Magnetic field lines and current sheets for an orbiting neutron star binary with the magnetic moment of one
star aligned with the rotation axis, and the magnetic moment of the other star tilted and antialigned with the rotation axis.
The stars are not spinning, i.e., R_{LC,∗} =
∞. Fields from each star encircle the other star and force
fields coming off the second star backwards toroidally.
This movie shows the corotating field pattern as the orbit progresses.
Magnetic field lines and current sheets for an orbiting neutron star binary with the magnetic moment of one star
aligned with the rotation axis, and the magnetic moment of the
other star tilted and antialigned with the rotation axis. The
stars are spinning rapidly at ∼ ms periods, with R_{LC,∗} /R_∗ =
2.7.
Stellar spin winds fields backwards toroidally.
This movie shows the corotating field pattern as the orbit progresses.
This three-year project, performed by Princeton University in partnership with the University of Minnesota and Brookhaven National Laboratory, examined geologic carbon sequestration in regard to CO2 leakage and potential subsurface liabilities. The research resulted in basin-scale analyses of CO2 and brine leakage in light of uncertainties in the characteristics of leakage processes, and generated frameworks to monetize the risks of leakage interference with competing subsurface resources. The geographic focus was the Michigan sedimentary basin, for which a 3D topographical model was constructed to represent the hydrostratigraphy. Specifically for Ottawa County, a statistical analysis of the hydraulic properties of underlying sedimentary formations was conducted. For plausible scenarios of injection into the Mt. Simon sandstone, leakage rates were estimated and fluxes into shallow drinking-water aquifers were found to be less than natural analogs of CO2 fluxes. We developed the Leakage Impact Valuation (LIV) model in which we identified stakeholders and estimated costs associated with leakage events. It was found that costs could be incurred even in the absence of legal action or other subsurface interference because there are substantial costs of finding and fixing the leak and from injection interruption. We developed a model framework called RISCS, which can be used to predict monetized risk of interference with subsurface resources by combining basin-scale leakage predictions with the LIV method. The project has also developed a cost calculator called the Economic and Policy Drivers Module (EPDM), which comprehensively calculates the costs of carbon sequestration and leakage, and can be used to examine major drivers for subsurface leakage liabilities in relation to specific injection scenarios and leakage events. Finally, we examined the competitiveness of CCS in the energy market. This analysis, though qualitative, shows that financial incentives, such as a carbon tax, are needed for coal combustion with CCS to gain market share. In another part of the project we studied the role of geochemical reactions in affecting the probability of CO2 leakage. A basin-scale simulation tool was modified to account for changes in leakage rates due to permeability alterations, based on simplified mathematical rules for the important geochemical reactions between acidified brines and caprock minerals. In studies of reactive flows in fractured caprocks, we examined the potential for permeability increases, and the extent to which existing reactive transport models would or would not be able to predict it. Using caprock specimens from the Eau Claire and Amherstburg, we found that substantial increases in permeability are possible for caprocks that have significant carbonate content, but minimal alteration is expected otherwise. We also found that while the permeability increase may be substantial, it is much less than what would be predicted from hydrodynamic models based on mechanical aperture alone because the roughness that is generated tends to inhibit flow.
Complete dataset of pore water chemical parameters measured at the Marsh Resource Meadowlands Mitigation Bank, a tidal marsh within the New Jersey Meadowlands, from March 2011 to April 2012. Analytes measured include dissolved methane, sulfate, dissolved organic carbon, temperature, salinity, and pH. Measurements were conducted using porewater dialysis samplers, and water was sampled from the surface to a depth of 60 cm.
This dataset contains all the data, model and MATLAB codes used to generate the figures and data reported in the article (DOI: 10.1002/2014JD022278). The data was generated during September 2013 and February 2014 using the Ocean-Land-Atmosphere Model also provided with this package. The data was generated using the computational resources supported by the PICSciE OIT High Performance Computing Center and Visualization Laboratory at Princeton University. The dataset contains a pdf Readme file which explains in detail how the data can be used. Users are recommended to go through this file before using the data.
This movie shows the dynamical behavior of field lines seeded on one of the stars. We find
a clear cyclical process operating in the magnetosphere. First, field lines from one star can attach to the second star. Second, as the orbit progresses these field lines
develop twist and are expelled outward past the second
star as closed loops. Third, these loops open up to infinity and then reconnect on the far side of the first star
opposite to the second. Fourth, the orbital motion will
bring the second star back into contact with the closed
loops, and they reattach to the second star.
A subset of the Fermi-LAT public data for use with NPTFit:
https://github.com/bsafdi/NPTFit
The data here is for use with the Jupyter example notebooks provided with the
main code. Details of the files provided are given below. All files are provided
as numpy arrays binned as nside=128 HEALPix maps.
For the full public data, see:
http://fermi.gsfc.nasa.gov/ssc/data/access/
