Spatial distinction and temporal stability of water microelements in the North Platte River and Lake McConaughy , Nebraska

Abstract Season-to-season persistence of soil moisture drought varies across North America. Such interseasonal autocorrelation can have modest skill in forecasting future conditions several months in advance. Because robust instrumental observations of precipitation span less than 100 years, the temporal stability of the relationship between seasonal moisture anomalies is uncertain. The North American Seasonal Precipitation Atlas (NASPA) is a gridded network of separately reconstructed cool-season (December–April) and warm-season (May–July) precipitation series and offers new insights on the intra-annual changes in drought for up to 2000 years. Here, the NASPA precipitation reconstructions are rescaled to represent the long-term soil moisture balance during the cool season and 3-month-long atmospheric moisture during the warm season. These rescaled seasonal reconstructions are then used to quantify the frequency, magnitude, and spatial extent of cool-season drought that was relieved or reversed during the following summer months. The adjusted seasonal reconstructions reproduce the general patterns of large-scale drought amelioration and termination in the instrumental record during the twentieth century and are used to estimate relief and reversals for the most skillfully reconstructed past 500 years. Subcontinental-to-continental-scale reversals of cool-season drought in the following warm season have been rare, but the reconstructions display periods prior to the instrumental data of increased reversal probabilities for the mid-Atlantic region and the U.S. Southwest. Drought relief at the continental scale may arise in part from macroscale ocean–atmosphere processes, whereas the smaller-scale regional reversals may reflect land surface feedbacks and stochastic variability.

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Qualified temperature, salinity and dissolved oxygen climatologies in a changing Adriatic Sea

Ocean Science Discussions ◽

10.5194/osd-11-331-2014 ◽

2014 ◽

Vol 11 (1) ◽

pp. 331-390

Author(s):

M. Lipizer ◽

E. Partescano ◽

A. Rabitti ◽

A. Giorgetti ◽

A. Crise

Keyword(s):

Dissolved Oxygen ◽

Adriatic Sea ◽

Eastern Mediterranean ◽

Temporal Stability ◽

The South ◽

The North ◽

Synthetic Temperature ◽

Oxygen Utilisation ◽

Oxygen Minimum

Abstract. An updated climatology, based on a comprehensive dataset (1911–2009) of temperature, salinity and dissolved oxygen, has been produced for the whole Adriatic Sea with the Variational Inverse Method using the DIVA software. Climatological maps were produced at 26 levels and validated with Ordinary Cross Validation and with real vs. synthetic Temperature–Salinity diagram intercomparison. The concept of Climatology–Observation Misfit (COM) has been introduced as an estimate of the physical variability associated with the climatological structures. In order to verify the temporal stability of the climatology, long-term variability has been investigated in the Mid Adriatic and the South Adriatic Pits, regarded as the most suitable records of possible long-term changes. Compared with previous climatologies, this study reveals a surface temperature rise (up to 2 °C), a clear deep dissolved oxygen minimum in the South Adriatic Gyre and a bottom summer oxygen minimum in the North Adriatic. Below 100 m all properties profoundly differ between the Middle and the South Adriatic. The South Adriatic Pit clearly shows the remote effects of the Eastern Mediterranean Transient, while no effect is observed in Middle Adriatic Pits. The deepest part of the South Adriatic seems now to be significantly saltier (+0.18 since the period 1911–1914, with an increase of +0.018 decade−1 since the late 1940s) and warmer (+0.54 °C since 1911–1914), even though a long-term temperature trend could not be statistically demonstrated. Conversely, the Middle Adriatic Pits present a long-term increase in apparent oxygen utilisation (+0.77 mL L−1 since 1911–1914, with a constant increase of +0.2 mL L−1 decade−1 after the 1970s).

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Helicopter Electromagnetic and Magnetic Geophysical Survey Data for Portions of the North Platte River and Lodgepole Creek, Nebraska, June 2008

Open-File Report ◽

10.3133/ofr20091110 ◽

2009 ◽

Cited By ~ 3

Author(s):

Bruce D. Smith ◽

Jared D. Abraham ◽

James C. Cannia ◽

Patricia Hill

Keyword(s):

Survey Data ◽

Geophysical Survey ◽

Platte River ◽

The North

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Greater predation by Double-crested Cormorants on cutthroat versus rainbow trout fingerlings stocked in a Wyoming river

Canadian Journal of Zoology ◽

10.1139/z99-164 ◽

1999 ◽

Vol 77 (12) ◽

pp. 1984-1990 ◽

Cited By ~ 5

Author(s):

James R Lovvorn ◽

Daniel Yule ◽

Clayton E Derby

Keyword(s):

Rainbow Trout ◽

Cutthroat Trout ◽

Phalacrocorax Auritus ◽

Limited Data ◽

Platte River ◽

The North ◽

Rainbow Trout Oncorhynchus Mykiss ◽

Oncorhynchus Clarki Bouvieri ◽

Pelecanus Erythrorhynchos ◽

Yellowstone Cutthroat Trout

We studied the relative vulnerability of Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri) versus rainbow trout (Oncorhynchus mykiss) stocked as fingerlings in the North Platte River, Wyoming, to Double-crested Cormorant (Phalacrocorax auritus) predation. Cutthroat fingerlings decreased as a fraction of the population from stocking in late June to electrofishing surveys in the following October and March. In contrast, the fraction of cutthroat fingerlings among tagged fingerlings eaten by cormorants collected on the river was significantly greater than that in the population when originally stocked. More limited data from pellets regurgitated by adult cormorants at a nearby colony and in American White Pelicans (Pelecanus erythrorhynchos) collected on the river showed the same trend toward greater percentages of cutthroat trout being consumed than were present among trout stocked. There were no differences in cormorant predation rates on the Eagle Lake strain of rainbow trout reared under shaded versus partially shaded conditions, or between Auburn and Bar BC strains of Snake River (Yellowstone) cutthroat trout. On the North Platte River, cutthroat trout fingerlings were more susceptible to cormorant predation than rainbow trout of similar size that were stocked simultaneously.

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Historical Changes in Large River Fish Assemblages of the Americas

Historical Changes in Large River Fish Assemblages of the Americas ◽

10.47886/9781888569728.ch14 ◽

2005 ◽

Keyword(s):

Native Species ◽

Fish Assemblages ◽

Fish Fauna ◽

Large River ◽

Platte River ◽

Water Diversions ◽

The North ◽

As Species ◽

South Platte ◽

The City

<em>Abstract.</em>—From its headwaters in the Rocky Mountains, the Platte River drains 230,362 km<sup>2</sup> in Colorado, Wyoming, and Nebraska. The Platte River is formed by the confluence of the North Platte and South Platte near the city of North Platte, Nebraska, and receives additional flow from the Loup and Elkhorn rivers that drain the Sand Hills region of Nebraska. Water diversions for mining and irrigation began in the 1840s in Colorado and Wyoming, and irrigation diversions in Nebraska began in the 1850s. Construction of dams for control of river flows commenced on the North Platte River in Wyoming in 1904. Additional dams and diversions in the North Platte, South Platte, and Platte rivers have extensively modified natural flow patterns and caused interruptions of flows. Pollution, from mining, industrial, municipal, and agricultural sources, and introductions of 24 nonnative species have also taken their toll. Fishes of the basin were little studied before changes in land use, pollution, and introduction of exotic species began. The current fish fauna totals approximately 100 species from 20 families. Native species richness declines westward, but some species find refugia in western headwaters streams. Declines in 26 native species has led to their being listing as species of concern by one or more basin states.

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