A Two-Cool-Season Wind Profiler–Based Analysis of Westward-Directed Gap Flow through the Columbia River Gorge

Neiman, Paul J.; Gottas, Daniel J.; White, Allen B.

doi:10.1175/MWR-D-19-0026.1

Title: A Two-Cool-Season Wind Profiler–Based Analysis of Westward-Directed Gap Flow through the Columbia River Gorge

Full Record
Other Related Research

Abstract

Abstract This observational study of westward-directed gap flows through the Columbia River Gorge uses three radar wind profilers during two winter seasons between October 2015 and April 2017, with a focus on the gap-exit region at Troutdale, Oregon. Of the 92 gap-flow events identified at Troutdale, the mean duration was 38.5 h, the mean gap-jet speed was 12 m s−1, and the mean gap-flow depth was 570 m MSL. The mean gap-jet height and gap-flow depth were situated below the top of the inner gorge, while a maximum depth of 1087 m MSL was contained within the gorge’s outer-wall rim. The mean gap-flow depth was deepest in the cold-air source region east of the gorge and decreased westward to the coast. Strong gap-flow events were longer lived, deeper, and capped by stronger vertical shear than their weak counterparts, and strong (weak) events were forced primarily by a cold-interior anticyclone (offshore cyclone). Deep gap-flow events were longer lived, stronger, and had weaker capping vertical shear than shallow events, and represented a combination of gap-flow and synoptic forcing. Composite temporal analysis shows that gap-flow strength (depth) was maximized midevent (early event), freezing rain was most prevalent during the second half of themore »« less

Authors:

Neiman, Paul J. ^[1]; Gottas, Daniel J. ^[1]; White, Allen B. ^[1]

NOAA/Earth System Research Laboratory/Physical Sciences Division, Boulder, Colorado

Publication Date:: Thu Dec 05 00:00:00 EST 2019

Research Org.:: National Oceanic and Atmospheric Administration (NOAA), Silver Spring, MD (United States). Office of Oceanic and Atmospheric Research

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE)

OSTI Identifier:: 1577226

Alternate Identifier(s):: OSTI ID: 1799310

Grant/Contract Number:: EE0007605

Resource Type:: Published Article

Journal Name:: Monthly Weather Review

Additional Journal Information:: Journal Name: Monthly Weather Review Journal Volume: 147 Journal Issue: 12; Journal ID: ISSN 0027-0644

Publisher:: American Meteorological Society

Country of Publication:: United States

Language:: English

Subject:: 54 ENVIRONMENTAL SCIENCES; Meteorology & Atmospheric Sciences; Mesoscale processes; Orographic effects; Cold pools; Jets; Precipitation; Forecasting

Citation Formats


                    Neiman, Paul J., Gottas, Daniel J., and White, Allen B. A Two-Cool-Season Wind Profiler–Based Analysis of Westward-Directed Gap Flow through the Columbia River Gorge.  United States: N. p., 2019. 
Web.  doi:10.1175/MWR-D-19-0026.1.

Copy to clipboard


                    Neiman, Paul J., Gottas, Daniel J., & White, Allen B. A Two-Cool-Season Wind Profiler–Based Analysis of Westward-Directed Gap Flow through the Columbia River Gorge.  United States.  https://doi.org/10.1175/MWR-D-19-0026.1

Copy to clipboard


                    Neiman, Paul J., Gottas, Daniel J., and White, Allen B. Thu .  
"A Two-Cool-Season Wind Profiler–Based Analysis of Westward-Directed Gap Flow through the Columbia River Gorge".  United States.  https://doi.org/10.1175/MWR-D-19-0026.1.

Copy to clipboard


                    
@article{osti_1577226,

  title        = {A Two-Cool-Season Wind Profiler–Based Analysis of Westward-Directed Gap Flow through the Columbia River Gorge},

  author       = {Neiman, Paul J. and Gottas, Daniel J. and White, Allen B.},

  abstractNote = {Abstract This observational study of westward-directed gap flows through the Columbia River Gorge uses three radar wind profilers during two winter seasons between October 2015 and April 2017, with a focus on the gap-exit region at Troutdale, Oregon. Of the 92 gap-flow events identified at Troutdale, the mean duration was 38.5 h, the mean gap-jet speed was 12 m s−1, and the mean gap-flow depth was 570 m MSL. The mean gap-jet height and gap-flow depth were situated below the top of the inner gorge, while a maximum depth of 1087 m MSL was contained within the gorge’s outer-wall rim. The mean gap-flow depth was deepest in the cold-air source region east of the gorge and decreased westward to the coast. Strong gap-flow events were longer lived, deeper, and capped by stronger vertical shear than their weak counterparts, and strong (weak) events were forced primarily by a cold-interior anticyclone (offshore cyclone). Deep gap-flow events were longer lived, stronger, and had weaker capping vertical shear than shallow events, and represented a combination of gap-flow and synoptic forcing. Composite temporal analysis shows that gap-flow strength (depth) was maximized midevent (early event), freezing rain was most prevalent during the second half of the event, and accumulated precipitation was greatest late-event. Gap-flow events tended to begin (end) during the evening (morning) hours and were most persistent in January. Surface wind gusts and snow occurrences around Portland, Oregon, were associated primarily with the deepest gap flows, whereas freezing rain occurred predominantly during shallow gap flows.},

  doi          = {10.1175/MWR-D-19-0026.1},

  journal      = {Monthly Weather Review},

  number       = 12,

  volume       = 147,

  place        = {United States},

  year         = {Thu Dec 05 00:00:00 EST 2019},

  month        = {Thu Dec 05 00:00:00 EST 2019}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Publisher's Version of Record
https://doi.org/10.1175/MWR-D-19-0026.1

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 6 works

Citation information provided by
Web of Science

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE PAGES and OSTI.GOV collections:

A Real-Time Online Data Product that Automatically Detects Easterly Gap-Flow Events and Precipitation Type in the Columbia River Gorge

Journal Article Neiman, Paul J. ; Gottas, Daniel J. ; White, Allen B. ; ... - Journal of Atmospheric and Oceanic Technology

A real-time, hourly updated, online graphical data product that displays the depth and strength of easterly gap flow in the Columbia River Gorge using a 915-MHz Doppler wind profiler is presented. During precipitation events, this data product also displays observed precipitation accumulation and diagnosed precipitation type using measurements provided by a collocated heated tipping-bucket rain gauge, an optical disdrometer, and temperature and relative humidity sensors. Automated algorithms that determine the existence and depth of the gap flow, as well as precipitation type, are described. The Columbia River Gorge is the only major gap in the Cascade Mountains of Oregon andmore »« less
Cited by 5
https://doi.org/10.1175/JTECH-D-18-0088.1
Gap Flows Along the Columbia River Observed During the WFIP2 Field Campaign

Technical Report Ghate, Virendra P. ; Olson, Joseph B. ; Szoldatits, Katherine E. ; ...

Data collected in the Columbia River Gorge and Basin Area during the second Wind Forecasting Improvement Project (WFIP2) was used to study gap flow events in the region. In particular, the relationship between 200 m zonal wind speed and the zonal mesoscale pressure gradient at Troutdale (West of the gorge), Wasco (east of the gorge), and Boardman (farther east of the gorge) sites was examined. An objective criterion was used to identify 169 (Troutdale), 161 (Wasco), and 113 (Boardman) gap flow days that had weak synoptic forcing. The 200 m zonal wind speed exhibited a linear relationship with the zonalmore »« less
https://doi.org/10.2172/1844342

Full Text Available
Producing Light Oil from a Frozen Reservoir: Reservoir and Fluid Characterization of Umiat Field, National Petroleum Reserve, Alaska

Technical Report Hanks, Catherine

Umiat oil field is a light oil in a shallow, frozen reservoir in the Brooks Range foothills of northern Alaska with estimated oil-in-place of over 1 billion barrels. Umiat field was discovered in the 1940’s but was never considered viable because it is shallow, in the permafrost, and far from any transportation infrastructure. The advent of modern drilling and production techniques has made Umiat and similar fields in northern Alaska attractive exploration and production targets. Since 2008 UAF has been working with Renaissance Alaska Inc. and, more recently, Linc Energy, to develop a more robust reservoir model that can bemore »« less
https://doi.org/10.2172/1080462

Full Text Available
Impact of model improvements on 80 m wind speeds during the second Wind Forecast Improvement Project (WFIP2)

Journal Article Bianco, Laura ; Djalalova, Irina V. ; Wilczak, James M. ; ... - Geoscientific Model Development (Online)

During the second Wind Forecast Improvement Project (WFIP2; October 2015–March 2017, held in the Columbia River Gorge and Basin area of eastern Washington and Oregon states), several improvements to the parameterizations used 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 weather prediction (NWP) models were tested during four 6-week reforecast periods (one for each season). For these tests the models were run in control (CNT) and experimental (EXP) configurations, with the EXP configuration including all the improved parameterizations. The impactsmore »« less
Cited by 12
https://doi.org/10.5194/gmd-12-4803-2019
Risk-Based Cleanup Actions for Closure of a Brown field Site

Conference Rice, H W ; Feild, J F ; Farr, Jr, L C

Operating as a rail yard from approximately 1908 to 1987, Station Place is a 7.1-acre (4,046 square meter) property located in the downtown Portland, Oregon, River District Urban Renewal Area. The site soils were impacted with metals and polynuclear aromatic hydrocarbon compounds (PAHs). Benzene and select PAHs were detected in the shallow groundwater. Residual non-aqueous phase liquid (NAPL) was detected within the shallow saturated zone between 15 and 40 feet (4.5 to 12 meters) below grade and in the Troutdale Formation (used for municipal water supply at up-gradient location) at depths of up to 80 feet (24 meters) below grade.more »« less

Similar Records