The timing of arrival of 81 migratory species in response to the North Atlantic Oscillation (NAO) was studied at two Finnish bird observatories (1970 /99). Timing was determined for the first migrants and for the peak of migration, as well as for the early, median and late phases of migration, defined as the dates when the seasonal cumulative sum of birds reached 5%, 50% and 95%, respectively. ...

Using four different climate models, we investigate sea level pressure variability in the extratropical North Atlantic in the preindustrial climate (1750AD) and at the Last Glacial Maximum (LGM, 21 kyrs before present) in order to understand how changes in atmospheric circulation can affect signals recorded in climate proxies. In general, the models exhibit a significant reduction in interannua...

Amidst stormy atmospheric circulation, there are prominent recurrent patterns of variability in the planetary circulation, such as the Antarctic Oscillation (AAO), Arctic Oscillation (AO) or North Atlantic Oscillation (NAO), and the Pacific–North America (PNA) pattern. The role of the synoptic eddy and low-frequency flow (SELF) feedback in the formation of these dominant low-frequency modes is ...

1. Increases in global temperatures have created concern about effects of climatic variability on populations, and climate has been shown to affect population dynamics in an increasing number of species. Testing for effects of climate on population densities across a species' distribution allows for elucidation of effects of climate that would not be apparent at smaller spatial scales. 2. Using...

A simple theoretical model is proposed to clarify how synoptic-scale waves drive the life cycle of the North Atlantic Oscillation (NAO) with a period of nearly two weeks. This model is able to elucidate what determines the phase of the NAO and an analytical solution is presented to indicate a high similarity between the dynamical processes of the NAO and zonal index, which is not derived analyt...

Abstract The atmospheric impact on sea level variability in the Baltic Sea different time scales was investigated. Northern Hemisphere teleconnection patterns, namely, North Atlantic Oscillation (NAO), Arctic (AO) and Scandinavia (SCAND) were employed, a strong but non-stationary relationship found. SCAND appeared to be most relevant mean monthly variations throughout year. A negative correlati...

Abstract Based on the database of Subseasonal to Seasonal (S2S) Prediction project World Weather Research Programme (WWRP) / Climate (WCRP), influence North Atlantic Oscillation (NAO) Madden- Julian (MJO) and its forecast skill is investigated. It found that most models can capture MJO phase changes following positive negative NAO events. About 20 days after initialized with a (negative) NAO, a...

The anomalously wet winter of 2010 had a very important impact on the Portuguese hydrological system. Owing to the detrimental effects of reduced precipitation in Portugal on the environmental and socio-economic systems, the 2010 winter was predominantly beneficial by reversing the accumulated precipitation deficits during the previous hydrological years. The recorded anomalously high precipita...

We performed population genetic analyses on the American eel (Anguilla rostrata) with three main objectives. First, we conducted the most comprehensive analysis of neutral genetic population structure to date to revisit the null hypothesis of panmixia in this species. Second, we used this data to provide the first estimates of contemporary effective population size (Ne ) and to document tempora...