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North Atlantic Oscillation (NAO) and insect damage in Serbian forests
Duci? V.,Lukovi? Jelena,Milenkovi? M.,?ur?i? Nina
Archives of Biological Sciences , 2012, DOI: 10.2298/abs1201215d
Abstract: This paper examines the relationship between North Atlantic Oscillation (NAO) and damage made by insects in Serbian forests. The damage has been separated into three groups: bark beetles, gypsy moth and damage made by other insects. For North Atlantic Oscillation the NAO index is used. The period of investigation was 1969-2001. Data were studied on an annual scale as well as with five-year moving averages. Analysis showed a statistically significant correlation for NAO index and gypsy moth.
North Atlantic Oscillation (NAO) and precipitation in Galicia (Spain)
GARCíA, N. O.;GIMENO, L.;DE LA TORRE, L.;NIETO, R.;A?EL, J. A.;
Atmósfera , 2005,
Abstract: in this study we investigate the time-scale at which nao and enso are associated with the precipitation in galicia (northwestern of spain), looking for possible climate predictors. the existence of preferred frequencies in all series was analyzed by using ss a (singular spectral analysis), whereas the statistical significance of the results was checked by using the monte-carlo method. results suggest that nao and precipitation in galicia could be related at a time scale of 8 years whereas the influence of enso is not significant.
Track Patterns of Landfalling and Coastal Tropical Cyclones in the Atlantic Basin, Their Relationship with the North Atlantic Oscillation (NAO), and the Potential Effect of Global Warming  [PDF]
Terrence A. McCloskey, Thomas A. Bianchette, Kam-Biu Liu
American Journal of Climate Change (AJCC) , 2013, DOI: 10.4236/ajcc.2013.23A002
Abstract:

Even though the degree of damage inflicted by North Atlantic tropical cyclones (TCs) is highly dependent upon track location and proximity to land, the spatial characteristics of TCs are generally understudied. We investigated the spatial relationships between landfall locations and track patterns of all Cape Verde-type landfalling and coastal TCs that have affected the continental coastline of the western Atlantic Basin by region for the period 1851-2008. The degree of recurvature for these TCs increases progressively from the Central America/Caribbean coast (CA) through the Gulf of Mexico (GOM), Florida peninsula (FLOR), and Atlantic (ATL) coasts. The date (month) of occurrence shows similar increases from the GOM through ATL. These patterns for landfall location, track pattern, and occurrence date generally follow the intra-seasonal movement and intensity variations of the Bermuda High (BH), as represented by increasing North Atlantic Oscillation (NAO) index values from CA through FLOR. Analysis suggests that the region of landfall is primarily controlled by two factors: the amplitude of track recurvature and the longitude at which recurvature begins to dominate track shape. Both of these important steering controls are predominantly influenced by the strength and position of the BH, with increasing strength and/or more northeasterly position of the BH progressively driving landfall from Central America through the Gulf of Mexico and the Atlantic seaboard out to the open sea. The paleorecord suggests that the latitudinal position of the BH exerts an important control over the location of hurricane landfall along the western North Atlantic on millennial time scales. This suggests that global warming may result in a northern shift in TC tracks and increased frequency of landfalls in northern locations.

Variability of the ocean carbon cycle in response to the North Atlantic Oscillation  [cached]
Kathrin M. Keller,Fortunat Joos,Christoph C. Raible,Valentina Cocco
Tellus B , 2012, DOI: 10.3402/tellusb.v64i0.18738
Abstract: Climate modes such as the North Atlantic Oscillation (NAO), representing internal variability of the climate system, influence the ocean carbon cycle and may mask trends in the sink of anthropogenic carbon. Here, utilising control runs of six fully coupled Earth System Models, the response of the ocean carbon cycle to the NAO is quantified. The dominating response, a seesaw pattern between the subtropical gyre and the subpolar Northern Atlantic, is instantaneous (<3 months) and dynamically consistent over all models and with observations for a range of physical and biogeochemical variables. All models show asymmetric responses to NAO+ and NAO forcing, implying non-linearity in the connection between NAO and the ocean carbon cycle. However, model differences in regional expression and magnitude and conflicting results with regard to air–sea flux and CO2 partial pressure remain. Typical NAO-driven variations are ±10 mmol/m3 in the surface concentration of dissolved inorganic carbon and alkalinity and ±8 ppm in the air–sea partial pressure difference. The effect on the basin-wide air–sea CO2 flux is small due to compensating fluxes on the sub-basin scale. Two models show a reduced carbon sink in the north-eastern North Atlantic during negative NAO phases, qualitatively in accordance with the observed decline during a phase of predominantly negative NAO. The results indicate that wind-driven dynamics are the main driver of the response to the NAO, which – via vertical mixing, upwelling and the associated entrainment of dissolved inorganic carbon and nutrients – leave an imprint on surface pCO2 and the air–sea CO2 flux as well as on biological export production, pH and the calcium carbonate saturation state. The biogeochemical response to the NAO is predominantly governed by vertical exchange between the surface and the thermocline; large-scale horizontal transport mechanisms are of minor importance.
Teleconnections of Inter-Annual Streamflow Fluctuation in Slovakia with Arctic Oscillation, North Atlantic Oscillation, Southern Oscillation, and Quasi-Biennial Oscillation Phenomena
Pavla PEKAROVA,Jan PEKAR,
Pavla PEKAROVA
,Jan PEKAR

大气科学进展 , 2007,
Abstract: The aim of the paper is to analyze a possible teleconnection of Quasi-Biennial Oscillation (QBO), Southern Oscillation (SO), North Atlantic Oscillation (NAO), and Arctic Oscillation (AO) phenomena with longterm streamflow fluctuation of the Bela River (1895-2004) and Cierny Hron River (1931-2004) (central Slovakia). Homogeneity, long-term trends, as well as inter-annual dry and wet cycles were analyzed for the entire 1895-2004 time series of the Bela River and for the 1931-2004 time series of the Cierny Hron River.Inter-annual fluctuation of the wet and dry periods was identified using spectral analysis. The most significant period is that of 3.6 years. Other significant periods are those of 2.35 years, 13.5 years, and 21 years.Since these periods were found in other rivers of the world, as well as in SO, NAO, and AO phenomena,they can be considered as relating to the general regularity of the Earth.
Is the decadal variability in the tropical Atlantic a precursor to the NAO?
I. Wainer, J. Servain,G. Clauzet
Annales Geophysicae (ANGEO) , 2008,
Abstract: In the past two decades climate research in the tropical Atlantic with respect to the inter-hemispheric gradient of sea surface temperature (SST) emphasized the predominance of decadal-scale variability. Our results show that this mode of variability is prevalent only for part of the last 130-years record (the 1880s, the 1920s and, especially, the 1970s). There is a lag of a few months between the decadal variations of the inter-hemispheric gradient of SST and the decadal variability of the North Atlantic Oscillation (NAO). This seems to indicate that the 10-year variability first develops in the tropics and then propagates polewards. The inter-hemispheric gradient of SST mode should be thought as episodic and not as a periodic oscillation.
The response of Iberian rivers to the North Atlantic Oscillation
J. Lorenzo-Lacruz, S. M. Vicente-Serrano, J. I. López-Moreno, J. C. González-Hidalgo,E. Morán-Tejeda
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2011,
Abstract: In this study we analyzed the influence of the North Atlantic Oscillation (NAO) on the streamflow in 187 sub-basins of the Iberian Peninsula. Monthly and one-month lagged correlations were conducted to assess the spatio-temporal extent of the NAO influence on Iberian river discharges. Analysis of the persistence of the winter NAO throughout the year was also undertaken, together with analysis of streamflow anomalies during positive and negative NAO phases. Moving-window correlation analyses were conducted to assess potential changes in the temporal evolution of the NAO influence on Iberian streamflows. The results show that the NAO has a large impact on surface water resources throughout the Iberian Peninsula during winter, and in the Atlantic watershed during autumn. We showed that water resources management and snowmelt are causing the persistent dependence of streamflows on the previous winter NAO. We found that strongly positive streamflow anomalies occurred during winter, especially in the Atlantic watershed, and provide evidence of non-stationarity and spatial variability in the NAO influence on Iberian water resources.
The response of Iberian rivers to the North Atlantic Oscillation
J. Lorenzo-Lacruz,S. M. Vicente-Serrano,J. I. López-Moreno,J. C. González-Hidalgo
Hydrology and Earth System Sciences Discussions , 2011, DOI: 10.5194/hessd-8-4459-2011
Abstract: In this study we analyzed the influence of the North Atlantic Oscillation (NAO) on the streamflow in 187 sub-basins of the Iberian Peninsula. Monthly and one-month lagged correlations were conducted to assess the spatio-temporal extent of the NAO influence on Iberian river discharges. Analysis of the persistence of the winter NAO throughout the year was also undertaken, together with analysis of streamflow anomalies during positive and negative NAO phases. Moving-window correlation analyses were conducted to assess potential changes in the temporal evolution of the NAO influence on Iberian streamflows. The results show that the NAO has a large impact on surface water resources throughout the Iberian Peninsula during winter, and in the Atlantic watershed during autumn. We showed that water resources management and snowmelt are causing the persistent dependence of streamflows on the previous winter NAO. We found that strongly positive streamflow anomalies occurred during winter, especially in the Atlantic watershed, and provide evidence of non-stationarity and spatial variability in the NAO influence on Iberian water resources.
Interannual and interdecadal variations in the North Atlantic Oscillation spatial shift
XiaoJian Zhang,LiYa Jin,ChunZhu Chen,DongSheng Guan,MingZhi Li
Chinese Science Bulletin , 2011, DOI: 10.1007/s11434-011-4607-8
Abstract: The spatial shift of the North Atlantic Oscillation (NAO) is analyzed by using the Twentieth Century Reanalysis version 2 dataset and identifying NAO action centers directly on winter mean sea-level pressure (SLP) anomaly maps. The spatial shift of the NAO is characterized by four NAO spatial shift indices: the zonal and meridional shifts of the NAO southern and northern action centers. It is found that the zonal and meridional shift trends of the NAO action centers move along a path of southwest-northwest direction. Spectral analysis shows that the four NAO spatial shift indices have periodicity of 2–6 years and the NAO index has periodicity of 2–3 years in terms of high-frequency variations. On a decadal time scale, the NAO spatial shift indices are closely (positively) related to the NAO index, which is in agreement with previous studies of the relationship between the NAO index and the spatial shift of the NAO pattern. However, there is no relationship between the NAO index and the meridional shift of the northern action center on an interannual time scale. The significant relationship between the NAO index and the interannual variability of NAO spatial shift indices is very likely to be associated with synoptic-scale Rossby wave breaking, which generates surface pressure anomalies and thus affects the phase and pattern of the NAO. The correlations of winter westerly winds over 90°W-0° and the NAO index and the NAO spatial shift indices have a ‘+ + ’ structure from the Equator to the North Pole. Although there is close correlation between the NAO spatial shift indices and the strength of the zonal winds in the North Atlantic region, the effect of the zonal winds on the NAO spatial shift differs at different latitudes. Hence, the role of the zonal winds is probably a result of the NAO spatial shifts.
The North Atlantic Oscillation controls air pollution transport to the Arctic
S. Eckhardt, A. Stohl, S. Beirle, N. Spichtinger, P. James, C. Forster, C. Junker, T. Wagner, U. Platt,S. G. Jennings
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2003,
Abstract: This paper studies the interannual variability of pollution pathways from northern hemisphere (NH) continents into the Arctic. Using a 15-year model simulation of the dispersion of passive tracers representative of anthropogenic emissions from NH continents, we show that the North Atlantic Oscillation (NAO) exerts a strong control on the pollution transport into the Arctic, particularly in winter and spring. For tracer lifetimes of 5 (30) days, surface concentrations in the Arctic winter are enhanced by about 70% (30%) during high phases of the NAO (in the following referred to as NAO+) compared to its low phases (NAO-). This is mainly due to great differences in the pathways of European pollution during NAO+ and NAO- phases, respectively, but reinforced by North American pollution, which is also enhanced in the Arctic during NAO+ phases. In contrast, Asian pollution in the Arctic does not significantly depend on the NAO phase. The model results are confirmed using remotely-sensed NO2 vertical atmospheric columns obtained from seven years of satellite measurements, which show enhanced northward NO2 transport and reduced NO2 outflow into the North Atlantic from Central Europe during NAO+ phases. Surface measurements of carbon monoxide (CO) and black carbon at high-latitude stations further corroborate the overall picture of enhanced Arctic pollution levels during NAO+ phases
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