scholarly journals Influence of Global Weather Conditions on Timing of the Spring Migration of Birds in the Kaniv Nature Reserve (Central Ukraine)

2019 ◽  
Vol 53 (2) ◽  
pp. 141-148
Author(s):  
V. N. Grishchenko
Keyword(s):  
North Atlantic Oscillation ◽  
Southern Africa ◽  
North Atlantic ◽  
Short Distance ◽  
Nature Reserve ◽  
Bird Species ◽  
Weather Conditions ◽  
Spring Migration ◽  
Intermediate Group ◽  
Wintering Birds

Abstract I studied the effect of North Atlantic Oscillation (NAO) on the phenology of spring migration of birds in Central Ukraine. Data for arrival and departure of 92 species collected in 1987 to 2018 were used. The statistically significant correlation was found for 33 (35.9 %) bird species. 50 coefficients were negative (82.0 %) and 11 ones — positive (18.0 %). The majority of relationships have been shown in February (12) and March (22). In April, they became more rarely (5). There was only one significant value for January and May. For 20 species correlations were found with averaged indices including three months (January to March). The relationships with NAO indices were much commoner for the short-distance migrants (63.3 % of studied species) than for birds wintering in tropical and Southern Africa (20.5 %) and the intermediate group (18.8 %). Wintering birds showed 8 significant coefficients in 3 species (42.9 %). Statistically significant coefficients of correlation ranged in absolute values from 0.35 to 0.80. The average absolute values were very close for different groups of species. The overall mean made 0.50 ± 0.01 (n = 61).

scholarly journals Nonlinear time series models for the North Atlantic Oscillation

2020 ◽  
Vol 6 (2) ◽  
pp. 141-157
Author(s):  
Thomas Önskog ◽  
Christian L. E. Franzke ◽  
Abdel Hannachi
Keyword(s):  
Time Series ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Nonlinear Models ◽  
Weather Conditions ◽  
Dominant Mode ◽  
Statistical Properties ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

Abstract. The North Atlantic Oscillation (NAO) is the dominant mode of climate variability over the North Atlantic basin and has a significant impact on seasonal climate and surface weather conditions. This is the result of complex and nonlinear interactions between many spatio-temporal scales. Here, the authors study a number of linear and nonlinear models for a station-based time series of the daily winter NAO index. It is found that nonlinear autoregressive models, including both short and long lags, perform excellently in reproducing the characteristic statistical properties of the NAO, such as skewness and fat tails of the distribution, and the different timescales of the two phases. As a spin-off of the modelling procedure, we can deduce that the interannual dependence of the NAO mostly affects the positive phase, and that timescales of 1 to 3 weeks are more dominant for the negative phase. Furthermore, the statistical properties of the model make it useful for the generation of realistic climate noise.

Nonlinear time series models for the North Atlantic Oscillation

2020 ◽  
Author(s):  
Abdel Hannachi ◽  
Thomas Önskog ◽  
Christian Franzke
Keyword(s):  
Time Series ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Nonlinear Models ◽  
Weather Conditions ◽  
Dominant Mode ◽  
Statistical Properties ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

<p>The North Atlantic Oscillation (NAO) is the dominant mode of climate variability over the North Atlantic basin and has a significant impact on seasonal climate and surface weather conditions. This is the result of complex and nonlinear interactions between many spatio-temporal scales. Here, the authors study a number of linear and nonlinear models for a station-based time series of the daily winter NAO index. It is found that nonlinear autoregressive models including both short and long lags perform excellently in reproducing the characteristic statistical properties of the NAO, such as skewness and fat tails of the distribution and the different time scales of the two phases. As a spinoff of the modelling procedure, we are able to deduce that the interannual dependence of the NAO mostly affects the positive phase and that timescales of one to three weeks are more dominant for the negative phase. The statistical properties of the model makes it useful for the generation of realistic climate noise.</p>

scholarly journals Changes in spring arrival dates of Central European bird species over the past 100 years

2020 ◽  
Vol 66 (3) ◽  
Author(s):  
László Bozó ◽  
Tibor Csörgő
Keyword(s):  
Short Distance ◽  
Recent Observation ◽  
Bird Species ◽  
Spring Migration ◽  
Observation Data ◽  
Long Distance ◽  
Endogenous Rhythms ◽  
The Past ◽  
Arrival Dates ◽  
Spring Arrival

Over the past decades, spring temperatures have increased in temperate regions, which resulted in birds arriving earlier in spring. Nonetheless, the timing of some species’ spring migration relies on endogenous rhythms that are not affected by climate change. In this study, we analysed changes in the spring arrival dates of 36 bird species over two periods in 22 towns and villages in Southeast Hungary and West Romania. The first period covered the national spring migration counts between 1894 and 1926, while the second period took place between 2005 and 2019 and is based on our recent observation data. Our results show, that the average spring arrival dates of most long-distance migrant species have not changed significantly over the past 100 years. In contrast, in cases of medium and short-distance migrants, most species arrive earlier recently than in the past. This may be caused by the fact, that the migration habit of long-distance migrants is characterized by strong genetic determinants, so they can not react as quickly to the warmer spring weather in Europe as the medium and short-distance migrants. However, in cases of some long-distance migrants, the timing of spring migration changed due to the drying of wintering grounds.

scholarly journals North Atlantic Oscillation timing of long- and short-distance migration

2002 ◽  
Vol 71 (6) ◽  
pp. 1002-1014 ◽  
Author(s):  
Mads C. Forchhammer ◽  
Eric Post ◽  
Nils CHR. Stenseth
Keyword(s):  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Short Distance
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