Geography & Atmospheric Science Scholarly Works

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  • Publication
    Comparing Approximated Heat Stress Measures Across the United States
    (GeoHealth, 2024-01-23) Parks, Robbie M.; Tuholske, Cascade; Ahn, Yoonjung
    Climate change is escalating the threat of heat stress to global public health, with the majority of humans today facing increasingly severe and prolonged heat waves. Accurate weather data reflecting the complexity of measuring heat stress is crucial for reducing the impact of extreme heat on health worldwide. Previous studies have employed Heat Index (HI) and Wet Bulb Globe Temperature (WBGT) metrics to understand extreme heat exposure, forming the basis for heat stress guidelines. However, systematic comparisons of meteorological and climate data sets used for these metrics and the related parameters, like air temperature, humidity, wind speed, and solar radiation crucial for human thermoregulation, are lacking. We compared three heat measures (HImax, WBGTBernard, and WBGTLiljegren) approximated from gridded weather data sets (ERA5‐Land, PRISM, Daymet) with ground‐based data, revealing strong agreement from HI and WBGTBernard (R 2 0.76–0.95, RMSE 1.69–6.64°C). Discrepancies varied by Köppen‐Geiger climates (e.g., Adjusted R 2 HImax 0.88–0.95, WBGTBernard 0.79–0.97, and WBGTLiljegren 0.80–0.96), and metrological input variables (Adjusted R 2 T max 0.86–0.94, T min 0.91–0.94, Wind 0.33, Solarmax 0.38, Solaravg 0.38, relative humidity 0.51–0.74). Gridded data sets can offer reliable heat exposure assessment, but further research and local networks are vital to reduce measurement errors to fully enhance our understanding of how heat stress measures link to health outcomes.
  • Publication
    The impact of agricultural colonization and deforestation on orchid bees (Apidae: Euglossini) in the Brazilian Amazon
    (Elsevier, 2024-05) Christopher Brown, J.; Corrêa Neto, José de Jesus; Ribeiro, Cristiano Feitosa; Oliveira Pinheiro, Márcio Luiz
    Researchers have studied orchid bees for decades to determine the impact of tropical deforestation on biodiversity. Our objective was to determine impacts on orchid bees at scales other than forest patches/fragments, as called for in the broader literature on the impacts of habitat fragmentation on biodiversity. We examine an orchid bee survey, which employed chemical baits and live netting in rapid assessments, across the entire state of Rondônia in the Brazilian Amazon. We analyze the relationships between age of agricultural settlement of collection zones and the immediate land cover (closed vs. open canopy of land use/land cover) of collection sites on orchid bee abundance, richness, and composition. The survey reveals a highly diverse community (2497 individuals, represented by 5 genera and 48 species across 12 collection zones and 130 sample locations). Species richness declined significantly between conservation units and older settlement zones, but richness in newer settlement zones remained at an intermediate, insignificantly different level. Significantly greater abundance was found within conservation units, less in newer settlement zones, and even less in older settlement zones. Species composition was significantly different when comparing the conservation unit and older settlement categories of collection zone. Closed canopy species richness and abundance were significantly higher than that found in open canopy. Composition also differed significantly between open and closed canopy land cover canopy types. Eulaema nigrita and several Euglossa species are identified as particularly strong indicators of degraded and preserved environments, respectively.
  • Publication
    “The Indians Complain, and with Good Cause”: Allotting Standing Rock—U.S. Policy Meets a Tribe’s Assertion of Rights
    (MDPI, 2024-07-05) Egbert, Stephen; Meisel, Joshua J.
    Land allotment was embraced by the U.S. Government in the late 1800s and early 1900s as part of a solution to the “Indian problem”, the goal of which was assimilation into the Euro-American cultural and economic system. As a progressivist program, it was imposed with enthusiasm and confidence, dividing reservations into rectangular land parcels (allotments) in the belief that the allotment recipients would become yeoman farmers of the Jeffersonian mold. Tribes were unable to thwart the imposition of allotment, despite their best efforts, and its devastating long-term effects are now well known. Much less is understood, however, about the efforts of various tribes, sometimes successful and sometimes not, to obtain modifications to the terms of allotment imposed on them. We describe how the people of the Standing Rock Reservation in North and South Dakota successfully advocated for modifications which worked to their significant advantage. We draw heavily from the outgoing correspondence and allotment records of the Special Allotting Agent, Carl Gunderson, along with contemporaneous records of legislative proceedings and other documents. The successful efforts of the people of Standing Rock resulted not only in equitable access to scarce timber, but in allotments to numerous individuals who otherwise would have been ineligible. The net impact was the additional allotment of nearly 400,000 acres (160,000 ha) to over 1800 individuals who otherwise would have received nothing.
  • Publication
    The slow violence of climate security
    (Elsevier, 2024-07-25) O'Lear, Shannon
    This paper considers how the Intergovernmental Panel on Climate Change (IPCC) engages in world-making around risk that sets up a harmful basis for thinking about climate security. This inquiry offers a reading of a recent IPCC report chapter as a form of world-making and epistemic violence through its limited portrayal of risk. A core argument made in this paper is that the selective representation of risk sets up the potential for slow violence outcomes and practices can perpetuate unjust harm. It matters how the IPCC portrays risk, because the organization is in a unique position to influence how security practitioners understand connections between climate change and security. This paper draws on concepts of world-making, epistemic violence, and slow violence, and it builds on previous critiques of the IPCC’s selective representation of climate change. It suggests alternative opportunities for understanding human contributions to the current state of our planetary environment through an example of another well-known, world-making representation of the water cycle. Overhauling the way that the water cycle is presented as influenced by human activity offers insights to possibilities to create transformative, less harmful pathways for understanding and engaging with the changing climate.
  • Publication
    Automated Mapping of Historical Native American Land Allotments at the Standing Rock Sioux Reservation Using Geographic Information Systems
    (MDPI, 2021-03-20) Meisel, Joshua Jerome; Egbert, Stephen L.; Brewer, Joseph P. II; Li, Xingong
    The General Allotment Act of 1887, also known as the Dawes Act, established the legal basis for the United States government to break up remaining tribally-owned reservation lands in the U.S. by allotting individual parcels to tribal members and selling the remaining “surplus.” This research explores the processes involved in mapping these historical allotments and describes a method to automatically generate spatial data of allotments. A custom geographic information systems (GIS) tool was created that takes tabular based allotment land descriptions and digital Public Land Survey (PLSS) databases to automatically generate spatial and attribute data of those land parcels. The Standing Rock Sioux Tribe of North and South Dakota was used as the initial study area to test the mapping technique, which resulted in successfully auto-mapping over 99.1% of allotted lands on the reservation, including the smallest aliquot parcels. This GIS technique can be used to map any tribal lands or reservation with allotment data available, and currently it can be used to map over 120 individual reservations using publicly available data from the Bureau of Land Management (BLM).
  • Publication
    Indigenous research sovereignties: Sparking the deeper conversations we need
    (Sage, 2023-05-23) Johnson, Jay T.; Brewer, Joseph P., II; Nelson, Melissa K.; Palmer, Mark H.; Louis, Renee Pualani
    This article seeks to spark a conversation and further debate through the 15 papers and 3 commentaries comprising this special issue entitled “Indigenous Research Sovereignty.” By inviting the authors to publish in this special edition and address Indigenous Research Sovereignty from a variety of viewpoints, we have brought together a collection that inspires, transforms, and expands on the ways in which Indigenous and non-Indigenous researchers are engaging with Indigenous communities to address the research agendas of communities across the globe. Through our work together over the past 8 years, the editorial team have identified eight themes within this broad concept of Indigenous Research Sovereignty. This article provides an introduction to those eight themes in the broadest strokes, while the papers and commentaries explore and refine them with significant depth. We seek to spark a conversation, we do not intend to provide answers to any of the dilemma facing Indigenous communities as they engage, or choose not to engage, in research. Our primary goal is to express an all-encompassing concern for the protection of Indigenous Communities’ inherent rights and knowledges.
  • Publication
    Environment and Planning F: Special issue on Indigenous Research Sovereignty
    (Sage, 2023) Johnson, Jay T.; Brewer, Joseph P., II; Nelson, Melissa K.; Palmer, Mark H.; Louis, Renee Pualani
  • Publication
    Climate Decision-Making
    (Annual Reviews, 2020-06-08) Orlove, Ben; Shwom, Rachael; Markowitz, Ezra; Cheong, So-Min
    Climate change decision-making has emerged in recent decades as an area of research and practice, expanding on an earlier focus on climate policy. Defined as the study of decisions relevant for climate change, it draws on developments in decision science, particularly advances in the study of cognitive and deliberative processes in individuals and organizations. The effects of climate, economic, social, and other framings on decision-making have been studied, often showing that nonclimate frames can be as effective as, or more effective than, climate frames in promoting decision-making and action. The concept of urgency, linked to the ideas of climate crisis and climate emergency, has taken on importance in recent years. Research on climate decision-making has influenced numerous areas of climate action, including nudges and other behavioral interventions, corporate social responsibility, and Indigenous decision-making. Areas of transformational change, such as strategic retreat in the face of sea-level rise, are emerging.
  • Publication
    Conversion of Abandoned Property to Green Space as a Strategy to Mitigate the Urban Heat Island Investigated with Numerical Simulations
    (AMS, 2020-11-01) Cady, Timothy J.; Rahn, David A.; Brunsell, Nathaniel A.; Lyles, Ward
    Impervious surfaces and buildings in the urban environment alter the radiative balance and surface energy exchange and can lead to warmer temperatures known as the urban heat island (UHI), which can increase heat-related illness and mortality. Continued urbanization and anthropogenic warming will enhance city temperatures worldwide, raising the need for viable mitigation strategies. Increasing green space throughout a city is a viable option to lessen the impacts of the UHI but can be difficult to implement. The potential impact of converting existing vacant lots in Kansas City, Missouri, to green spaces is explored with numerical simulations for three heat-wave events. Using data on vacant property and identifying places with a high fraction of impervious surfaces, the most suitable areas for converting vacant lots to green spaces is determined. Land-use/land-cover datasets are modified to simulate varying degrees of feasible conversion of urban to green spaces in these areas, and the local cooling effect using each strategy is compared with the unmodified simulation. Under more aggressive greening strategies, a mean local cooling impact of 0.5°–1.0°C is present within the focus area itself during the nighttime hours. Some additional cooling via the “park cool island” is possible downwind of the converted green spaces under the more aggressive scenarios. Although moderate and conservative strategies of conversion could still lead to other benefits, those strategies have little impact on cooling. Only an aggressive approach yields significant cooling.
  • Publication
    Lake volume variation in the endorheic basin of the Tibetan Plateau from 1989 to 2019
    (Nature Research, 2022-10-08) Wang, Junxiao; Wang, Liuming; Li, Mengyao; Zhu, Liping; Li, Xingong
    Lake storage change serves as a unique indicator of natural climate change on the Tibetan Plateau (TP). However, comprehensive lake storage data, especially for lakes smaller than 10 km2, are still lacking in the region. In this dataset, we completed a census of annual relative lake volume (RLV) for 976 lakes, which are larger than 1 km2, on the endorheic basin of the Tibetan Plateau (EBTP) during 1989–2019 using Landsat imagery and digital terrain models. Our method first identifies individual lakes, determines their analysis extents and calculates annual lake area from Landsat imagery. It then derives lake area-elevation relationship, estimates lake surface elevation, and calculates RLV. Validation and comparison with several existing datasets indicate our data are more reliable and comprehensive. Our study complements existing lake datasets by providing a complete and long-term lake water volume change data for the region.
  • Publication
    Retrieving the global distribution of the threshold of wind erosion from satellite data and implementing it into the Geophysical Fluid Dynamics Laboratory land–atmosphere model (GFDL AM4.0/LM4.0)
    (European Geosciences Union, 2020-01-03) Pu, Bing; Ginoux, Paul; Guo, Huan; Hsu, N. Christina; Kimball, John; Marticorena, Beatrice; Malyshev, Sergey; Naik, Vaishali; O'Neill, Norman T.; García-Pando, Carlos Pérez; Paireau, Juliette; Prospero, Joseph M.; Shevliakova, Elena; Zhao, Ming
    Dust emission is initiated when surface wind velocities exceed the threshold of wind erosion. Many dust models used constant threshold values globally. Here we use satellite products to characterize the frequency of dust events and land surface properties. By matching this frequency derived from Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue aerosol products with surface winds, we are able to retrieve a climatological monthly global distribution of the wind erosion threshold (Vthreshold) over dry and sparsely vegetated surfaces. This monthly two-dimensional threshold velocity is then implemented into the Geophysical Fluid Dynamics Laboratory coupled land–atmosphere model (AM4.0/LM4.0). It is found that the climatology of dust optical depth (DOD) and total aerosol optical depth, surface PM10 dust concentrations, and the seasonal cycle of DOD are better captured over the “dust belt” (i.e., northern Africa and the Middle East) by simulations with the new wind erosion threshold than those using the default globally constant threshold. The most significant improvement is the frequency distribution of dust events, which is generally ignored in model evaluation. By using monthly rather than annual mean Vthreshold, all comparisons with observations are further improved. The monthly global threshold of wind erosion can be retrieved under different spatial resolutions to match the resolution of dust models and thus can help improve the simulations of dust climatology and seasonal cycles as well as dust forecasting.
  • Publication
    Evolution of Ecological Security in the Tableland Region of the Chinese Loess Plateau Using a Remote-Sensing-Based Index
    (MDPI, 2020-04-24) Sun, Congjian; Li, Xiaoming; Zhang, Wenqiang; Li, Xingong
    Maintaining optimal ecological security is a serious issue in the Chinese Loess Plateau (CLP). Remote sensing ecological indexes (RSEI) of three main tableland regions of the CLP were calculated based on spectral information provided by remote sensing imaging satellites between 2000 and 2018. We were able to use RSEI values to systematically evaluate the temporal and spatial variation in the regional ecological environment and determine the influential factors that mainly associated with these changes. The results showed that between 2000 and 2018, the ecological environment improved, remained stable, and deteriorated, respectively, in the Gansu, Shaanxi, and Shanxi tablelands. Regions with poor or fair RSEIs were concentrated around the main river basins, while regions with moderate RSEIs were associated with poor ecological conditions and poor areas. The significant spatiotemporal variation in RSEI indicates that the ecological system in this region is relatively fragile. We also observed that natural factors such as the temperature, potential evapotranspiration, and precipitation had the greatest influence on the overall ecological quality. The rapid increase in the regional population and human activity played an important role in the variation in the regional RSEI. This research will provide important information on controlling regional soil erosion and ecological restoration in the CLP.
  • Publication
    Accurate and Efficient Calculation of Three-Dimensional Cost Distance
    (MDPI, 2020-05-27) Chen, Yaqian; She, Jiangfeng; Li, Xingong; Zhang, Shuhua; Tan, Junzhong
    Cost distance is one of the fundamental functions in geographical information systems (GISs). 3D cost distance function makes the analysis of movement in 3D frictions possible. In this paper, we propose an algorithm and efficient data structures to accurately calculate the cost distance in discrete 3D space. Specifically, Dijkstra’s algorithm is used to calculate the least cost between initial voxels and all the other voxels in 3D space. During the calculation, unnecessary bends along the travel path are constantly corrected to retain the accurate least cost. Our results show that the proposed algorithm can generate true Euclidean distance in homogeneous frictions and can provide more accurate least cost in heterogeneous frictions than that provided by several existing methods. Furthermore, the proposed data structures, i.e., a heap combined with a hash table, significantly improve the algorithm’s efficiency. The algorithm and data structures have been verified via several applications including planning the shortest drone delivery path in an urban environment, generating volumetric viewshed, and calculating the minimum hydraulic resistance.
  • Publication
    Modeling dust sources, transport, and radiative effects at different altitudes over the Tibetan Plateau
    (European Geosciences Union, 2020-02-07) Hu, Zhiyuan; Huang, Jianping; Zhao, Chun; Jin, Qinjian; Ma, Yuanyuan; Yang, Ben
    Mineral dust plays an important role in the climate of the Tibetan Plateau (TP) by modifying the radiation budget, cloud macro- and microphysics, precipitation, and snow albedo. Meanwhile, the TP, with the highest topography in the world, can affect intercontinental transport of dust plumes and induce typical distribution characteristics of dust at different altitudes. In this study, we conduct a quasi-global simulation to investigate the characteristics of dust source contribution and transport over the TP at different altitudes by using a fully coupled meteorology–chemistry model, the Weather Research and Forecasting model with chemistry (WRF-Chem), with a tracer-tagging technique. Generally, the simulation reasonably captures the spatial distribution of satellite-retrieved dust aerosol optical depth (AOD) at different altitudes. Model results show that dust particles are emitted into atmosphere through updrafts over major desert regions and then transported to the TP. The East Asian dust (mainly from the Gobi and Taklamakan deserts) is transported southward and is lifted up to the TP, contributing a mass loading of 50 mg m−2 at a height of 3 km and 5 mg m−2 at a height of 12 km over the northern slope of the TP. Dust from North Africa and the Middle East are concentrated over both of the northern and southern slopes below 6 km, where mass loadings range from 10 to 100 and 1 to 10 mg m−2 below 3 km and above 9 km, respectively. As the dust is transported to the north and over the TP, mass loadings are 5–10 mg m−2 above a height of 6 km. The dust mass flux carried from East Asia to the TP is 7.9 Tg yr−1, mostly occurring at heights of 3–6 km. The dust particles from North Africa and the Middle East are transported eastward following the westerly jet and then are carried into the TP at the west side with dust mass fluxes of 7.8 and 26.6 Tg yr−1, respectively. The maximum mass flux of the North African dust mainly occurs at 0–3 km (3.9 Tg yr−1), while the Middle Eastern dust occurs at 6–9 km (12.3 Tg yr−1). The dust outflow occurs on the east side (−17.89 Tg yr−1) and south side (−11.22 Tg yr−1) of the TP, with a peak value (8.7 Tg yr−1) at 6–9 km. Moreover, the dust (by mass) is concentrated within the size range of 1.25–5.0 µm and the dust (by particle number) is concentrated in the size range of 0.156–1.25 µm. Compared with other aerosols, the dust contributes to more than 50 % of the total AOD over the TP. The direct radiative forcing induced by the dust is −1.28 W m−2 at the top of the atmosphere (cooling), 0.41 W m−2 in the atmosphere (warming), and −1.68 W m−2 at the surface (cooling). Our quantitative analyses of the dust contributions from different source regions and the associated radiative forcing can help us to better understand the role of dust on the climate over the TP and surrounding regions.
  • Publication
    Effective radiative forcing in the aerosol–climate model CAM5.3-MARC-ARG
    (European Geosciences Union, 2018-11-02) Grandey, Benjamin S.; Rothenberg, Daniel; Avramov, Alexander; Jin, Qinjian; Lee, Hsiang-He; Liu, Xiaohong; Lu, Zheng; Albani, Samuel; Wang, Chien
    Abstract We quantify the effective radiative forcing (ERF) of anthropogenic aerosols modelled by the aerosol–climate model CAM5.3-MARC-ARG. CAM5.3-MARC-ARG is a new configuration of the Community Atmosphere Model version 5.3 (CAM5.3) in which the default aerosol module has been replaced by the two-Moment, Multi-Modal, Mixing-state-resolving Aerosol model for Research of Climate (MARC). CAM5.3-MARC-ARG uses the ARG aerosol-activation scheme, consistent with the default configuration of CAM5.3. We compute differences between simulations using year-1850 aerosol emissions and simulations using year-2000 aerosol emissions in order to assess the radiative effects of anthropogenic aerosols. We compare the aerosol lifetimes, aerosol column burdens, cloud properties, and radiative effects produced by CAM5.3-MARC-ARG with those produced by the default configuration of CAM5.3, which uses the modal aerosol module with three log-normal modes (MAM3), and a configuration using the modal aerosol module with seven log-normal modes (MAM7). Compared with MAM3 and MAM7, we find that MARC produces stronger cooling via the direct radiative effect, the shortwave cloud radiative effect, and the surface albedo radiative effect; similarly, MARC produces stronger warming via the longwave cloud radiative effect. Overall, MARC produces a global mean net ERF of −1.79±0.03 W m−2, which is stronger than the global mean net ERF of −1.57±0.04 W m−2 produced by MAM3 and −1.53±0.04 W m−2 produced by MAM7. The regional distribution of ERF also differs between MARC and MAM3, largely due to differences in the regional distribution of the shortwave cloud radiative effect. We conclude that the specific representation of aerosols in global climate models, including aerosol mixing state, has important implications for climate modelling.
  • Publication
    Impacts on cloud radiative effects induced by coexisting aerosols converted from international shipping and maritime DMS emissions
    (European Geosciences Union, 2018-11-28) Jin, Qinjian; Grandey, Benjamin S.; Rothenberg, Daniel; Avramov, Alexander; Wang, Chien
    International shipping emissions (ISE), particularly sulfur dioxide, can influence the global radiation budget by interacting with clouds and radiation after being oxidized into sulfate aerosols. A better understanding of the uncertainties in estimating the cloud radiative effects (CREs) of ISE is of great importance in climate science. Many international shipping tracks cover oceans with substantial natural dimethyl sulfide (DMS) emissions. The interplay between these two major aerosol sources on CREs over vast oceanic regions with a relatively low aerosol concentration is an intriguing yet poorly addressed issue confounding estimation of the CREs of ISE. Using an Earth system model including two aerosol modules with different aerosol mixing configurations, we derive a significant global net CRE of ISE (−0.153 W m−2 with a standard error of ±0.004 W m−2) when using emissions consistent with current ship emission regulations. This global net CRE would become much weaker and actually insignificant (−0.001 W m−2 standard error of ±0.007 W m−2) if a more stringent regulation were adopted. We then reveal that the ISE-induced CRE would achieve a significant enhancement when a lower DMS emission is prescribed in the simulations, owing to the sublinear relationship between aerosol concentration and cloud response. In addition, this study also demonstrates that the representation of certain aerosol processes, such as mixing states, can influence the magnitude and pattern of the ISE-induced CRE. These findings suggest a reevaluation of the ISE-induced CRE with consideration of DMS variability.
  • Publication
    Consistent response of Indian summer monsoon to Middle East dust in observations and simulations
    (European Geosciences Union, 2015-09-02) Jin, Q.; Wei, J.; Yang, Z.-L.; Pu, B.; Huang, J.
    The response of the Indian summer monsoon (ISM) circulation and precipitation to Middle East dust aerosols on sub-seasonal timescales is studied using observations and the Weather Research and Forecasting model coupled with online chemistry (WRF-Chem). Satellite data show that the ISM rainfall in coastal southwest India, central and northern India, and Pakistan is closely associated with the Middle East dust aerosols. The physical mechanism behind this dust–ISM rainfall connection is examined through ensemble simulations with and without dust emissions. Each ensemble includes 16 members with various physical and chemical schemes to consider the model uncertainties in parameterizing short-wave radiation, the planetary boundary layer, and aerosol chemical mixing rules. Experiments show that dust aerosols increase rainfall by about 0.44 mm day−1 (~10 % of the climatology) in coastal southwest India, central and northern India, and north Pakistan, a pattern consistent with the observed relationship. The ensemble mean rainfall response over India shows a much stronger spatial correlation with the observed rainfall response than any other ensemble members. The largest modeling uncertainties are from the boundary layer schemes, followed by short-wave radiation schemes. In WRF-Chem, the dust aerosol optical depth (AOD) over the Middle East shows the strongest correlation with the ISM rainfall response when dust AOD leads rainfall response by about 11 days. Further analyses show that increased ISM rainfall is related to enhanced southwesterly monsoon flow and moisture transport from the Arabian Sea to the Indian subcontinent, which are associated with the development of an anomalous low-pressure system over the Arabian Sea, the southern Arabian Peninsula, and the Iranian Plateau due to dust-induced heating in the troposphere. The dust-induced heating in the mid-upper troposphere is mainly located in the Iranian Plateau rather than the Tibetan Plateau. This study demonstrates a thermodynamic mechanism that links remote desert dust emissions in the Middle East to ISM circulation and precipitation variability on sub-seasonal timescales, which may have implications for ISM rainfall forecasts.
  • Publication
    Irrigation-Induced Environmental Changes around the Aral Sea: An Integrated View from Multiple Satellite Observations
    (MDPI, 2017-08-31) Jin, Qinjian; Wei, Jiangfeng; Yang, Zong-Liang; Lin, Peirong
    The Aral Sea basin (ASB) is one of the most environmentally vulnerable regions to climate change and human activities. During the past 60 years, irrigation has greatly changed the water distribution and caused severe environmental issues in the ASB. Using remote sensing data, this study investigated the environmental changes induced by irrigation activities in this region. The results show that, in the past decade, land water storage has significantly increased in the irrigated upstream regions (13 km3 year−1) but decreased in the downstream regions (−27 km3 year−1) of the Amu Darya River basin, causing a water storage decrease in the whole basin (−20 km3 year−1). As a result, the water surface area of the Aral Sea has decreased from 32,000 in 2000 to 10,000 km2 in 2015. The shrinking Aral Sea exposed a large portion of the lake bottom to the air, increasing (decreasing) the daytime (nighttime) temperatures by about 1 °C year−1 (0.5 °C year−1). Moreover, there were other potential environmental changes, including drier soil, less vegetation, decreasing cloud and precipitation, and more severe and frequent dust storms. Possible biases in the remote sensing data due to the neglect of the shrinking water surface area of the Aral Sea were identified. These findings highlight the severe environmental threats caused by irrigation in Central Asia and call attention to sustainable water use in such dryland regions.
  • Publication
    Sensing Physiological Change and Mental Stress in Older Adults From Hot Weather
    (Institute of Electrical and Electronics Engineers, 2020-03-20) Cheong, So-Min; Bautista, Carlos; Ortiz, Luis
    This study combines wearable sensors, weather data, and self-reported mood surveys to assess mental stress on older adults from heat experience. It is designed as a pilot and feasibility study in preparation for a large-scale experiment of older adults' mental wellbeing during extreme heat events. Results show that on-body temperatures from two i-Button sensors coupled with heart rate monitored from a smart watch are important indicators to evaluate individualized heat stress given a relatively uniform outdoor temperature. Furthermore, assessing their mood in their own environment demonstrates potential for understanding mental wellbeing that can change with varying time and location.
  • Publication
    Rainfall Prediction in the State of Paraíba, Northeastern Brazil Using Generalized Additive Models
    (MDPI, 2020-09-04) Dantas, Leydson G.; dos Santos, Carlos A. C.; de Olinda, Ricardo A.; de Brito, José I. B.; Santos, Celso A. G.; Martins, Eduardo S. P. R.; de Oliveira, Gabriel; Brunsell, Nathaniel A.
    The state of Paraíba is part of the semi-arid region of Brazil, where severe droughts have occurred in recent years, resulting in significant socio-economic losses associated with climate variability. Thus, understanding to what extent precipitation can be influenced by sea surface temperature (SST) patterns in the tropical region can help, along with a monitoring system, to set up an early warning system, the first pillar in drought management. In this study, Generalized Additive Models for Location, Scale and Shape (GAMLSS) were used to filter climatic indices with higher predictive efficiency and, as a result, to perform rainfall predictions. The results show the persistent influence of tropical SST patterns in Paraíba rainfall, the tropical Atlantic Ocean impacting the rainfall distribution more effectively than the tropical Pacific Ocean. The GAMLSS model showed predictive capability during summer and southern autumn in Paraíba, highlighting the JFM (January, February and March), FMA (February, March and April), MAM (March, April and May), and AMJ (April, May and June) trimesters as those with the highest predictive potential. The methodology demonstrates the ability to be integrated with regional forecasting models (ensemble). Such information has the potential to inform decisions in multiple sectors, such as agriculture and water resources, aiming at the sustainable management of water resources and resilience to climate risk.