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In this paper, Jupiter's Great Red Spot (GRS) is used to determine properties of the Jovian atmosphere that cannot otherwise be found. These properties include the potential vorticity of the GRS and its neighboring jet streams, the shear imposed on the GRS by the jet streams, and the vertical entropy gradient (i.e., Rossby deformation radius). The cloud cover of the GRS, which is often used to define the GRS's area and aspect ratio, is found to differ significantly from the region of the GRS's potential vorticity anomaly. The westward-going jet stream to the north of the GRS and the eastward-going jet stream to its south are each found to have a large potential vorticity "jump." The jumps have opposite signs, and as a consequence of their interaction with the GRS, the shear imposed on the GRS is reduced. The aspect ratio of the GRS's potential vorticity anomaly depends on the ratio of the imposed shear to the strength of the anomaly. The east-west to north-south aspect ratio is found to be ϳ2:1, but without the opposing jumps it would be much greater. The GRS's high-speed collar and quiescent interior require that the potential vorticity in the interior be approximately half that in the collar. No other persistent geophysical vortex has a significant local minimum of potential vorticity in its interior, and laboratory vortices with such a minimum are unstable.

The east-west striped pattern of clouds in Jupiter's weather layer is accompanied by a zonal flow containing 12 eastward-going jet streams alternating in latitude with westwardgoing jet streams. Based on theory, simulation and observations of the Earth's oceans and atmosphere, it is conjectured that Jupiter's weather layer is made of bands of constant potential vorticity (PV), where the interfaces between bands are at the latitudes of the maxima of the eastward-going jet streams. It is speculated that the mixing of PV on Jupiter is analogous to the mixing of salt in the ocean by the Phillips effect, which causes the salt density to form a monotonic 'staircase'. It is hypothesized that the PV in Jupiter's weather layer is also a staircase, decreasing from north to south. PV is a function of vorticity, as well as parameters with unknown values, e.g. the vertical stratification and the zonal flow beneath the observable weather layer. Therefore, these hypotheses cannot be tested directly. Using an atmospheric model that contains these unknown parameters, we solved the inverse problem and found values of the unknown parameters (and their uncertainties) that best fit Jovian observations. The unknown parameters influence how the zonal flow interacts with large vortices, e.g. the Great Red Spot (GRS; the largest and longest-lived Jovian vortex, centred at 23• S) and the Oval BA (the second largest vortex, centred at 33• S). Although we found that the PV distribution is approximately piecewiseconstant and that the peaks of the eastward-going jet streams are at the latitudes of PV interfaces, there is also a PV interface at 20• S, where there is a westward-going jet stream. We find that the zonal PV is not a monotonic staircase due to the 'backwards' interface at 20• S. We show that this backwards interface is necessary to make the GRS nearly round, and that without that interface, the Red Spot would be highly elongated in the east-west direction and probably unstable.

We present a novel methodology for integration of high-angle/horizontal (HA/HZ) well data into 3D geomodels as a natural extension to well placement workflows. Log interpretation, typically done in 2D cross-sections, is based on 1-D automated inversion, yielding near-wellbore reservoir structure and properties. 2D cross-section, updated by inversion and further refined using 2D/3D modeling, is subsequently retrofitted into the geomodel so as to minimally perturb the original topology. Changes in positions/dips/azimuths of boundaries and faults, cell properties, and further local grid refinements are applied automatically. The updated geomodel honors high-resolution logs and low-resolution seismic/nearby wells data. We demonstrate this on a typical real-time well placement scenario. Electromagnetic log interpretation codes are integrated as a high performance computing (HPC) Web service into a geosteering/model update workflow. As the initial model, we use 3D geomodel constructed from seismic/vertical well data. A "curtain" cross-section is extracted, edited based on 1D inversion, and further refined to match HA/HZ logs through 2D and 3D forward modeling, by changing properties/dips/layer thicknesses /fault positions, while preserving the original topology. Then, updated node coordinates and cell properties of the affected pillar grid region are calculated to optimally retrofit the changed 2D cross-section into the grid. These changes are then automatically applied to the 3D model. For quality control, we recompute the 2D cross-section from the refined geomodel. Ultimately, we arrive at the geomodel that honors both seismic and resistivity well-log data. The combination, in a single workflow, of physics-based log modeling codes, Services-Oriented Architecture, HPC framework, and the solver to optimally retrofit 2D cross-sections into 3D models, creates a qualitatively new opportunity for well placement engineers. This integrated workflow (1) maximizes the value of deep directional resistivity well-logs and real-time well placement interpretation by incorporating them into the source of data for building geomodels; (2) radically speeds up the model refinement loop by automatically calculating and applying the modifications to 3D reservoir model; (3) enables geoscientists to directly refine geomodels while geosteering. The latter has not been a standard practice, hindered by challenges of scale difference between geomodels and well-logs and lack of availability of efficient modeling codes.

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