Seasonal range prediction over North America has been based on intraseasonal and interannual variability related to the Pacific North America (PNA) pattern and El Niño and Southern Oscillation (ENSO), respectively. These phenomena have an impact on the occurrence of atmospheric blocking and the long-term conditions for North America. Similar relationships may be found for seasonal range prediction over South America. Previous studies have examined ENSOrelated variability of the South Pacific Jetstream as well as atmospheric blocking. Using the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalyses, the character of the monthly circulations were studied over the South Pacific/South America sector from 2000-2016. Initial results show that there is a negative correlation in the upper air circulation over the East Pacific and South America during winter for ENSO. Also, the interannual variability in the jet-stream pattern for the region as related to ENSO shows a 180° phase difference. Finally, there is evidence that the circulation pattern for the 2000-2016 may be different from that of the latter part of the 20th century as indicated by a recent reversal of the interdecadal variability of atmospheric blocking over the South Pacific Region.
Geochemical fingerprinting using gas chromatography techniques is a proven alternative or additional tool to traditional approaches for the production back-allocation such as metering or production logging tools. It can be applied in various scenarios, from commingled reservoirs in a single well to allocation of multiple wells or entire fields produced via the same evacuation system. The approach is fast, cost-effective and does not require interruption of production, thus enabling frequent monitoring of production. The method is based on detailed comparison of fluid compositions obtained from gas chromatography of representative samples acquired from the point of interest (single reservoir, well, etc.), called further the 'end-member' and the 'commingled fluid' to be allocated. Production allocation using a geochemical fingerprinting approach has been successfully used across the globe with specific traction in North America, the North Sea region and the Middle East.Our method is based on analysis of ratios of heights of neighboring chromatographic peaks (compounds) rather than the single peak heights or areas that all the chromatograms have in common. Such approach reduces inconsistencies between light and heavy hydrocarbons due to some problems of reproducibility during the sampling or during the analysis. It also allows us to tackle issues related to the changes in compositions of end-members during production. In addition, the resolution manages the non-linearity of the equations derived from the physics of the mixtures. The non-Gaussian distribution of the errors is taken into account to comply with the maximum likelihood. Thus, a solid theoretical framework is established to avoid current issues encountered when peak ratios are utilized. Benefits of this method include firstly, a complete management of the uncertainties on the proportions of end-members and on each individual peak ratio employed. In addition to minimization of 'calibration' lab mixtures, elimination of manual peak selection (sometimes subjective). Finally, with this methodology employed heir in there is theoretically, no limitation on the number of end-members.In this paper we demonstrate our approach applied successfully on a series of case studies including biodegraded oils and 'annoyingly' similar fluids. We demonstrate that our approach can be successfully and cost-effectively applied to allow for more reliable reservoir/field management.
The overall purpose of this paper is to post-evaluate the predictability of Hurricane Florence using the Advanced Research Weather Research Forecast (WRF) (ARW) version of a mesoscale model. This was performed over the period from 0000 UTC 13 September 2018 through 0000 UTC 18 September 2018. The WRF ARW core resolution used here was the 27-km grid spacing chosen to in order to balance finer resolution against in house processing time and storage. The large-scale analysis showed that a change in the Northern Hemisphere flow regime, especially the flow in the western part of the Northern Hemisphere may have contributed partly to the reduced forward speed of the tropical cyclone. In order to measure the predictability of a system, we will use different convective and boundary layer schemes initialized from the same conditions. The results demonstrated that the sign of the local IRE tendency was similar to that of the Northern Hemisphere Integrated Enstrophy. The results also showed that when the boundary layer, convective, and cloud microphysical schemes of the model were varied, the areal coverage of heavy precipitation of Florence was under-forecast by approximately 10% or more, and the heaviest amounts were under-forecast by an average of about 20%.
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