Tagging moisture sources with Lagrangian and inertial tracers: application to intense atmospheric river events

Abstract. Two Lagrangian tracer tools are evaluated for studies on atmospheric moisture sources and pathways. In these methods, a moisture volume is assigned to each particle, which is then advected by the wind flow. Usual Lagrangian methods consider this volume to remain constant and the particle to follow flow path lines exactly. In a different approach, the initial moisture volume can be considered to depend on time as it is advected by the flow due to thermodynamic processes. In this case, the tracer volume drag must be taken into account. Equations have been implemented and moisture convection was taken into account for both Lagrangian and inertial models. We apply these methods to evaluate the intense atmospheric rivers that devastated (i) the Pacific Northwest region of the US and (ii) the western Iberian Peninsula with flooding rains and intense winds in early November 2006 and 20 May 1994, respectively. We note that the usual Lagrangian method underestimates moisture availability in the continent, while active tracers achieve more realistic results.

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Tagging moisture sources with Lagrangian and inertial tracers: Application to intense atmospheric river events

10.5194/esd-2018-8 ◽

2018 ◽

Author(s):

Vicente Pérez-Muñuzuri ◽

Jorge Eiras-Barca ◽

Daniel Garaboa-Paz

Keyword(s):

The United States ◽

Atmospheric Moisture ◽

Atmospheric Rivers ◽

North West ◽

Atmospheric River ◽

Moisture Sources ◽

West Region ◽

The Pacific ◽

Lagrangian Tracers ◽

Thermodynamic Processes

Abstract. Two Lagrangian tracers tools are evaluated for studies on atmospheric moisture sources and pathways. In these methods, a moisture volume is assigned to each particle which is then advected by the wind flow. Usual Lagrangian methods consider this volume to remain constant and the particle follows flow path lines exactly. In a different approach, the initial moisture volume can be considered to depend on time as it is advected by the flow, due to thermodynamic processes. In this case, the tracer volume drag must be taken into account. Equations have been implemented and moisture convection was taken into account for both Lagrangian and inertial models. We apply these methods to evaluate the intense atmospheric rivers that devastated (i) the Pacific North West region of the United States, and (ii) the Western of the Iberian Peninsula, with flooding rains and intense winds in early November 2006, and May 20, 1994, respectively. We note that the usual Lagrangian method underestimates moisture availability in the continent while active tracers achieve more realistic results.

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Radiocarbon Calibration around AD 1900 from Scots Pine (Pinus Sylvestris) tree rings from Northern Norway

Radiocarbon ◽

10.1017/rdc.2019.99 ◽

2019 ◽

Vol 61 (6) ◽

pp. 1775-1784

Author(s):

Helene Svarva ◽

Pieter Grootes ◽

Martin Seiler ◽

Terje Thun ◽

Einar Værnes ◽

...

Keyword(s):

Pinus Sylvestris ◽

Pacific Northwest ◽

Scots Pine ◽

Tree Rings ◽

Fossil Fuels ◽

Pacific Coast ◽

Northern Norway ◽

Pine Tree ◽

The Pacific ◽

The Us

ABSTRACTTo resolve an inconsistency around AD 1895 between radiocarbon (14C) measurements on oak from the British Isles and Douglas fir and Sitka spruce from the Pacific Northwest, USA, we measured the 14C content in single-year tree rings from a Scots pine tree (Pinus sylvestris L.), which grew in a remote location in Saltdal, northern Norway. The dataset covers the period AD 1864–1937 and its results are in agreement with measurements from the US Pacific coast around 1895. The most likely explanation for older ages in British oak in this period seems to be 14C depletion associated with the combustion of fossil fuels.

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(Re)considering Squirrel––From Object of Rescue to Multispecies Kin

Journal of Childhood Studies ◽

10.18357/jcs.v43i1.18265 ◽

2018 ◽

Vol 43 (1) ◽

pp. 60-67

Author(s):

Angela Molloy Murphy

Keyword(s):

Early Childhood ◽

Pacific Northwest ◽

Classroom Community ◽

Early Childhood Classroom ◽

Childhood Education ◽

Nature And Culture ◽

The Pacific ◽

Child Centered ◽

Northwest Region

This is a story situated in the Pacific Northwest region of North America, where encounters with a non-native “rescue” squirrel present disequilibrium for an educator and surprises for an early childhood classroom community. Thinking with Haraway, Latour, and common world frameworks challenges the educator’s “back to nature” narrative and generates opportunities to engage with different perspectives about the intersection of nature and culture, human and nonhuman kin, and the limiting quality of anthropocentric, child-centered pedagogies in early childhood education.

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A Climatological Study of National Weat her Service Watches, Warnings, and Advisories and Landfalling Atmospheric Rivers in the Western U.S. 2006–2018

Weather and Forecasting ◽

10.1175/waf-d-20-0212.1 ◽

2021 ◽

Author(s):

Samuel M. Bartlett ◽

Jason M. Cordeira

Keyword(s):

Water Vapor ◽

Pacific Northwest ◽

Vapor Transport ◽

Water Vapor Transport ◽

Synoptic Scale ◽

Flash Flooding ◽

Atmospheric Rivers ◽

The Pacific ◽

Central Regions ◽

Heavy Snow

AbstractAtmospheric rivers (ARs) are synoptic-scale phenomena associated with long, narrow corridors of enhanced low-level water vapor transport. Landfalling ARs may produce numerous beneficial (e.g. drought amelioration and watershed recharge) and hazardous (e.g. flash flooding and heavy snow) impacts that may require the National Weather Service (NWS) to issue watches, warnings, and advisories (WWAs) for hazardous weather. Prior research on WWAs and ARs in California found that 50–70% of days with flood-related and 60–80% of days with winter weather-related WWAs occurred on days with landfalling ARs in California. The present study further investigates this relationship for landfalling ARs and WWAs during the cool seasons of 2006–2018 across the entire western U.S. and considers additional dimensions of AR intensity and duration. Across the western U.S., regional maxima of 70–90% of days with WWAs issued for any hazard type were associated with landfalling ARs. In the Pacific Northwest and Central regions, flood-related and wind-related WWAs were also more frequently associated with more intense and longer duration ARs. While a large majority of days with WWAs were associated with landfalling ARs, not all landfalling ARs were necessarily associated with WWAs (i.e., not all ARs are hazardous). For example, regional maxima of only 50–70% of AR days were associated with WWAs issued for any hazard type. However, as landfalling AR intensity and duration increased, the association with a WWA and the “hazard footprint” of WWAs increased quasi-exponentially across the western U.S.

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Understanding Decision Making by Families About Youth Football Participation Postconcussion

Health Promotion Practice ◽

10.1177/1524839920945255 ◽

2020 ◽

pp. 152483992094525

Author(s):

Emily Kroshus ◽

Deborah Bowen ◽

Douglas Opel ◽

Sara P. D. Chrisman ◽

Frederick P. Rivara

Keyword(s):

Pacific Northwest ◽

Decision Aid ◽

Sports Participation ◽

The United States ◽

Football Players ◽

Contact Sport ◽

Sample Mean ◽

Youth Football ◽

The Pacific ◽

Northwest Region

Many families are concerned about their child’s risk of concussion, and some seek counsel from clinicians about whether or not to return to contact sports participation postinjury. The present study sought to identify factors that parents weight most heavily in forming their preferences regarding whether their child should return to contact sport after recovering from a concussion. Survey data were collected from 568 parents of youth football players (aged 7–14 years) in the Pacific Northwest region of the United States (73% response rate). Approximately two thirds (63%) of parents preferred that their child retire from football after one or two concussions. Multivariable linear regression indicated parents above the sample mean in terms of how strongly they valued football participation preferred their child stop after more concussions than parents below the sample mean (β = .44, standard error [SE] = 0.06, p < .001). Factors endorsed by the most parents as making them “much more likely” to want their child to stop playing football included the belief that their child will experience cognitive issues later in life as a result of concussions (65.0%) and that their child will get another concussion while playing football (43.5%). Within the context of a clinical visit postconcussion, physicians may need to help families clarify their values related to football participation and provide information about the potential outcomes of returning to contact sport. A formalized shared decision aid could help support consistent implementation of this potentially challenging conversation.

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Mapping “At Risk” Snow in the Pacific Northwest

Journal of Hydrometeorology ◽

10.1175/jhm543.1 ◽

2006 ◽

Vol 7 (5) ◽

pp. 1164-1171 ◽

Cited By ~ 138

Author(s):

Anne W. Nolin ◽

Christopher Daly

Keyword(s):

At Risk ◽

Snow Cover ◽

Pacific Northwest ◽

Climate Warming ◽

The United States ◽

Cold Climate ◽

Temperature Threshold ◽

Precipitation Regime ◽

The Pacific ◽

Northwest Region

Abstract One of the most visible and widely felt impacts of climate warming is the change (mostly loss) of low-elevation snow cover in the midlatitudes. Snow cover that accumulates at temperatures close to the ice-water phase transition is at greater risk to climate warming than cold climate snowpacks because it affects both precipitation phase and ablation rates. This study maps areas in the Pacific Northwest region of the United States that are potentially at risk of converting from a snow-dominated to a rain-dominated winter precipitation regime, under a climate-warming scenario. A data-driven, climatological approach of snow cover classification is used to reveal these “at risk” snow zones and also to examine the relative frequency of warm winters for the region. For a rain versus snow temperature threshold of 0°C the at-risk snow class covers an area of about 9200 km2 in the Pacific Northwest region and represents approximately 6.5 km3 of water. Many areas of the Pacific Northwest would see an increase in the number of warm winters, but the impacts would likely be concentrated in the Cascade and Olympic Ranges. A number of lower-elevation ski areas could experience negative impacts because of the shift from winter snows to winter rains. The results of this study point to the potential for using existing datasets to better understand the potential impacts of climate warming.

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