scholarly journals Heligmosomoides johnsoni sp. nov. (Nematoda: Heligmosomatidae) from the heather vole, Phenacomys intermedius Merriam

1973 ◽  
Vol 51 (12) ◽  
pp. 1243-1247 ◽  
Author(s):  
R. L. Rausch ◽  
V. R. Rausch
Keyword(s):  
Olympic Mountains ◽  
Phenacomys Intermedius

Heligmosomoides johnsoni sp. nov. is described from the cecum of the heather vole, Phenacomys intermedius Merriam, from the Olympic Mountains, Washington. The absence of longitudinal cuticular ridges dorsally separates H. johnsoni from species of Heligmosomoides other than H. hudsoni (Cameron, 1937), which occurs in varying lemmings, Dicrostonyx spp., and from which H. johnsoni is distinguished by its longer spicules, form of the dorsal ray, and other characters. Both Phenacomys and Dicrostonyx have a specialized cecum, with long villi around which the nematodes are found tightly coiled. The zoogeography of heligmosomid nematodes in Phenacomys is briefly discussed.

THE SPATIAL DISTRIBUTION AND LONGEVITY OF ONGOING PERMANENT FOREARC DEFORMATION SURROUNDING THE OLYMPIC MOUNTAINS

2019 ◽  
Author(s):  
Kristin Morell ◽  
◽  
Theron Finley ◽  
Lucinda J. Leonard ◽  
Christine Regalla
Keyword(s):  
Spatial Distribution ◽  
Olympic Mountains

scholarly journals Historical Variations of Lemon Creek Glacier, Alaska, and Their Relationship to the Climatic Record

1964 ◽  
Vol 5 (37) ◽  
pp. 77-86 ◽  
Author(s):  
Calvin J. Heusser ◽  
Melvin G. Marcus
Keyword(s):  
Field Research ◽  
Focus Of Attention ◽  
Ice Age ◽  
Research Project ◽  
Related Research ◽  
Olympic Mountains ◽  
Temperature Trends ◽  
Ice Field ◽  
Climatic Record ◽  
Last Ice Age

AbstractLemon Creek Glacier served as the focus of attention of the Juneau Ice Field Research Project from 1953 through 1958, during which period glaciological and related research was accomplished. This paper provides an historical framework for those studies by (1) considering variations of Lemon Creek Glacier in recent centuries and during millennia since the last ice age, and (2) describing certain relationships which appear to exist between these variations and the climatic record.It is found that Lemon Creek Glacier has been receding intermittently since a maximumc. 1750 and by 1958 had lostc. 25 per cent of the former area. Most rapid recession occurred during the periods 1891–1902 and 1929–58. Behaviour of the glacier sincec. 1750 reveals a parallelism with glaciers in most of the regions where temperature trends have been graphed as well as with other glaciers of the Juneau Ice Field. The advances of the 1950’s observed in the Rocky, Cascade and Olympic Mountains do not, however, show up in the Juneau area. Lemon Creek Glacier has not advanced more than 375 m. beyond the 1750 position, if at all, during the last 10,000 yr.

scholarly journals Flow of Blue Glacier, Olympic Mountains, Washington, U.S.A.

1974 ◽  
Vol 13 (68) ◽  
pp. 187-212 ◽  
Author(s):  
Mark F. Meier ◽  
W. Barclay Kamb ◽  
Clarence R. Allen ◽  
Robert P. Sharp
Keyword(s):  
Maximum Velocity ◽  
Ice Thickness ◽  
Center Line ◽  
Surface Slope ◽  
Channel Narrowing ◽  
Olympic Mountains ◽  
Principal Axes ◽  
Flow Effects ◽  
Surface Ice ◽  
Longitudinal Extension

Velocity and strain-rate patterns in a small temperate valley glacier display flow effects of channel geometry, ice thickness, surface slope, and ablation. Surface velocities of 20–55 m/year show year-to-year fluctuations of 1.5–3 m/year. Transverse profiles of velocity have the form of a higher-order parabola modified by the effects of flow around a broad bend in the channel, which makes the velocity profile asymmetric, with maximum velocity displaced toward the outside of the bend. Marginal sliding rates are 5–22 m/year against bedrock and nil against debris. Velocity vectors diverge from the glacier center-line near the terminus, in response to surface ice loss, but converge toward it near the firn line because of channel narrowing. Plunge of the vectors gives an emergence flow component that falls short of balancing ice loss by about 1 m/year. Center-line velocities vary systematically with ice thickness and surface slope. In the upper half of the reach studied, effects of changing thickness and slope tend to compensate, and velocities are nearly constant; in the lower half, the effects are cumulative and velocities decrease progressively down-stream. Where the slope increases down-stream from 7° to 9°, reflecting a bedrock step, there is localized longitudinal extension of 0.03 year–1followed by compression of 0.08 year–1where the slope decreases. Marginal shear (up to 0.5 year–1) is strongly asymmetric due to flow around the bend: the stress center-line, where one of the principal axes becomes longitudinal, is displaced 150 m toward the inside of the bend. This effect is prominently visible in the crevasse pattern. Ice fluxes calculated independently by “laminar” flow theory and by continuity disagree in a way which shows that internal deformation of the ice is controlled not by local surface slope but by an effective slope that is nearly constant over the reach studied.

scholarly journals The Sensitivity of Orographic Precipitation to Flow Direction: An Idealized Modeling Approach

2017 ◽  
Vol 18 (6) ◽  
pp. 1673-1688 ◽  
Author(s):  
Lee Picard ◽  
Clifford Mass
Keyword(s):  
Pacific Northwest ◽  
Wind Direction ◽  
Flow Direction ◽  
Three Dimensional ◽  
Washington State ◽  
Directional Sensitivity ◽  
Orographic Precipitation ◽  
Major Question ◽  
Olympic Mountains ◽  
Physics Model

Abstract A major question regarding orographic precipitation is its sensitivity to flow direction, with some research suggesting substantial sensitivity. To examine this issue, this paper describes a full physics model with realistic three-dimensional terrain that is forced by a single input sounding. This system is used to investigate the sensitivity of orographic precipitation to wind direction over the Pacific Northwest for conditions approximating an atmospheric river. The model results show considerable modulation of regional precipitation as flow direction changes, with results for four Washington State river drainages agreeing well with previous observational studies. It is shown that precipitation amounts over such drainages can vary substantially with very small changes in the direction of the incoming flow. To explore the origin of directional sensitivity of precipitation over the Olympic Mountains of western Washington State, additional experiments were carried out using modified terrain fields with smoothed or idealized Olympic Mountains, or with nearby orography removed. These simulations suggest that the sensitivity of Olympic Mountain precipitation to wind direction is more strongly modulated by the presence of surrounding orography than by the specific geometry of the Olympic Mountains.

Nonparametric Methodology to Estimate Precipitating Ice from Multiple-Frequency Radar Reflectivity Observations

2018 ◽  
Vol 57 (11) ◽  
pp. 2605-2622 ◽  
Author(s):  
Mircea Grecu ◽  
Lin Tian ◽  
Gerald M. Heymsfield ◽  
Ali Tokay ◽  
William S. Olson ◽  
...  
Keyword(s):  
Estimation Method ◽  
Optimal Estimation ◽  
Radar Reflectivity ◽  
Nonparametric Method ◽  
Multiple Frequency ◽  
Radar Observations ◽  
Triple Frequency ◽  
Olympic Mountains ◽  
Field Campaigns

AbstractIn this study, a nonparametric method to estimate precipitating ice from multiple-frequency radar observations is investigated. The method does not require any assumptions regarding the distribution of ice particle sizes and relies on an efficient search procedure to incorporate information from observed particle size distributions (PSDs) in the estimation process. Similar to other approaches rooted in optimal-estimation theory, the nonparametric method is robust in the presence of noise in observations and uncertainties in the forward models. Over 200 000 PSDs derived from in situ observations collected during the Olympic Mountains Experiment (OLYMPEX) and Integrated Precipitation and Hydrology Experiment (IPHEX) field campaigns are used in the development and evaluation of the nonparametric estimation method. These PSDs are used to create a database of ice-related variables and associated computed radar reflectivity factors at the Ku, Ka, and W bands. The computed reflectivity factors are used to derive precipitating ice estimates and investigate the associated errors and uncertainties. The method is applied to triple-frequency radar observations collected during OLYMPEX and IPHEX. Direct comparisons of estimated ice variables with estimates from in situ instruments show results consistent with the error analysis. Global application of the method requires an extension of the supporting PSD database, which can be achieved through the processing of information from additional past and future field campaigns.

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