Empirical and modeled synoptic cloud climatology of the Arctic Ocean

A daily climatology of the atmospheric circulation of the Arctic and the associated cloud conditions were determined. These are used for comparisons with the variability of general circulation model, generated circulation, and cloud cover for the same region

Rediscovery and status of Cylindera (s. str.) lunalonga (Schaupp, 1884) (Coleoptera: Carabidae: Cicindelinae) in the San Joaquin Valley of California with a comparison to a Sierra Nevada population

Surveys for adult Cylindera (s. str.) lunalonga (Schaupp) (Coleoptera: Carabidae: Cicindelinae) were conducted between 2001 and 2011 at over 80 sites throughout the species’ historic range in the San Joaquin Valley and Sierra Nevada Mountains of California. Previously considered extirpated from the Valley, these surveys resulted in finding adults at 18 sites, several with large populations (>50 individuals). As suggested by historic records, our studies confirmed that the Valley populations of Cy. lunalonga occur in what were historically wetland sites, but are now lowland agricultural croplands. Adults were always associated with wet, muddy soil within and along the edges of irrigation ditches. A comparison of morphology, behavior, habitat, and conservation is made with the only known extant Sierra Nevada population

Cloud cover determination in polar regions from satellite imagery

A definition is undertaken of the spectral and spatial characteristics of clouds and surface conditions in the polar regions, and to the creation of calibrated, geometrically correct data sets suitable for quantitative analysis. Ways are explored in which this information can be applied to cloud classifications as new methods or as extensions to existing classification schemes. A methodology is developed that uses automated techniques to merge Advanced Very High Resolution Radiometer (AVHRR) and Scanning Multichannel Microwave Radiometer (SMMR) data, and to apply first-order calibration and zenith angle corrections to the AVHRR imagery. Cloud cover and surface types are manually interpreted, and manual methods are used to define relatively pure training areas to describe the textural and multispectral characteristics of clouds over several surface conditions. The effects of viewing angle and bidirectional reflectance differences are studied for several classes, and the effectiveness of some key components of existing classification schemes is tested

Cloud cover determination in polar regions from satellite imagery

The principal objectives of this project are: (1) to develop suitable validation data sets to evaluate the effectiveness of the International Satellite Cloud Climatology Project (ISCCP) operational algorithm for cloud retrieval in polar regions and to validate model simulations of polar cloud cover; (2) to identify limitations of current procedures for varying atmospheric surface conditions, and to explore potential means to remedy them using textural classifiers; and (3) to compare synoptic cloud data from a control run experiment of the GISS climate model II with typical observed synoptic cloud patterns

Pilot study and evaluation of a SMMR-derived sea ice data base

Data derived from the Nimbus 7 scanning multichannel microwave radiometer (SMMR) are discussed and the types of problems users have with satellite data are documented. The development of software for assessing the SMMR data is mentioned. Two case studies were conducted to verify the SMMR-derived sea ice concentrations and multi-year ice fractions. The results of a survey of potential users of SMMR data are presented, along with SMMR-derived sea ice concentration and multiyear ice fraction maps. The interaction of the Arctic atmosphere with the ice was studied using the Nimbus 7 SMMR. In addition, the characteristics of ice in the Arctic ocean were determined from SMMR data

Vapour flux divergence and moisture budget calculations for Labrador-Ungava

L'auteur emploie les données aérologiques des deux saisons hivernales 1956-57 et 1957-58 pour estimer le bilan d'humidité.Il évalue la divergence du flux de vapeur d'eau entre la surface et 500 mh. suivant deux méthodes. La première consiste à déterminer la divergence horizontale à partir de cartes des composantes du flux (en employant une grille latitude — longitude). Il y a une bonne corrélation entre la répartition des précipitations mensuelles en hiver et les cartes de divergence de flux quoique, sauf dans le sud-est, les pertes par évaporation semblent trop faibles. La seconde méthode, basée sur les relevés à huit niveaux dans le triangle Stephenville - Goose - Sept-Iles donne de moins bons résultats.L'auteur compare ensuite la divergence turbulente du Hux de vapeur d'eau, suivant la première méthode, avec une évaluation de la différence entre les précipitations et l'évaporation ; la corrélation entre les évaluations aérologiques et de surface dans le Labrador - Ungava n'est pas aussi bonne qu'on aurait pu l'espérer.For the two winter seasons 1956-57 and 1957-58, the author uses aerological data to estimate the moisture budget for the Labrador - Ungava peninsula.Two methods of estimating the vapour flux-divergence between the surface and 500 mb. are described. In the first, the horizontal divergence is determined from separate maps of the flux components with reference to a latitude - longitude grid. A comparison of the resulting maps of flux-divergence with the winter maps of mean monthly precipitation show an agreement in pattern, although allowing for evaporation losses, the amounts appear to be generally too low except in the south-east. The second method, using a triangle technique (Stephenville - Goose - Sept- Iles) at eight levels proved less reliable. A detailed comparison is made of estimates of the total and eddy flux-divergence (based on the first method) and precipitation minus evaporation estimates, and significant differences are discussed. The results show that correspondence between aerological and surface estimate of precipitation minus evaporation a Labrador - Ungava is not as satisfactory as might be hoped

GOVERNMENT REVENUES AND EXPENDITURES IN GUINEA-BISSAU: CAUSALITY AND COINTEGRATION

The paper establishes empirically the temporal causality and long run relationship between government expenditures and government revenues for the case of Guinea-Bissau - a low income country under stress (LICUS) in Africa. A macroeconomic model is developed to lay out the hypothesis of a spend-tax behavior in the country¡¯s public finances management system. Empirical validation is carried out by means of a traditional Granger-causality test and the estimation of an error correction model between expenditures and revenues.Public Finances, Causality Tests, Cointegration Analysis

Composing Scalable Nonlinear Algebraic Solvers

Most efficient linear solvers use composable algorithmic components, with the most common model being the combination of a Krylov accelerator and one or more preconditioners. A similar set of concepts may be used for nonlinear algebraic systems, where nonlinear composition of different nonlinear solvers may significantly improve the time to solution. We describe the basic concepts of nonlinear composition and preconditioning and present a number of solvers applicable to nonlinear partial differential equations. We have developed a software framework in order to easily explore the possible combinations of solvers. We show that the performance gains from using composed solvers can be substantial compared with gains from standard Newton-Krylov methods.Comment: 29 pages, 14 figures, 13 table