Process‐Level Evaluation of a Hyper‐Resolution Forest Snow Model Using Distributed Multisensor Observations

Water Resources Research, Journal Year: 2020, Volume and Issue: 56(9)

Published: Aug. 28, 2020

Abstract The complex dynamics of snow accumulation and melt processes under forest canopies entail major observational modeling challenges, as they vary strongly in space time. In this study, we present novel data sets acquired with mobile multisensor platforms subalpine boreal stands. These include spatially temporally resolved measurements shortwave longwave irradiance, air surface temperatures, wind speed, depth, all coregistered to canopy structure information. We then apply the energy balance model FSM2 obtain concurrent, distributed simulations snowpack at very high (“hyper”) resolution (2 m). Our allow us assess performance alternative representation strategies within level individual components a explicit manner. demonstrate benefit accounting for detailed spatial patterns radiation transfer through show importance describing attenuation by using stand‐scale metrics. With proposed representation, snowmelt discontinuous stands were successfully reproduced. Hyper‐resolution resolving these effects provide an optimal basis assessing snow‐hydrological impacts disturbances validating improving land models intended coarser‐scale applications.

Language: Английский

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Influences of North Pacific Ocean Domain Extent on the Western U.S. Winter Hydroclimatology in Variable‐Resolution CESM

Journal of Geophysical Research Atmospheres, Journal Year: 2020, Volume and Issue: 125(14)

Published: June 15, 2020

Abstract Variable‐resolution global climate models (VRGCMs) are a dynamical downscaling method that can reach spatiotemporal scales needed for regional assessments. Over the years, several users of VRGCMs have assumed where location and extent refinement domain should be based on knowledge prevailing storm tracks resolution dependence important processes (e.g., atmospheric rivers [ARs] orographic uplift), but effect high‐resolution size simulation downstream hydroclimatic phenomena has not been systematically evaluated. Here, we use variable in Community Earth System Model (VR‐CESM) to perform such test. To do this, three VR‐CESM grids were generated span entire, two thirds, one third North Pacific evaluated 30‐year climatology using Atmospheric Intercomparison Project protocols. Simulations compared with reanalysis products offshore (fifth‐generation European Centre Medium‐Range Weather Forecasts [ERA5]) onshore (Livneh, 2015, https://doi.org/10.1038/sdata.2015.42 , Parameter‐elevation Regressions Independent Slopes [PRISM]) western United States. The westward expansion influenced integrated vapor transport (IVT), which was generally high biased minimally impacted AR characteristics. Due slight differences landfalling counts States, California winter precipitation improved domain. Western U.S. mountain snowpack surface temperatures insensitive more by changes topographic and/or land model version. Given minimal simulated hydroclimate over Pacific, advise future studies focus grid better resolving heterogeneity.

Language: Английский

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The Ecology of River Ice

Journal of Geophysical Research Biogeosciences, Journal Year: 2021, Volume and Issue: 126(9)

Published: Aug. 17, 2021

Abstract Many of the world's rivers are ice‐covered during winter months but increasing evidence indicates that extent river ice will shift substantially as winters warm. However, our knowledge lags far behind growing season, limiting understanding how loss affect rivers. Physical, chemical, and biological processes change from headwaters to large rivers; thus, we expect resulting effects on ecology could also vary with size, a result associated changes in geomorphology, temperature regimes, connectivity. To conceptualize these relationships, review typically disparate literature compare what is known smallest largest In doing so, show ability link across networks made difficult by primary focus larger lack study ecosystem winter. address some gaps, provide new scenarios analyses annual importance gross productivity (GPP) varies size. We projected varied large‐scale watershed characteristics such north‐south orientation GPP was greatest Finally, highlight information needed fill gaps improve may climate regimes shift.

Language: Английский

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Monitoring the daily evolution and extent of snow drought

Natural hazards and earth system sciences, Journal Year: 2022, Volume and Issue: 22(3), P. 869 - 890

Published: March 16, 2022

Abstract. Snow droughts are commonly defined as below-average snowpack at a point in time, typically 1 April the western United States (wUS). This definition is valuable for interpreting state of but obscures temporal evolution snow drought. Borrowing from dynamical systems theory, we applied phase diagrams to visually examine daily water equivalent (SWE) and accumulated precipitation conditions maritime, intermountain, continental climates wUS using station observations well spatially distributed estimates SWE precipitation. Using percentile-based drought definition, highlighted decision-relevant aspects such onset, evolution, termination. The diagram approach can be used tandem with reveal variability type extent. When combined streamflow or other environmental data, spatial help inform monitoring early warning link impacts on ecosystems, resources, recreation. A web tool introduced allowing users create real-time historic diagrams.

Language: Английский

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Winter runoff events pose an unquantified continental-scale risk of high wintertime nutrient export

Environmental Research Letters, Journal Year: 2022, Volume and Issue: 17(10), P. 104044 - 104044

Published: Oct. 1, 2022

Abstract Winters in snow-covered regions have warmed, likely shifting the timing and magnitude of nutrient export, leading to unquantified changes water quality. Intermittent, seasonal, permanent snow covers more than half global land surface. Warming has reduced cold conditions that limit winter runoff transport, while season snowmelt, amount precipitation falling as rain, rain-on-snow increased. We used existing geospatial datasets (rain-on-snow frequency overlain on nitrogen phosphorous inventories) identify areas contiguous United States (US) where quality could be threatened by this change. Next, illustrate potential export impacts these events, we examined flow turbidity data from a large regional event States’ largest river basin, Mississippi River Basin. show rain-on-snow, major flood-generating mechanism for globe (Berghuijs et al 2019 Water Resour. Res. 55 4582–93; Berghuijs 2016 Geophys. Lett. 43 4382–90), affects 53% US puts 50% phosphorus pools (43% US) at risk groundwater surface water. Further, Basin demonstrates events large, cascading transport. suggest assumption low wintertime discharge transport historically no longer holds. Critically, however, lack sufficient accurately measure predict episodic potentially continental scales.

Language: Английский

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Technical note: Precipitation-phase partitioning at landscape scales to regional scales

Hydrology and earth system sciences, Journal Year: 2020, Volume and Issue: 24(11), P. 5317 - 5328

Published: Nov. 14, 2020

Abstract. Water management throughout the western United States largely relies on partitioning of cool season mountain precipitation into rain and snow, particularly snow as it maximizes available water for warm use. Recent studies indicate a shift toward increased falling rain, which is consistent with warming climate. An approach presented to estimate precipitation-phase across landscapes from 1948 present by combining fine-scale gridded data coarse-scale freezing level an atmospheric reanalysis. A marriage these sets allows new spatial patterns trends in over elevational latitudinal gradients major supply basins. This product used California diagnostic indicator changing phase watersheds. Results show largest increases during past 70 years lower elevation watersheds located within climatological rain–snow transition regions northern spring. Further development can inform adaptive strategy implementation face

Language: Английский

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Future of Winter in Northeastern North America: Climate Indicators Portray Warming and Snow Loss That Will Impact Ecosystems and Communities

Northeastern Naturalist, Journal Year: 2022, Volume and Issue: 28(sp11)

Published: Feb. 2, 2022

Winters in northeastern North America have warmed faster than summers, with impacts on ecosystems and society. Global climate models (GCMs) indicate that winters will continue to warm lose snow the future, but uncertainty remains regarding magnitude of warming. Here, we project future trends winter indicators under lower higher climate-warming scenarios based emission levels across at a fine spatial scale (1/16°) relevant climate-related decision making. Under both scenarios, coincident increases days above freezing, decreases cover, fewer nights below freezing. Deep snowpacks become increasingly short-lived, decreasing from historical baseline 2 months subnivium habitat <1 month warmer, higher-emissions scenario. Warmer temperatures allow invasive pests such as Adelges tsugae (Hemlock Woolly Adelgid) Dendroctonus frontalis (Southern Pine Beetle) expand their range northward due reduced overwinter mortality. The elevations remain more resilient warming compared southerly coastal regions. Decreases natural snowpack warmer point toward need for adaptation mitigation multi-million-dollar winter-recreation forest-management economies.

Language: Английский

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With warming, spring streamflow peaks are more coupled with vegetation green‐up than snowmelt in the northeastern United States

Hydrological Processes, Journal Year: 2022, Volume and Issue: 36(6)

Published: May 30, 2022

Abstract In forested watersheds, climate change may have substantial implications for both ecological and hydrological processes by altering the snow vegetation seasonal dynamics. However, to date, there been few studies which systematically analysed their combined effects on streamflow behaviour at watershed scale. Using long‐term remote‐sensed data snowpack measurements, we characterized patterns in timings of green‐up/senescence subsequent growing season length, as well development/disappearance duration. We further investigated correlations phenological variations with cumulative percentiles daily over two transition periods: vernal (between snowmelt green‐up) autumnal senescence development) windows. found significantly lengthened ~30 days last four decades study watershed, driven earlier green‐up later senescence. The snowfall decreased ~2.4 cm, duration has shortened ~25 days, mostly disappearance. While were no significant changes lengths windows, normalized distributions window widened low‐frequency peak flow shifted period. Interestingly, although disappearance timing advanced ~18 was evidence spring discharge. Our results suggest that decreases winter duration, impacts dynamics regimes windows weakened. Meanwhile, are more closely mediated time. This emphasizes importance understanding responses prediction future watersheds.

Language: Английский

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Cold-season freeze frequency is a pervasive driver of subcontinental forest growth

Proceedings of the National Academy of Sciences, Journal Year: 2022, Volume and Issue: 119(18)

Published: April 27, 2022

Significance The reduction of freeze exposure with winter warming has consequences for carbon sequestration by northern forests. Quantifying the impact these changes on tree growth is, however, challenging because among- and within-tree species variability in tolerance phenological cues. Here, we provide a comprehensive assessment response to cold-season frequency days using an extensive tree-ring dataset covering Canada’s Our study shows that responses vary direction magnitude clade but also leaf-out strategy, age size, environmental factors. Such quantification can help predict terrestrial dynamics under climate change.

Language: Английский

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Evaluation of the association between climate warming and the spread and proliferation of Ixodes scapularis in northern states in the Eastern United States

Ticks and Tick-borne Diseases, Journal Year: 2023, Volume and Issue: 15(1), P. 102286 - 102286

Published: Nov. 27, 2023

Ixodes scapularis (the blacklegged tick) is widely distributed in forested areas across the eastern United States. The public health impact of I. greatest north, where nymphal stage ticks commonly bite humans and serve as primary vectors for multiple human pathogens. There were dramatic increases tick's distribution abundance over last half-century northern part US, climate warming mentioned a driver these changes. In this review, we summarize evidence observed spread proliferation being driven by warming. Although laboratory small-scale field studies have provided insights into how temperature humidity survival reproduction scapularis, using associations to predict broad-scale patterns more challenging. Numerous efforts been undertaken model at state, regional, global scales based on landscape variables, but outcomes ambiguous. Across models, functional relationships between seasonal or annual measures heat, cold, precipitation, tick presence inconsistent. contribution relative variables was poorly defined. Over half-century, occurred parallel with population increase white-tailed deer, most important reproductive host adults, US. strong deer playing key role facilitate US century. However, due lack spatially temporally congruent data, climate, landscape, are rarely included same thus limiting ability evaluate their contributions interactions defining geographic range ticks. We conclude that change expansion remains uncertain.

Language: Английский

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