Comment on wes-2021-72

doi:10.5194/wes-2021-72-rc2

Abstract

We investigate the sensitivity of turbine-height wind speed forecast to initial condition (IC) uncertainties over the Columbia River Gorge (CRG) and Columbia River Basin (CRB) for two typical weather phenomena, i.e., local thermal gradient induced marine air intrusion and a cold frontal passage. Four types of turbine-height wind forecast anomalies and their associated IC uncertainties related to local thermal gradients and large-scale circulations are identified using the self-organizing map (SOM) technique. The four SOM types are categorized into two patterns, each accounting for half of the ensemble members. The first pattern corresponds to IC uncertainties that alter the wind forecast through modulating weather system, which produces the strongest wind anomalies in the CRG and CRB. In the second pattern, the moderate local thermal gradient and large-scale circulation uncertainties jointly contribute to wind forecast anomaly. We analyze the cross-section of wind and temperature anomalies through the gorge to explore the evolution of vertical features of each SOM type. The turbine-height wind anomalies induced by large-scale IC uncertainties are more concentrated near the front. In contrast, turbine-height wind anomalies induced by the local IC thermal uncertainties are found above the surface thermal anomalies. Moreover, the wind forecast accuracy in the CRG and CRB are limited by IC uncertainties in a few specific regions, e.g., the 2-m temperature within the basin and large-scale circulation over the northeast Pacific around 140° W.

Highlights

20 Renewable energy have become an alternative to fossil fuels in the last few decades (Al-Dousari et al, 2019) and windgenerated electricity has seen huge growth worldwide (Shaw et al, 2019)
We investigate the sensitivity of turbine-height wind speed forecast to initial condition (IC) uncertainties over the Columbia River Gorge (CRG) and Columbia River Basin (CRB) for two typical weather phenomena, i.e., local thermal gradient induced marine air intrusion and a cold frontal passage
To successfully manage wind energy, it is of immense importance to accurately forecast the power supplied to the power grid (Siuta et al, 2017a), 25 which relies on the performance of numeral weather prediction (NWP) models in representing the flow features (Siuta et al, 2017b; Willis et al, 2018; Smith and Ancell, 2019) A major challenge in forecasting wind power generation using NWP models is the significant variability in the planetary boundary layer (PBL) flows (Smith and Ancell, 2017)

Summary

Introduction

20 Renewable energy have become an alternative to fossil fuels in the last few decades (Al-Dousari et al, 2019) and windgenerated electricity has seen huge growth worldwide (Shaw et al, 2019). It provided more than 8.7% of Unite States electrical power production in 2020 (https://www.eia.gov/electricity/monthly), ranking as the top renewable energy source (National Renewable Energy Laboratory, 2008; Shaw et al, 2009; Oren, 2012; Willis et al, 2018).

Objectives

Methods

Results