Effects of the North Atlantic Oscillation (NAO) on combined temperature and precipitation winter modes in the Mediterranean mountains: Observed relationships and projections for the 21st century

2011 ◽  
Vol 77 (1-2) ◽  
pp. 62-76 ◽  
Author(s):  
J.I. López-Moreno ◽  
S.M. Vicente-Serrano ◽  
E. Morán-Tejeda ◽  
J. Lorenzo-Lacruz ◽  
A. Kenawy ◽  
...  
Keyword(s):  
North Atlantic Oscillation ◽  
21St Century ◽  
North Atlantic ◽  
The North ◽  
Temperature And Precipitation ◽  
Mediterranean Mountains ◽  
The North Atlantic ◽  
The Mediterranean ◽  
The North Atlantic Oscillation

scholarly journals Cyclones causing wind storms in the Mediterranean: characteristics, trends and links to large-scale patterns

2010 ◽  
Vol 10 (7) ◽  
pp. 1379-1391 ◽  
Author(s):  
K. M. Nissen ◽  
G. C. Leckebusch ◽  
J. G. Pinto ◽  
D. Renggli ◽  
S. Ulbrich ◽  
...  
Keyword(s):  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Positive Phase ◽  
East Atlantic ◽  
The North ◽  
The North Atlantic ◽  
Wind Storms ◽  
The Mediterranean ◽  
Wind Events ◽  
The North Atlantic Oscillation

Abstract. A climatology of cyclones with a focus on their relation to wind storm tracks in the Mediterranean region (MR) is presented. Trends in the frequency of cyclones and wind storms, as well as variations associated with the North Atlantic Oscillation (NAO), the East Atlantic/West Russian (EAWR) and the Scandinavian variability pattern (SCAND) are discussed. The study is based on the ERA40 reanalysis dataset. Wind storm tracks are identified by tracking clusters of adjacent grid boxes characterised by extremely high local wind speeds. The wind track is assigned to a cyclone track independently identified with an objective scheme. Areas with high wind activity – quantified by extreme wind tracks – are typically located south of the Golf of Genoa, south of Cyprus, southeast of Sicily and west of the Iberian Peninsula. About 69% of the wind storms are caused by cyclones located in the Mediterranean region, while the remaining 31% can be attributed to North Atlantic or Northern European cyclones. The North Atlantic Oscillation, the East Atlantic/West Russian pattern and the Scandinavian pattern all influence the amount and spatial distribution of wind inducing cyclones and wind events in the MR. The strongest signals exist for the NAO and the EAWR pattern, which are both associated with an increase in the number of organised strong wind events in the eastern MR during their positive phase. On the other hand, the storm numbers decrease over the western MR for the positive phase of the NAO and over the central MR during the positive phase of the EAWR pattern. The positive phase of the Scandinavian pattern is associated with a decrease in the number of winter wind storms over most of the MR. A third of the trends in the number of wind storms and wind producing cyclones during the winter season of the ERA40 period may be attributed to the variability of the North Atlantic Oscillation.

scholarly journals Seasonal Climate Trends, the North Atlantic Oscillation, and Salamander Abundance in the Southern Appalachian Mountain Region

2010 ◽  
Vol 49 (8) ◽  
pp. 1597-1603 ◽  
Author(s):  
Robert J. Warren ◽  
Mark A. Bradford
Keyword(s):  
North Atlantic Oscillation ◽  
North Atlantic ◽  
The North ◽  
Temperature And Precipitation ◽  
Southern Appalachian ◽  
Southern Appalachian Mountain ◽  
The North Atlantic ◽  
The North Atlantic Oscillation ◽  
Precipitation Trends

Abstract The North Atlantic Oscillation (NAO) is a large-scale climate teleconnection that coincides with worldwide changes in weather. Its impacts have been documented at large scales, particularly in Europe, but not as much at regional scales. Furthermore, despite documented impacts on ecological dynamics in Europe, the NAO’s influence on North American biota has been somewhat overlooked. This paper examines long-term temperature and precipitation trends in the southern Appalachian Mountain region—a region well known for its biotic diversity, particularly in salamander species—and examines the connections between these trends and NAO cycles. To connect the NAO phase shifts with southern Appalachian ecology, trends in stream salamander abundance are also examined as a function of the NAO index. The results reported here indicate no substantial long-term warming or precipitation trends in the southern Appalachians and suggest a strong relationship between cool season (November–April) temperature and precipitation and the NAO. More importantly, trends in stream salamander abundance are best explained by variation in the NAO as salamanders are most plentiful during the warmer, wetter phases.

scholarly journals Asian Jet Waveguide and a Downstream Extension of the North Atlantic Oscillation

2004 ◽  
Vol 17 (24) ◽  
pp. 4674-4691 ◽  
Author(s):  
Masahiro Watanabe
Keyword(s):  
East Asia ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Wave Train ◽  
East Asian ◽  
The North ◽  
The North Atlantic ◽  
The Mediterranean ◽  
The North Atlantic Oscillation ◽  
Asian Jet Waveguide

Abstract Anomalous atmospheric fields associated with the North Atlantic Oscillation (NAO) are analyzed on interannual and intraseasonal time scales in order to examine the extent to which the NAO is a regional phenomenon. Analyses on the interannual time scale reveal that the NAO signal is relatively confined to the Euro–Atlantic sector in December while it extends toward East Asia and the North Pacific in February. The difference is most clearly seen in the meridional wind anomaly, which shows a wave train along the Asian jet, collocated with an anomalous vorticity source near the jet entrance. Diagnoses using a linear barotropic model indicate that this wave train is interpreted as quasi-stationary Rossby waves trapped on the Asian jet waveguide, and effectively excited by the anomalous upper-level convergence over the Mediterranean Sea. It is found that, when the NAO accompanies the Mediterranean convergence (MC) anomaly, most frequently seen in February, the NAO indeed has a much wider horizontal structure than the classical picture, rather similar to the Arctic Oscillation. In such cases interannual variability of the NAO is tied to the East Asian climate variability such that the positive NAO tends to bring a surface warming over East Asia. Similar results are obtained from an analysis of individual NAO events based on low-pass-filtered daily fields, which additionally identified that the downstream extension occurs at the decay stage of the NAO event and the MC anomaly appears to be induced by the Ekman pumping associated with the NAO. The signal of the MC anomaly can be detected even at 5 days before the peak of the NAO, suggesting that the NAO influence to East Asia is predictable to some extent; therefore, monitoring the developing NAO event is useful to the medium-range weather forecast in East Asian countries.

Influence of climate drivers and the North Atlantic Oscillation on beech growth at marginal sites across the Mediterranean

2015 ◽  
Vol 66 (3) ◽  
pp. 229-242 ◽  
Author(s):  
K Chen ◽  
I Dorado-Liñán ◽  
L Akhmetzyanov ◽  
G Gea-Izquierdo ◽  
T Zlatanov ◽  
...  
Keyword(s):  
North Atlantic Oscillation ◽  
North Atlantic ◽  
The North ◽  
The North Atlantic ◽  
The Mediterranean ◽  
The North Atlantic Oscillation

scholarly journals Effect of large-scale modes of total variability of the atmosphere and ocean in the Atlantic-European region on the climate of Belarus

2020 ◽  
Vol 64 (5) ◽  
pp. 609-616
Author(s):  
S. A. Lysenko ◽  
V. F. Loginov ◽  
I. V. Buyakov
Keyword(s):  
North Atlantic Oscillation ◽  
Air Temperature ◽  
North Atlantic ◽  
Large Scale ◽  
European Region ◽  
The North ◽  
Temperature And Precipitation ◽  
Acceleration And Deceleration ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

We have established the relationships of quasicyclic components in changes of air temperature and precipitation in Belarus with large-scale modes of general variability of the atmosphere and ocean in the Atlantic-European region. When the summer air temperature changes in Belarus and in Eastern Europe, a quasi-60-year oscillation is identified, which coincides in phase with the Atlantic multi-decadal oscillation. It is shown that the time series of winter air temperature in Belarus contain a quasi-8-year component synchronized with a similar component of the North Atlantic Oscillation. Moreover, the periods of acceleration and deceleration of winter warming in Belarus coincide with the upward and downward quasi-30-year phases of the North Atlantic Oscillation, respectively. The latter are also consistent with fluctuations in moisture content in Belarus and Europe. Based on the established patterns, we have concluded that the rapid rise in winter temperatures, slowing down of summer warming and deterioration in water supply in the southern regions of Belarus observed in the last decade are part of a natural cycle lasting about 30 years, developing against the background of a long-term trend of anthropogenic global warming. 

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