E-Supplement to the Relocation of the Seismicity in Central Asia using the Global RSTT model
Explore the source record for details and available documents.
Chiang, Andrea↗
SEARCH · Engineering Papers
Results for “Asia”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Global source apportionment of aerosols into major emission regions and sectors over 1850–2017
Anthropogenic emissions of aerosols and precursor gases have changed significantly in the past few decades around the world. In this study, the Explicit Aerosol Source Tagging (EAST) system is merged into the Energy Exascale Earth System Model version 1 (E3SMv1) to quantify the variations in anthropogenic aerosol concentrations, source contributions, and their subsequent radiative impact in four major emission regions across the globe during 1850–1980, 1980–2010, and 2010–2017. In North America and Europe, changes in anthropogenic PM 2.5 were mainly caused by changes in emissions from local energy and industrial sectors. The local industrial sector caused the largest increase in PM 2.5 in East Asia during 1980–2010 and decrease during 2010–2017. In South Asia, the increase in energy-related emissions dominated the rise in PM 2.5 levels during 1980–2017. During 1850–1980, the increases in emissions from North America contributed to the increase in the European PM 2.5 burden by 1.7 mg m -2 and the sources from the Europe were also responsible for the PM 2.5 burden increase in East Asia and South Asia by about 1.0 mg m -2 . During 1980–2010, East Asia contributed to an increase of 0.4–0.6 mg m -2 in the PM 2.5 burden in North America and Europe, while South Asia contributed about 0.3 mg m -2 . During 2010–2017, the contributions from East Asia to the PM 2.5 burdens in the North America, Europe, and South Asia declined by 0.3–0.6 mg m -2 due to the clean air actions in China, while the contributions from South Asia still increased due to the continuous increase in emissions in South Asia. The historical changes in aerosols had an impact on effective radiative forcing through aerosol–radiation interactions (ERF ari ). During 1980–2010, a decline in North American aerosols resulted in a positive ERF ari change (warming effect) in Europe and a decline in aerosols in Europe caused a warming effect in Russia and northern China. The changes in ERF ari from the increase and decrease in aerosols in China during 1980–2010 and 2010–2017, respectively, are comparable in magnitude. The continuous aerosol increases in South Asia from 1980 to 2017 resulted in negative ERF ari (cooling) changes in South Asia, Southeast Asia, and southern China.
54 ENVIRONMENTAL SCIENCES↗
Performance evaluation of CMIP6 models on the Arctic-Siberian Plain teleconnection affecting the East Asian heat waves
The frequency and intensity of summer heat waves in East Asia have increased sharply in recent decades, significantly impacting public health and the economy. The Arctic-Siberian Plain (ASP) teleconnection pattern has been identified as a key driver, with ASP warming amplifying atmospheric circulation patterns conducive to extreme temperatures. This study evaluates the ability of Coupled Model Inter-comparison Project phase 6 models to simulate the ASP pattern across interannual variability (IAV) and intra-seasonal variability (ISV) timescales using the Common Basis Function method. The multi-model mean shows statistically significant pattern correlations with ERA5 reanalysis, with correlation coefficients of 0.90 and 0.99 for IAV and ISV, respectively. While the ASP pattern is generally well captured, models exhibit substantial inter-model diversity in the intensity and position of anticyclonic anomalies over the ASP and East Asia. Models with ASP pattern variability similar to reanalysis better reproduce extreme East Asian temperatures, whereas those over- or underestimating ASP variability exhibit lower skill. These performance differences are related to differences in simulating key variables associated with the development of the ASP pattern. Our findings highlight the role of the ASP pattern in modulating extreme heat events, as models with improved ASP simulations align more closely with observed temperature extremes. Refining ASP representations in models could enhance seasonal heat wave predictions, improving climate adaptation strategies.
Arctic-Siberian Plain (ASP)↗
Probing Cretaceous-Paleogene crustal thickness in southern Tibet using quartz-zircon chronobarometry
Knowledge of the crustal thickness history of southern Tibet during the India-Asia collision is key to understanding what deformation mechanisms accommodated northward propagating crustal shortening. Thermoisotopic models suggest that a relatively thin margin of southern Asia persisted from ca. 200 to 45 Ma whereas trace element paleodepth proxies are interpreted to indicate a thinning phase from ca. 100 to 65 Ma when the crust reached ∼30 km-thickness. As neither of these methods directly measures crustal thickness, resolution of this conflict awaits development of a method that can. Here, in this study, we place bounds on the thickening history of southern Tibet using coupled quartz-zircon thermobarometry and U-Pb geochronology of granitoid plutons in the Gangdese batholith. We find that crustal thicknesses were as high (or higher) as 60–75 km at 65 Ma, or 10–15 Ma prior to the onset of hard continental collision. Magmatic inflation in the lower crust likely contributed to crustal thickening and thermal weakening of the lower crust, suggesting that pure shear in the lower crust was likely the primary accommodation mechanism for N-S shortening during collision. These data are in partial agreement with results of thermoisotopic models of crustal thickness but contradict thickness histories derived from empirical trace element proxies.
Chronobarometry↗
Urbanization exacerbates continental- to regional-scale warming
Urbanization is usually ignored when estimating past changes in large-scale climate and for future climate projections since cities historically covered a small fraction of the Earth’s surface. Here, by combining global land surface temperature observations with historical estimates of urban area, we demonstrate that the urban contribution to continental- to regional-scale warming has become non-negligible, especially for rapidly urbanizing regions and countries in Asia. Consequently, expected urban expansion over the next century suggests further increased urban influence on large-scale surface climate in the future (approximately 0.16 K for North America and Europe for high-emission scenario in 2100). Based on these results, also seen for air temperature, we argue that, in line with other forms of land use/land cover change, urbanization should be explicitly included in climate change assessments. This requires incorporation of dynamic urban extent and biophysics in current-generation Earth system models to quantify potential urban feedback on the climate system across scales.
Chakraborty, TC↗
Increased Asian Sulfate Aerosol Emissions Remarkably Enhance Sahel Summer Precipitation
Observational evidence shows that Sahel summer precipitation has experienced a considerable increase since the 1980s, coinciding with significant diverging trends of increased sulfate emissions in Asia and decreased emissions in Europe (dipole pattern of aerosols between Asia and Europe). The decrease in European sulfate aerosols has substantial effects on the Sahel summer precipitation increase, but the corresponding effect of increased Asian sulfate is unknown. Multi-model simulations in the Precipitation Driver and Response Model Intercomparison Project (PDRMIP) show, compared to decreased European aerosols, that increased Asian aerosols similarly enhance the Sahel summer precipitation but with different large-scale atmospheric circulation changes. Further analysis of the Sixth Coupled Model Intercomparison Project (CMIP6) simulations under historical attribution and various emission scenarios reinforces the results about the climate impacts of anthropogenic aerosols and suggests that in future scenarios with strong international cooperation and rapid climate mitigations (SSP2-45), the Sahel drought will be intensified likely due to the decline in Asian aerosol emissions. Our results suggest that Asian anthropogenic aerosols are likely a non-negligible driver of the recent recovery in Sahel precipitation amounts
54 ENVIRONMENTAL SCIENCES↗
Radiocarbon Fingerprinting Black Carbon Source History in the Himalayas
Abstract Black carbon (BC) is considered as an important contributor to the Himalayan glaciers melt in the past few decades. However, the long‐term source apportionment of BC remains unclear. Here we present the first radiocarbon ( 14 C)‐based annual variation of BC source apportionment in an ice core spanning the period of 1959–2012 drilled from the Southeastern Tibetan Plateau, a receptor site of South Asia outflow. We find fossil fuel combustion is a major contribution (73% ± 5%), yet the biomass burning fraction ( ƒ biomass ) has grown from 24% ± 4% to 30% ± 4% since 1990. Intriguingly, we further find the ƒ biomass demonstrating a robust correlation with South Asian wildfires linked to climate oscillations. Thus, for mitigating BC impacts on Himalayan glaciers, South Asia's transition from fossil fuels to clean energy is a more efficient and urgent strategy than reducing residential biomass burning.
Wang, Mo [State Key Laboratory of Tibetan Plateau ↗
The Collaborative Seismic Earth Model: Generation 2
Geological interpretations, earthquake source inversions and ground motion modeling, among other applications, require models that jointly resolve crustal and mantle structure. With the second generation of the Collaborative Seismic Earth Model (CSEM2), we present a global multi-resolution tomographic Earth model that serves this purpose. The model evolves through successive regional- and global-scale refinements. While the first generation aggregated regional models, with this study, we ensure consistency between all individual submodels, resulting in a model that accurately explains wave propagation across scales. Recent regional tomographic models were incorporated, comprising continental-scale inversions for Asia and Africa, as well as regional inversions for the Western US, Central Andes, Iran, and Southeast Asia. Across all regional refinements, over 793,000 source-receiver pairs contributed. Moreover, the long-wavelength Earth model (LOWE) introduces large-scale structures outside of pre-existing local refinements. A full-waveform inversion for global anisotropic P-and S-wave speed structure over a total of 194 iterations with a minimum period of 50 s on a large data set of 1 hr of waveform data from 2,423 earthquakes and over 6 million source-receiver pairs ensures that regional updates in the crust and uppermost mantle translate into updates of deeper, global-scale structure. To test the performance of CSEM2, we evaluate waveform fits between observed and synthetic seismograms at 50 s for an independent data set on the global scale, and on the regional scale for lower periods. We accurately simulate waveforms within and across regional refinements, maintaining the original resolution of the submodels embedded in the global framework.
58 GEOSCIENCES↗
Effect of Rocky Mountains and Tibetan Plateau 1998 Spring Land Temperature on N. American and East Asian Summer Precipitation Anomalies
This work follows up on the GEWEX/LS4P Phase I (LS4P-I) experiments, a community effort highlighting the spring land surface temperature anomalies in the Tibetan Plateau (TP) as a useful source for subseasonal to seasonal (S2S) prediction of summer precipitation in global hot spot regions, particularly in East Asia and North America. This paper extends the investigation to both the US Rocky Mountain (RM) region and the TP, considering the 1998 summer drought/flood event in North America/East Asia, respectively, as a case study. A previously developed initialization method for land surface temperature/subsurface temperature (LST/SUBT) is used in the NCEP Global Forecast System, coupled with a land model, SSiB2 (GFS/SSiB2), to produce observed RM cold May temperature anomaly. Forward simulation yields June precipitation anomalies at five remote locations. Likewise, the TP warm May temperature anomaly also produces June precipitation anomalies at these five locations. The effects of RM (cold) and TP (warm) temperature anomalies are consistent in the US South Coastal regions and the south Yangtze River Basin, yielding 49% (42%) of observed drought and 34% (44%) of observed flood, respectively. These LST/SUBT effects in RM and TP induce a global large-scale wave train linking North America with the TP, affecting the subtropical westerly jet and thereby modulating summer precipitation. Global SST effect is examined for comparison but does not yield statistically significant June precipitation anomalies in GFS/SSiB2. Furthermore, this study adds to evidence that high-mountain LST effects in the RM and TP are first-order sources of S2S precipitation predictability in summer months.
Nayak, Hara Prasad [University of California, Los ↗
Regional and Temporal Variability of Atmospheric River Seasonality: Influences of Detection Algorithms and Moisture Transport Dynamics
Abstract Understanding the regional and temporal variability of atmospheric river (AR) seasonality is crucial for preparedness and mitigation of extreme events. While ARs were thought to peak in winter, recent research shows they exhibit region‐specific seasonality and are heavily influenced by the chosen detection algorithm. This study examines the link between the year‐to‐year consistency of peak‐AR activity to the presence of a dominant seasonal pattern, considering both location and algorithm choice. Regions are categorized by their temporal characteristics: consistent patterns (e.g., East Asia), patterns with occasional outliers (e.g., British Columbia coast), and regions lacking a clear dominant peak season (e.g., South Atlantic, parts of Australia). Hence, not all regions display a consistent seasonal cycle of AR activity. This study quantifies the extent to which a region experiences a dominant peak season of AR activity (or lacks one) and offers insights to enhance decision‐making in water management, natural hazard preparedness, and forecasting. Furthermore, given our finding that detection algorithms influence the peak season of AR activity, we also examine two diagnostic variables representative of moisture transport to corroborate our results. Integrated vapor transport, which captures meridional and zonal moisture transport, and Moist Wave Activity, representing moisture intrusions from lower to higher latitudes, are examined. Our analysis indicates that inconsistencies in the seasonal cycle of AR activity are not solely due to discrepancies in detection algorithms but also arise from changes in moisture transport. Plain Language Summary Atmospheric rivers (ARs) are critical weather phenomena that can cause extreme events like heavy rainfall and flooding. Understanding when and where ARs are most likely to occur throughout the year is essential for preparing and responding to these events. Traditionally, ARs were thought to peak in winter, but recent studies show this varies by region. Our study helps address the challenge decision‐makers face in anticipating and preparing for AR events by providing insights into the consistency of peak seasonal patterns across different areas. Some regions, like East Asia, and the British Columbia coast, show a consistent peak season, while others, like the South Atlantic and parts of Australia, have significant year‐to‐year variations, making it hard to identify a dominant season. To better understand these changes over time, the study also examines how moisture moves in the atmosphere, using Integrated Vapor Transport (which looks at moisture movement in various directions) and Moist Wave Activity (which tracks moisture shifts from lower to higher latitudes). The findings suggest that inconsistencies in AR patterns are due not only to detection methods but also due to changes in moisture transport. Key Points The peak season of atmospheric river activity can change depending on the year in some areas Interannual variations in the peak season can make identifying a dominant season challenging for some regions Frequent shifts in peak season across years reflect inconsistencies tied to detection algorithms and to underlying dynamics
Kamnani, Diya↗
A physically interpretable precursor framework for sub-seasonal prediction of Northern Hemisphere flash flourishing
Flash flourishing describes rapid vegetation increases that can quickly reshape land–atmosphere exchanges and impacts on ecosystem, yet its large-scale precursors, circulation context, and sub-seasonal predictability remain poorly understood. Here, we identified onset-stage circulation regimes across northern extratropical latitudes (NEL; >30°N) using 200 and 1000 hPa geopotential height, and examined their regional expressions over eastern Asia, western North America, and Europe. Flash flourishing onset in East Asian was associated with a baroclinic circulation regime and was preceded by a North Atlantic sea surface temperature (SST) precursor at a four-pentad lead. In contrast, onset in western North American and European preferentially occurred under barotropic regimes, preconditioned by Great Plains soil moisture at three-pentad lead and North Atlantic SST at a four-pentad lead, respectively. Ridge regression forecasts revealed regime-dependent sub-seasonal predictability, with mean out-of-sample R 2 exceeding 0.3 up to lead times of two pentads in East Asia, three pentads in western North America, and four pentads in Europe. Together, these findings established a mechanistic and regionally specific framework for anticipating rapid vegetation greening at sub-seasonal timescales.
Kong, Xiangxu [Nanjing Univ. of Information Scienc↗
Session 3: Agrivoltaics Pathways [Slides]
This presentation was developed for a webinar series for the USAID's South Asia Group for Energy (SAGE) and South Asia Regional Energy Partnership (SAREP). The presentation includes insights into agrivoltaic site assessment planning, including what is needed for a farm assessment, solar panel system design from the agricultural perspective, variables that go into crop selection, and environmental impact, sustainability, and agritourism, technical parameters for developing an agrivoltaics project, including what makes up a PV feasibility study, understanding variables that go into technology and equipment selection, agrivoltaic installation and agricultural integration, and monitoring and maintenance throughout the life of the project, and agrivoltaic financial planning, risk mitigation, and debt equity issues.
14 SOLAR ENERGY↗
Floating photovoltaic power plants: A review of energy yield, reliability, and operation and maintenance
Photovoltaic (PV) systems are essential for the transition to sustainable energy, reducing fossil fuel dependence and mitigating climate change. Although PV requires minimal land area — PV can meet the European Union's energy needs using only 0.26% of its land — space for deployment is often scarce in densely populated regions. Floating photovoltaics (FPV) offer an effective solution to land-use challenges by installing PV systems on floating structures in water bodies. FPV is a growing niche within PV with a cumulative installed capacity reaching 7.7 GW globally by 2023. Almost 90% of the installed FPV capacity is in Asia, with close to 50% of in China alone, while the Netherlands and France are the largest markets outside Asia. FPV shows strong potential to support climate targets, but still faces challenges like regulatory barriers, cost competitiveness compared to ground-based PV (GPV), and uncertainties about environmental impacts and system reliability. FPV systems are currently installed mainly on sheltered inland waters, such as quarry lakes, irrigation ponds and reservoirs. FPV technical standards are still being developed. Guidelines have been published by the World Bank, DNV, and Solar Power Europe, and emerging national standards from South Korea, China, and Singapore address design, components, and safety. The International Electrotechnical Commission (IEC) is working on formal standards for floats, mooring systems, and electrical connectors. However, the published best practices lack quantitative guidance for yield modelling and reliability, which this report aims to address. It provides data-driven insights, models, and parameters essential for accurate energy yield, reliability, and maintenance predictions over FPV systems' lifetimes.
14 SOLAR ENERGY↗
North America’s Potential for an Environmentally Sustainable Nickel, Manganese, and Cobalt Battery Value Chain
The Detroit Big Three General Motors (GMs), Ford, and Stellantis predict that electric vehicle (EV) sales will comprise 40–50% of the annual vehicle sales by 2030. Among the key components of LIBs, the LiNixMnyCo1−x−yO2 cathode, which comprises nickel, manganese, and cobalt (NMC) in various stoichiometric ratios, is widely used in EV batteries. This review reveals NMC cathodes from laboratory research. Furthermore, this study examines the environmental effect of NMC cathode production for EV batteries (including coating technologies), encompassing aspects such as energy consumption, water usage, and air emissions. Although gaps persist in NMC cathode environmental assessments (NMC111, NMC532, NMC622, and NMC811), limited life cycle assessments “(LCA)” have been conducted. Most available data originate from Asia (primarily China), accounting for 85% of the production of EV LIB cathode materials. The concept of battery passports for data collection on LIB components has been proposed to facilitate material traceability as a system for ensuring a sustainable supply chain for critical minerals. The automotive industry’s shift to electrification necessitates a sustainable supply chain from mine to vehicle end-of-life. As the critical mineral supply moves from Asia to North America, environmentally friendly industrial methods must be studied to provide this supply chain direction.
25 ENERGY STORAGE↗
Building Capacity: Solar Photovoltaics Site Assessment and Feasibility Study
While Bhutan is abundant with clean energy hydropower, there are dry months in winter when solar energy could reduce expensive power inputs and bolster Bhutan's energy resilience and independence. As the country explores solar photovoltaic (PV) development as an option to achieve that goal, grid planners and renewable energy experts are partnering with the South Asia Group for Energy (SAGE) to determine the benefits and challenges of building solar energy systems in Bhutan.
14 SOLAR ENERGY↗
Widespread windthrow in Southeast Asian tropical forests verified by satellite observations
Windthrow, defined as abrupt tree mortality caused by intense winds, is well documented in the Neotropics but remains largely unverified in Asian tropical forests. Using Landsat 8 imagery for the period 2020-2022 and established spectral (shortwave-infrared, near-infrared, and red band composites) and morphological criteria (fan-shaped geometry and sharp boundaries), this study verified the presence of windthrow across Sumatra, Borneo, and New Guinea and produced the first georeferenced inventory of 60 events in the region. Event sizes were right-skewed, with many small gaps and few large (>200 ha) disturbances. Orientations were anisotropic, with concentrations of windthrow events pointing west to northwest-to-north and eastward, both aligning with known pathways of organized convection in the Maritime Continent of Southeast Asia. Detection was conservatively biased low by cloud cover, long revisit intervals, and the exclusion of land-use areas. This study provides a verified baseline that enables reproducible mapping with higher resolution sensors and field observations to quantify windthrow frequency, severity, and ecological significance.
Asia’s tropical forests↗
Middle and Late-Holocene coastal environments of far Southeastern Russia as inferred from palynological and diatom data
Existing discontinuous palynological records from coastal and river valley exposures, with varying quality of radiocarbon control, suggested that the regional Holocene climate in southern areas of the Russian Far East was characterized by as many as 10 fluctuations in temperature and/or precipitation. In this study, palynological data from Zerkalnoye Lake, located on the western coast of the Sea of Japan, indicate a gradual decline in temperature through the Middle and Late-Holocene with a Holocene thermal maximum between 8800 and 5500 cal yr BP. Three wetter than present intervals, marked by an increase in Pinus koraiensis, occurred c. 3600–3500 cal yr BP, 2340–2050 cal yr BP, and 1830–1800 cal yr BP. The Zerkalnoye record shows the dominance of Quercus-broadleaf forests during the Middle and Early Holocene, although Quercus shows a gradual decrease as climate cooled during this interval. Diatom analysis of the Zerkalnoye sediments documents that the site was a shallow bay or coastal lagoon until c. 3540 cal yr BP. After that time, a freshwater lake was established, which had variable marine influences probably caused by sea level changes following deglaciation. The diatom data indicate a cool water interval between 2900 and 2580 cal yr BP, also noted in other sites in the region. Changes in the basin’s depositional environment do not affect the palynological record, indicating such sites can provide reliable paleovegetational and paleoclimatic records. In conclusion, the discrepancies of the various regional paleoclimatic scenarios indicate the need for the further collection of continuous records from coastal to alpine zones in this region of northeastern Asia.
Environmental sciences↗
Introduction to the 3-Part Agrivoltaics Knowledge Series: Agrivoltaics 101 [Slides]
Overview of the history, current deployment, Applications, and potential benefits and trade-offs for agrivoltaics. Presented to a public audience in south Asia as part of a three-part webinar series through SAREP.
14 SOLAR ENERGY↗