scholarly journals E-DATA: A Comprehensive Field Campaign to Investigate Evaporation Enhanced by Advection in the Hyper-Arid Altiplano

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 745 ◽  
Author(s):  
Francisco Suárez ◽  
Felipe Lobos ◽  
Alberto de la Fuente ◽  
Jordi Vilà-Guerau de Arellano ◽  
Ana Prieto ◽  
...  
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Open Water ◽  
Water Evaporation ◽  
Distributed Temperature Sensing ◽  
Field Campaign ◽  
Spatial And Temporal Scales ◽  
Airborne Measurements ◽  
Dry Air ◽  
Evaporation Dynamics

In the endorheic basins of the Altiplano, water is crucial for sustaining unique ecological habitats. Here, the wetlands act as highly localized evaporative environments, and little is known about the processes that control evaporation. Understanding evaporation in the Altiplano is challenging because these environments are immersed in a complex topography surrounded by desert and are affected by atmospheric circulations at various spatial scales. Also, these environments may be subject to evaporation enhancement events as the result of dry air advection. To better characterize evaporation processes in the Altiplano, the novel Evaporation caused by Dry Air Transport over the Atacama Desert (E-DATA) field campaign was designed and tested at the Salar del Huasco, Chile. The E-DATA combines surface and airborne measurements to understand the evaporation dynamics over heterogeneous surfaces, with the main emphasis on the open water evaporation. The weather and research forecasting model was used for planning the instruments installation strategy to understand how large-scale air flow affects evaporation. Instrumentation deployed included: meteorological stations, eddy covariance systems, scintillometers, radiosondes and an unmanned aerial vehicle, and fiber-optic distributed temperature sensing. Additional water quality and CO2 fluxes measurements were carried out to identify the link between meteorological conditions and the biochemical dynamics of Salar del Huasco. Our first results show that, in the study site, evaporation is driven by processes occurring at multiple spatial and temporal scales and that, even in the case of available water and energy, evaporation is triggered by mechanical turbulence induced by wind.

Resource selection in a high-altitude rangeland equid, the kiang (Equus kiang): influence of forage abundance and quality at multiple spatial scales

2014 ◽  
Vol 92 (3) ◽  
pp. 239-249 ◽  
Author(s):  
Antoine St-Louis ◽  
Steeve D. Côté
Keyword(s):  
High Altitude ◽  
Resource Selection ◽  
Large Scale ◽  
Plant Biomass ◽  
Spatial Scales ◽  
Plant Quality ◽  
The Tibetan Plateau ◽  
Higher Plant ◽  
Feeding Site ◽  
Spatial And Temporal Scales

Herbivores foraging in arid and seasonal environments often face choices between plant patches varying in abundance and nutritional quality at several spatial and temporal scales. Because of their noncompartmented digestive system, equids typically rely on abundant forage to meet their nutrient requirements. In forage-limited environments, therefore, scarcity of food resources represents a challenge for wild equids. We investigated hierarchical resource-selection patterns of kiangs (Equus kiang Moorcroft, 1841), a wild equid inhabiting the high-altitude steppes of the Tibetan Plateau, hypothesizing that vegetation abundance would be the main factor driving resource selection at a large scale and that plant quality would influence resource selection at finer scales. We investigated resource-selection patterns at three spatial levels (habitat, feeding site, and plant (vegetation groups, i.e., grasses, sedges, forbs, and shrubs)) during summer and fall. At the habitat level, kiangs selected both mesic and xeric habitats in summer and only xeric habitats (plains) during fall. At the feeding-site level, feeding sites had higher plant biomass and percentage of green foliage than random sites in the same habitats. At the plant level, grasses were selected over forbs and shrubs, and sedges were used in proportion to their availability during all seasons. Our results indicate that resource-selection patterns in kiangs vary across scales and that both forage abundance and quality play a role in resource selection. Plant quality appeared more important than hypothesized, possibly to increase daily nutrient intake in forage-limited and highly seasonal high-altitude rangelands.

scholarly journals Downstream Changes in Odonate (Insecta: Odonata) Communities along a Suburban to Urban Gradient: Untangling Natural and Anthropogenic Effects

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 201
Author(s):  
Wade B. Worthen ◽  
R. Kile Fravel ◽  
Connor P. Horne
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Principal Component ◽  
Open Water ◽  
Information Criteria ◽  
Habitat Characteristics ◽  
Small Scale ◽  
Larval Abundance ◽  
Percent Cover ◽  
Surrounding Landscape

The community structure of lotic odonates (Insecta: Odonata) changes downstream, but it is difficult to untangle natural and anthropogenic causes. We surveyed larvae and adults at 15 sites along the Reedy River in Greenville Co., SC, USA, from sites in forested suburban landscapes through the urban core of the city of Greenville. We used principal component analyses and Akaike information criteria models to describe the relationships between larval and adult community descriptors (abundance, richness, and diversity) and habitat characteristics at several spatial scales, including water chemistry, sediment and detritus, aquatic and streamside vegetation, and the percent cover of landforms in the surrounding landscape. At all scales, larval abundance, richness, and diversity correlated with the amount of detritus. At a small scale, adult indices correlated with the amount of sunlight and streamside vegetation. Zygopteran community composition was nested at a large scale; richness and diversity did not correlate with changes in the landscape but increased downstream. Anisopteran composition was also nested, but richness correlated with the percent cover of field, wetland, and open water in the habitat and was unrelated to downstream site position. Landscape transformation affected anisopterans more than zygopterans by opening habitats that facilitate these generalist heliotherms.

scholarly journals The application of science to the management of Atlantic salmon (Salmo salar): integration across scales

1998 ◽  
Vol 55 (S1) ◽  
pp. 303-311 ◽  
Author(s):  
John D Armstrong ◽  
James WA Grant ◽  
Harvey L Forsgren ◽  
Kurt D Fausch ◽  
Richard M DeGraaf ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Life Histories ◽  
Large Scale ◽  
Scale Effects ◽  
Spatial Scales ◽  
Small Scale ◽  
Spatial And Temporal Scales ◽  
Management Plans ◽  
Broad Scale ◽  
The Way

The need for integration across spatial and temporal scales in applying science to the management of Atlantic salmon is considered. The factors that are currently believed to affect the production of anadromous adult Atlantic salmon (synthesized from recent reviews) are arranged in a hierarchy in which any given process overrides those processes at lower levels. There is not a good correlation between levels in the process hierarchy and levels in hierarchies of scale. This demonstrates the importance of integrating across scales in identifying the optimum foci for targeting management action. It is not possible to generalize on the need for integration across scales within management plans. This is because of the complex ecology of salmon, the broad range of characteristics of the systems of which they are a part, and the fact that both local scale and broad scale management can have broad scale effects. Many uncertainties remain regarding the large-scale components of the ecology of salmon, the way that small-scale mechanisms interact with life histories, and the way that different factors interact to limit production of fish. When more is understood of these processes, it is likely that generalized rules might be developed to predict the management requirements for stream systems. In the meantime, it is essential that there is good integration among managers working at different scales and it is important that management systems operating at all spatial scales include high-calibre expertise to compensate for the present paucity of general rules.

scholarly journals Review of Aerosol–Cloud Interactions: Mechanisms, Significance, and Challenges

2016 ◽  
Vol 73 (11) ◽  
pp. 4221-4252 ◽  
Author(s):  
Jiwen Fan ◽  
Yuan Wang ◽  
Daniel Rosenfeld ◽  
Xiaohong Liu
Keyword(s):  
Radiative Forcing ◽  
Large Scale ◽  
Dynamic Properties ◽  
Global Climate ◽  
Spatial Scales ◽  
Cloud Microphysics ◽  
Large Variability ◽  
Spatial And Temporal Scales ◽  
Aerosol Cloud ◽  
Aerosol Cloud Interactions

Abstract Over the past decade, the number of studies that investigate aerosol–cloud interactions has increased considerably. Although tremendous progress has been made to improve the understanding of basic physical mechanisms of aerosol–cloud interactions and reduce their uncertainties in climate forcing, there is still poor understanding of 1) some of the mechanisms that interact with each other over multiple spatial and temporal scales, 2) the feedbacks between microphysical and dynamical processes and between local-scale processes and large-scale circulations, and 3) the significance of cloud–aerosol interactions on weather systems as well as regional and global climate. This review focuses on recent theoretical studies and important mechanisms on aerosol–cloud interactions and discusses the significances of aerosol impacts on radiative forcing and precipitation extremes associated with different cloud systems. The authors summarize the main obstacles preventing the science from making a leap—for example, the lack of concurrent profile measurements of cloud dynamics, microphysics, and aerosols over a wide region on the observation side and the large variability of cloud microphysics parameterizations resulting in a large spread of modeling results on the modeling side. Therefore, large efforts are needed to escalate understanding. Future directions should focus on obtaining concurrent measurements of aerosol properties and cloud microphysical and dynamic properties over a range of temporal and spatial scales collected over typical climate regimes and closure studies, as well as improving understanding and parameterizations of cloud microphysics such as ice nucleation, mixed-phase properties, and hydrometeor size and fall speed.

scholarly journals Improving a plot-scale methane emission model and its performance at a Northeastern Siberian tundra site

2013 ◽  
Vol 10 (12) ◽  
pp. 20005-20046 ◽  
Author(s):  
Y. Mi ◽  
J. van Huissteden ◽  
F. J. W. Parmentier ◽  
A. Gallagher ◽  
A. Budishchev ◽  
...  
Keyword(s):  
Water Table ◽  
Vegetation Type ◽  
Spatial Scales ◽  
Open Water ◽  
Soil Freezing ◽  
Subsurface Water ◽  
Water Evaporation ◽  
Model Parameters ◽  
Emission Model ◽  
Ch4 Emissions

Abstract. In order to better address the feedbacks between climate and wetland methane (CH4) emissions, we tested several mechanistic improvements to the wetland CH4 emission model Peatland-VU with a longer Arctic dataset than any other model: (1) inclusion of an improved hydrological module; (2) incorporation of a gross primary productivity (GPP) module; (3) a more realistic soil-freezing scheme. A long time series of field measurements (2003–2010) from a tundra site in Northeastern Siberia is used to validate the model, and the Generalized Likelihood Uncertainty Estimation (GLUE) methodology is used to test the sensitivity of model parameters. Peatland-VU is able to capture both the annual magnitude and seasonal variations of the CH4 flux, water table position and soil thermal properties. However, detailed daily variations are difficult to evaluate due to data limitation. Improvements due to the inclusion of a GPP module are less than anticipated, although this component is likely to become more important at larger spatial scales because the module can accommodate the variations in vegetation traits better than at plot-scale. Sensitivity experiments suggest that the methane production rate factor, the methane plant oxidation parameter, the reference temperature for temperature dependent decomposition, and the methane plant transport rate factor are the most important parameters affecting the data fit, regardless of vegetation type. Both wet and dry vegetation cover are sensitive to the minimum water table level, in addition to the runoff threshold and open water correction factor and the subsurface water evaporation and evapotranspiration correction factors, respectively. These results shed light on model parameterization and future improvement of CH4 modelling. However, high spatial variability of CH4 emissions within similar vegetation/soil units and data quality prove to impose severe limits on model testing and improvement.

scholarly journals Opto-E-Dura: a Soft, Stretchable ECoG Array for Multimodal, Multi-scale Neuroscience

2020 ◽  
Author(s):  
Aline F. Renz ◽  
Jihyun Lee ◽  
Klas Tybrandt ◽  
Maciej Brzezinski ◽  
Dayra A. Lorenzo ◽  
...  
Keyword(s):  
Brain Function ◽  
Large Scale ◽  
Spatial Scales ◽  
Biological Tissues ◽  
Great Promise ◽  
Wide Field ◽  
Electrode Arrays ◽  
Spatial And Temporal Scales ◽  
Multi Scale ◽  
The Brain

AbstractSoft, stretchable materials hold great promise for the fabrication of biomedical devices due to their capacity to integrate gracefully with and conform to biological tissues. Conformal devices are of particular interest in the development of brain interfaces where rigid structures can lead to tissue damage and loss of signal quality over the lifetime of the implant. Interfaces to study brain function and dysfunction increasingly require multimodal access in order to facilitate measurement of diverse physiological signals that span the disparate temporal and spatial scales of brain dynamics. Here we present the Opto-e-Dura, a soft, stretchable, 16-channel electrocorticography array that is optically transparent. We demonstrate its compatibility with diverse optical and electrical readouts enabling multimodal studies that bridge spatial and temporal scales. The device is chronically stable for weeks, compatible with wide-field and 2-photon calcium imaging and permits the repeated insertion of penetrating multi-electrode arrays. As the variety of sensors and effectors realizable on soft, stretchable substrates expands, similar devices that provide large-scale, multimodal access to the brain will continue to improve fundamental understanding of brain function.

scholarly journals Quantifying the effects of land use and model scale on water partitioning and water ages using tracer-aided ecohydrological models

2021 ◽  
Vol 25 (4) ◽  
pp. 2239-2259
Author(s):  
Aaron Smith ◽  
Doerthe Tetzlaff ◽  
Lukas Kleine ◽  
Marco Maneta ◽  
Chris Soulsby
Keyword(s):  
Land Use ◽  
Large Scale ◽  
Overland Flow ◽  
Spatial Scales ◽  
Water Flux ◽  
Model Performance ◽  
Remote Sensing Data ◽  
Spatial And Temporal Scales ◽  
Water Partitioning ◽  
Northeastern Germany

Abstract. Quantifying how vegetation mediates water partitioning at different spatial and temporal scales in complex, managed catchments is fundamental for long-term sustainable land and water management. Estimations from ecohydrological models conceptualising how vegetation regulates the interrelationships between evapotranspiration losses, catchment water storage dynamics, and recharge and runoff fluxes are needed to assess water availability for a range of ecosystem services and evaluate how these might change under increasing extreme events, such as droughts. Currently, the feedback mechanisms between water and mosaics of different vegetation and land cover are not well understood across spatial scales, and the effects of different scales on the skill of ecohydrological models needs to be clarified. We used the tracer-aided ecohydrological model EcH2O-iso in an intensively monitored 66 km2 mixed land use catchment in northeastern Germany to quantify water flux–storage–age interactions at four model grid resolutions (250, 500, 750, and 1000 m). This used a fusion of field (including precipitation, soil water, groundwater, and stream isotopes) and remote sensing data in the calibration. Multicriteria calibration across the catchment at each resolution revealed some differences in the estimation of fluxes, storages, and water ages. In general, model sensitivity decreased and uncertainty increased with coarser model resolutions. Larger grids were unable to replicate observed streamflow and distributed isotope dynamics in the way smaller pixels could. However, using isotope data in the calibration still helped constrain the estimation of fluxes, storage, and water ages at coarser resolutions. Despite using the same data and parameterisation for calibration at different grid resolutions, the modelled proportion of fluxes differed slightly at each resolution, with coarse models simulating higher evapotranspiration, lower relative transpiration, increased overland flow, and slower groundwater movement. Although the coarser resolutions also revealed higher uncertainty and lower overall model performance, the overall results were broadly similar. The study shows that tracers provide effective calibration constraints on larger resolution ecohydrological modelling and help us understand the influence of grid resolution on the simulation of vegetation–soil interactions. This is essential in interpreting associated uncertainty in estimating land use influence on large-scale “blue” (ground and surface water) and “green” (vegetation and evaporated water) fluxes, particularly for future environmental change.

scholarly journals Upscaling land-use effects on water partitioning and water ages using tracer-aided ecohydrological models

2020 ◽  
Author(s):  
Aaron A. Smith ◽  
Doerthe Tetzlaff ◽  
Lukas Kleine ◽  
Marco Maneta ◽  
Chris Soulsby
Keyword(s):  
Land Use ◽  
Large Scale ◽  
Overland Flow ◽  
Spatial Scales ◽  
Water Flux ◽  
Model Performance ◽  
Spatial And Temporal Scales ◽  
Groundwater Movement ◽  
Ne Germany ◽  
Water Partitioning

Abstract. Quantifying how vegetation mediates water partitioning at different spatial and temporal scales in complex, managed catchments is fundamental for long-term sustainable land and water management. Estimations from ecohydrological models conceptualizing how vegetation regulates the inter-relationships between catchment water storage dynamics, evapotranspiration losses, and recharge/runoff fluxes are needed to assess water availability for a range of ecosystem services; and evaluate how these might change under increasing extreme events, such as droughts. Currently, the feedback mechanisms between water and mosaics of different vegetation/land cover are not well understood across spatial scales and the effects of scale on the skill of ecohydrological models needs to be clarified. We used the tracer-aided ecohydrological model EcH2O-iso in an intensively monitored 66 km2 mixed land-use catchment in NE Germany to quantify water flux-storage-age interactions at four model-grid resolutions (250, 500, 750, and 1000 m). This used a fusion of field (including precipitation, soil water, groundwater, and stream isotopes) and remote sensed data in the calibration. Multi-criteria calibration across the catchment at each resolution revealed some differences in the estimation of fluxes, storages, and water ages. Larger grid-resolutions were unable to replicate observed streamflow and distributed isotope dynamics in the way smaller pixels could. However, using isotope data in the calibration still helped in constraining the estimation of fluxes, storage and water ages at coarser resolutions. Despite using the same data and parameterisation for calibration at different grid resolutions, the modelled proportion of fluxes differed slightly at each resolution, with coarse models simulating higher evapotranspiration, lower relative transpiration, increased overland flow, and slower groundwater movement. Although the coarser resolutions also revealed higher uncertainty and lower overall model performance, the overall results were broadly consistent. The study shows that tracers provide effective calibration constraints on larger resolution ecohydrological modelling and help understand the influence of grid-resolution on the simulation of vegetation-soil interactions. This is essential in interpreting associated uncertainty in estimating land-use influence on large-scale blue (ground and surface water) and green (vegetation and evaporated water) fluxes, particularly for future environmental change.

Suborbital Measurements of Spectral Aerosol Optical Depth and Its Variability at Subsatellite Grid Scales in Support of CLAMS 2001

2005 ◽  
Vol 62 (4) ◽  
pp. 993-1007 ◽  
Author(s):  
J. Redemann ◽  
B. Schmid ◽  
J. A. Eilers ◽  
R. Kahn ◽  
R. C. Levy ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Large Scale ◽  
Spatial Scales ◽  
The United States ◽  
Horizontal Distance ◽  
Airborne Measurements ◽  
Low Level ◽  
Modis Aod

Abstract As part of the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) experiment, 10 July–2 August 2001, off the central East Coast of the United States, the 14-channel NASA Ames Airborne Tracking Sunphotometer (AATS-14) was operated aboard the University of Washington’s Convair 580 (CV-580) research aircraft during 10 flights (∼45 flight hours). One of the main research goals in CLAMS was the validation of satellite-based retrievals of aerosol properties. The goal of this study in particular was to perform true over-ocean validations (rather than over-ocean validation with ground-based, coastal sites) at finer spatial scales and extending to longer wavelengths than those considered in previous studies. Comparisons of aerosol optical depth (AOD) between the Aerosol Robotic Network (AERONET) Cimel instrument at the Chesapeake Lighthouse and airborne measurements by AATS-14 in its vicinity showed good agreement with the largest r-square correlation coefficients at wavelengths of 0.38 and 0.5 μm (>0.99). Coordinated low-level flight tracks of the CV-580 during Terra overpass times permitted validation of over-ocean Moderate Resolution Imaging Spectroradiometer (MODIS) level 2 (MOD04_L2) multiwavelength AOD data (10 km × 10 km, nadir) in 16 cases on three separate days. While the correlation between AATS-14- and MODIS-derived AOD was weak with an r square of 0.55, almost 75% of all MODIS AOD measurements fell within the prelaunch estimated uncertainty range Δτ = ±0.03 ± 0.05τ. This weak correlation may be due to the small AODs (generally less than 0.1 at 0.5 μm) encountered in these comparison cases. An analogous coordination exercise resulted in seven coincident over-ocean matchups between AATS-14 and Multiangle Imaging Spectroradiometer (MISR) measurements. The comparison between AATS-14 and the MISR standard algorithm regional mean AODs showed a stronger correlation with an r square of 0.94. However, MISR AODs were systematically larger than the corresponding AATS values, with an rms difference of ∼0.06. AATS data collected during nine extended low-level CV-580 flight tracks were used to assess the spatial variability in AOD at horizontal scales up to 100 km. At UV and midvisible wavelengths, the largest absolute gradients in AOD were 0.1–0.2 per 50-km horizontal distance. In the near-IR, analogous gradients rarely reached 0.05. On any given day, the relative gradients in AOD were remarkably similar for all wavelengths, with maximum values of 70% (50 km)−1 and more typical values of 25% (50 km)−1. The implications of these unique measurements of AOD spatial variability for common validation practices of satellite data products and for comparisons to large-scale aerosol models are discussed.

scholarly journals Understanding and predicting large-scale hydrological variability in a changing environment

2020 ◽  
Vol 383 ◽  
pp. 141-149
Author(s):  
Nicolas Massei ◽  
Daniel G. Kingston ◽  
David M. Hannah ◽  
Jean-Philippe Vidal ◽  
Bastien Dieppois ◽  
...  
Keyword(s):  
Water Resource Management ◽  
Large Scale ◽  
Spatial Scales ◽  
Regional Scale ◽  
System Response ◽  
Event Scale ◽  
Spatial And Temporal Scales ◽  
Hydrological Variability ◽  
New Findings

Abstract. In a context of climate, environmental, ecological and socio-economical changes, understanding and predicting the response of hydrological systems on regional to global spatial scales, and on infra-seasonal to multidecadal time-scales, are major topics that must be considered to tackle the challenge of water resource management sustainability. In this context, a number of strongly-linked key issues need to be addressed by the scientific community, including: (i) identifying climate drivers of hydrological variations, (ii) understanding the multi-frequency characteristics of hydroclimate variability, including evolution of extremes (meteorological/hydrological event scale to long-term natural/internal climate- or anthropogenic-driven variations and trends), (iii) assessing the influence of local- to regional-scale basin properties on hydrological system response to climate variability and change, (iv) identifying the evolving contribution of anthropogenic water use in observed hydrological variations. Based on pan-European collaborations, activities of the EURO-FRIEND “Large-scale variations in hydrological characteristics” group aim at generating new findings to improve our understanding of hydrological systems behavior sensu lato (i.e. surface and sub-surface) on large spatial and temporal scales (i.e continental – multidecadal). Through selected examples, this contribution emphasizes recent research developments in characterizing and modeling of climate-hydrology linkages at different temporal and spatial scales, as well as recent insights on climate-hydrology scaling characteristics (i.e. long-term persistence, dependance of processes, of hydrological behaviors, of large-scale climate/hydrology linkages on time-/spatial scales), long-term hydrometeorological reconstructions, and large-scale hydrological model refinement taking into account spatial heterogeneity of watershed physical characteristics.

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