Wind Forecasting Improvement Project In Complex Terrain Near the Columbia River Gorge

2019 ◽  
Author(s):  
James McCaa ◽  
◽  
Eric P. Grimit ◽  
Mark Stoelinga ◽  
Justin Sharp ◽  
...  
Keyword(s):  
Complex Terrain ◽  
Columbia River ◽  
Improvement Project ◽  
Wind Forecasting

scholarly journals Identification and Characterization of Persistent Cold Pool Events from Temperature and Wind Profilers in the Columbia River Basin

2019 ◽  
Vol 58 (12) ◽  
pp. 2533-2551 ◽  
Author(s):  
Katherine McCaffrey ◽  
James M. Wilczak ◽  
Laura Bianco ◽  
Eric Grimit ◽  
Justin Sharp ◽  
...  
Keyword(s):  
Wind Speed ◽  
River Basin ◽  
Weather Prediction ◽  
Microwave Radiometer ◽  
Columbia River ◽  
Columbia River Basin ◽  
Cold Pool ◽  
Improvement Project ◽  
Study Region ◽  
Wind Profilers

AbstractCold pool events occur when deep layers of stable, cold air remain trapped in a valley or basin for multiple days, without mixing out from daytime heating. With large impacts on air quality, freezing events, and especially on wind energy production, they are often poorly forecast by modern mesoscale numerical weather prediction (NWP) models. Understanding the characteristics of cold pools is, therefore, important to provide more accurate forecasts. This study analyzes cold pool characteristics with data collected during the Second Wind Forecast Improvement Project (WFIP2), which took place in the Columbia River basin and Gorge of Oregon and Washington from fall 2015 until spring 2017. A subset of the instrumentation included three microwave radiometer profilers, six radar wind profilers with radio acoustic sounding systems, and seven sodars, which together provided seven sites with collocated vertical profiles of temperature, humidity, wind speed, and wind direction. Using these collocated observations, we developed a set of criteria to determine if a cold pool was present based on stability, wind speed, direction, and temporal continuity, and then developed an automated algorithm based on these criteria to identify all cold pool events over the 18 months of the field project. Characteristics of these events are described, including statistics of the wind speed distributions and profiles, stability conditions, cold pool depths, and descent rates of the cold pool top. The goal of this study is a better understanding of these characteristics and their processes to ultimately lead to improved physical parameterizations in NWP models, and consequently improve forecasts of cold pool events in the study region as well at other locations that experiences similar events.

scholarly journals Characterizing NWP Model Errors Using Doppler-Lidar Measurements of Recurrent Regional Diurnal Flows: Marine-Air Intrusions into the Columbia River Basin

2020 ◽  
Vol 148 (3) ◽  
pp. 929-953 ◽  
Author(s):  
Robert M. Banta ◽  
Yelena L. Pichugina ◽  
W. Alan Brewer ◽  
Aditya Choukulkar ◽  
Kathleen O. Lantz ◽  
...  
Keyword(s):  
River Basin ◽  
Cross Sections ◽  
Columbia River ◽  
Columbia River Basin ◽  
Doppler Lidar ◽  
Model Errors ◽  
Improvement Project ◽  
Wind Speeds ◽  
Nwp Model ◽  
Marine Air

Abstract 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 studying recurrent atmospheric flows, here a regional summertime diurnal sea breeze and subsequent marine-air intrusion into the arid interior of Oregon–Washington, where these winds are an important wind-energy resource. These marine intrusions were sampled by three scanning Doppler lidars in the Columbia River basin as part of the Second Wind Forecast Improvement Project (WFIP2), using data from summer 2016. Lidar time–height cross sections of wind speed identified 8 days when the diurnal flow cycle (peak wind speeds at midnight, afternoon minima) was obvious and strong. The 8-day composite time–height cross sections of lidar wind speeds are used to validate those generated by the operational NCEP–HRRR model. HRRR simulated the diurnal wind cycle, but produced errors in the timing of onset and significant errors due to a premature nighttime demise of the intrusion flow, producing low-bias errors of 6 m s−1. Day-to-day and in the composite, whenever a marine intrusion occurred, HRRR made these same errors. The errors occurred under a range of gradient wind conditions indicating that they resulted from the misrepresentation of physical processes within a limited region around the measurement locations. Because of their generation within a limited geographical area, field measurement programs can be designed to find and address the sources of these NWP errors.

Doppler-Lidar Evaluation of HRRR-Model Skill at Simulating Summertime Wind Regimes in the Columbia River Basin during WFIP2

2021 ◽  
Author(s):  
Robert M. Banta ◽  
Yelena L. Pichugina ◽  
Lisa S. Darby ◽  
W. Alan Brewer ◽  
Joseph B. Olson ◽  
...  
Keyword(s):  
Wind Speed ◽  
Pressure Gradient ◽  
Large Scale ◽  
Surface Wind ◽  
Columbia River ◽  
Surface Heating ◽  
Model Errors ◽  
Improvement Project ◽  
Near Surface ◽  
Wind Regimes

AbstractComplex-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 Doppler lidars deployed during WFIP2 define and characterize summertime wind regimes and their large-scale contexts, and provide insight into NWP model errors by examining differences in the ability of a model [NOAA’s High-Resolution Rapid-Refresh (HRRR-version1)] to forecast wind-speed profiles for different regimes. Seven regimes were identified based on daily time series of the lidar-measured rotor-layer winds, which then suggested two broad categories. First, in three regimes the primary dynamic forcing was the large-scale pressure gradient. Second, in two regimes the dominant forcing was the diurnal heating-cooling cycle (regional sea-breeze-type dynamics), including the marine intrusion previously described, which generates strong nocturnal winds over the region. The other two included a hybrid regime and a non-conforming regime. For the large-scale pressure-gradient regimes, HRRR had wind-speed biases of ~1 m s−1 and RMSEs of 2-3 m s−1. Errors were much larger for the thermally forced regimes, owing to the premature demise of the strong nocturnal flow in HRRR. Thus, the more dominant the role of surface heating in generating the flow, the larger the errors. Major errors could result from surface heating of the atmosphere, boundary-layer responses to that heating, and associated terrain interactions. Measurement/modeling research programs should be aimed at determining which modeled processes produce the largest errors, so those processes can be improved and errors reduced.

scholarly journals The Second Wind Forecast Improvement Project (WFIP2): Observational Field Campaign

2019 ◽  
Vol 100 (9) ◽  
pp. 1701-1723 ◽  
Author(s):  
James M. Wilczak ◽  
Mark Stoelinga ◽  
Larry K. Berg ◽  
Justin Sharp ◽  
Caroline Draxl ◽  
...  
Keyword(s):  
Wind Energy ◽  
Pacific Northwest ◽  
Complex Terrain ◽  
Weather Prediction ◽  
Grid Cell ◽  
Department Of Energy ◽  
Improvement Project ◽  
Field Campaign ◽  
Energy Applications ◽  
Nwp Model

AbstractThe Second Wind Forecast Improvement Project (WFIP2) is a U.S. Department of Energy (DOE)- and National Oceanic and Atmospheric Administration (NOAA)-funded program, with private-sector and university partners, which aims to improve the accuracy of numerical weather prediction (NWP) model forecasts of wind speed in complex terrain for wind energy applications. A core component of WFIP2 was an 18-month field campaign that took place in the U.S. Pacific Northwest between October 2015 and March 2017. A large suite of instrumentation was deployed in a series of telescoping arrays, ranging from 500 km across to a densely instrumented 2 km × 2 km area similar in size to a high-resolution NWP model grid cell. Observations from these instruments are being used to improve our understanding of the meteorological phenomena that affect wind energy production in complex terrain and to evaluate and improve model physical parameterization schemes. We present several brief case studies using these observations to describe phenomena that are routinely difficult to forecast, including wintertime cold pools, diurnally driven gap flows, and mountain waves/wakes. Observing system and data product improvements developed during WFIP2 are also described.

scholarly journals Evaluating the WFIP2 updates to the HRRR model using scanning Doppler lidar measurements in the complex terrain of the Columbia River Basin

2020 ◽  
Vol 12 (4) ◽  
pp. 043301 ◽  
Author(s):  
Yelena L. Pichugina ◽  
Robert M. Banta ◽  
W. Alan Brewer ◽  
L. Bianco ◽  
C. Draxl ◽  
...  
Keyword(s):  
River Basin ◽  
Complex Terrain ◽  
Columbia River ◽  
Columbia River Basin ◽  
Doppler Lidar ◽  
Lidar Measurements

scholarly journals The Second Wind Forecast Improvement Project (WFIP2): General Overview

2019 ◽  
Vol 100 (9) ◽  
pp. 1687-1699 ◽  
Author(s):  
William J. Shaw ◽  
Larry K. Berg ◽  
Joel Cline ◽  
Caroline Draxl ◽  
Irina Djalalova ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Complex Terrain ◽  
Weather Prediction ◽  
Integrated Approach ◽  
Department Of Energy ◽  
Scale Model ◽  
Improvement Project ◽  
Mesoscale Models ◽  
Operational Forecasts ◽  
Forecast Models

AbstractIn 2015 the U.S. Department of Energy (DOE) initiated a 4-yr study, the Second Wind Forecast Improvement Project (WFIP2), to improve the representation of boundary layer physics and related processes in mesoscale models for better treatment of scales applicable to wind and wind power forecasts. This goal challenges numerical weather prediction (NWP) models in complex terrain in large part because of inherent assumptions underlying their boundary layer parameterizations. The WFIP2 effort involved the wind industry, universities, the National Oceanographic and Atmospheric Administration (NOAA), and the DOE’s national laboratories in an integrated observational and modeling study. Observations spanned 18 months to assure a full annual cycle of continuously recorded observations from remote sensing and in situ measurement systems. The study area comprised the Columbia basin of eastern Washington and Oregon, containing more than 6 GW of installed wind capacity. Nests of observational systems captured important atmospheric scales from mesoscale to NWP subgrid scale. Model improvements targeted NOAA’s High-Resolution Rapid Refresh (HRRR) model to facilitate transfer of improvements to National Weather Service (NWS) operational forecast models, and these modifications have already yielded quantitative improvements for the short-term operational forecasts. This paper describes the general WFIP2 scope and objectives, the particular scientific challenges of improving wind forecasts in complex terrain, early successes of the project, and an integrated approach to archiving observations and model output. It provides an introduction for a set of more detailed BAMS papers addressing WFIP2 observational science, modeling challenges and solutions, incorporation of forecasting uncertainty into decision support tools for the wind industry, and advances in coupling improved mesoscale models to microscale models that can represent interactions between wind plants and the atmosphere.

scholarly journals Improved Prediction of Cold-Air Pools in the Weather Research and Forecasting Model Using a Truly Horizontal Diffusion Scheme for Potential Temperature

2021 ◽  
Vol 149 (1) ◽  
pp. 155-171
Author(s):  
Robert S. Arthur ◽  
Katherine A. Lundquist ◽  
Joseph B. Olson
Keyword(s):  
Complex Terrain ◽  
Potential Temperature ◽  
Weather Research And Forecasting ◽  
Horizontal Gradient ◽  
Improvement Project ◽  
Near Surface ◽  
Cold Air ◽  
Vertical Range ◽  
Gradient Calculation ◽  
Weather Research

AbstractThe terrain-following vertical coordinate system used by many atmospheric models, including the Weather Research and Forecasting (WRF) Model, is prone to errors in regions of complex terrain. These errors stem, in part, from the calculation of horizontal gradients within the diffusion term of the momentum or scalar evolution equations. In WRF, such gradients can be calculated along coordinate surfaces, or using metric terms that help account for grid skewness. However, neither of these options ensures a truly horizontal gradient calculation, especially if a grid cell is skewed enough that the heights of the neighboring grid points used in the calculation fall outside the vertical range of the cell. In this work, an improved scheme that uses Taylor series approximations to vertically interpolate variables to the level necessary for a truly horizontal gradient calculation is implemented in WRF for the diffusion of potential temperature. The scheme is validated using an atmosphere-at-rest configuration, in which spurious flows develop only as a result of numerical errors and can thus be used as a proxy for model performance. Following validation, the method is applied to the simulation of cold-air pools (CAPs), which occur in regions of complex terrain and are characterized by strong near-surface temperature gradients. Using the truly horizontal scheme, idealized simulations demonstrate reduced numerical mixing in a quiescent CAP, and a realistic case study in the Columbia River basin shows a reduction in positive wind speed bias by up to roughly 20% compared to observations from the Second Wind Forecast Improvement Project.

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