The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.
The site is secure.
The
https://
ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.
David (Dave) D. Turner authored and/or contributed to the following articles/publications.
On the estimation of boundary layer heights: A machine learning approach
The planetary boundary-layer height (zi) is a key parameter used in atmospheric models for estimating the exchange of heat, momentum and moisture between the surface and the free troposphere. Near-surface atmospheric and subsurface properties (such as soil temperature, relative humidity etc.) are known to have an impact on zi. Nevertheless, prec...
Institution National Oceanic and Atmospheric Administration - NOAA
Characteristics of Tropopause Polar Vortices Based on Observations over the Greenland Ice Sheet
Tropopause polar vortices (TPVs) are long-lived, coherent vortices based on the dynamic tropopause and characterized by potential vorticity anomalies. TPVs exist primarily in the Arctic with potential impacts ranging from surface cyclone generation and Rossby wave interactions to dynamic changes in sea ice. While previous analyses have focused o...
Institution National Oceanic and Atmospheric Administration - NOAA
Improving Wind Energy Forecasting through Numerical Weather Prediction Model Development
The primary goal of the Second Wind Forecast Improvement Project (WFIP2) is to advance the state-of-the-art of wind energy forecasting in complex terrain. To achieve this goal, a comprehensive 18-month field measurement campaign was conducted in the region of the Columbia River basin. The observations were used to diagnose and quantify systemati...
Institutions National Oceanic and Atmospheric Administration - NOAA Earth System Research Laboratory - ESRL National Center for Atmospheric Research - NCAR
The GEWEX Land-Atmosphere FeedbackObservatory (GLAFO)
In the 21st century, due to climate change, a further increase in extreme events is expected. We must understand and predict these events as best as possible for the protection of humankind and the environment as well as for supporting a sustainable development of the Earth system. In particular, it is essential to realize this for the land syst...
Institution National Oceanic and Atmospheric Administration - NOAA
The second Wind Forecast Improvement Project (WFIP2) is a multiagency field campaign held in the Columbia Gorge area (October 2015–March 2017). The main goal of the project is to understand and improve the forecast skill of numerical weather prediction (NWP) models in complex terrain, particularly beneficial for the wind energy industry. This re...
Institution National Oceanic and Atmospheric Administration - NOAA
Proper behavior of physics parameterizations in numerical models at grid sizes of order 1 km is a topic of current research. Modifications to parameterization schemes to accommodate varying grid sizes are termed “scale aware.” The general problem of grids on which a physical process is partially resolved is called the “gray zone” or “terra incog...
Institutions National Oceanic and Atmospheric Administration - NOAA Earth System Research Laboratory - ESRL
Unmanned aerial capabilities offer exciting new perspectives on the Arctic atmosphere and the US Department of Energy is working with partners to offer such perspectives to the research community. Thorough understanding of aerosols, clouds, boundary layer structure and radiation is required to improve representation of the Arctic atmosphere i...
Institution National Oceanic and Atmospheric Administration - NOAA
Representing shallow cumulus in numerical weather prediction and climate models is a significant challenge. Misrepresenting these subgrid-scale clouds can result in large errors in the downwelling shortwave radiative flux at surface, resulting in large errors in the surface temperature that results in feedbacks into the accuracy of the thermodyn...
Institution National Oceanic and Atmospheric Administration - NOAA
The Bay Area Flood Protection Association has just recently begun funding the Physical Sciences Division and Global Systems Division (GSD) of NOAA’s Earth System Research Lab (NOAA-ESRL), as well as the NOAA Cooperative Institute for Research in the Atmosphere (CIRA), to design and build a specialized nowcast / forecast system for the 9 Californ...
Institution National Oceanic and Atmospheric Administration - NOAA
Various methods have been developed to characterize cloud type, otherwise referred to as cloud regime. These include manual sky observations, combining radiative and cloud vertical properties observed from satellite, surface-based remote sensing, and digital processing of sky imagers. While each method has inherent advantages and disadvantages, ...
Institution National Oceanic and Atmospheric Administration - NOAA
Synergistic remote sensing of the atmosphere, combined with adaptive techniques, offers unprecedented opportunities to characterise the evolution of key atmospheric features such as the Atmospheric Boundary Layer (ABL). Using long-duration, high-resolution, profiling observations from active and passive ground-based remote sensing systems during...
Institution National Oceanic and Atmospheric Administration - NOAA
The Verification of the Origins of Rotation in Tornadoes Experiment Southeast (VORTEX-SE) provides a wealth of long-duration, high-resolution, vertically pointing observations from active and passive ground-based remote sensing systems enabling characterization of the Atmospheric Boundary Layer (ABL) development over distinct regions that are we...
Institution National Oceanic and Atmospheric Administration - NOAA
The 2015 Plains Elevated Convection at Night (PECAN) field campaign provided a wealth of intensive observations for improving understanding of interplay between the Great Plains low-level jet (LLJ), mesoscale convective systems (MCSs), and other phenomena in the nocturnal boundary layer. This case study utilizes PECAN ground-based Doppler and wa...
Institution National Oceanic and Atmospheric Administration - NOAA
Ground-based temperature and humidity profiling: combining active and passive remote sensors
Thermodynamic profiles in the planetary boundary layer (PBL) are important observations for a range of atmospheric research and operational needs. These profiles can be retrieved from passively sensed spectral infrared (IR) or microwave (MW) radiance observations or can be more directly measured by active remote sensors such as water vapor diffe...
Institution National Oceanic and Atmospheric Administration - NOAA
The wind-energy (WE) industry relies on numerical weather prediction (NWP) forecast models as foundational or base models for many purposes, including wind-resource assessment and wind-power forecasting. During the Second Wind Forecast Improvement Project (WFIP2) in the Columbia River Basin of Oregon and Washington, a significant effort was made...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
The Method of Object-based Diagnostic Evaluation (MODE) is used to perform an object-based verification of approximately 1400 forecasts of composite reflectivity from the operational HRRR during April–September 2019. In this study, MODE is configured to prioritize deep, moist convective storm cells typical of those that produce severe weather ac...
Institution National Oceanic and Atmospheric Administration - NOAA
Connecting Land–Atmosphere Interactions to Surface Heterogeneity in CHEESEHEAD19
The Chequamegon Heterogeneous Ecosystem Energy-Balance Study Enabled by a High-Density Extensive Array of Detectors 2019 (CHEESEHEAD19) is an ongoing National Science Foundation project based on an intensive field campaign that occurred from June to October 2019. The purpose of the study is to examine how the atmospheric boundary layer (ABL) res...
Institution National Oceanic and Atmospheric Administration - NOAA
Evaluation of the Rapid Refresh Numerical Weather Prediction Model over Arctic Alaska
Despite a need for accurate weather forecasts for societal and economic interests in the U.S. Arctic, thorough evaluations of operational numerical weather prediction in the region have been limited. In particular, the Rapid Refresh Model (RAP), which plays a key role in short-term forecasting and decision-making, has seen very limited assessmen...
Institution National Oceanic and Atmospheric Administration - NOAA
Ground-based Doppler-lidar instrumentation provides atmospheric wind data at dramatically improved accuracies and spatial/temporal resolutions. These capabilities have provided new insights into atmospheric flow phenomena, but they also should have a strong role in NWP model improvement. Insight into the nature of model errors can be gained by s...
Institution National Oceanic and Atmospheric Administration - NOAA
The interactions between equatorial convection and humidity as a function of height, at a range of time scales, remain an important research frontier. The ability of surface-based microwave radiometry to contribute to such research is assessed using retrievals of the vertical structure of atmospheric humidity above the equatorial Indian Ocean, d...
Institution National Oceanic and Atmospheric Administration - NOAA
A Composite Perspective on Bore Passages during the PECAN Campaign
Atmospheric bores have been shown to have a role in the initiation and maintenance of elevated convection. Previous observational studies of bores have been case studies of more notable events. However, this creates a selection bias towards extraordinary cases while discussions of the differences between bores that favor convective initiation an...
Institution National Oceanic and Atmospheric Administration - NOAA
One year of Coherent Doppler Lidar (CDL) data collected at the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) site in Oklahoma was analyzed to provide profiles of vertical velocity variance, skewness, and kurtosis for cases of cloud-free convective boundary layers. The variance was normalized by the Deardorff convective velo...
Institution National Oceanic and Atmospheric Administration - NOAA
Stratiform Cloud-Hydrometeor Assimilation for HRRR and RAP Model Short-Range Weather Prediction
Accurate cloud and precipitation forecasts are a fundamental component of short-range data assimilation/model prediction systems such as the NOAA 3-km High-Resolution Rapid Refresh (HRRR) or the 13-km Rapid Refresh (RAP). To reduce cloud and precipitation spinup problems, a nonvariational assimilation technique for stratiform clouds was develope...
Institution National Oceanic and Atmospheric Administration - NOAA
Nocturnal convection is often initiated by mechanisms that cannot be easily observed within the large gaps between rawinsondes or by conventional surface networks. To improve forecasts of such events, we evaluate the systematic impact of assimilating a collocated network of high-frequency, ground-based thermodynamic and kinematic profilers colle...
Institution National Oceanic and Atmospheric Administration - NOAA
Attenuated backscatter measurements from a Vaisala CL31 ceilometer and a modified form of the well-known slope method are used to derive the ceilometer extinction profiles during rain events, restricted to rainfall rates (RRs) below approximately 10 mm/h. RR estimates from collocated S-band radar and portable disdrometer are used to derive the R...
Institution National Oceanic and Atmospheric Administration - NOAA
A Description of the MYNN Surface-Layer Scheme
The surface-layer scheme controls the degree of coupling between the model surface and the atmosphere. Traditionally, surface-layer schemes have been developed to be paired with certain planetary boundary layer (PBL) schemes, but this singular pairing is too narrow in scope for modern physics suites, since the surfac...
Institution National Oceanic and Atmospheric Administration - NOAA
Optimal Estimation Retrievals and Their Uncertainties: What Every Atmospheric Scientist Should Know
Remote sensing instruments are heavily used to provide observations for both the operational and research communities. These sensors do not provide direct observations of the desired atmospheric variables, but instead, retrieval algorithms are necessary to convert the indirect observations into the variable of interest. It is critical to be awar...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
The performance of a novel water vapor broadband differential absorption lidar (BB-DIAL) is evaluated. This compact, eye-safe, diode-laser-based prototype was developed by Vaisala. It was designed to operate unattended in all weather conditions, and to provide height-resolved measurements of water vapor mixing ratio in the lower troposphere. Eva...
Institution National Oceanic and Atmospheric Administration - NOAA
Developing and improving numerical weather prediction models such as the Rapid Refresh (RAP) and High-Resolution Rapid Refresh (HRRR) requires a well-designed, easy-to-use evaluation capability using observations. Owing to the very complex nonlinear interactions between the data assimilation system and the representation of various physics compo...
Institution National Oceanic and Atmospheric Administration - NOAA
Observational case study of a persistent cold pool and gap flow in the Columbia River Basin
Persistent cold pools form as layers of cold stagnant air within topographical depressions mainly during wintertime when the near-surface air cools and/or the air aloft warms and daytime surface heating is insufficient to mix out the stable layer. An area often affected by persistent cold pools is the Columbia River Basin in the Pacific Northwes...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
Evaluation of a Land–Atmosphere Coupling Metric Computed from a Ground-Based Infrared Interferometer
Land–atmosphere feedbacks are a critical component of the hydrologic cycle. Vertical profiles of boundary layer temperature and moisture, together with information about the land surface, are used to compute land–atmosphere coupling metrics. Ground-based remote sensing platforms, such as the Atmospheric Emitted Radiance Interferometer (AERI), ca...
Institution National Oceanic and Atmospheric Administration - NOAA
Evaluation and Applications of Multi-Instrument Boundary-Layer Thermodynamic Retrievals
Recent reports have highlighted the need for improved observations of the atmosphere boundary layer. In this study, we explore the combination of ground-based active and passive remote sensors deployed for thermodynamic profiling to analyze various boundary-layer observation strategies. Optimal-estimation retrievals of thermodynamic profiles fro...
Institution National Oceanic and Atmospheric Administration - NOAA
During the second Wind Forecast Improvement Project (WFIP2; Oct 2015–Mar 2017, Columbia River Gorge and Basin area) several improvements to the parameterizations applied in the High Resolution Rapid Refresh (HRRR – 3?km horizontal grid spacing) and the High Resolution Rapid Refresh Nest (HRRRNEST – 750?m horizontal grid spacing) Numerical Weathe...
Institution National Oceanic and Atmospheric Administration - NOAA
This study used 20 years of Oklahoma Mesonet data to investigate the changes of near surface water vapor mixing ratio (qv) during the afternoon to evening transition (AET). Similar to past studies, increases in qv are found to occur near sunset. However, the location, magnitude, and timing of the qv maximum occurring during the AET are shown to ...
Institution National Oceanic and Atmospheric Administration - NOAA
The ability of Atmospheric Emitted Radiance Interferometer (AERI) and Doppler lidar (DL) wind profile observations to impact short-term forecasts of convection is explored by assimilating retrievals into a partially cycled convection-allowing ensemble analysis and forecast system. AERI and DL retrievals were obtained over 12 days using a mobile ...
Institutions National Center for Atmospheric Research - NCAR National Oceanic and Atmospheric Administration - NOAA
The Perdigão: Peering into Microscale Details of Mountain Winds
A grand challenge from the wind energy industry is to provide reliable forecasts on mountain winds several hours in advance at microscale (∼100 m) resolution. This requires better microscale wind-energy physics included in forecasting tools, for which field observations are imperative. While mesoscale (∼1 km) measurements abound, microscale proc...
Institution National Oceanic and Atmospheric Administration - NOAA
Bore-ing into Nocturnal Convection
There has been a recent wave of attention given to atmospheric bores in order to understand how they evolve and initiate and maintain convection during the night. This surge is attributable to data collected during the 2015 Plains Elevated Convection at Night (PECAN) field campaign. A salient aspect of the PECAN project is its focus on using mul...
Institution National Oceanic and Atmospheric Administration - NOAA
Due to lack of high spatial and temporal resolution boundary layer (BL) observations, the rapid changes in near storm environment are not well represented in current convective-scale numerical models. Better representation of the near storm environment in model initial conditions will likely further improve the forecasts of severe convective wea...
Institution National Oceanic and Atmospheric Administration - NOAA
The High Resolution Rapid Refresh (HRRR) model became operational at the National Center for Environmental Prediction (NCEP) in 2014 but the HRRR’s performance over certain regions of the coterminous US has not been well studied. In the present study, we evaluated how well version 2 of the HRRR, which became operational at NCEP in August 2016, s...
Institution National Oceanic and Atmospheric Administration - NOAA
Observations of near-surface vertical wind profiles and vertical momentum fluxes obtained from a Doppler lidar and instrumented towers deployed during VORTEX-SE in the spring of 2017 are analyzed. In particular, departures from the predictions of Monin–Obukhov similarity theory (MOST) are documented on thunderstorm days, both in the warm air mas...
Institution National Oceanic and Atmospheric Administration - NOAA
The second Radiative Heating in Underexplored Bands Campaign (RHUBC-II) was conducted in 2009 by the U.S. Department of Energy Atmospheric Radiation Measurement program to improve water vapor spectroscopy in the far-infrared spectral region. RHUBC-II was located in an extremely dry region of Chile to ensure very low opacities in this spectral re...
Institution National Oceanic and Atmospheric Administration - NOAA
In previous work, the similarity relationship for the water vapor variance in the interfacial layer (IL) at the top of the convective boundary layer (CBL) was proposed to be proportional to the convective velocity scale, and the gradients of the water vapor mixing ratio and the Brunt?Vaisala frequency in the entrainment zone. In the presence of ...
Institution National Oceanic and Atmospheric Administration - NOAA
During spring 2016 and spring 2017, a vertically pointing, S-band Frequency Modulated Continuous Wave radar (UMass FMCW) was deployed in northern Alabama under the auspices of the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX)-Southeast. In total, ~14 weeks of data were collected, in conditions ranging from quiescent cl...
Institution National Oceanic and Atmospheric Administration - NOAA
Improvements to the AERIoe Thermodynamic Profile Retrieval Algorithm
Temperature and humidity profiles in the atmospheric boundary layer (i.e., from the surface to 3 km) can be retrieved from ground-based spectral infrared observations made by the atmospheric emitted radiance interferometer (AERI) at high temporal and moderate vertical resolution. However, the retrieval is an ill-posed problem, and thus there are...
Institution National Oceanic and Atmospheric Administration - NOAA
Mobile systems equipped with remote sensing instruments capable of simultaneous profiling of temperature, moisture, and wind at high temporal resolutions can offer insights into atmospheric phenomena that the operational network cannot. Two recently developed systems, the Space Science and Engineering Center (SSEC) Portable Atmospheric Research ...
Institution National Oceanic and Atmospheric Administration - NOAA
Shallow Cumulus in WRF Parameterizations Evaluated against LASSO Large-Eddy Simulations
Representation of shallow cumulus is a challenge for mesoscale numerical weather prediction models. These cloud fields have important effects on temperature, solar irradiance, convective initiation, and pollutant transport, among other processes. Recent improvements to physics schemes available in the Weather Research and Forecasting (WRF) Model...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
Stratiform liquid-bearing clouds (LBCs), defined herein as either pure liquid or mixed-phase clouds, have a large impact on the surface radiation budget across the Arctic. LBCs lasting at least 6 h are observed at Summit, Greenland, year-round with a maximum in occurrence during summer. Mean cloud-base height is below 1 km for 85% of LBC cases i...
Institution National Oceanic and Atmospheric Administration - NOAA
Observationally derived rise in methane surface forcing mediated by water vapour trends
Atmospheric methane (CH4) mixing ratios exhibited a plateau between 1995 and 2006 and have subsequently been increasing. While there are a number of competing explanations for the temporal evolution of this greenhouse gas, these prominent features in the temporal trajectory of atmospheric CH4 are expected to perturb the surface energy balance th...
Institution National Oceanic and Atmospheric Administration - NOAA
Using Deep Learning to Emulate and Accelerate a Radiative Transfer Model
This paper describes the development of U-net++ models, a type of neural network that performs deep learning, to emulate the shortwave Rapid Radiative Transfer Model (RRTM). The goal is to emulate the RRTM accurately in a small fraction of the computing time, creating a U-net++ that could be used as a parameterization in numerical weather predic...
Institution National Oceanic and Atmospheric Administration - NOAA
The vertical structures of a leading outflow boundary ahead of a continental nocturnal MCS and of the upstream environment are examined in order to answer the question of whether this vertical structure affects new cell formation and thus MCS maintenance. The MCS in question, observed on 15 July 2015 as part of the Plains Elevated Convection at ...
Institution National Oceanic and Atmospheric Administration - NOAA
A remote sensing method to retrieve the mean temperature of cloud liquid using ground-based microwave radiometer measurements is evaluated and tested by comparisons with direct cloud temperature information inferred from ceilometer cloud-base measurements and temperature profiles from radiosonde soundings. The method is based on the dependence o...
Institution National Oceanic and Atmospheric Administration - NOAA
This study explores water vapor turbulence in the convective boundary layer (CBL) using the Raman lidar observations from the Atmospheric Radiation Measurement site located at Darwin, Australia. An autocovariance technique was used to separate out the random instrument error from the atmospheric variability during time periods when the CBL is cl...
Institution National Oceanic and Atmospheric Administration - NOAA
Precipitation regimes over central Greenland inferred from 5 years of ICECAPS observations
A novel method for classifying Arctic precipitation using ground based remote sensors is presented. Using differences in the spectral variation of microwave absorption and scattering properties of cloud liquid water and ice, this method can distinguish between different types of snowfall events depending on the presence or absence of condensed l...
Institution National Oceanic and Atmospheric Administration - NOAA
The unambiguous retrieval of cloud phase from polarimetric lidar observations is dependent on the assumption that only cloud scattering processes affect polarization measurements. A systematic bias of the traditional lidar depolarization ratio can occur due to a lidar system's inability to accurately measure the entire backscattered signal dynam...
Institution National Oceanic and Atmospheric Administration - NOAA
Response of the Land-Atmosphere System Over North-Central Oklahoma During the 2017 Eclipse
On 21 August 2017, a solar eclipse occurred over the continental United States resulting in a rapid reduction and subsequent increase of solar radiation over a large region of the country. The eclipse's effect on the land-atmosphere system is documented in unprecedented detail using a unique array of sensors deployed at three sites in north-cent...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
A 2-yr cloud microphysical property dataset derived from ground-based remote sensors at the Atmospheric Radiation Measurement site near Barrow, Alaska, was used as input into a radiative transfer model to compute radiative heating rate (RHR) profiles in the atmosphere. Both the longwave (LW; 5–100 μm) and shortwave (SW; 0.2–5 μm) RHR profiles sh...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
A New Research Approach for Observing and Characterizing Land–Atmosphere Feedback
Forecast errors with respect to wind, temperature, moisture, clouds, and precipitation largely correspond to the limited capability of current Earth system models to capture and simulate land–atmosphere feedback. To facilitate its realistic simulation in next-generation models, an improved process understanding of the related complex interaction...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
Multiband downwelling thermal measurements of zenith sky radiance, along with cloud boundary heights, were used in a retrieval algorithm to estimate cloud optical depth and effective particle diameter of thin ice clouds in the Canadian High Arctic. Ground-based thermal infrared (IR) radiances for 150 semitransparent ice clouds cases were acquire...
Institution National Oceanic and Atmospheric Administration - NOAA
The objectives of this study are to determine the finescale characteristics of the wind and temperature fields associated with a prefrontal wind-shift line and to contrast them with those associated with a strong cold front. Data from a mobile, polarimetric, X-band, Doppler radar and from a surveillance S-band radar, temperature profiles retriev...
Institution National Oceanic and Atmospheric Administration - NOAA
While radiosondes have provided atmospheric scientists an accurate high-vertical-resolution profile of the troposphere for decades, they are unable to provide high-temporal-resolution observations without significant recurring expenses. Remote sensing technology, however, has the ability to monitor the evolution of the atmosphere in unprecedente...
Institution National Oceanic and Atmospheric Administration - NOAA
Satellite and ground-based microwave radiometers are routinely used for the retrieval of liquid water path (LWP) under all atmospheric conditions. The retrieval of water vapor and LWP from ground-based radiometers during rain has proved to be a difficult challenge for two principal reasons: the inadequacy of the nonscattering approximation in pr...
Institution National Oceanic and Atmospheric Administration - NOAA
Observing Convective Aggregation
Convective self-aggregation, the spontaneous organization of initially scattered convection into isolated convective clusters despite spatially homogeneous boundary conditions and forcing, was first recognized and studied in idealized numerical simulations. While there is a rich history of observational work on convective clustering and organiza...
Institution National Oceanic and Atmospheric Administration - NOAA
Greenland Clouds Observed in CALIPSO-GOCCP: Comparison with Ground-Based Summit Observations
Spaceborne lidar observations from the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite provide the first-ever observations of cloud vertical structure and phase over the entire Greenland Ice Sheet. This study leverages CALIPSO observations over Greenland to pursue two investigations. First, the GCM-Oriented...
Institution National Oceanic and Atmospheric Administration - NOAA
Downwelling radiances at the Earth's surface measured by the Far-Infrared Spectroscopy of the Troposphere (FIRST) instrument in an environment with integrated precipitable water (IPW) as low as 0.03 cm are compared with calculated spectra in the far-infrared and mid-infrared. FIRST (a Fourier transform spectrometer) was deployed from August thro...
Institution National Oceanic and Atmospheric Administration - NOAA
Complex-terrain locations often have repeatable near-surface wind patterns, such as synoptic gap flows and local thermally forced flows. An example is the Columbia River Valley in east-central Oregon-Washington, a significant wind-energy-generation region and the site of the Second Wind-Forecast Improvement Project (WFIP2). Data from three Doppl...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
Each year the U.S. government makes significant investments in improving weather forecasts from numerical weather prediction models that are run operationally within the National Weather Service. Although the primary purpose is saving lives and property, more accurate forecasts can create substantial efficiency gains when they elicit improved be...
Institution National Oceanic and Atmospheric Administration - NOAA
This study presents the first full annual cycle (2019–2020) of ambient surface aerosol particle number concentration measurements (condensation nuclei > 20 nm, N20) collected at Summit Station (Summit), in the centre of the Greenland Ice Sheet (72.58∘ N, −38.45∘ E; 3250 ma.s.l.). The mean surface concentration in 2019 was 129 cm−3, with the 6 h ...
Institution National Oceanic and Atmospheric Administration - NOAA
Improved forecasts of atmospheric river (AR) events, which provide up to half the annual precipitation in California, may reduce impacts to water supply, lives, and property. We evaluate quantitative precipitation forecasts (QPF) from the High-Resolution Rapid Refresh model version 3 (HRRRv3) and version 4 (HRRRv4) for five AR events that occurr...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
Forecasts from numerical weather prediction (NWP) models play a critical role in many sectors of the American economy. Improvements to operational NWP model forecasts are generally assumed to provide significant economic savings through better decision making. But is this true? Since 2014, several new versions of the High-Resolution Rapid Refres...
Institution National Oceanic and Atmospheric Administration - NOAA
Thermodynamic profiles are often retrieved from the multi-wavelength brightness temperature observations made by microwave radiometers (MWRs) using regression methods (linear, quadratic approaches), artificial intelligence (neural networks), or physical iterative methods. Regression and neural network methods are tuned to mean conditions derived...
The second Wind Forecast Improvement Project (WFIP2) is an 18-month field campaign in the Pacific Northwest U.S.A., whose goal is to improve the accuracy of numerical-weather-prediction forecasts in complex terrain. The WFIP2 campaign involved the deployment of a large suite of in situ and remote sensing instrumentation, including eight 915-MHz ...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
Studies of land-atmosphere interactions under clear sky and low cumulus cloud conditions are common from long-term observatories like at the southern great plains (SGP). How well the relationships and responses of surface radiative and turbulent heat fluxes determined from these investigations hold for more heterogeneous surfaces in other climat...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
We demonstrate the combination of three Doppler lidars, a water vapor differential absorption lidar and a temperature rotational Raman lidar for the investigation of the interactions between the land-surface and the atmospheric boundary layer. This combination of scanning lidars was operated for the first time during the Land-Atmosphere Feedback...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
Trends in Downwelling Longwave Radiance Over the Southern Great Plains
Downwelling longwave radiation is an important part of the surface energy budget. Spectral trends in the downwelling longwave radiance (DLR) provide insight into the radiative drivers of climate change. In this research, we process and analyze a 23-year DLR record measured by the Atmospheric Emitted Radiance Interferometer (AERI) at the U.S. Dep...
Institution National Oceanic and Atmospheric Administration - NOAA
Observing Profiles of Derived Kinematic Field Quantities Using a Network of Profiling Sites
Observations of thermodynamic and kinematic parameters associated with derivatives of the thermodynamics and wind fields, namely, advection, vorticity, divergence, and deformation, can be obtained by applying Green’s theorem to a network of observing sites. The five nodes that comprise the Atmospheric Radiation Measurement (ARM) Southern Great P...
Institution National Oceanic and Atmospheric Administration - NOAA
Passive ground-based remote sensing of radiation fog
Accurate boundary layer temperature and humidity profiles are crucial for successful forecasting of fog, and accurate retrievals of liquid water path are important for understanding the climatological significance of fog. Passive ground-based remote sensing systems such as microwave radiometers (MWRs) that have multiple channels between 22–31 GH...
Institution National Oceanic and Atmospheric Administration - NOAA
During the Chequamegon Heterogeneous Ecosystem Energy-balance Study Enabled by a High-density Extensive Array of Detectors 2019 (CHEESEHEAD19) field campaign, held in the summer of 2019 in northern Wisconsin, USA, active and passive ground-based remote sensing instruments were deployed to understand the response of the planetary boundary layer t...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
Each year the U.S. government makes significant investments in improving weather forecast models. In this paper, we use a multidisciplinary approach to examine how utilities can benefit from improved wind-speed forecasts to more efficiently use wind-generated electricity and subsequently increase economic activity. Specifically, we examine how i...
Institution National Oceanic and Atmospheric Administration - NOAA
The High-Resolution Rapid Refresh (HRRR) is a convection-allowing implementation of the Weather Research and Forecasting model (WRF-ARW) with hourly data assimilation that covers the conterminous United States and Alaska and runs in real time at the NOAA National Centers for Environmental Prediction. Implemented operationally at NOAA/NCEP in 201...
Institution National Oceanic and Atmospheric Administration - NOAA
The High-Resolution Rapid Refresh (HRRR) is a convection-allowing implementation of the Advanced Weather Research and Forecast model (WRF-ARW) that covers the conterminous United States and Alaska and runs hourly (for CONUS; every three hours for Alaska) in real time at the National Centers for Environmental Prediction. The high-resolution forec...
Institution National Oceanic and Atmospheric Administration - NOAA
Profiles of atmospheric temperature and water vapor from remotely sensed platforms provide critical observations within the temporal and spatial gaps of the radiosonde network. The 2017 National Academies of Science Decadal Survey highlighted that observations of the planetary boundary layer (PBL) from the current space-based observing system ar...
Institution National Oceanic and Atmospheric Administration - NOAA
Land–Snow Data Assimilation Including a Moderately Coupled Initialization Method Applied to NWP
Initialization methods are needed for geophysical components of Earth system prediction models. These methods are needed from medium-range to decadal predictions and also for short-range Earth system forecasts in support of safety (e.g., severe weather), economic (e.g., energy), and other applications. Strongly coupled land–atmosphere data assim...
Institution National Oceanic and Atmospheric Administration - NOAA
Retrievals of Ozone in the Troposphere and Lower Stratosphere Using FTIR Observations Over Greenland
When retrieving geophysical parameters, it is advantageous to have an estimate of prior information that is based on observations with associated uncertainties, but this is often not possible. Long-term ground-based remote sensing measurements and the ozonesonde program at Summit Station, Greenland, provide an opportunity to create a unique fram...
Institutions National Center for Atmospheric Research - NCAR National Oceanic and Atmospheric Administration - NOAA
Selected case studies of precipitating ice clouds at Dome-C (Antarctic Plateau) are used to test a new approach for the estimation of ice cloud reflectivity at 24 GHz (12.37 mm of wavelength) using ground-based far infrared spectral measurements from the REFIR-PAD Fourier transform spectroradiometer and backscattering/depolarization lidar profi...
Institution National Oceanic and Atmospheric Administration - NOAA
Boundary layer moisture variability at the ARM Eastern North Atlantic Observatory
Boundary layer moisture variability at the Eastern North Atlantic (ENA) site is examined at monthly and daily time scales using 5 years of ground-based observations and output from European Center for Medium range Weather Forecast (ECMWF) reanalysis model. The annual cycle of the mixed layer water budgets is presented to estimate the relative co...
Institution National Oceanic and Atmospheric Administration - NOAA
The Impact of Nonzenith Elevation Angles on Ground-Based Infrared Thermodynamic Retrievals
Observing thermodynamic profiles within the planetary boundary layer is essential to understanding and predicting atmospheric phenomena because of the significant exchange of sensible and latent heat between the land and atmosphere within that layer. The Atmospheric Emitted Radiance Interferometer (AERI) is a ground-based infrared spectrometer u...
Institution National Oceanic and Atmospheric Administration - NOAA
Model Evaluation by Measurements from Collocated Remote Sensors in Complex Terrain
Model improvement efforts involve an evaluation of changes in model skill in response to changes in model physics and parameterization. When using wind measurements from various remote sensors to determine model forecast accuracy, it is important to understand the effects of measurement-uncertainty differences among the sensors resulting from di...
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
Scientific challenges to characterizing the wind resource in the marine atmospheric boundary layer
With the increasing level of offshore wind energy investment, it is correspondingly important to be able to accurately characterize the wind resource in terms of energy potential as well as operating conditions affecting wind plant performance, maintenance, and lifespan. Accurate resource assessment at a particular site supports investment decis...
Institution National Oceanic and Atmospheric Administration - NOAA
The accurate forecast of persistent orographic cold-air pools in numerical weather prediction models is essential for the optimal integration of wind energy into the electrical grid during these events. Model development efforts during the Second Wind Forecast Improvement Project (WFIP2) aimed to address the challenges also related to this. We e...
Institution National Oceanic and Atmospheric Administration - NOAA
Boundary layer moisture variability at the Eastern North Atlantic (ENA) site during marine conditions is examined at monthly and daily timescales using 5 years of ground-based observations and output from the European Center for Medium range Weather Forecast (ECMWF) reanalysis model. The annual cycle of the mixed-layer total water budgets is pre...
Abstract Climate and numerical weather prediction models require assumptions to represent the vertical distribution of subgrid-scale clouds, which have radiative transfer implications. In this study, nearly 25 years of ground-based radar and lidar observations of vertical cloud profiles at the Atmospheric Radiation Measurement Program (ARM) Sou...
Institution National Oceanic and Atmospheric Administration - NOAA
Factors Affecting The Rapid Recovery Of Cape On 31 March 2016 During Vortex-Southeast
Abstract In this study, we analyze various sources of CAPE in the environment and their contributions to its time tendency that will complement forecast models and operational analyses that are relatively temporally (~1 h) coarse. As a case study, the relative roles of direct insolation and near-surface moisture advection in the recovery CAPE o...
Institution National Oceanic and Atmospheric Administration - NOAA
The ability of high-resolution mesoscale models to simulate near-surface and subsurface meteorological processes is critical for representing land–atmosphere feedback processes. The High-Resolution Rapid Refresh (HRRR) model is a 3-km numerical weather prediction model that has been used operationally since 2014. In this study, we evaluated the ...
Institution National Oceanic and Atmospheric Administration - NOAA
The structure and evolution of the atmospheric boundary layer (ABL) under clear-sky fair weather conditions over mountainous terrain is dominated by the diurnal cycle of the surface energy balance and thus strongly depends on surface snow cover. We use data from three passive ground-based infrared spectrometers deployed in the East River Valley ...
Institution National Oceanic and Atmospheric Administration - NOAA
The performance of version 4 of the NOAA High-Resolution Rapid Refresh (HRRR) numerical weather prediction model for near-surface variables, including wind, humidity, temperature, surface latent and sensible fluxes, and longwave and shortwave radiative fluxes, is examined over the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SG...
Institution National Oceanic and Atmospheric Administration - NOAA
Observations of Fog-Aerosol Interactions Over Central Greenland
Supercooled fogs can have an important radiative impact at the surface of the Greenland Ice Sheet, but they are difficult to detect and our understanding of the factors that control their lifetime and radiative properties is limited by a lack of observations. This study demonstrates that spectrally resolved measurements of downwelling longwave r...
Institution National Oceanic and Atmospheric Administration - NOAA
Land–atmosphere interactions play a critical role in both the atmospheric water and energy cycles. Changes in soil moisture and vegetation alter the partitioning of surface water and energy fluxes, influencing diurnal evolution of the planetary boundary layer (PBL). The mixing-diagram framework has proven useful in understanding the evolution of...
Institution National Oceanic and Atmospheric Administration - NOAA
Low-powered commercially available coherent Doppler lidar (CDL) wind profilers provide continuous measurement of vertical profiles of wind in the lower troposphere, usually close to or up to the top of the planetary boundary layer. The vertical extent of these wind profiles is limited by the availability of scatterers and thus varies substantial...
Institution National Oceanic and Atmospheric Administration - NOAA
When testing hypotheses about which of two competing models is better, say A and B, the difference is often not significant. An alternative, complementary approach, is to measure how often model A is better than model B regardless of how slight or large the difference. The hypothesis concerns whether or not the percentage of time that model A is...
Institutions National Center for Atmospheric Research - NCAR National Oceanic and Atmospheric Administration - NOAA
Low-level jets (LLJs) are an important nocturnal source of wind energy in the U.S. Great Plains. An August 2017 lidar-based field-measurement campaign [the Land–Atmosphere Feedback Experiment (LAFE)] studied LLJs over the central SGP site in Oklahoma and found nearly equal occurrences of the usual southerly jets and postfrontal northeasterly jet...
Institution National Oceanic and Atmospheric Administration - NOAA
The object-based verification procedure described in a recent paper (Duda and Turner 2021) was expanded herein to compare forecasts of composite reflectivity and 6-h precipitation objects between the two most recent operational versions of the High-Resolution Rapid Refresh (HRRR) model, versions 3 and 4, over an expanded set of warm season cases...
Institution National Oceanic and Atmospheric Administration - NOAA
Doppler-lidar wind-profile measurements at three sites were used to evaluate NWP model errors from two versions of NOAA’s 3-km-grid HRRR model, to see whether updates in the latest version 4 reduced errors when compared against the original version 1. Nested (750-m grid) versions of each were also tested to see how grid spacing affected forecast...
Institution National Oceanic and Atmospheric Administration - NOAA
A Case Study Investigating the Low Summertime CAPE Behavior in the Global Forecast System
Convective available potential energy (CAPE) is an important index for storm forecasting. Recent versions (v15.2 and v16) of the Global Forecast System (GFS) predict lower values of CAPE during summertime in the continental United States than analysis and observation. We conducted an evaluation of the GFS in simulating summertime CAPE using an e...
Institution National Oceanic and Atmospheric Administration - NOAA
In this study, we investigate the parametric sensitivity of near-surface variables, such as sensible heat flux, latent heat flux, ground heat flux, hub-height wind speed and land surface temperature, to the parameters used in the rapid update cycle (RUC) land surface model (LSM) during a winter and summer periods. The model simulations are compa...
Institution National Oceanic and Atmospheric Administration - NOAA
Advanced Quantitative Precipitation Information (AQPI) is a synergistic project that combines observations and models to improve monitoring and forecasts of precipitation, streamflow, and coastal flooding in the San Francisco Bay area. As an experimental system, AQPI leverages more than a decade of research, innovation, and implementation of a s...
Institution National Oceanic and Atmospheric Administration - NOAA
Toward a Global Planetary Boundary Layer Observing System: The NASA PBL Incubation Study Team Report
A global Planetary Boundary Layer (PBL) observing system is urgently needed to address fundamental PBL science questions and societal applications related to weather, climate and air quality. This PBL observing system should optimally combine new space-based observations of the PBL thermodynamic structure with complementary surface-based and su...
Institution National Oceanic and Atmospheric Administration - NOAA
Radiative transfer (RT) is a crucial but computationally expensive process in numerical weather/climate prediction. We develop neural networks (NN) to emulate a common RT parameterization called the Rapid Radiative Transfer Model (RRTM), with the goal of creating a faster parameterization for the Global Forecast System (GFS) v16. In previous wor...
Institution National Oceanic and Atmospheric Administration - NOAA
Challenges of Operational Weather Forecast Verification and Evaluation
Operational agencies face significant challenges related to the verification and evaluation of weather forecasts. These challenges were investigated in a series of online workshops and polls engaging operational personnel from six countries. Five key themes emerged: inadequate verification approaches for both existing and emerging products; inco...
Institution National Oceanic and Atmospheric Administration - NOAA