, followed by olive groves and orchards. Gaussian Process Regression (GPR) combined with kriging were used to map copper concentration in topsoils and to evidence the presence of outliers. GPR proved to be performant in predicting Cu concentration, especially in combination with kriging, accounting for 66% of Cu deviance. The derived maps are novel as they include information about the importance of topsoil properties in the copper mapping process, thus improving its accuracy. Both models highlight the influence of land management practices in copper concentration and the strong correlation between topsoil copper and vineyards.

Research areas: Agriculture
Desert Dust, Industrialization, and Agricultural Fires: Health Impacts of Outdoor Air Pollution in Africa (2019)

The African continent continuously experiences extreme aerosol load conditions, during which the World Health Organization clean air standard of 10 μg/m<SUP>3</SUP> of PM<SUB>2.5</SUB> mass is systematically exceeded. Africa holds the world largest source of desert dust emissions, undergoes strong industrial growth, and produces approximately a third of the Earth's biomass burning aerosol particles. Sub-Saharan biomass burning is driven by agricultural practices, such as burning fields and bushes in the postharvest season for fertilization, land management, and pest control. Thus, these emissions are predominantly anthropogenic. Here we use global atmospheric composition, climate, and health models to simulate the chemical composition of the atmosphere and calculate the mortality rates for Africa by distinguishing between purely natural, industrial/domestic, and biomass burning emissions. Air quality-related deaths in Africa rank within the top leading causes of death in Africa. Our results of 780,000 premature deaths annually point to the extensive health impacts of natural emissions, high mortality rate caused by industrialization in Nigeria and South Africa, and a smaller extent by fire emissions in Central and West Africa. In Africa, 43,000 premature deaths are linked to biomass burning mainly driven by agriculture. Our results also show that natural sources, in particular windblown dust emissions, have large impacts on air quality and human health in Africa.

Research areas: Environmental Impacts
Smoke emissions from biomass burning in a Mediterranean shrubland (2010)

Gaseous and particulate samples from the smoke from prescribed burnings of a shrub-dominated forest with some pine trees in Lousa Mountain, Portugal, in May 2008, have been collected. From the gas phase Fourier transform infrared (FTIR) measurements, an average modified combustion efficiency of 0.99 was obtained, suggesting a very strong predominance of flaming combustion. Gaseous compounds whose emissions are promoted in fresh plumes and during the flaming burning phase, such as CO2, acetylene and propene, produced emission factors higher than those proposed for savannah and tropical forest fires. Emission factors of species that are favoured by the smouldering phase (e.g. CO and CH4) were below the values reported in the literature for biomass burning in other ecosystems. The chemical composition of fine (PM2.5) and coarse (PM2.510) particles was achieved using ion chromatography (water-soluble ions), instrumental neutron activation analysis (trace elements) and a thermaloptical transmission technique (organic carbon and elemental carbon). Approximately 50% of the particulate mass was carbonaceous in nature with a clear dominance of organic carbon. The organic carbon-to-elemental carbon ratios up to 300, or even higher, measured in the present study largely exceeded those reported for fires in savannah and tropical forests. More than 30 trace elements and ions have been determined in smoke aerosols, representing in total an average contribution of about 7% to the PM10 mass.

Research areas: Environmental Impacts
Biomass Burning Over the United States East Coast and Western North Atlantic Ocean: Implications for Clouds and Air Quality (2021)

Biomass burning (BB) aerosol events were characterized over the U.S. East Coast and Bermuda over the western North Atlantic Ocean (WNAO) between 2005 and 2018 using a combination of ground-based observations, satellite data, and model outputs. Days with BB influence in an atmospheric column (BB days) were identified using criteria biased toward larger fire events based on anomalously high AERONET aerosol optical depth (AOD) and MERRA-2 black carbon (BC) column density. BB days are present year-round with more in June-August (JJA) over the northern part of the East Coast, in contrast to more frequent events in March-May (MAM) over the southeast U.S. and Bermuda. BB source regions in MAM are southern Mexico and by the Yucatan, Central America, and the southeast U.S. JJA source regions are western parts of North America. Less than half of the BB days coincide with anomalously high PM<SUB>2.5</SUB> levels in the surface layer, according to data from 14 IMPROVE sites over the East Coast. Profiles of aerosol extinction suggest that BB particles can be found in the boundary layer and into the upper troposphere with the potential to interact with clouds. Higher cloud drop number concentration and lower drop effective radius are observed during BB days. In addition, lower liquid water path is found during these days, especially when BB particles are present in the boundary layer. While patterns are suggestive of cloud-BB aerosol interactions over the East Coast and the WNAO, additional studies are needed for confirmation.

Research areas: Environmental Impacts
Trade Layoffs and Hate in the United States (2021)

ObjectiveRecent events (e.g., Brexit) have highlighted how globalization may foster hostility toward outgroups in developed democracies. Is trade competition systematically related to hate in the United States?MethodsI conduct a countylevel statistical analysis using data from the Trade Adjustment Assistance program, the FBI's Hate Crime Statistics database, and the Southern Poverty Law Center's hate group map over the period of 20032017.ResultsCounties with more traderelated layoffs tend to have more hate groups, though not hate crimes, even after accounting for changes in unemployment rates. The relationship between trade layoffs and hate groups is strongest in counties that have recently experienced larger decreases in the share of the white population.ConclusionsAlthough existing studies on diffuse economic vulnerability and hate find a weak connection between economic factors and hate, trade layoffs can explain some variation in local hate group activity.

Research areas: Habitat Conversion/Fragmentation
Manure Application Decisions Impact Nitrous Oxide and Carbon Dioxide Emissions during NonGrowing Season Thaws (2019)

 Core Ideas Manure injection increased N2O emissions vs. broadcast and broadcast + plow application. Winter thaws increased N2O and CO2 emissions, particularly in soils injected with manure. The impacts of manure application decisions may extend beyond the growing season to influence N2O and CO2 fluxes during winter thaw events. Climate and agricultural management are strong drivers of greenhouse gas (GHG) emissions, but little is known about potential interactions among these drivers. Climate change will likely increase the frequency of wintertime thaws in northern agricultural systems, which have been shown to induce large pulses of carbon dioxide (CO2) and nitrous oxide (N2O). We tested the hypothesis that different manure application practices would interact with thaw events to produce GHG emission pulses of different sizes. Specifically, we expected manure injection would increase CO2 and N2O emissions relative to other manure application methods by enhancing subsurface microbial substrate availability. We conducted a laboratory incubation study with frozen, intact soil cores from a continuous corn (Zea mays L.) system under three manure application methods: broadcast, broadcast + plow, and injection. Cores were subjected to three temperature treatments over 8 d: frozen (7C), freezethaw (alternating 7 and 5C), and thaw (5C). In the freezethaw and thaw treatments, cumulative N2O emissions were 2 to 20 times greater in injected versus broadcast treatments (6.5 mg N2ON m2 averaged across broadcast treatments); cumulative CO2 emissions were up to two times higher in injected versus broadcast treatments (1017 mg CO2C m2 averaged across broadcast treatments). Our results suggest that the impacts of manure application choices extend beyond the growing season to increase N2O and CO2 emissions during wintertime thaws, potentially interacting with a warming climate to increase GHG emissions.

Research areas: Greenhouse Gases
Global trends in evapotranspiration dominated by increases across large cropland regions (2020)

Irrigated croplands require large annual water inputs and are critical to global food production. Actual evapotranspiration (AET) is a main index of water use in croplands, and several remote-sensing products have been developed to quantify AET at the global scale. In this study, we estimate global trends in actual AET, potential ET (PET), and precipitation rate (PP) utilizing the MODIS Evapotranspiration product (20012018) within the Google Earth Engine cloud-computing environment. We then introduce a new index based on a combination of AET, PET, and PP estimatesthe evapotranspiration warning index (ETWI)which we use to evaluate the sustainability of observed AET trends. We show that while AET has not considerably changed across global natural lands, it has significantly increased across global croplands (+14%  5%). The average ETWI for global croplands is 0.40  0.25, which is largely driven by an extreme trend in AET, exceeding both PET and PP trends. Furthermore, the trends in water and energy limited areas demonstrate, on a global scale, while AET and PET do not have significant trends in both water and energy limited areas, the increasing trend of PP in energy-limited areas is more than water-limited areas. Averaging cropland ETWI trends at the country level further revealed nonsustainable trends in cropland water consumptions in Thailand, Brazil, and China. These regions were also found to experiencing some of the largest increases in net primary production (NPP) and solar-induced fluorescence (SIF), suggesting that recent increases in food production may be dependent on unsustainable water inputs. Globally, irrigated maize was found to be associated with nonsustainable AET trends relative to other crop types. We present an online open access application designed to enable near real-time monitoring and improve the understanding of global water consumption and availability.

Research areas: Habitat Conversion/Fragmentation
Understanding the Potential of Wind Farm Exploitation in Tropical Island Countries: A Case for Indonesia (2021)

Countries worldwide must dramatically reduce their emissions to achieve the goal of limiting temperature increases in line with the Paris Agreement. Involving developing countries in global actions on emission reduction will greatly enhance the effectiveness of global warming mitigation. This study investigated the feasibility of establishing a wind farm at four onshore and three offshore sites in Indonesia. Installing wind turbines with the highest hub height, largest rotor diameter, and lowest cut-in and rated wind speed in an identified area off Wetar Island presented the highest time-based availability and a capacity factor of 46%, as well as the highest power-based availability at 76%. The levelized cost of electricity at 0.082 USD/kWh was comparable to that of power generated from fossil fuels, which ranges from 0.07 to 0.15 USD/kWh in Indonesia. Increasing the feed-in-tariff for wind power from the current 0.08 USD/kWh would provide sufficient incentive for investment. Moving subsidies from fossil fuels toward renewables would facilitate the transition to low-carbon renewables without increasing the financial burden on the country.

Research areas: Energy Production/Use
Global emissions of NH3, NOx, and N2O from biomass burning and the impact of climate change (2021)

Emissions of ammonia (NH3), oxides of nitrogen (NOx; NO +NO2), and nitrous oxide (N2O) from biomass burning were quantified on a global scale for 2001 to 2015. On average biomass burning emissions at a global scale over the period were as follows: 4.53  0.51 Tg NH3 year1, 14.65  1.60 Tg NOx year1, and 0.97  0.11 Tg N2O year1. Emissions were comparable to other emissions databases. Statistical regression models were developed to project NH3, NOx, and N2O emissions from biomass burning as a function of burn area. Two future climate scenarios (RCP 4.5 and RCP 8.5) were analyzed for 20502055 (mid-century) and 20902095 (end of century). Under the assumptions made in this study, the results indicate emissions of all species are projected to increase under both the RCP 4.5 and RCP 8.5 climate scenarios.Implications: This manuscript quantifies emissions of NH3, NOx, and N2O on a global scale from biomass burning from 20012015 then creates regression models to predict emissions based on climate change. Because reactive nitrogen emissions have such an important role in the global nitrogen cycle, changes in these emissions could lead to a number of health and environmental impacts.

Research areas: Environmental Impacts