Multi-satellite observed responses of precipitation and its extremes to interannual climate variability

The consistency of precipitation variability estimated from the multiple satellite-based observing systems is assessed. There is generally good agreement between TRMM TMI, SSM/I, GPCP and AMSRE datasets for the inter-annual variability of precipitation since 1997 but the HOAPS dataset appears to overestimate the magnitude of variability. Over the tropical ocean the TRMM 3B42 dataset produces unrealistic variabilitys. Based upon deseasonalised GPCP data for the period 1998-2008, the sensitivity of global mean precipitation (P) to surface temperature (T) changes (dP/dT) is about 6%/K, although a smaller sensitivity of 3.6%/K is found using monthly GPCP data over the longer period 1989-2008. Over the tropical oceans dP/dT ranges from 10-30%/K depending upon time-period and dataset while over tropical land dP/dT is -8 to -11%/K for the 1998-2008 period. Analyzing the response of the tropical ocean precipitation intensity distribution to changes in T we find the wetter area P shows a strong positive response to T of around 20%/K. The response over the drier tropical regimes is less coherent and varies with datasets, but responses over the tropical land show significant negative relationships over an interannual time-scale. The spatial and temporal resolutions of the datasets strongly influence the precipitation responses over the tropical oceans and help explain some of the discrepancy between different datasets. Consistency between datasets is found to increase on averaging from daily to 5-day time-scales and considering a 1o (or coarser) spatial resolution. Defining the wet and dry tropical ocean regime by the 60th percentile of P intensity, the 5-day average, 1o TMI data exhibits a coherent drying of the dry regime at the rate of -20%/K and the wet regime becomes wetter at a similar rate with warming

Quantum Corrections To The Electronic Transport Properties Of The \u27Free-Electron\u27 Metallic Glass Mgzn

The conductivity and the Hall effect of three-dimensional Mg xZn100-x glasses are studied as a function of magnetic field (

Determining the origin and age of the Westland beech (Nothofagus) gap, New Zealand, using fungus beetle genetics

The formation and maintenance of the Nothofagus beech gap in the South Island, New Zealand, has been the focus of biogeographical debate since the 1920s. We examine the historical process of gap formation by investigating the population genetics of fungus beetles: Brachynopus scutellaris (Staphylinidae) inhabits logs and is absent from the beech gap, and Hisparonia hystrix (Nitidulidae) is contiguous through the gap and is found commonly on sooty mould growing on several plant species. Both species show distinctive northern and southern haplotype distributions while H. hystrix recolonized the gap as shown by definitive mixing. B. scutellaris shows two major haplotype clades with strong geographical concordance, and unlike H. hystrix, has clearly defined lineages that can be partitioned for molecular dating. Based on coalescence dating methods, disjunct lineages of B. scutellaris indicate that the gap was formed less than 200 000 years ago. Phylogenetic imprints from both species reveal similar patterns of population divergence corresponding to recent glacial cycles, favouring a glacial explanation for the origin of the gap. Post-gap colonization by H. hystrix may have been facilitated by the spread of Leptospermum scoparium host trees to the area, and they may be better at dispersing than B. scutellaris which may be constrained by fungal host and/or microhabitat. The gap-excluded species B. scutellaris is found in both beech and podocarp-broadleaf forests flanking the Westland gap and its absence in the gap may be related to incomplete recolonization following glacial retreat. We also discuss species status and an ancient polymorphism within B. scutellaris