Modern geodetic and atmospheric data sets have demonstrated that changes in the solid earth's rotation rate are closely coupled to changes in the atmosphere's angular momentum over a range of subseasonal through interannual time scales. Nevertheless, limits to the correspondence between changes in the momenta of the two bodies exist at both ends of the spectrum resolvable by the data. At high frequencies we show that changes in the length of day as short as a fortnight can now be attributed almost entirely to atmospheric forcing; more rapid fluctuations in the length of day, however, cannot be shown to coincide with atmospheric behavior, a result we blame mostly on errors remaining in both the geodetic and atmospheric series rather than on the neglect of some other component of the momentum budget. On the decadal time scale, nonatmospheric processes, believed primarily to involve coremantle coupling, dominate the global momentum budget. Our analysis of the low‐frequency component of the difference between the momenta of the solid earth and atmosphere during 1976–1988 shows it to consist of a general trend interrupted by three major changes in slope. Whether this result indicates that coremantle coupling is a nonsteady phenomenon or that unmodeled oceanic processes are responsible for the intermittency of the difference series is presently uncertain.

No abstract

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83). Elevation, as used in this report, refers to distance above the Upper Klamath Lake Vertical Datum (UKLVD), which is used by the Bureau of Reclamation for reporting the elevation of Upper Klamath Lake.

For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment-visit http://www.usgs.gov or call 1-888-ASK-USGS.For an overview of USGS information products, including maps, imagery, and publications, visit http://store.usgs.gov.Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. DatumsVertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 (NGVD 29).Horizontal coordinate information is referenced to the World Geodetic System of 1984 (WGS 84).Elevation, as used in this report, refers to distance above the vertical datum. Supplemental InformationConcentrations of chemical constituents in water are given in either milligrams per liter (mg/L) or micrograms per liter (µg/L). AbstractThe frequency of deep ventilation events in Crater Lake, a caldera lake in the Oregon Cascade Mountains, was simulated in six future climate scenarios, using a 1-dimensional deep ventilation model (1DDV) that was developed to simulate the ventilation of deep water initiated by reverse stratification and subsequent thermobaric instability. The model was calibrated and validated with lake temperature data collected from 1994 to 2011. Wind and air temperature data from three general circulation models and two representative concentration pathways were used to simulate the change in lake temperature and the frequency of deep ventilation events in possible future climates. The lumped model air2water was used to project lake surface temperature, a required boundary condition for the lake model, based on air temperature in the future climates.The 1DDV model was used to simulate daily water temperature profiles through 2099. All future climate scenarios projected increased water temperature throughout the water column and a substantive reduction in the frequency of deep ventilation events. The least extreme scenario projected the frequency of deep ventilation events to decrease from about 1 in 2 years in current conditions to about 1 in 3 years by 2100. The most extreme scenario considered projected the frequency of deep ventilation events to be about 1 in 7.7 years by 2100. All scenarios predicted that the temperature of the entire water column will be greater than 4 °C for increasing lengths of time in the future and that the conditions required for thermobaric instability induced mixing will become rare or non-existent.The disruption of deep ventilation by itself does not provide a complete picture of the potential ecological and water quality consequences of warming climate to Crater Lake. Estimating the effect of warming climate on deep water oxygen depletion and water clarity will require careful modeling stu...

Physical, sexual and psychological abuse were examined as risk factors for pregnancy-related anxiety with resilience and social support as mediators. Pregnant women ( n = 638) completed measures of pregnancy-related anxiety, resilience, perceived social support and childhood abuse. Women with an abuse history had higher pregnancy-related anxiety scores ( m = 64.40) than other women ( m = 55.36). All abuse types independently predicted pregnancy-related anxiety; resilience and social support were mediators. Results highlight the value of antenatal screening for pregnancy-related anxiety including specific risk factors such as child abuse. Programs such as the Midwife Continuity of Care are useful in encouraging disclosure.