Analysis of 27 satellite orbits to determine odd zonal harmonics in the geopotential

The odd zonal harmonics in the geopotential are the terms independent of longitude and antisymmetric about the Equator: they define the ‘pear-shape’ effect. The coeffecients J₃, J₅, J₇,…of these harmonics have been evaluated by analysing the variations in eccentricity of 27 orbits covering wide range of inclinations. We use again most of the orbits from our previous (1969) evaluations, but we now have the advantage of 3 accurate orbits at inclinations between 60° and 66°, where the variations in eccentricity become very large, and 3 near-equatorial orbits, at inclinations between 3° and 15°, whereas previously there were none at inclinations lower than 28°. The new data lead to much more accurate and reliable values for the coeffecients. Our recommended set, which terminates at J₁₇, is

$\text{10}{}^9\text{J}{}_3\text{= ?2531 ± 7}\text{10}{}^9\text{J}{}_{11}\text{= 159 ± 16}\text{J}{}_5\text{= ?246 ± 9}\text{J}{}_{13}\text{= ?131 ± 22}\text{J}{}_7\text{= ?326 ± 11}\text{J}{}_{15}\text{= ?26 ±24}\text{J}{}_9\text{= ?94 ± 12}\text{J}{}_{17}\text{= ?258 ± 19}$

. With this new set of values the pear-shape tendency of the Earth amounts to 44.7 m at the poles, instead of the previous 40 m, though the new geoid is within 1 m of the old at latitudes away from the poles.     

Infrasound Radiated During the Montana Earthquake of 1959 August 18

Summary Seismic waves caused by earthquakes radiate infrasound into the atmosphere as they proceed over the Earth's surface. Several instances of such sound waves radiated locally by seismic waves passing through the Washington, D.C., area have been observed at the infrasonic station there. A notable instance was the great Montana earthquake of 1959 August 18. Measurements of the radiated infrasound gave data on the seismic waves, including their travel times, local speeds, directions of travel, amplitudes, and waveforms.     

Spatial drought reconstructions for central High Asia based on tree rings

Spatial reconstructions of drought for central High Asia based on a tree-ring network are presented. Drought patterns for central High Asia are classified into western and eastern modes of variability. Tree-ring based reconstructions of the Palmer drought severity index (PDSI) are presented for both the western central High Asia drought mode (1587–2005), and for the eastern central High Asia mode (1660–2005). Both reconstructions, generated using a principal component regression method, show an increased variability in recent decades. The wettest epoch for both reconstructions occurred from the 1940s to the 1950s. The most extreme reconstructed drought for western central High Asia was from the 1640s to the 1650s, coinciding with the collapse of the Chinese Ming Dynasty. The eastern central High Asia reconstruction has shown a distinct tendency towards drier conditions since the 1980s. Our spatial reconstructions agree well with previous reconstructions that fall within each mode, while there is no significant correlation between the two spatial reconstructions.     

Private sector involvement in urban governance: The case of Business Improvement Districts and Town Centre Management partnerships in England

Although it has many merits, the voluminous literature on urban governance gives scant attention to the actual involvement and positioning of business elites and businesses within Public-Private Partnerships. There is also little consensus among academics as to why the private sector become involved in such schemes. This paper begins to address these issues through a critical empirical examination of how and why the private sector is involved with three English Town Centre Management (TCM) partnerships and the Business Improvement District (BID) subsidiaries all three partnerships have recently developed. In order to do this, the empirical study is guided by a conceptual framework that foregrounds the relationship between (a) the opening up and monitoring of ‘institutional space’ by partnerships and the state, and (b) the motivations and ‘constrained agency’ of the business elites. The paper demonstrates that the positioning of the private sector is more multifarious and fractured than previous studies of urban governance have suggested. It also reveals that business elites and businesses view their participation as an ‘investment’ that needs to accrue significant financial returns and that partnership and state officials are highly selective in their choice of ‘who governs’.