Assessment of the impact of the planetary scale on the decay of blocking and the use of phase diagrams and enstrophy as a diagnostic

It was shown that abrupt changes in the large-scale structure of atmospheric flows may lead to the rapid decay of blocking. Analysis of phase diagrams made it possible to identify when sharp changes occurred in the dynamics of the system. The connection of these changes to the decay of blocking was estimated for three blocking events in the Southern Hemisphere. In addition to phase diagrams, enstrophy was used as a diagnostic tool for the analysis of blocking events. From the results of this analysis, four scenarios for the decay mechanisms were determined: (i) decay with a lack of synoptic-scale support, (ii) decay with an active role for synoptic processes, and (iii–iv) either of these mechanisms in the interaction with an abrupt change in the character of the planetary-scale flow.     

Mass-radius relationships and constraints on the composition of Pluto,II

A new estimate of Pluto's mass within the range of possible masses considered in an earlier work has enabled us to refine our model of Pluto's interior.     

Small-Mammal Data on Early and Middle Holocene Climates and Biotic Communities in the Bonneville Basin, USA

Archaeological investigations in Camels Back Cave, western Utah, recovered a series of small-mammal bone assemblages from stratified deposits dating between ca. 12,000 and 500 ¹⁴C yr B.P. The cave's early Holocene fauna includes a number of species adapted to montane or mesic habitats containing grasses and/or sagebrush (e.g., Lepus townsendii, Marmota flaviventris, Reithrodontomys megalotis, and Brachylagus idahoensis) which suggest that the region was relatively cool and moist until after 8800 ¹⁴C yr B.P. Between ca. 8600 and 8100 ¹⁴C yr B.P. these mammals became locally extinct, taxonomic diversity declined, and there was an increase in species well-adapted to xeric, low-elevation habitats, including ground squirrels, Lepus californicus and Neotoma lepida. The early small-mammal record from Camels Back Cave is similar to the 11,300–6000 ¹⁴C yr B.P. mammalian sequence from Homestead Cave, northwestern Utah, and provides corroborative data on Bonneville Basin paleoenvironments and mammalian responses to middle Holocene desertification.     

Climatological features of blocking anticyclones: a study of Northern Hemisphere CCM1 model blocking events in present-day and double CO2 concentration atmospheres

 Using output made with the National Center for Atmospheric Research (NCAR) Community Climate Model Version 1 (CCM1), the characteristics of blocking events over the Northern Hemisphere in a ten-year present day control simulation with a CO₂ concentration of 330 ppm were compared to those in a previously analyzed observational three-year climatology. The characteristics of blocking events in a double present-day CO₂ concentration simulation were then compared to those in the control simulation in order to evaluate how these characteristics might change in an increased CO₂ atmosphere. The results demonstrated that in the Northern Hemisphere the CCM1 correctly simulated many characteristics of blocking events such as average annual number of occurrences, annual variations is size and intensity, and preferred formation regions. A more detailed analysis (i.e., by region and season) revealed some differences between the CCM1 and observed blocking events for characteristics such as mean frequency of occurrence, intensity, size and duration. In addition, the model failed to capture adequately the occurrence of blocking events over the western Asian continent. A comparison of the double CO₂ concentration run to the control showed that, in general, blocking events were more persistent and weaker, but of similar size in the increased CO₂ atmosphere. Also, some statistically significant regional and seasonally dependent changes were found in the frequency of occurrence, duration, and intensity. Finally, a correlation between block size and intensity, significant at the 99% confidence level, was found in each climatology. This result is similar to a correlation found in the analysis of observations. Received: 8 May 1995 / Accepted: 20 September 1996     

The Bonneville Estates Rockshelter rodent fauna and changes in Late Pleistocene–Middle Holocene climates and biogeography in the Northern Bonneville Basin,USA

Excavations at Bonneville Estates Rockshelter, Nevada recovered rodent remains from stratified deposits spanning the past ca. 12,500 ¹⁴C yr BP (14,800 cal yr BP). Specimens from horizons dating to the late Pleistocene and early Holocene include species adapted to montane and moist and cool habitats, including yellow-bellied marmot (Marmota flaviventris) and bushy-tailed woodrat (Neotoma cinerea). Shortly after 9000 ¹⁴C BP (10,200 cal yr BP) these mammals became locally extinct, or nearly so, taxonomic diversity declined, and the region became dominated by desert woodrats (Neotoma lepida) and other species well-adapted to xeric, low-elevation settings. The timing and nature of changes in the Bonneville Estates rodent fauna are similar to records reported from nearby Homestead and Camels Back caves and provide corroborative data on terminal Pleistocene–early Holocene environments and mammalian responses to middle Holocene desertification. Moreover, the presence of northern pocket gopher (Thomomys talpoides) at Bonneville Estates adds to a sparse regional record for that species and, similar to Homestead Cave, it appears that the ca. 9500 ¹⁴C yr BP (10,800 cal yr BP) replacement of the northern pocket gopher by Botta's pocket gopher in the Great Salt Lake Desert vicinity was also in response to climate change.     

Heavy load and high potential: anthropogenic pressures and their impacts on the water quality along a lowland river (Western Bug,Ukraine)

A pronounced pollution of surface water bodies in the Western Bug River Basin, Ukraine, has been caused by outdated or overloaded wastewater treatment plants, agriculture, industry and coal mining. These pressures have led to a generally poor state of both chemical and microbiological variables creating health risks of various kinds. The state of surface water quality for the Western Bug and five main tributaries was assessed by measuring physical, chemical and microbiological indicators during field campaigns in autumn 2009 and spring 2010. Longitudinal profiles were sampled to identify major sources of pollution and to reveal dominant processes of matter turnover. In addition, the occurrence of antibiotic resistant strains in isolates from stations along the Bug River was investigated. Results clearly underpin the negative impact of the Poltva River as a major source of pollution for the Bug River and further outline an elevated potential health risk from pathogenic bacteria originating from this source. Despite these devastating impacts, a high elimination potential of the Bug River with respect to primary organic loads as well as elimination of pathogenic bacteria was observed particularly at Dobrotvir Reservoir. Further downstream, pollution is kept high because of untreated waste effluents and phytoplankton mass developments due to high phosphorus concentrations.     

Geomechanical properties of sandy soil near Scanzano Jonico (Basilicata, Italy)

The soils of the Ionian coastal zone, except those in proximity to Taranto where overconsolidated clays outcrop, are not currently well known from the perspective of their physical characteristics and mechanical behaviour. This note report a series of data from laboratory and on site tests (SPT and CPT) that have made it possible to undertake interesting quantitative comparisons as well as verifying some correlations proposed in the literature. The results show how to deal with, at least for more obviously sandy soils, medium and/or high density sands, to which can be attributed friction angles even of the order of 40° and greater, while the soils nearer the surface show notable variability related to the presence of soils with finer grain size distribution.     

The importance of choosing precipitation datasets

Precipitation data are important for hydrometeorological analyses, yet there are many ways to measure precipitation. The impact of station density analysed by the current study by comparing measurements from the Missouri Mesonet available via the Missouri Climate Center and Community Collaborative Rain, Hail, and Snow (CoCoRaHS) measurements archived at the program website. The CoCoRaHS data utilize citizen scientists to report precipitation data providing for much denser data resolution than available through the Mesonet. Although previous research has shown the reliability of CoCoRaHS data, the results here demonstrate important differences in details of the spatial and temporal distribution of annual precipitation across the state of Missouri using the two data sets. Furthermore, differences in the warm and cold season distributions are presented, some of which may be related to interannual variability such as that associated with the El Niño and Southern Oscillation. The contradictory results from two widely‐used datasets display the importance in properly choosing precipitation data that have vastly differing temporal and spatial resolutions. With significantly different yearly aggregated precipitation values, the authors stress caution in selecting 1 particular rainfall dataset as conclusions drawn could be unrepresentative of the actual values. This issue may be remediated by increased spatiotemporal coverage of precipitation data.     

The role of short-wave troughs on the formation and development of sea-effect snowbands in the western Black Sea

Theoretical and Applied Climatology - The short waves (less than 6000 km) embedded within the long waves and the resulting short-wave troughs have an effect on the sea-effect snow (SES)....     

Mass-radius relationships in icy satellites after voyager

Using improved data for the masses and radii of the satellites of Jupiter and Saturn, models accounting for self-compression effects are presented for the interiors of Europa, Ganymede, Callisto, Rhea, and Titan. For the differentiated models, two different possible scenarios for heat transport are treated, as well as two different compositions for the silicate component. Undifferentiated models are also treated. In each case, the models of Ganymede, Callisto, and Titan show noticeable similarities. It is found that estimates of the ice-rock ratio are dependent upon the assumptions made about the heat transport mechanisms, the rock composition, and on the distribution of rock and ice in the satellite's interior.