SUMMARYTwo series of 12-hr and Z+hr forecast 500 mb. 1,000 mb and 1,000-500 mb thickness charts have been computed electronically using the Sawyer-Bushby (1053) two-parameter baroclinic model of the atmosphere. The results are compared with the actual charts, and a good degree of correspondence is found between the actual and computed charts.

A cross-dipole technology was used to evaluate a carbonate formation in southeastern New Mexico to determine fracture trends in a waterflooded environment. The measurements were first made in open hole, then in cased hole before and after fracture stimulation. The cross-dipole data were processed to find the amount of shearwave anisotropy and the associated azimuth. The results demonstrate that stimulated fractures create a substantial anisotropy and a well-defined azimuth behind casing. More important, by evaluating the anisotropy magnitude and azimuth from the cased-hole data, we can determine the fracture extent along the borehole and its azimuth in the formation. The fracture extent is also consistent with that from a radioactive tracer measurement. The results of this study suggest that cross-dipole acoustic logging is an effective technology for cased-hole fracture stimulation evaluation.

If the exterior fluid did pass right up the centre then the circulation would remain constant, but it is possible that it gets mixed before reaching the cap and that the circulation generated by the smaller density at the cap is exactly cancelled by Reynolds stresses in the mixing region.

SUMMARYThe system of partial differential equations given by Sawyer and Bushby (1953) for the rates of change of the 1,000-500-mb thickness and the 500-mb contour height have been solved on an electronic computing machine for three synoptic situations and the fields of vertical motion were also computed. The results, described in this paper, show reasonable agreement with actuality. The implied 1,000-mb height tendencies also agree quite well with those actually observed.

SUMMARYA series of experiments is described in numerical forecasting in which the wind field at mid-tropospheric level is derived from a stream function, but the wind shear in the lower troposphere is computed in a variety of ways. The results show that the overestimation of the pressures in the region of anticyclones, which is inherent in models in which the mid-tropospheric wind field is assumed to be geostrophic, is significantly reduced.