A5042414931- Meteorological Phenomena and Simulations
- Tropical and Extratropical Cyclones Research
- Wind and Air Flow Studies
- Climate variability and models
- Atmospheric aerosols and clouds
- Aeolian processes and effects
- Coastal and Marine Dynamics
- Ocean Waves and Remote Sensing
- Precipitation Measurement and Analysis
- Ionosphere and magnetosphere dynamics
- Atmospheric and Environmental Gas Dynamics
- Cryospheric studies and observations
- Atmospheric Ozone and Climate
- Fluid Dynamics and Turbulent Flows
- Atmospheric chemistry and aerosols
- Planetary Science and Exploration
- Oceanographic and Atmospheric Processes
- Geophysics and Gravity Measurements
- Soil Moisture and Remote Sensing
- Fluid Dynamics and Vibration Analysis
- Climate change and permafrost
- Wind Energy Research and Development
- Landslides and related hazards
- Methane Hydrates and Related Phenomena
- Hydrology and Watershed Management Studies
NSF National Center for Atmospheric Research
1999-2022
National Centre for Atmospheric Science
2020
Universitat de les Illes Balears
2020
Universität Innsbruck
2020
University of Trento
2020
Federal Office of Meteorology and Climatology MeteoSwiss
2020
Météo-France
2020
University of Virginia
2020
Central Institution for Meteorology and Geodynamics
2013-2016
University of Vienna
2009-2016
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...
The Mediterranean countries are experiencing important challenges related to the water cycle, including shortages and floods, extreme winds, ice/snow storms, that impact critically socioeconomic vitality in area (causing damage property, threatening lives, affecting energy transportation sectors, etc.). There gaps our understanding of cycle its dynamics include variability Sea budget feedback on continental precipitation through air–sea interactions, aquifer recharge, river discharge, soil...
The Terrain-Induced Rotor Experiment (T-REX) is a coordinated international project, composed of an observational field campaign and research program, focused on the investigation atmospheric rotors closely related phenomena in complex terrain. T-REX took place during March April 2006 lee southern Sierra Nevada eastern California. Atmospheric have been traditionally defined as quasi-two-dimensional vortices that form parallel to downwind mountain ridge under conditions conducive generation...
This study shows that turbulent kinetic energy (TKE) estimates, derived from static LiDARs in Doppler Beam Swing (DBS) mode, permit a qualitative and quantitative characterization analysis of structures as wind turbine wakes, convective or shear generated eddies the lower atmospheric boundary layer. The analysed data, collected by WINDCUBE™ v1 park Austria, is compared to sonic data WINd Turbine Wake EXperiment Wieringermeer (WINTWEX-W). Although turbulence measurements with are limited...
Under the influence of east-northeasterly trade winds, island Hawaii generates a wake that extends about 200 km to west-southwest. During HaRP project in July and August 1990, five surveys were carried out by NCAR Electra. The patterns wind aerosol concentration revealed these flights suggest Hawaii's consists two large quasi-steady counterrotating eddies. southern clockwise-rotating eddy carries heavy load due input from Kī volcano. At eastern end wake, eddies are potentially warmer more...
Two-dimensional simulations of the 11 January 1972 Boulder, Colorado, windstorm, obtained from diverse nonhydrostatic models, are intercompared with special emphasis on turbulent breakdown topographically forced gravity waves, as part preparation for Mesoscale Alpine Programme field phase. The sounding used to initialize models is more representative actual lower stratosphere than those applied in previous simulations. Upper-level breaking predicted by all comparable horizontal locations and...
Abstract A case study is presented of the secondary potential vorticity (PV) banners over northern Adriatic that occurred in an early stage a bora on 7 November 1999 during Mesoscale Alpine Programme (MAP) Special Observation Period. The dynamics and structure lee‐side cross‐mountain flow past Dinaric Alps were investigated using data collected dual‐aircraft (NCAR Electra NOAA P‐3)MAP Intensive Observing Period 15 mission high‐resolution numerical simulations. observational employs...
Abstract Using the National Science Foundation (NSF)–NCAR Gulfstream V and NSF–Wyoming King Air research aircraft during Terrain-Induced Rotor Experiment (T-REX) in March–April 2006, six cases of Sierra Nevada mountain waves were surveyed with 126 cross-mountain legs. The goal was to identify influence tropopause on entering stratosphere. During each flight leg, part variation observed parameters due parameter layering, heaving up down waves. Diagnosis combined wave-layering signal aided...
Abstract The primary goal of this study is to explore the potential for estimating vertical velocity (VV) air from surface stratosphere, using widely available radiosonde and dropsonde data. rise fall rates radiosondes dropsondes, respectively, are a combination VV atmosphere still-air rise–fall rates. calculated basic fluid dynamics characteristics systems. This validates technique derive data demonstrates its value. can be easily implemented by other users various scientific applications....
Numerical simulations of flow over steep terrain using 11 different nonhydrostatic numerical models are compared and analyzed. A basic benchmark five other test cases simulated in a two-dimensional framework the same initial state, which is based on conditions during Intensive Observation Period (IOP) 6 Terrain-Induced Rotor Experiment (T-REX), intense mountain-wave activity was observed. All use an identical horizontal resolution 1 km vertical resolution. The six various heights: 100-m...
Atmospheric turbulence generated in flow over mountainous terrain is studied using airborne situ and cloud radar measurements the Medicine Bow Mountains southeast Wyoming, USA. During NASA Orographic Clouds Experiment (NASA06) 2006, two complex mountain cases were documented by University of Wyoming King Air research aircraft carrying Cloud Radar. The structure its intensity across range are described variance vertical velocity cube root energy dissipation rate ɛ 1/3 (EDR). For a...
Abstract In this essay, we highlight some challenges the atmospheric community is facing concerning adequate treatment of flows over mountains and their implications for numerical weather prediction (NWP), climate simulations, impact modeling. With recent increases in computing power (and hence model resolution) models start to face new limitations (such as instability steep terrain). At same time there a growing need sufficiently reliable NWP output drive various (for hydrology, air...
The NOAA Global Monitoring Laboratory (NOAA/GML) operates a network of Atmospheric Baseline Observatories (ABOs) dedicated to long-term measurements Earth’s changing climate system.  These facilities, spanning the Pacific Basin from Arctic Antarctic, are located in Alaska, Hawaii, American Samoa, and Antarctica.  Operational for over 50-years, has begun investing new sustainable infrastructure implementing net-zero initiatives.The Mauna Loa Observatory (MLO),...
For decades, our understanding of the carbon cycle has relied on a limited network direct and remote sensing systems to measure atmospheric greenhouse gases (GHGs). This allowed for broad both natural human-caused sources sinks GHGs. However, this is inadequate monitor subtle emission changes resulting from climate change, mitigation efforts, interventions. Moving forward, new technologies, combined with existing ones, will need be enhanced through public-private partnerships build capable...
Systematic – regular and routine observations are vital for understanding monitoring the Earth climate system. observation networks, traditionally built operated by public sector, provide relevant data that inform models respective pathways, forecasts, products services. Critical in regard, particular, high precision, accurate, comprehensive greenhouse gas measurements. Initiatives enhancing such networks scaling up collection important, as is doing this a sustainable manner...
The island of St. Vincent and the other Windward Islands in southeastern Caribbean were chosen as a field site for study weak mountain wakes. By authors' definition, "weak wake" forms when potential vorticity generated by is not strong enough to advect itself into eddies; rather, it simply advected downstream ambient flow. GOES-8 Landsat sunglint images unambiguously revealed that mountainous have remarkably long straight length Vincent's wake exceeds 300 km although its width only 20 km....
A wake is traditionally defined as the region of nearly stagnant flow downstream a body in uniform stream. In stratified fluid, motions and density surfaces an obstacle become primarily horizontal; vertical component vorticity associated with wake, coexisting stable stratification, implies that there potential (PV) wake. Recent work has demonstrated dissipation aloft, breaking mountain wave over isolated peak, produces dipole PV downstream; dipolar dipole. Although one may infer existence...
The effect of bottom friction on fluid flow past an isolated obstacle is investigated in the shallow-water framework. controlling parameter for this nondimensional number, defined as a ratio to inertia. With stress related horizontal wind via standard bulk aerodynamic formula, number proportional surface roughness, scale obstacle, and inverse upstream depth. Thus, under otherwise identical conditions, larger obstacles will be more "viscous." Bottom modifies vorticity generation several ways,...
Abstract The skill of a mesoscale model in predicting orographic precipitation during high-impact events the Sierra Nevada, and sensitivity that to choice microphysical parameterization horizontal resolution, are examined. fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) four bulk schemes examined Dudhia ice scheme, Schultz, GSFC, Reisner2 mixed-phase schemes. verification dataset consists ground measurements from...
Abstract High-resolution observations from scanning Doppler and aerosol lidars, wind profiler radars, as well surface aircraft measurements during the Terrain-induced Rotor Experiment (T-REX) provide first comprehensive documentation of small-scale intense vortices associated with atmospheric rotors that form in lee mountainous terrain. Although are already recognized potential hazards for aircraft, it is proposed these vortices, or subrotors, most dangerous features because strong shear...
Abstract While statistical analyses and observations show that severe bora with maximum gusts exceeding 40 m s−1 can occur in all parts of the Adriatic, research to date has been mainly focused on dynamics structure northern Adriatic. Examined a significantly lesser degree is less predictable counterpart southern where Dinaric Alps are higher, broader, steeper, upwind layer generally well defined. Identification main differences sequence mesoscale macroscale events leading onset eastern...
Three-dimensional simulations of the daytime thermally induced valley wind system for an idealized valley–plain configuration, obtained from nine nonhydrostatic mesoscale models, are compared with special emphasis on evolution along-valley wind. The models use same initial and lateral boundary conditions, standard parameterizations turbulence, radiation, land surface processes. mean (averaged over cross section) is similar all except a time shift between individual up to 2 h slight...
Abstract Trapped lee wave interference over double bell-shaped obstacles in the presence of surface friction is examined. Idealized high-resolution numerical experiments with nonhydrostatic Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) are performed to examine influence a frictional boundary layer and nonlinearity on impact wave-induced separation formation rotors. The appearance constructive destructive interference, controlled by ratio ridge distance intrinsic horizontal...