A5046667824- Cryospheric studies and observations
- Climate variability and models
- Hydrology and Watershed Management Studies
- Meteorological Phenomena and Simulations
- Climate change and permafrost
- Soil Moisture and Remote Sensing
- Flood Risk Assessment and Management
- Plant Water Relations and Carbon Dynamics
- Atmospheric and Environmental Gas Dynamics
- Landslides and related hazards
- Water-Energy-Food Nexus Studies
- Water resources management and optimization
- Hydrology and Drought Analysis
- Precipitation Measurement and Analysis
- Arctic and Antarctic ice dynamics
- Winter Sports Injuries and Performance
- Tree-ring climate responses
- Hydrological Forecasting Using AI
- Fire effects on ecosystems
- Tropical and Extratropical Cyclones Research
- demographic modeling and climate adaptation
- Forest Insect Ecology and Management
- Remote Sensing and LiDAR Applications
- Soil and Unsaturated Flow
- Geophysics and Gravity Measurements
NSF National Center for Atmospheric Research
2016-2025
Research Applications (United States)
2014-2024
Research Applications Laboratory
2020-2024
U.S. National Science Foundation
2024
University of Göttingen
2023
University of Colorado System
2013-2021
University of Colorado Boulder
2005-2021
Oregon State University
2021
University Corporation for Atmospheric Research
2020
University of Washington
2019
This paper presents recent efforts to understand the relative accuracies of different instrumentation and gauges with various windshield configurations measure snowfall. Results from National Center for Atmospheric Research (NCAR) Marshall Field Site will be highlighted. site hosts a test bed assess solid precipitation measurement techniques is joint collaboration between Oceanic Administration (NOAA), NCAR, Weather Service (NWS), Federal Aviation (FAA). The involves testing new other in...
Abstract This work advances a unified approach to process‐based hydrologic modeling enable controlled and systematic evaluation of multiple model representations (hypotheses) processes scaling behavior. Our approach, which we term the Structure for Unifying Multiple Modeling Alternatives (SUMMA), formulates general set conservation equations, providing flexibility experiment with different spatial representations, flux parameterizations, parameter values, time stepping schemes. In this...
Abstract Climate change is expected to accelerate the hydrologic cycle, increase fraction of precipitation that rain, and enhance snowpack melting. The enhanced hydrological cycle also snowfall amounts due increased moisture availability. These processes are examined in this paper Colorado Headwaters region through use a coupled high-resolution climate–runoff model. Four simulations annual over conducted. verified using Snowpack Telemetry (SNOTEL) data. Results then presented regarding grid...
Measurements of soil moisture, both its global distribution and temporal variations, are required to study the water carbon cycles. A network in situ moisture stations is needed supplement datasets from satellite sensors. We demonstrate that signals routinely recorded by Global Positioning System (GPS) receivers for precise positioning applications can also be related surface variations. Over a three month interval, GPS‐derived estimates 300 m 2 area closely match fluctuations top 5 cm...
Snow is an important component of the climate system and a critical storage in hydrologic cycle. However, situ observations snow distribution are sparse, remotely sensed products imprecise only available at coarse spatial scale. GPS geodesists have long recognized that can affect signal, but it has not been shown receiver placed standard geodetic orientation be used to measure depth. In this paper, changes depth clearly tracked corresponding multipath modulation signal. Results for two...
Abstract In mountain terrain, well-configured high-resolution atmospheric models are able to simulate total annual rain and snowfall better than spatial estimates derived from in situ observational networks of precipitation gauges, significantly radar or satellite-derived estimates. This conclusion is primarily based on comparisons with streamflow snow basins across the western United States Iceland, Europe, Asia. Even though they outperform gridded datasets gauge networks, still disagree...
Measurements of soil moisture at various spatial and temporal scales are needed to study the water carbon cycles. While satellite missions have been planned measure global scales, these also need ground-based data validate their observations retrieval algorithms. Here, we demonstrate that signals routinely recorded by Global Positioning System (GPS) receivers installed crustal deformation for geophysical studies could be used provide a network sensors. The sensitivity is seen in reflected...
Abstract Statistical downscaling is widely used to improve spatial and/or temporal distributions of meteorological variables from regional and global climate models. This important because models are spatially coarse (50–200 km) often misrepresent extremes in variables, such as temperature precipitation. However, these methods rely on current estimates the largely assume that small-scale distribution will not change significantly a modified climate. In this study authors compare data...
Abstract This work advances a unified approach to process‐based hydrologic modeling, which we term the “Structure for Unifying Multiple Modeling Alternatives (SUMMA).” The modeling framework, introduced in companion paper, uses general set of conservation equations with flexibility choice process parameterizations (closure relationships) and spatial architecture. second paper specifies model their approximations, describes biophysical currently supported within illustrates how framework can...
Abstract Estimating spatially distributed parameters remains one of the biggest challenges for large‐domain hydrologic modeling. Many modeling efforts rely on inconsistent parameter fields, e.g., patchwork patterns resulting from individual basin calibrations, fields generated through default transfer functions that relate geophysical attributes to model parameters, or constant, values. This paper provides an initial assessment a multiscale regionalization (MPR) method over large...
Abstract A high-resolution climate model (4-km horizontal grid spacing) is used to examine the following question: How will long-term changes in impact partitioning of annual precipitation between evapotranspiration and runoff Colorado Headwaters? This question examined using a sensitivity approach which eight years current compared future created by modifying signal with perturbation from NCAR Community Climate System Model, version 3 (CCSM3), forced A1B scenario for greenhouse gases out...
Abstract Information relevant for most hydrologic applications cannot be obtained directly from the native‐scale outputs of climate models. As a result model output must downscaled, often using statistical methods. The plethora downscaling methods requires end‐users to make selection. This work is intended provide with aid in making an informed We assess four commonly used methods: daily and monthly disaggregated‐to‐daily Bias Corrected Spatial Disaggregation (BCSDd, BCSDm), Asynchronous...
Abstract Gridded precipitation and temperature products are inherently uncertain because of myriad factors, including interpolation from a sparse observation network, measurement representativeness, errors. Generally uncertainty is not explicitly accounted for in gridded or temperature; if it represented, often included an ad hoc manner. A lack quantitative estimates hydrometeorological forcing fields limits the application advanced data assimilation systems other tools land surface...
Abstract. The rationale for using multi-model ensembles in climate change projections and impacts research is often based on the expectation that different models constitute independent estimates; therefore, a range of allows better characterisation uncertainties representation system than single model. However, it known groups share literature, ideas representations processes, parameterisations, evaluation data sets even sections model code. Thus, nominally might have similar biases because...
Reflected Global Positioning System (GPS) signals can be used to infer information about soil moisture in the vicinity of GPS antenna. Interference direct and reflected causes composite signal, observed using signal-to-noise ratio (SNR) data, undulate with time while satellite ascends or descends at relatively low elevation angles. The change affects both phase SNR modulation pattern its magnitude. In order more thoroughly understand mechanism how leads a modulation, we built an...
Abstract Tropical cyclones have enormous costs to society through both loss of life and damage infrastructure. There is good reason believe that such storms will change in the future as a result changes global climate system may important socioeconomic implications. Here high-resolution regional modeling experiment presented using Weather Research Forecasting (WRF) Model investigate possible tropical cyclones. These simulations were performed for period 2001–13 ERA-Interim product boundary...
Abstract The assessment of climate change impacts on water resources involves several methodological decisions, including choices global models (GCMs), emission scenarios, downscaling techniques, and hydrologic modeling approaches. Among these, model structure selection parameter calibration are particularly relevant usually have a strong subjective component. goal this research is to improve understanding the role these decisions effects processes. study conducted in three basins located...
Abstract Recent bark beetle epidemics have caused regional‐scale tree mortality in many snowmelt‐dominated headwater catchments of western North America. Initial expectations increased streamflow not been supported by observations, and the basin‐scale response annual is largely unknown. Here we quantified responses during decade following die‐off eight infested Colorado River headwaters one nearby control catchment. We employed three alternative empirical methods: (i) double‐mass comparison...
Abstract Gridded spatiotemporal maps of precipitation are essential for hydrometeorological and ecological analyses. In the United States, most these datasets developed using Cooperative Observer (COOP) network ground-based measurements, interpolation, Parameter–Elevation Regressions on Independent Slopes Model (PRISM) to map measurements places where data not available. Here, we evaluate two daily gridded at ° resolution against independent observations from over 100 snow pillows in...
Abstract. Accurate knowledge of snow depth distributions in mountain catchments is critical for applications hydrology and ecology. Recently, a method was proposed to map at meter-scale resolution from very-high-resolution stereo satellite imagery (e.g., Pléiades) with an accuracy close 0.5 m. However, the validation limited probe measurements unmanned aircraft vehicle (UAV) photogrammetry, which sampled fraction topographic variability. We improve upon this evaluation using accurate maps...