69 research outputs found
Recommended from our members
Geostrophic and Sverdrup transports as indices of flow in the Gulf of Alaska
The intensification of cyclonic winds in the Gulf of Alaska
during winter belies the relatively constant geostrophic circulation
as being indicative of actual flow. In the absence of direct current
measurements, effects of various meteorological phenomena have
been eliminated from monthly mean sea level measurements over the
decade 1950 to 1959, and the resulting height anomalies equated to
monthly mean Sverdrup transports. A linear relationship is obtained,
except during summer when it permits an estimate of the increase in
recorded sea level due to runoff. The data suggest that during summer
the geostrophic transport is a good indication of general flow,
but that during winter the distribution of mass does not adjust to the
Sverdrup transport, and the resulting barotrophic flow is about one
and one-half times the geostrophic flow during this period. Mean
seasonal Sverdrup transport indicates maximum recirculation in the
Gulf of Alaska gyre during winter, a reduced but equal recirculation
during summer and fall, but none during spring.
These results conflict with existing interpretations of flow in
the Gulf of Alaska, and should form the basis for renewed oceanographic
explorations in this region
Comprehensive Second-Order Adjoint Sensitivity Analysis Methodology (2nd-ASAM) Applied to a Subcritical Experimental Reactor Physics Benchmark: III. Effects of Imprecisely Known Microscopic Fission Cross Sections and Average Number of Neutrons per Fission
The Second-Order Adjoint Sensitivity Analysis Methodology (2nd-ASAM) is applied to compute the first-order and second-order sensitivities of the leakage response of a polyethylene-reflected plutonium (PERP) experimental system with respect to the following nuclear data: Group-averaged isotopic microscopic fission cross sections, mixed fission/total, fission/scattering cross sections, average number of neutrons per fission (), mixed /total cross sections, /scattering cross sections, and /fission cross sections. The numerical results obtained indicate that the 1st-order relative sensitivities for these nuclear data are smaller than the 1st-order sensitivities of the PERP leakage response with respect to the total cross sections but are larger than those with respect to the scattering cross sections. The vast majority of the 2nd-order unmixed sensitivities are smaller than the corresponding 1st-order ones, but several 2nd-order mixed relative sensitivities are larger than the 1st-order ones. In particular, several 2nd-order sensitivities for 239Pu are significantly larger than the corresponding 1st-order ones. It is also shown that the effects of the 2nd-order sensitivities of the PERP benchmark’s leakage response with respect to the benchmark’s parameters underlying the average number of neutrons per fission, , on the moments (expected value, variance, and skewness) of the PERP benchmark’s leakage response distribution are negligible by comparison to the corresponding effects (on the response distribution) stemming from uncertainties in the total cross sections, but are larger than the corresponding effects (on the response distribution) stemming from uncertainties in the fission and scattering cross sections
Application of Inverse Gamma Transport to Material Thickness Identification with SGRD Code
- …