Links between multidecadal and interdecadal climatic oscillations in the North Atlantic and regional climate variability of northern France and England since the 17th century (original) (raw)
Related papers
Journal of Geophysical Research, 2007
1] In this paper, the temporal dynamics of precipitation in northwestern France in relation to the dominant climatic pattern in Europe were investigated. The general trends and the nonstationary behavior of the North Atlantic Oscillation (NAO) were described using fractal analysis and Fourier spectral and continuous wavelet analysis of a NAO index time series over the 1865-2004 period. The 44-year and 8-year multidecadal components showed a clear increasing power during the second half of the last century. The possible link between rainfall variability and the NAO was then investigated. The links between the NAO and rainfall were not as obvious, as NAO-like components were not easily retrieved in the precipitation records: Relationships between the NAO and rainfall were very likely at certain timescales but were not systematically very obvious. For instance, the characteristic quasi-biennal oscillation (QBO) of the NAO was barely detected in precipitation, but a %6-year fluctuation beginning in the 90s was found to be statistically significant at a 95% confidence limit After investigating a possible link with the Southern Oscillation Index, the occurrence of this fluctuation in the beginning of the 90s could be related to the observed shift of the QBO toward slightly higher frequencies in the NAO time series. On the other hand, a modulation of the QBO by a %6-year interannual fluctuation would suggest the existence of a %6-year climate pattern that could affect precipitation and, to a lesser extent, the NAO. Cross-wavelet analysis between the NAO and precipitation revealed a loss in correlation across the 1970-2005 period, which seemed to be the fact of a QBO-like fluctuation. This loss of correlation was related to the above-mentioned shift of the QBO and 6-year rainfall interannual band since the 90s. Citation: Massei, N., A. Durand, J. Deloffre, J. P. Dupont, D. Valdes, and B. Laignel (2007), Investigating possible links between the North Atlantic Oscillation and rainfall variability in northwestern France over the past 35 years,
A European pattern climatology 1766–2000
Climate Dynamics, 2007
Using monthly independently reconstructed gridded European fields for the 500 hPa geopotential height, temperature, and precipitation covering the last 235 years we investigate the temporal and spatial evolution of these key climate variables and assess the leading combined patterns of climate variability. Seasonal European temperatures show a positive trend mainly over the last 40 years with absolute highest values since 1766. Precipitation indicates no clear trend. Spatial correlation technique reveals that winter, spring, and autumn covariability between European temperature and precipitation is mainly influenced by advective processes, whereas during summer convection plays the dominant role. Empirical Orthogonal Function analysis is applied to the combined fields of pressure, temperature, and precipitation. The dominant patterns of climate variability for winter, spring, and autumn resemble the North Atlantic Oscillation and show a distinct positive trend during the past 40 years for winter and spring. A positive trend is also detected for summer pattern 2, which reflects an increased influence of the Azores High towards central Europe and the Mediter-ranean coinciding with warm and dry conditions. The question to which extent these recent trends in European climate patterns can be explained by internal variability or are a result of radiative forcing is answered using cross wavelets on an annual basis. Natural radiative forcing (solar and volcanic) has no imprint on annual European climate patterns. Connections to CO 2 forcing are only detected at the margins of the wavelets where edge effects are apparent and hence one has to be cautious in a further interpretation.
International Journal of Climatology, 2010
The relationships between the main patterns of variability of the Atlantic sea-surface temperatures (SSTs) and the European land-surface temperatures (LSTs) at interannual-to-multidecadal time scales are investigated along the period 1872-2004. Principal component analysis (PCA) is used firstly to obtain the main spatio-temporal patterns of variability of the LSTs and SSTs. Singular Spectral Analysis (SSA) is then used to decompose the time series associated with these patterns into nonlinear trends and quasi-periodic oscillations, searching for common oscillatory modes to the SSTs and LSTs. The potential predictability of the LSTs based on the SSTs is also analysed. Regarding the SSA results, three robust oscillations of periods around 13.7, 7.5 and 5.2 years, present both in the Atlantic SSTs and northwestern European LSTs, were isolated. These oscillations were found to be associated mainly with a quadripolar SST pattern in the North Atlantic region, usually related to the North Atlantic Oscillation (NAO) atmospheric mode of variability. The predictability study revealed that the SSTs of the Atlantic Ocean are able to account for about 12% of the northwestern European LSTs variance. Additionally, an oscillatory component with period around 3.6 years was identified, but no significant connection between SST and LST was found for this mode. In addition, at this time scale, we find that the El Niño-Southern Oscillation (ENSO) is leading the Atlantic SST quadripolar pattern by 6 months. Finally, the analysis of the nonlinear trends showed the presence of oscillations with periods around 60-100 years, both in the SSTs and LSTs. At these later time scales, our results reveal that the multidecadal behaviour of the southern European LSTs is related to Atlantic Multidecadal Oscillation (AMO) during the period 1872-1940, unlike the northern and eastern European LSTs, while, during the period 1941-2004, the AMO sign seems to be present in whole Europe.
Global and Planetary Change, 2006
The North Atlantic Oscillation (NAO) is the leading mode of atmospheric variability in the North Atlantic region, influencing storm tracks and creating a dipole pattern of precipitation from north to south across Western Europe. This distinct spatial distribution of precipitation provides a framework that can be potentially used to identify and reconstruct patterns of past NAOforced climate variability. In this study we use tree-ring width series from Western Europe, in conjunction with principal components analysis and advanced spectral methods, to prospect for quasi-periodic climate signals that are forced by the NAO. We identify a robust 25-yr anti-phased synchronization in climate variability between Scandinavia and the Mediterranean during the 17th-20th centuries. The amplitude of the 25-yr beat displays a long-term modulation in northern and southern Europe, with minimum amplitude during the late Maunder Minimum. This amplitude minimum coincides with a maximum in Δ 14 C, suggesting a potential solar or oceanic influence on the intensity of the 25-yr band of quasi-periodic variability.
A reconstruction of the Atlantic Multidecadal Oscillation (AMO) for the last 1200 years
2010
Sea surface temperatures (SSTs) in the North Atlantic Ocean show multidecadal fluctuations known as the Atlantic Multidecadal Oscillation (AMO) . The AMO has been related to the thermohaline circulation, which implies a strong association to large-scale climate variability. Indeed, the variability of a wide range of climate parameters in the North Atlantic region has been related to the AMO, e.g. temperatures, precipitation, drought and hurricanes. Moreover, the AMO seems to influence the Asian summer monsoon, and South American precipitation. Most of these relationships have been established analyzing the short observational records or from experiments with climate models. In order to establish the stability of the multidecadal oscillation in the AMO as well as the association with climate, it is necessary to extend the record further back in time. Using tree-ring data from the Northern Hemisphere a reconstruction of the AMO, spanning AD 800 to 2000 is presented. The reconstruction suggests anomalously warm North Atlantic SSTs from ca. AD 900 to 1050, coinciding with the "Medieval Warm Period", as well as a phase between 1100 and 1400 with relatively little interdecadal variability. There is a prolonged negative phase of AMO from ca. 1600-1860, i.e. during the "Little Ice Age" (LIA). The multidecadal variability of approximately 40-80 years remains constant throughout the record, except around ca 1500-1700, i.e. during the LIA, when it breaks down.
Geology, 2009
The El Niño-Southern Oscillation (ENSO) is a pacemaker of global climate, and the accurate prediction of future climate change requires an understanding of the ENSO variability. Recently, much-debated aspects of the ENSO have included its long-term past and future changes and its associations with the North Atlantic and European sectors, potentially in interaction with the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. Here we present the fi rst European dendroclimatic precipitation reconstruction that extends through the alternating climate phases of the Medieval Climate Anomaly and the Little Ice Age. We show that northern Europe underwent a severe precipitation defi cit during the Medieval Climate Anomaly, which was synchronous with droughts in various ENSO-sensitive regions worldwide, while the subsequent centuries during the Little Ice Age were markedly wetter. We attribute this drought primarily to an interaction between the ENSO and the North Atlantic Oscillation, and to a lesser (or negligible) degree to an interaction between the ENSO and the Atlantic Multidecadal Oscillation.
Theoretical and Applied Climatology, 2012
The North Atlantic Oscillation (NAO) obtained using instrumental and documentary proxy predictors from Eurasia is found to be characterized by a quasi 60-year dominant oscillation since 1650. This pattern emerges clearly once the NAO record is time integrated to stress its comparison with the temperature record. The integrated NAO (INAO) is found to well correlate with the length of the day (since 1650) and the global surface sea temperature record HadSST2 and HadSST3 (since 1850). These findings suggest that INAO can be used as a good proxy for global climate change, and that a~60-year cycle exists in the global climate since at least 1700. Finally, the INAO~60-year oscillation well correlates with the~60year oscillations found in the historical European aurora record since 1700, which suggests that this~60-year dominant climatic cycle has a solar-astronomical origin.