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Flow Anomalies (flow + anomaly)

Distribution by Scientific Domains

Earth and Environmental Science	80%

Selected Abstracts

Decadal variability of the Danube river flow in the lower basin and its relation with the North Atlantic Oscillation

INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 10 2002
Norel Rîmbu
Abstract The decadal variability (>5 years) of the Danube river flow in the lower basin and its connection with the North Atlantic Oscillation (NAO) is analysed for the period 1931,95. Associated linkages with precipitation (PP) in the European sector, global sea surface temperature (SST) and atmospheric circulation for the period 1931,81, and the 500 hPa geopotential heights (G500) over the Northern Hemisphere for the period 1948,95 are also investigated. The results show that there is an out-of-phase relationship between the time series of the Danube river flow anomalies and the NAO index. The time series of a PP index, defined as the average of normalized precipitation anomalies over a large area including the Danube basin, presents a time evolution similar to that of the river flow anomalies. The correlation maps between the river flow anomalies and global SST show coherent large-scale patterns. High values of the Danube river flow are associated with a tripole-like SST structure in the North Atlantic similar to that appearing during the negative phase of the NAO, and with negative SST anomalies in the central North Pacific and positive SST anomalies in the eastern and central tropical Pacific. Physically consistent sea level pressure and 500 hPa geopotential height are obtained. Copyright © 2002 Royal Meteorological Society. [source]

Patterns of convection in the tropical pacific and their influence on New Zealand weather

INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 2 2002
John W. Kidson
Abstract Characteristic patterns of convection in the tropical Pacific Ocean have previously been inferred from analysis of outgoing longwave radiation (OLR), and associated with year-to-year variations in El Niño (EN),Southern Oscillation events. This study examines both the effects of these convection patterns on the New Zealand climate, and the more general influence of tropical convection on the New Zealand sector of the Southern Hemisphere. The Southern Hemisphere circulation, as a whole, is found to be most strongly influenced by equatorial convection near the Philippines, and in a broad band over the central Pacific. Where increased convection occurs west of 160°E, La Niña-like (LN) conditions prevail. When the anomalous convective activity is located near the dateline, in ,moderate' EN conditions, SW flow prevails over New Zealand. This gives way to stronger WSW anomalies as the centre of convection is displaced further eastwards and a second centre of reduced convection becomes prominent west of the dateline in strong EN (EN+) events. The changes in wind regimes over the New Zealand region implied by the hemispheric 1000 hPa height fields are supported by mean sea-level pressure differences between a number of New Zealand and adjacent island stations. Indices of the zonal flow show a weak reduction in strength of the westerlies for LN OLR composites, and no apparent effects for EN composites, whereas EN+ conditions strongly favour above-normal westerlies. The meridional flow over New Zealand is skewed towards more frequent southerlies in both the EN and EN+ composites, whereas LN conditions favour northerly flow anomalies. A change is also observed in the frequency of New Zealand-area ,weather regimes'. Enhanced convection centred on 5°S and east of the dateline, as found in the EN+ composites, leads to an increase in zonal regimes and a corresponding decrease in blocking regimes. The direct influence of tropical OLR variations on New Zealand temperature and precipitation has also been assessed. These indicate that the response is not simply one of degree. Different spatial anomaly patterns in the climatic elements result from the varying regional circulation patterns, and these need to be considered if present climate-forecasting schemes are to be improved. Copyright © 2002 Royal Meteorological Society. [source]

Thermal versus dynamical tropopause in upper-tropospheric balanced flow anomalies

THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 562 2000
V. Wirth
Abstract This paper systematically investigates differences between the thermal and the dynamical tropopause for upper-tropospheric balanced flow anomalies. Idealized cyclonic and anticyclonic anomalies are considered, which are either axisymmetric or plane symmetric. Given a distribution of potential vorticity (PV), the inversion problem is solved numerically to obtain the corresponding balanced flow (i.e. wind and temperature). The control parameter is the aspect ratio of the PV anomaly, which governs the partitioning into a thermal and a dynamical anomaly. For PV anomalies of intermediate and tall aspect ratios, the location of the thermal tropopause differs significantly from the location of the dynamical tropopause. The thermal tropopause is rather indistinct for intermediate aspect ratios, while it is sharp and well defined for both tall and shallow anomalies. A barotropic deformation flow field superimposed on a plane symmetric anomaly induces an ageostrophic wind which modifies the static stability throughout the PV anomaly such that the thermal and dynamical tropopauses evolve differently. Recent observations concerning the correlation between the thermal and ozone tropopauses can be interpreted consistently in terms of the present results. [source]

The Free Cash Flow Anomaly Revisited: Finnish Evidence

JOURNAL OF BUSINESS FINANCE & ACCOUNTING, Issue 7-8 2006
Annukka Jokipii
Abstract:, This paper examines the performance of an investment strategy based on free cash flows using financial statement data of Finnish companies during the period 1992-2002. The analysis in this paper is motivated by the so-called free cash flow anomaly previously documented e.g. in Hackel, Livnat and Rai (2000). Using annual financial statement information, we identify large-capitalization companies with positive free cash flows, low free cash flow multiples, and low financial leverage. Since a portfolio of these companies is found to consistently outperform the market index, our results suggest that the free cash flow anomaly also exists in the Finnish stock market. [source]