High resolution simulation of recent Arctic and Antarctic stratospheric chemical ozone loss compared to observations

Simulations of polar ozone losses were performed using the three-dimensional high-resolution (1° × 1°) chemical transport model MIMOSA-CHIM. Three Arctic winters 1999–2000, 2001–2002, 2002–2003 and three Antarctic winters 2001, 2002, and 2003 were considered for the study. The cumulative ozone loss in the Arctic winter 2002–2003 reached around 35% at 475K inside the vortex, as compared to more than 60% in 1999–2000. During 1999–2000, denitrification induces a maximum of about 23% extra ozone loss at 475K as compared to 17% in 2002–2003. Unlike these two colder Arctic winters, the 2001–2002 Arctic was warmer and did not experience much ozone loss. Sensitivity tests showed that the chosen resolution of 1° ×1° provides a better evaluation of ozone loss at the edge of the polar vortex in high solar zenith angle conditions. The simulation results for ozone, ClO, HNO3, N2O, and NOy for winters 1999–2000 and 2002–2003 were compared with measurements on board ER-2 and Geophysica aircraft respectively. Sensitivity tests showed that increasing heating rates calculated by the model by 50% and doubling the PSC (Polar Stratospheric Clouds) particle density (from 5 × 10-3 to 10-2 cm-3) refines the agreement with in situ ozone, N2O and NOy levels. In this configuration, simulated ClO levels are increased and are in better agreement with observations in January but are overestimated by about 20% in March. The use of the Burkholder et al. (1990) Cl2O2 absorption cross-sections slightly increases further ClO levels especially in high solar zenith angle conditions. Comparisons of the modelled ozone values with ozonesonde measurement in the Antarctic winter 2003 and with Polar Ozone and Aerosol Measurement III (POAM III) measurements in the Antarctic winters 2001 and 2002, shows that the simulations underestimate the ozone loss rate at the end of the ozone destruction period. A slightly better agreement is obtained with the use of Burkholder et al. (1990) Cl2O2 absorption cross-sections

West African gas pipeline (WAGP) project: Associated problems and possible remedies

Global focus is gradually turning away from crude oil as a major source of energy to natural gas due to its abundant availability, environmental friendliness and cost effectiveness, this has effectively increased the transboundary pipeline networks with minimal consideration to the impact at which the offshore segment of such projects could have on the environment. This paper considers Nigeria's present engagement in transboundary transportation of 11.3 billion cubic meters per day (11.3 BCMPD) of natural gas to Benin, Togo and Ghana for thermal and industrial uses through a 1,033 km pipeline network out of which 617 km is a submerged offshore pipeline network. The study is necessitated by the alarming frequency at which hydrocarbon pipeline failure occurs in Nigeria with the resulting economy, environmental and human consequences. It was discovered that any failure along the offshore segment of the pipelength poses high risk of hydrate formation and dissolution of some constituents which could result to problems ranging from behavioral nature (e.g. fish excitement, increased activities and scattering in the waterbody) to chronic poisoning, fire outbreak, loss of human lives and livestock and climate change. Development of pragmatic management scheme, robust leak detection model and predictive model on natural gas flow pattern in waterbody are recommended. © 2009 Springer Netherlands

Italy and EMU as a 'Vincolo Esterno': empowering the technocrats, transforming the state

This case study analyses how the Italian 'core executive' operated in the negotiation of the Maastricht Treaty provisions on Economic and Monetary Union. The record of the Italian negotiators on EMU is examined in the framework of a 'two-level' bargaining game. It argues that policy was largely driven by a small technocratic elite, with limited ministerial involvement. The overarching foreign policy imperatives were to maintain Italian participation at the heart of the European integration process and to reduce the asymmetry of monetary power with Germany. Domestically, however, the technocratic elite shared a belief in the need for externally-imposed economic discipline (a vincolo esterno - external constraint), to overcome the problems posed by the partitocrazia - the domination of government by parties. EMU was used to effect domestic reform by redistributing power. In the process they unleashed powerful transformative effects on the Italian state. The domestic effects of EMU were thus much more far-reaching than the Italian impact at the European level on the final EMU agreement