Recent uclageog_oapdeposits items

Encampment geographies: Refuge, return, and refusal

Fri, 8 May 2026 00:00:00 +0000

Thinking from Los Angeles, amid the expanding criminalization of homelessness, we advance a conceptual framework of encampment geographies. We argue that the homeless encampment must be understood in relation to state power, specifically the state as landlord. As residents of state spaces—sidewalks, shelters, interim housing—encampment dwellers are institutionalized. This includes interpellation in humanitarian exchange, notably through forms of mutual aid that emerge in the interstices of state violence. Drawing on ethnographic research and movement histories at Aetna Street, we present three encampment geographies: return, refuge, and refusal. We conceptualize the encampment as a site of enforced return and a space of refuge whose residents are akin to refugees. In doing so, we situate the homeless encampment in a global geography of camps, drawing on literatures that are attentive to expulsion, containment, and asylum. Yet encampment residents refuse enclosure, in particular,...

COMMON SENSE LAW: Making Right/s in the Liberal City

Fri, 1 May 2026 00:00:00 +0000

Abstract This article, co‐authored by encampment and university scholars, is concerned with how homeless persons challenge rightlessness. We do so by advancing a conceptual framework of common sense law, arguing that such contestations take place not only in courtrooms but also in the lived spaces of homelessness. Drawing on five years of ethnography, we foreground how homeless persons become proficient in the law as well as in self‐advocacy, navigating and resisting state power, be it the edicts of criminalization or the labyrinth of bureaucratization. In doing so, we seek to understand housing justice as rights from below as well as a process of making right, a form of redress for perceived injuries. Our conceptual framework of common sense law derives from the specificity of the North American context where homeless personhood is constituted both within and against liberal arrangements of property. Often deployed in spaces such as the street, where property arrangements are...

Bottom-up controls, ecological revolutions and diversification in the oceans through time

Fri, 17 Apr 2026 00:00:00 +0000

Animals originated in the oceans and evolved there for hundreds of millions of years before adapting to terrestrial environments. Today, oceans cover more than two-thirds of Earth and generate as much primary production as land. The path from the first macrobiota to modern marine biodiversity involved parallel increases in terrestrial nutrient input, marine primary production, species' abundance, metabolic rates, ecotypic diversity and taxonomic diversity. Bottom-up theories of ecosystem cascades arrange these changes in a causal sequence. At the base of marine food webs, nutrient fluxes and atmosphere-ocean chemistry interact with phytoplankton to regulate production. First-order consumers (e.g., zooplankton) might propagate changes in quantity and quality of phytoplankton to changes in abundance and diversity of larger predators (e.g., nekton). However, many uncertainties remain about the mechanisms and effect size of bottom-up control, particularly in oceans across the entire...

Marine Biodiversity and Geographic Distributions Are Independent on Large Scales

Fri, 17 Apr 2026 00:00:00 +0000

Fundamental ecological and evolutionary theories, such as community saturation and diversity-dependent diversification, assume that biotic competition restricts resource use, and thus limits realized niche breadth and geographic range size [1-3]. This principle is called competitive exclusion. The corollary (ecological release) posits that, after competitors disappear from a region, species that were previously excluded will invade. Hundreds of field experiments have demonstrated ecological release in living populations. However, few of these studies were conducted in marine environments, and almost no work extended beyond 10 years and 1,000 km² [4, 5]. In limited investigation of marine taxa at larger spatiotemporal scales, macroecologists and paleobiologists have observed little evidence of competitive exclusion [6-9]. Here, we quantified spatial trends in the rich and densely sampled fossil history of brachiopods and bivalves, while accounting for inconsistent...

Marine Biodiversity and Geographic Distributions Are Independent on Large Scales (vol 30, pg 115, 2020)

Fri, 17 Apr 2026 00:00:00 +0000

Marine Biodiversity and Geographic Distributions Are Independent on Large Scales (vol 30, pg 115, 2020)

Spatial standardization of taxon occurrence data-a call to action

Fri, 17 Apr 2026 00:00:00 +0000

Abstract: The fossil record is spatiotemporally heterogeneous: taxon occurrence data have patchy spatial distributions, and this patchiness varies through time. Large-scale quantitative paleobiology studies that fail to account for heterogeneous sampling coverage will generate uninformative inferences at best and confidently draw wrong conclusions at worst. Explicitly spatial methods of standardization are necessary for analyses of large-scale fossil datasets, because nonspatial sample standardization, such as diversity rarefaction, is insufficient to reduce the signal of varying spatial coverage through time or between environments and clades. Spatial standardization should control both geographic area and dispersion (spread) of fossil localities. In addition to standardizing the spatial distribution of data, other factors may be standardized, including environmental heterogeneity or the number of publications or field collecting units that report taxon occurrences....

Thermal niches of planktonic foraminifera are static throughout glacial?interglacial climate change

Fri, 17 Apr 2026 00:00:00 +0000

Abiotic niche lability reduces extinction risk by allowing species to adapt to changing environmental conditions in situ. In contrast, species with static niches must keep pace with the velocity of climate change as they track suitable habitat. The rate and frequency of niche lability have been studied on human timescales (months to decades) and geological timescales (millions of years), but lability on intermediate timescales (millennia) remains largely uninvestigated. Here, we quantified abiotic niche lability at 8-ka resolution across the last 700 ka of glacial-interglacial climate fluctuations, using the exceptionally well-known fossil record of planktonic foraminifera coupled with Atmosphere-Ocean Global Climate Model reconstructions of paleoclimate. We tracked foraminiferal niches through time along the univariate axis of mean annual temperature, measured both at the sea surface and at species' depth habitats. Species' temperature preferences were uncoupled from the global...

Spatially Heterogeneous Responses of Planktonic Foraminiferal Assemblages Over 700,000 Years of Climate Change

Fri, 17 Apr 2026 00:00:00 +0000

ABSTRACT: Aim: To determine the degree to which assemblages of planktonic foraminifera track thermal conditions. Location: The world's oceans. Time Period: The last 700,000 years of glacial–interglacial cycles. Major Taxa Studied: Planktonic foraminifera. Methods: We investigate assemblage dynamics in planktonic foraminifera in response to temperature changes using a global dataset of Quaternary planktonic foraminifera, together with a coupled Atmosphere–Ocean General Circulation Model (AOGCM) at 8000‐year resolution. We use ‘thermal deviance’ to assess assemblage responses to climate change, defined as the difference between the temperature at a given location and the bio‐indicated temperature (i.e., the abundance‐weighted average of estimated temperature optima for the species present). Results: Assemblages generally tracked annual mean temperature changes through compositional turnover, but thermal deviances are evident under certain conditions. The coldest‐adapted...

Introduction

Wed, 5 Nov 2025 00:00:00 +0000

Introduction

A twenty-first century structural change in Antarctica’s sea ice system

Wed, 12 Mar 2025 00:00:00 +0000

Abstract: From 1979 to 2016, total Antarctic sea ice extent experienced a positive trend with record winter maxima in 2012 and 2014. Record summer minima followed within the period 2017-2024, raising the possibility that the Antarctic sea ice system might be changing state. Here we use a Bayesian reconstruction of Antarctic sea ice extent which extends the record back to 1899, to show that the sequence of extreme minima in summer Antarctic sea ice extent is unlikely to have happened in the 20th century. We show that they represent a structural change in the sea ice system, manifest by increased persistence in the sea ice extent anomalies and a strongly reduced tendency to return to the mean state. Further, our analysis suggests that we may no longer rely on the past, long-term, behavior of the sea ice system to predict its future state. Extreme conditions may characterize the future state of Antarctic sea ice.

A fire deficit persists across diverse North American forests despite recent increases in area burned

Fri, 28 Feb 2025 00:00:00 +0000

Rapid increases in wildfire area burned across North American forests pose novel challenges for managers and society. Increasing area burned raises questions about whether, and to what degree, contemporary fire regimes (1984–2022) are still departed from historical fire regimes (pre-1880). We use the North American tree-ring fire-scar network (NAFSN), a multi-century record comprising >1800 fire-scar sites spanning diverse forest types, and contemporary fire perimeters to ask whether there is a contemporary fire surplus or fire deficit, and whether recent fire years are unprecedented relative to historical fire regimes. Our results indicate, despite increasing area burned in recent decades, that a widespread fire deficit persists across a range of forest types and recent years with exceptionally high area burned are not unprecedented when considering the multi-century perspective offered by fire-scarred trees. For example, ‘record’ contemporary fire years such as 2020 burned...

The pace of change of summertime temperature extremes

Sat, 9 Nov 2024 00:00:00 +0000

Summer temperature extremes can have large impacts on humans and the biosphere, and an increase in heat extremes is one of the most visible symptoms of climate change. Multiple mechanisms have been proposed that would predict faster warming of heat extremes than typical summer days, but it is unclear whether this is occurring. Here, we show that, in both observations and historical climate model simulations, the hottest summer days have warmed at the same pace as the median globally, in each hemisphere, and in the tropics from 1959 to 2023. In contrast, the coldest summer days have warmed more slowly than the median in the global average, a signal that is not simulated in any of 262 simulations across 28 CMIP6 models. The observed stretching of the cold tail indicates that observed summertime temperatures have become more variable despite the lack of hot day amplification. The interannual variability and trend in the warming of both hot and cold extremes compared to the median...

A Bayesian Model for 20th Century Antarctic Sea Ice Extent Reconstruction

Wed, 23 Oct 2024 00:00:00 +0000

Abstract: Antarctic sea ice, a key component in the complex Antarctic climate system, is an important driver and indicator of the global climate. In the relatively short satellite‐observed period from 1979 to 2022 the sea ice extent has continuously increased (contrasting a major decrease in Arctic sea ice) up to a dramatic decrease between 2014 and 2017. Recent years have seen record sea ice lows in February 2022–February 2023. We use a statistical ensemble reconstruction of Antarctic sea ice to put the observed changes into the historical context of the entire 20th century. We propose a seasonal Vector Auto‐Regressive Moving Average (VARMA) model fit in a Bayesian framework using regularized horseshoe priors on the regression coefficients to create a stochastic ensemble reconstruction of monthly Antarctic Sea ice extent from 1900 to 1979. This novel model produces a set of 2,500 plausible sea ice extent reconstructions for the sea ice by sector that incorporate the autocorrelation...

Enhancing glacier monitoring through adaptive smoothing of MODIS NDSI time series

Mon, 14 Oct 2024 00:00:00 +0000

Observation of glacier surface characteristics through remotely sensed time-series data is essential for understanding glacier seasonality, mass balance, and long-term trends. Yet, the reliability of these observations depends significantly on the quality of the time-series data. This study presents a meticulous preprocessing scheme to improve the quality of Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Snow Index (NDSI) time-series data for glacier monitoring. We propose a three-step algorithm specifically crafted to overcome the challenges associated with cloud contamination reduction, outlier removal and data gap handling. This innovative approach iteratively compares the median values of automatically adjusted asymmetrical moving windows to achieve convergence, removing outliers using minimal window size to keep the temporal resolution as high as possible. The methodology’s effectiveness is demonstrated through its application to two glaciers...

Correction for Slik et al., Phylogenetic classification of the world’s tropical forests

Fri, 16 Aug 2024 00:00:00 +0000

Correction for "Phylogenetic classification of the world's tropical forests, " by J. W. Ferry Slik, Janet Franklin, Víctor Arroyo- Rodríguez, Richard Field, Salomon Aguilar, Nikolay Aguirre, Jorge Ahumada, Shin-Ichiro Aiba, Luciana F. Alves, Anitha K, Andres Avella, Francisco Mora, Gerardo A. Aymard C., Selene B?ez, Patricia Balvanera, Meredith L. Bastian, Jean-François Bastin, Peter J. Bellingham, Eduardo van den Berg, Polyanna da Conceição Bispo, Pascal Boeckx, Katrin Boehning-Gaese, Frans Bongers, Brad Boyle, Fabian Brambach, Francis Q. Brearley, Sandra Brown, Shauna-Lee Chai, Robin L. Chazdon, Shengbin Chen, Phourin Chhang, George Chuyong, Corneille Ewango, Indiana M. Coronado, Jurgi Crist?bal-Azkarate, Heike Culmsee, Kipiro Damas, H. S. Dattaraja, Priya Davidar, Saara J. DeWalt, Hazimah Din, Donald R. Drake, Alvaro Duque, Giselda Durigan, Karl Eichhorn, Eduardo Schmidt Eler, Tsutomu Enoki, Andreas Ensslin, Adand? Belarmain Fandohan, Nina Farwig, Kenneth J. Feeley, Markus...

SMLFire1.0: a stochastic machine learning (SML) model for wildfire activity in the western United States

Thu, 1 Aug 2024 00:00:00 +0000

Abstract. The annual area burned due to wildfires in the western United States (WUS) increased by more than 300 % between 1984 and 2020. However, accounting for the nonlinear, spatially heterogeneous interactions between climate, vegetation, and human predictors driving the trends in fire frequency and sizes at different spatial scales remains a challenging problem for statistical fire models. Here we introduce a novel stochastic machine learning (SML) framework, SMLFire1.0, to model observed fire frequencies and sizes in 12 km × 12 km grid cells across the WUS. This framework is implemented using mixture density networks trained on a wide suite of input predictors. The modeled WUS fire frequency matches observations at both monthly (r=0.94) and annual (r=0.85) timescales, as do the monthly (r=0.90) and annual (r=0.88) area burned. Moreover, the modeled annual time series of both fire variables exhibit strong correlations (r≥0.6) with observations in 16 out of 18 ecoregions. Our...

Forest Carbon Storage in the Western United States: Distribution, Drivers, and Trends

Thu, 1 Aug 2024 00:00:00 +0000

Abstract: Forests are a large carbon sink and could serve as natural climate solutions that help moderate future warming. Thus, establishing forest carbon baselines is essential for tracking climate‐mitigation targets. Western US forests are natural climate solution hotspots but are profoundly threatened by drought and altered disturbance regimes. How these factors shape spatial patterns of carbon storage and carbon change over time is poorly resolved. Here, we estimate live and dead forest carbon density in 19 forested western US ecoregions with national inventory data (2005–2019) to determine: (a) current carbon distributions, (b) underpinning drivers, and (c) recent trends. Potential drivers of current carbon included harvest, wildfire, insect and disease, topography, and climate. Using random forests, we evaluated driver importance and relationships with current live and dead carbon within ecoregions. We assessed trends using linear models. Pacific Northwest (PNW) and Southwest...

Six Hundred Years of Reconstructed Atmospheric River Activity Along the US West Coast

Thu, 1 Aug 2024 00:00:00 +0000

Abstract: Atmospheric rivers (AR) are critically important to water resources management along the US west coast, driving variability in both droughts and floods across the region. Inter‐annual variability of ARs is well documented in the instrumental record back to the mid‐twentieth century, but long‐term variations in the frequency and landfall location of ARs along the US west coast are poorly understood due to limited records. This limitation impedes the ability to contextualize emerging trends and projections of AR activity. Here we use station‐based records of daily precipitation and tree‐ring records to present novel, spatially explicit estimates of daily AR occurrences in the first half of the twentieth century and annual AR counts over the last 600 years. First, we use neural networks and daily precipitation across Western North America to classify the daily occurrence of AR landfalls in three regions along the US west coast during the cold season back to 1916 CE....

Large contribution from anthropogenic warming to an emerging North American megadrought (vol 370, eabf3676, 2020)

Thu, 1 Aug 2024 00:00:00 +0000

Large contribution from anthropogenic warming to an emerging North American megadrought (vol 370, eabf3676, 2020)

A 500‐Year Tree Ring‐Based Reconstruction of Extreme Cold‐Season Precipitation and Number of Atmospheric River Landfalls Across the Southwestern United States

Thu, 1 Aug 2024 00:00:00 +0000

Abstract: This study develops a reconstruction of the frequency of extreme cold‐season precipitation and the occurrence of landfalling atmospheric river (AR) storm tracks across the southwestern Unites States using a network of tree ring chronologies and the Living Blended Drought Atlas (LBDA), a 500‐year tree ring based reconstruction of the summer Palmer Drought Severity Index. The first two rotated empirical orthogonal functions of the LBDA across the Southwest are shown to relate well to previously identified patterns of regional AR activity. Accordingly, the rotated empirical orthogonal functions also record patterns of extreme precipitation associated with those ARs, albeit with some uncertainty introduced by nonextreme precipitation. A network of chronologies sensitive to cold‐season precipitation is then used to reconstruct the occurrence of landfalling ARs and extreme precipitation along the southern Californian coast, demonstrating for the first time the feasibility...

Tree species explain only half of explained spatial variability in plant water sensitivity

Wed, 31 Jul 2024 00:00:00 +0000

Spatiotemporal patterns of plant water uptake, loss, and storage exert a first-order control on photosynthesis and evapotranspiration. Many studies of plant responses to water stress have focused on differences between species because of their different stomatal closure, xylem conductance, and root traits. However, several other ecohydrological factors are also relevant, including soil hydraulics, topographically driven redistribution of water, plant adaptation to local climatic variations, and changes in vegetation density. Here, we seek to understand the relative importance of the dominant species for regional-scale variations in woody plant responses to water stress. We map plant water sensitivity (PWS) based on the response of remotely sensed live fuel moisture content to variations in hydrometeorology using an auto-regressive model. Live fuel moisture content dynamics are informative of PWS because they directly reflect vegetation water content and therefore patterns of plant...

Critical transitions in the Amazon forest system

Thu, 18 Jul 2024 00:00:00 +0000

The possibility that the Amazon forest system could soon reach a tipping point, inducing large-scale collapse, has raised global concern1–3. For 65 million years, Amazonian forests remained relatively resilient to climatic variability. Now, the region is increasingly exposed to unprecedented stress from warming temperatures, extreme droughts, deforestation and fires, even in central and remote parts of the system1. Long existing feedbacks between the forest and environmental conditions are being replaced by novel feedbacks that modify ecosystem resilience, increasing the risk of critical transition. Here we analyse existing evidence for five major drivers of water stress on Amazonian forests, as well as potential critical thresholds of those drivers that, if crossed, could trigger local, regional or even biome-wide forest collapse. By combining spatial information on various disturbances, we estimate that by 2050, 10% to 47% of Amazonian forests will be exposed to compounding...

Predicting the distribution and habitat suitability of the smooth-coated otter (Lutrogale perspicillata) in lowland Nepal

Wed, 3 Jul 2024 00:00:00 +0000

Predicting the distribution and habitat suitability of the smooth-coated otter (Lutrogale perspicillata) in lowland Nepal

Anthropogenic Intensification of Cool‐Season Precipitation Is Not Yet Detectable Across the Western United States

Wed, 19 Jun 2024 00:00:00 +0000

Abstract: The cool season (November–March) of 2022–2023 was exceptional in the western United States (US), with the highest precipitation totals in ≥128 years in some areas. Recent precipitation extremes and expectations based on thermodynamics motivate us to evaluate the evidence for an anthropogenic intensification of western US cool‐season precipitation to date. Over cool seasons 1951–2023, trends in precipitation totals on the wettest cool‐season days were neutral or negative across the western US, and significantly negative in northern California and parts of the Pacific Northwest, counter to the expected net intensification effect from anthropogenic forcing. Multiple reanalysis data sets indicate a corresponding lack of increase in moisture transports into the western US, suggesting that atmospheric circulation trends over the North Pacific have counteracted the increases in atmospheric moisture expected from warming alone. The lack of precipitation intensification...

Correction to: Near‑global summer circulation response to the spring surface temperature anomaly in Tibetan Plateau –– the GEWEX/LS4P first phase experiment

Wed, 19 Jun 2024 00:00:00 +0000

https://doi.org/10.1007/s00382-024-07210-5. In this article 17 references, which were wrongly moved to the Supplementary Information, need to be added. The list of added references as given below: The original article has been corrected

Critical Commentary: Cities in a post-COVID world

Fri, 31 May 2024 00:00:00 +0000

This paper examines the effect of the COVID-19 pandemic and its related economic, fiscal, social and political fallout on cities and metropolitan regions. We assess the effect of the pandemic on urban economic geography at the intra- and inter-regional geographic scales in the context of four main forces: the social scarring instilled by the pandemic; the lockdown as a forced experiment; the need to secure the urban built environment against future risks; and changes in the urban form and system. At the macrogeographic scale, we argue the pandemic is unlikely to significantly alter the winner-take-all economic geography and spatial inequality of the global city system. At the microgeographic scale, however, we suggest that it may bring about a series of short-term and some longer-running social changes in the structure and morphology of cities, suburbs and metropolitan regions. The durability and extent of these changes will depend on the timeline and length of the pandemic.

Thinking with Bem Viver across rural and urban Amazonia: Indigenous and Black spaces of resistance

Fri, 24 May 2024 00:00:00 +0000

Thinking with Bem Viver across rural and urban Amazonia: Indigenous and Black spaces of resistance

Subseasonal-to-seasonal predictability of extreme precipitation and land forcing

Wed, 24 Apr 2024 00:00:00 +0000

Subseasonal-to-seasonal predictability of extreme precipitation and land forcing

Near-global summer circulation response to the spring surface temperature anomaly in Tibetan Plateau –– the GEWEX/LS4P first phase experiment

Wed, 10 Apr 2024 00:00:00 +0000

Abstract: Subseasonal to seasonal (S2S) prediction of droughts and floods is one of the major challenges of weather and climate prediction. Recent studies suggest that the springtime land surface temperature/subsurface temperature (LST/SUBT) over the Tibetan Plateau (TP) can be a new source of S2S predictability. The project “Impact of Initialized Land Surface Temperature and Snowpack on Subseasonal to Seasonal Prediction (LS4P)” was initiated to study the impact of springtime LST/SUBT anomalies over high mountain areas on summertime precipitation predictions. The present work explores the simulated global scale response of the atmospheric circulation to the springtime TP land surface cooling by 16 current state-of-the-art Earth System Models (ESMs) participating in the LS4P Phase I (LS4P-I) experiment. The LS4P-I results show, for the first time, that springtime TP surface anomalies can modulate a persistent quasi-barotropic Tibetan Plateau-Rocky Mountain Circumglobal (TRC)...

Feeling the Vibe: Relations and Praxes of a Black Sense of Place in Oakland, California

Wed, 10 Apr 2024 00:00:00 +0000

Feeling the Vibe: Relations and Praxes of a Black Sense of Place in Oakland, California

Characterizing the Role of Wind and Dust in Traffic Accidents in California

Sun, 7 Apr 2024 00:00:00 +0000

Wind is a common ground transportation hazard. In arid regions, wind-blown dust is an added risk. Here, we analyzed the relationship between accidents and wind speed, dust events to study how they may have contributed to vehicular accidents in California. The California Highway Patrol reports information about weather conditions that potentially contributed to traffic accidents, including a code for wind but not for reduced visibility due to dust. For the three counties that contain the major dust source regions in California (the Mojave Desert and the Imperial Valley), we found greater daily maximum wind speed for days with accidents coded for wind compared to all days with accidents. The percentage of people injured in accidents attributed for weather other than wind and coded for wind were the same; however, the percentage of people who died in wind-related accidents was about double the deaths in accidents caused by weather other than wind. At ground meteorological stations...

Improved subseasonal-to-seasonal precipitation prediction of climate models with nudging approach for better initialization of Tibetan Plateau-Rocky Mountain Circumglobal wave train and land surface conditions

Wed, 28 Feb 2024 00:00:00 +0000

Reliable subseasonal-to-seasonal (S2S) precipitation prediction is highly desired due to the great socioeconomical implications, yet it remains one of the most challenging topics in the weather/climate prediction research area. As part of the Impact of Initialized Land Temperature and Snowpack on Sub-seasonal to Seasonal Prediction (LS4P) project of the Global Energy and Water Exchanges (GEWEX) program, twenty-one climate models follow the LS4P protocol to quantify the impact of the Tibetan Plateau (TP) land surface temperature/subsurface temperature (LST/SUBT) springtime anomalies on the global summertime precipitation. We find that nudging towards reanalysis winds is crucial for climate models to generate atmosphere and land surface initial conditions close to observations, which is necessary for meaningful S2S applications. Simulations with nudged initial conditions can better capture the summer precipitation responses to the imposed TP LST/SUBT spring anomalies at hotspot...

Impact of frozen soil processes on soil thermal characteristics at seasonal to decadal scales over the Tibetan Plateau and North China

Wed, 31 Jan 2024 00:00:00 +0000

Abstract. Frozen soil processes are of great importance in controlling surface water and energy balances during the cold season and in cold regions. Over recent decades, considerable frozen soil degradation and surface soil warming have been reported over the Tibetan Plateau and North China, but most land surface models have difficulty in capturing the freeze-thaw cycle and few validations focus on the effects of frozen soil processes on soil thermal characteristics in these regions. This paper addresses these issues by introducing a physically more realistic and computationally more stable and efficient frozen soil module (FSM) into a land surface model—the third-generation Simplified Simple Biosphere model (SSiB3-FSM). To overcome the difficulties in achieving stable numerical solutions for frozen soil, a new semi-implicit scheme and a physics-based freezing-thawing scheme were applied to solve the governing equations. The performance of this model, as well as the effects of...

Regional climate model intercomparison over the Tibetan Plateau in the GEWEX/LS4P Phase I

Wed, 31 Jan 2024 00:00:00 +0000

Regional climate model intercomparison over the Tibetan Plateau in the GEWEX/LS4P Phase I

Simulation of summer climate over Central Asia shows high sensitivity to different land surface schemes in WRF

Wed, 31 Jan 2024 00:00:00 +0000

Abstract: Land surface processes are vital to the performance of regional climate models in dynamic downscaling application. In this study, we investigate the sensitivity of the simulation by using the weather research and forecasting (WRF) model at 10-km resolution to the land surface schemes over Central Asia. The WRF model was run for 19 summers from 2000 to 2018 configured with four different land surface schemes including CLM4, Noah-MP, Pleim-Xiu and SSiB, hereafter referred as Exp-CLM4, Exp-Noah-MP, Exp-PX and Exp-SSiB respectively. The initial and boundary conditions for the WRF model simulations were provided by the National Centers for Environmental Prediction Final (NCEP-FNL) Operational Global Analysis data. The ERA-Interim reanalysis (ERAI), the GHCN-CAMS and the CRU gridded data were used to comprehensively evaluate the WRF simulations. Compared with the reanalysis and observational data, the WRF model can reasonably reproduce the spatial patterns of summer mean...

Modeling the short-term fire effects on vegetation dynamics and surface energy in southern Africa using the improved SSiB4/TRIFFID-Fire model

Wed, 31 Jan 2024 00:00:00 +0000

Abstract. Fire causes abrupt changes in vegetation properties and modifies flux exchanges between land and atmosphere at subseasonal to seasonal scales. Yet these short-term fire effects on vegetation dynamics and surface energy balance have not been comprehensively investigated in the fire-coupled vegetation model. This study applies the SSiB4/TRIFFID-Fire (the Simplified Simple Biosphere Model coupled with the Top-down Representation of Interactive Foliage and Flora Including Dynamics with fire) model to study the short-term fire impact in southern Africa. Specifically, we aim to quantify how large impacts fire exerts on surface energy through disturbances on vegetation dynamics, how fire effects evolve during the fire season and the subsequent rainy season, and how surface-darkening effects play a role besides the vegetation change effects. We find fire causes an annual average reduction in grass cover by 4 %–8 % for widespread areas between 5–20∘ S and a tree cover reduction by...

A dominant mode in the first phase of the Asian summer monsoon rainfall: role of antecedent remote land surface temperature

Wed, 31 Jan 2024 00:00:00 +0000

A dominant mode in the first phase of the Asian summer monsoon rainfall: role of antecedent remote land surface temperature

Climate change will accelerate the high-end risk of compound drought and heatwave events

Sat, 20 Jan 2024 00:00:00 +0000

Compound drought and heatwave (CDHW) events have garnered increased attention due to their significant impacts on agriculture, energy, water resources, and ecosystems. We quantify the projected future shifts in CDHW characteristics (such as frequency, duration, and severity) due to continued anthropogenic warming relative to the baseline recent observed period (1982 to 2019). We combine weekly drought and heatwave information for 26 climate divisions across the globe, employing historical and projected model output from eight Coupled Model Intercomparison Project 6 GCMs and three Shared Socioeconomic Pathways. Statistically significant trends are revealed in the CDHW characteristics for both recent observed and model simulated future period (2020 to 2099). East Africa, North Australia, East North America, Central Asia, Central Europe, and Southeastern South America show the greatest increase in frequency through the late 21st century. The Southern Hemisphere displays a greater...

A Near Four-Decade Time Series Shows the Hawaiian Islands Have Been Browning Since the 1980s

Thu, 7 Dec 2023 00:00:00 +0000

The Hawaiian Islands have been identified as a global biodiversity hotspot. We examine the Normalized Difference Vegetation Index (NDVI) using Climate Data Records products (0.05 × 0.05°) to identify significant differences in NDVI between neutral El Niño-Southern Oscillation years (1984, 2019) and significant long-term changes over the entire time series (1982–2019) for the Hawaiian Islands and six land cover classes. Overall, there has been a significant decline in NDVI (i.e., browning) across the Hawaiian Islands from 1982 to 2019 with the islands of Lāna’i and Hawai’i experiencing the greatest decreases in NDVI (≥44%). All land cover classes significantly decreased in NDVI for most months, especially during the wet season month of March. Native vegetation cover across all islands also experienced significant declines in NDVI, with the leeward, southwestern side of the island of Hawai’i experiencing the greatest declines. The long-term trends in the annual total precipitation...

Vladimir Putin's territorial trap: what the invasion of Ukraine reveals about the contemporary war-sovereignty nexus

Tue, 19 Sep 2023 00:00:00 +0000

Vladimir Putin's territorial trap: what the invasion of Ukraine reveals about the contemporary war-sovereignty nexus

The Counties that Counted: Could 2020 Repeat 2016 in the US Electoral College?

Tue, 19 Sep 2023 00:00:00 +0000

Abstract: We briefly trace the claim that a set of counties across the three states of Michigan, Pennsylvania, and Wisconsin in large part determined the outcome of the 2016 presidential election. Rather than the demographic characteristics of the Census as such it is the meaning that these categories (young/old, Black/White, male/female, and so on) take on in particular places in which people’s lives are grounded that drives electoral outcomes. Given that the counties in question were ones in which Obama had performed well but which Trump won in 2016 and this shift was put down to his appeal to those “left behind” in the post-2008 economy, we focus on whether or not this localized appeal can be expected to continue in 2020.

Failing federalism? US dualist federalism and the 2020–22 pandemic

Tue, 19 Sep 2023 00:00:00 +0000

Failing federalism? US dualist federalism and the 2020–22 pandemic

Mussolini's Nation-Empire: Sovereignty and Settlement in Italy's Borderlands, 1922-1943.

Tue, 19 Sep 2023 00:00:00 +0000

Mussolini's Nation-Empire: Sovereignty and Settlement in Italy's Borderlands, 1922-1943.

The changing geography of social mobility in the United States

Tue, 19 Sep 2023 00:00:00 +0000

New evidence shows that intergenerational social mobility-the rate at which children born into poverty climb the income ladder-varies considerably across the United States. Is this current geography of opportunity something new or does it reflect a continuation of long-term trends? We answer this question by constructing data on the levels and determinants of social mobility across American regions over the 20th century. We find that the changing geography of opportunity-generating economic activity restructures the landscape of intergenerational mobility, but factors associated with specific regional structures of interpersonal and racial inequality that have "deep roots" generate persistence. This is evident in the sharp decline in social mobility in the Midwest as economic activity has shifted away from it and the consistently low levels of opportunity in the South even as economic activity has shifted toward it. We conclude that the long-term geography of social mobility can...

Fellini's Sense of Place

Tue, 19 Sep 2023 00:00:00 +0000

Fellini's Sense of Place

The association between county political inclination and obesity: Results from the 2012 presidential election in the United States

Sun, 17 Sep 2023 00:00:00 +0000

OBJECTIVE: We examined whether stable, county-level, voter preferences were significantly associated with county-level obesity prevalence using data from the 2012 US Presidential election. County voting preference for the 2012 Republican Party presidential candidate was used as a proxy for voter endorsement of personal responsibility approaches to reducing population obesity risk versus approaches featuring government-sponsored, multi-sectoral efforts like those recommended by the Centers for Disease Control Centers for Disease Control (CDC, 2009). METHOD: Cartographic visualization and spatial analysis were used to evaluate the geographic clustering of obesity prevalence rates by county, and county-level support for the Republican Party candidate in the 2012 U.S. presidential election. The spatial analysis informed the spatial econometric approach employed to model the relationship between political preferences and other covariates with obesity prevalence. RESULTS: After controlling...

Remote effects of Tibetan Plateau spring land temperature on global subseasonal to seasonal precipitation prediction and comparison with effects of sea surface temperature: the GEWEX/LS4P Phase I experiment

Wed, 16 Aug 2023 00:00:00 +0000

Abstract: The prediction skill for precipitation anomalies in late spring and summer months—a significant component of extreme climate events—has remained stubbornly low for years. This paper presents a new idea that utilizes information on boreal spring land surface temperature/subsurface temperature (LST/SUBT) anomalies over the Tibetan Plateau (TP) to improve prediction of subsequent summer droughts/floods over several regions over the world, East Asia and North America in particular. The work was performed in the framework of the GEWEX/LS4P Phase I (LS4P-I) experiment, which focused on whether the TP LST/SUBT provides an additional source for subseasonal-to-seasonal (S2S) predictability. The summer 2003, when there were severe drought/flood over the southern/northern part of the Yangtze River basin, respectively, has been selected as the focus case. With the newly developed LST/SUBT initialization method, the observed surface temperature anomaly over the TP has been partially...

A comparison of biomonitoring methodologies for surf zone fish communities.

Thu, 3 Aug 2023 00:00:00 +0000

Surf zones are highly dynamic marine ecosystems that are subject to increasing anthropogenic and climatic pressures, posing multiple challenges for biomonitoring. Traditional methods such as seines and hook and line surveys are often labor intensive, taxonomically biased, and can be physically hazardous. Emerging techniques, such as baited remote underwater video (BRUV) and environmental DNA (eDNA) are promising nondestructive tools for assessing marine biodiversity in surf zones of sandy beaches. Here we compare the relative performance of beach seines, BRUV, and eDNA in characterizing community composition of bony (teleost) and cartilaginous (elasmobranch) fishes of surf zones at 18 open coast sandy beaches in southern California. Seine and BRUV surveys captured overlapping, but distinct fish communities with 50% (18/36) of detected species shared. BRUV surveys more frequently detected larger species (e.g. sharks and rays) while seines more frequently detected one of the most...

Diet of a threatened endemic fox reveals variation in sandy beach resource use on California Channel Islands

Wed, 19 Jul 2023 00:00:00 +0000

The coastal zone provides foraging opportunities for insular populations of terrestrial mammals, allowing for expanded habitat use, increased dietary breadth, and locally higher population densities. We examined the use of sandy beach resources by the threatened island fox (Urocyon littoralis) on the California Channel Islands using scat analysis, surveys of potential prey, beach habitat attributes, and stable isotope analysis. Consumption of beach invertebrates, primarily intertidal talitrid amphipods (Megalorchestia spp.) by island fox varied with abundance of these prey across sites. Distance-based linear modeling revealed that abundance of giant kelp (Macrocystis pyrifera) wrack, rather than beach physical attributes, explained the largest amount of variation in talitrid amphipod abundance and biomass across beaches. δ13C and δ15N values of fox whisker (vibrissae) segments suggested individualism in diet, with generally low δ13C and δ15N values of some foxes consistent with...

Using dune restoration on an urban beach as a coastal resilience approach

Wed, 19 Jul 2023 00:00:00 +0000

Coastal dunes are globally recognized as natural features that can be important adaptation approaches for climate change along urban and natural shores. We evaluated the recovery of coastal dunes on an intensively groomed urban beach in southern California over a six-year period after grooming was discontinued. Restoration actions were minimal and included installation of three sides of perimeter sand fencing, cessation of mechanical grooming and driving, and the addition of seeds of native dune plants. To track recovery, we conducted physical and biological surveys of the restoration site and an adjacent control site (groomed beach) using metrics including sand accretion, elevation, foredune and hummock formation, vegetation recovery, and wildlife use. Sediment accretion, elevation, and geomorphic complexity increased over time in the restoration site, largely in association with sand fencing and dune vegetation. A foredune ridge (maximum elevation increase of 0.9 m) and...

Studying Displacement After a Disaster Using Large-Scale Survey Methods: Sumatra After the 2004 Tsunami

Sat, 1 Jul 2023 00:00:00 +0000

Understanding of human vulnerability to environmental change has advanced in recent years, but measuring vulnerability and interpreting mobility across many sites differentially affected by change remains a significant challenge. Drawing on longitudinal data collected on the same respondents who were living in coastal areas of Indonesia before the 2004 Indian Ocean tsunami and were re-interviewed after the tsunami, this paper illustrates how the combination of population-based survey methods, satellite imagery and multivariate statistical analyses has the potential to provide new insights into vulnerability, mobility and impacts of major disasters on population well-being. The data are used to map and analyze vulnerability to post-tsunami displacement across the provinces of Aceh and North Sumatra and to compare patterns of migration after the tsunami between damaged areas and areas not directly affected by the tsunami. The comparison reveals that migration after a disaster is...

Shadow is related to roughness but MODIS BRDF should not be used to estimate lateral cover

Thu, 22 Jun 2023 00:00:00 +0000

Shadow is related to roughness but MODIS BRDF should not be used to estimate lateral cover

Outdoor Residential Water Use Restrictions during Recent Drought Suppressed Disease Vector Abundance in Southern California

Thu, 15 Jun 2023 00:00:00 +0000

The California state government put restrictions on outdoor residential water use, including landscape irrigation, during the 2012-2016 drought. The public health implications of these actions are largely unknown, particularly with respect to mosquito-borne disease transmission. While residential irrigation facilitates persistence of mosquitoes by increasing the availability of standing water, few studies have investigated its effects on vector abundance. In two study sub-regions in the Los Angeles Basin, we examined the effect of outdoor residential water use restrictions on the abundance of the most important regional West Nile virus vector, Culex quinquefasciatus. Using spatiotemporal random forest models fit to Cx. abundance during drought and non-drought years, we generated counterfactual estimates of Cx. abundance under a hypothetical drought scenario without water use restrictions. We estimate that Cx. abundance would have been 44% and 39% larger...

Subjective well-being in China’s changing society

Wed, 31 May 2023 00:00:00 +0000

There is now recognition that a population's overall level of well-being is defined not just by income and wealth. Where we live and who we interact with are likely to be equally important in our overall levels of satisfaction with our lives. This thinking has stimulated studies of subjective well-being, or happiness, at both national and local scales. These studies suggest that where you live does matter, although it is health and family status that have the most direct effects on well-being. In this study, we use a detailed dataset on well-being from the China Household Finance Survey to reexamine well-being across China, where profound socioeconomic changes are taking place. The study controls for self-reported health and examines subjective well-being across extensive and varied Chinese urban and rural environments. We find that the earlier pessimism about China's well-being, which emphasized declining happiness, may be misplaced. We make two contributions: first, we show...

Examining the life course sequence of intending to move and moving

Fri, 19 May 2023 00:00:00 +0000

There is now a substantial body of research which examines the process of making decisions about moving. The questions of interest in that work and in this study using US data are, first, how do life course changes get translated into intentions to move, and second, to what extent are intentions realized or unrealized. This study extends previous work by considering a longer interval in the planning process, and by examining how life cycle changes create intentions, which in turn are translated, or not, into actual moves. We study the antecedents of the expressed intention to move and the outcomes which follow the expressed intention to move. We test the process of forming intentions and moving in the context of life course events and changes. We find that the subset of variables which create the intention to move vary subtly from the variables which create moves, though the triggering effects of family composition change are critical dimensions of both creating intentions and...

Human Capital Theory and Internal Migration: Do Average Outcomes Distort Our View of Migrant Motives?

Sat, 13 May 2023 00:00:00 +0000

By modelling the distribution of percentage income gains for movers in Sweden, using multinomial logistic regression, this paper shows that those receiving large pecuniary returns from migration are primarily those moving to the larger metropolitan areas and those with higher education, and that there is much more variability in income gains than what is often assumed in models of average gains to migration. This suggests that human capital models of internal migration often overemphasize the job and income motive for moving, and fail to explore where and when human capital motivated migration occurs.

Prospect theory and the decision to move or stay

Sat, 13 May 2023 00:00:00 +0000

Migration has always involved stress and risk. More risk-averse households are less likely to move, while less risk-averse households will seek out opportunities and migrate. We investigate how the theoretical contributions of prospect theory, and specifically the endowment effect, can provide new understanding about decisions whether to migrate or not. We test the hypothesis that risk aversion extends the length of stay in the dwelling and, by extension, in the local labor and housing markets. How long people remain in place is a function, we hypothesize, of their independently self-assessed propensity to take risks, after controlling for a range of demographic and socioeconomic characteristics. We use the theoretical insights of prospect theory and the endowment effect (the notion of the "use value" differing from the "exchange value") to explain the likelihood of staying after controlling for life-course events. The results confirm the explanatory power of self-assessed risk...

Reversals of national fortune, and social science methodologies

Fri, 12 May 2023 00:00:00 +0000

Among non-European regions colonized by Europeans, regions that were relatively richer five centuries ago (like Mexico, Peru, and India) tend to be poorer today, while regions that originally were relatively poorer (like the United States, Chile, and Australia) tend now to be richer. Acemoglu, Johnson, and Robinson (abbreviated AJR) established the generality of this reversal of fortune. Chanda, Cook, and Putterman (abbreviated CCP) have now reanalyzed it, taking as a unit of analysis populations rather than geographic regions. That is, India's population was Indian 500 y ago and is still overwhelmingly Indian today, whereas the United States' population was Native American 500 years ago but is overwhelmingly Old World (especially European) today. Reversals of fortune disappeared when CCP analyzed populations rather than geographic regions: for instance, the geographic region of the modern United States has become relatively richer since AD 1500, but the predominantly European...

Scripting climate futures: The geographical assumptions of climate planning

Wed, 26 Apr 2023 00:00:00 +0000

Scripting climate futures: The geographical assumptions of climate planning

Thirty years on: Planetary climate planning and the Intergovernmental Negotiating Committee

Wed, 26 Apr 2023 00:00:00 +0000

Thirty years on: Planetary climate planning and the Intergovernmental Negotiating Committee

An estimate of the number of tropical tree species

Mon, 17 Apr 2023 00:00:00 +0000

The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher's alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ∼ 40,000 and ∼ 53,000, i.e., at the high end of previous estimates. Contrary to common assumption, the Indo-Pacific region was found to be as species-rich as the Neotropics, with both regions having a minimum of ∼ 19,000-25,000 tree species. Continental Africa is relatively depauperate with a minimum of ∼ 4,500-6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological framework for estimating species richness in trees that may help refine species richness...

Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet

Sat, 15 Apr 2023 00:00:00 +0000

Thermally incised meltwater channels that flow each summer across melt-prone surfaces of the Greenland ice sheet have received little direct study. We use high-resolution WorldView-1/2 satellite mapping and in situ measurements to characterize supraglacial water storage, drainage pattern, and discharge across 6,812 km(2) of southwest Greenland in July 2012, after a record melt event. Efficient surface drainage was routed through 523 high-order stream/river channel networks, all of which terminated in moulins before reaching the ice edge. Low surface water storage (3.6 ± 0.9 cm), negligible impoundment by supraglacial lakes or topographic depressions, and high discharge to moulins (2.54-2.81 cm⋅d(-1)) indicate that the surface drainage system conveyed its own storage volume every <2 d to the bed. Moulin discharges mapped inside ∼52% of the source ice watershed for Isortoq, a major proglacial river, totaled ∼41-98% of observed proglacial discharge, highlighting the importance...

Spatial conservation planning framework for assessing conservation opportunities in the Atlantic Forest of Brazil

Sat, 15 Apr 2023 00:00:00 +0000

Historic rates of habitat change and growing exploitation of natural resources threaten avian biodiversity in the Brazilian Atlantic Forest, a global biodiversity hotspot. We implemented a twostage framework for conservation planning in the Atlantic Forest. First, we used ecological niche modeling to predict the distributions of 23 endemic bird species using 19 climatic metrics and 12 spectral and radar remote sensing metrics. Second, we utilized the principle of complementarity to prioritize new sites to augment the Atlantic Forest's existing reserves. The best predictors of bird distributions were precipitation metrics (the seasonality of rainfall) and radar remote sensing metrics (QSCAT). The existing protected areas do not include 10% of the habitat of each of the 23 endemic species. We propose a more economical set of protected areas by reducing the extent to which new sites duplicate the biodiversity content of existing protected areas. There is a high concordance between...

Night-time lights time series of tsunami damage, recovery, and economic metrics in Sumatra, Indonesia

Fri, 7 Apr 2023 00:00:00 +0000

On 26 December 2004, a magnitude 9.2 earthquake off the west coast of the northern Sumatra, Indonesia resulted in 160,000 Indonesians killed. We examine the Defense Meteorological Satellite Program-Operational Linescan System (DMSP-OLS) nighttime light imagery brightness values for 307 communities in the Study of the Tsunami Aftermath and Recovery (STAR), a household survey in Sumatra from 2004 to 2008. We examined night light time series between the annual brightness and extent of damage, economic metrics collected from STAR households and aggregated to the community level. There were significant changes in brightness values from 2004 to 2008 with a significant drop in brightness values in 2005 due to the tsunami and pre-tsunami nighttime light values returning in 2006 for all damage zones. There were significant relationships between the nighttime imagery brightness and per capita expenditures, and spending on energy and on food. Results suggest that Defense Meteorological Satellite...

Impact of frozen soil processes on soil thermal characteristics at seasonal to decadal scales over the Tibetan Plateau and North China