Detecting quasi-oscillations in the monthly precipitation regimes of the Iberian Peninsula

Abstract. A spectral analysis of the time series corresponding to the main monthly precipitation regimes of the Iberian Peninsula was performed using two methods, the Multi-Taper Method and Monte Carlo Singular Spectrum Analysis. The Multi-Taper Method gave a preliminary view of the presence of signals in some of the time series. Monte Carlo Singular Spectrum Analysis discriminated between potential oscillations and noise. From the results of the two methods it is concluded that there exist three significant quasi-oscillations at the 95% level of confidence: a 5.0 year quasi-oscillation and a long-term trend in the Atlantic pattern of March, a 3.2 year quasi-oscillation in the Cantabrian pattern of January, and a 4.0 year quasi-oscillation in the Catalonian pattern of February. These quasi-oscillations might be related to climatic variations with similar periodicities over the North Atlantic Ocean. The possible simultaneity of high values of precipitation generated by the significant quasi-oscillations and high sea–level pressures was studied by means of composite maps. It was found that high values of precipitation generated by the oscillations of the Atlantic patterns of January and March exist simultaneously with a specific high pressure structure over the North Atlantic Ocean, that allow cyclonic perturbations to cross the Iberian Peninsula. During the non-wet years, this high pressure structure moves northwards, keeping the track of the low pressure centers to the north, far from the Iberian Peninsula. On the other hand, high values of precipitation generated by the oscillation of the Cantabrian pattern of January exist simultaneously with a high pressure structure over the Galicia region and the Cantabrian Sea, that allow a northerly flow over the region. Also, a positive trend in the NAO index for March has been found, starting in the sixties, which is not evident for other winter months. This trend agrees with the decreasing trend found in the March Atlantic pattern.Key words. Meteorology and atmospheric dynamics (climatology; precipitation) Oceanography: general (climate and interannual variability)

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Prevalence of the Chloroflexi-Related SAR202 Bacterioplankton Cluster throughout the Mesopelagic Zone and Deep Ocean

Applied and Environmental Microbiology ◽

10.1128/aem.70.5.2836-2842.2004 ◽

2004 ◽

Vol 70 (5) ◽

pp. 2836-2842 ◽

Cited By ~ 92

Author(s):

R. M. Morris ◽

M. S. Rappé ◽

E. Urbach ◽

S. A. Connon ◽

S. J. Giovannoni

Keyword(s):

Time Series ◽

Pacific Ocean ◽

16S Rrna ◽

Atlantic Ocean ◽

North Atlantic ◽

North Atlantic Ocean ◽

16S Rrna Genes ◽

Rrna Genes ◽

The North ◽

The North Atlantic

ABSTRACT Since their initial discovery in samples from the north Atlantic Ocean, 16S rRNA genes related to the environmental gene clone cluster known as SAR202 have been recovered from pelagic freshwater, marine sediment, soil, and deep subsurface terrestrial environments. Together, these clones form a major, monophyletic subgroup of the phylum Chloroflexi. While members of this diverse group are consistently identified in the marine environment, there are currently no cultured representatives, and very little is known about their distribution or abundance in the world's oceans. In this study, published and newly identified SAR202-related 16S rRNA gene sequences were used to further resolve the phylogeny of this cluster and to design taxon-specific oligonucleotide probes for fluorescence in situ hybridization. Direct cell counts from the Bermuda Atlantic time series study site in the north Atlantic Ocean, the Hawaii ocean time series site in the central Pacific Ocean, and along the Newport hydroline in eastern Pacific coastal waters showed that SAR202 cluster cells were most abundant below the deep chlorophyll maximum and that they persisted to 3,600 m in the Atlantic Ocean and to 4,000 m in the Pacific Ocean, the deepest samples used in this study. On average, members of the SAR202 group accounted for 10.2% (±5.7%) of all DNA-containing bacterioplankton between 500 and 4,000 m.

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Heinrich Event 4 characterized by terrestrial proxies in southwestern Europe

Climate of the Past Discussions ◽

10.5194/cpd-9-647-2013 ◽

2013 ◽

Vol 9 (1) ◽

pp. 647-681 ◽

Cited By ~ 1

Author(s):

J. M. López-García ◽

H.-A. Blain ◽

M. Bennàsar ◽

M. Sanz ◽

J. Daura

Keyword(s):

Iberian Peninsula ◽

North Atlantic ◽

Deep Sea ◽

North Atlantic Ocean ◽

The North ◽

Heinrich Event ◽

The North Atlantic ◽

Small Vertebrate ◽

Vertebrate Assemblage ◽

First Time

Abstract. Heinrich Event 4 (H4) is well documented in the North Atlantic Ocean as a cooling event that occurred between 39 000 and 40 000 yr BP. Deep-sea cores around the Iberian Peninsula coastline have been analysed to characterize the H4 event, but there are no data on the terrestrial response to this event. Here we present for the first time an analysis of terrestrial proxies for characterizing the H4 event, using the small-vertebrate assemblage (comprising small mammals, squamates and amphibians) from Terrassa Riera dels Canyars, an archaeo-palaeontological deposit located on the seaboard of the northeastern Iberian Peninsula. This assemblage shows that the H4 event is characterized in northeastern Iberia by harsher and drier terrestrial conditions than today. Our results were compared with other proxies such as pollen, charcoal, phytolith, avifauna and large-mammal data available for this site, as well as with the general H4 event fluctuations and with other sites where H4 and the previous and subsequent Heinrich events (H5 and H3) have been detected in the Mediterranean and Atlantic regions of the Iberian Peninsula. We conclude that the terrestrial proxies follow the same patterns as the climatic and environmental conditions detected by the deep-sea cores at the Iberian margins.

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Interannual oscillations in winter rainfall over Europe. Iberia study case

Finisterra ◽

10.18055/finis1323 ◽

2012 ◽

Vol 46 (91) ◽

Cited By ~ 1

Author(s):

Pedro Tildes Gomes

Keyword(s):

Twentieth Century ◽

Iberian Peninsula ◽

North Atlantic ◽

Singular Spectrum Analysis ◽

Climate Signal ◽

The North ◽

Starting Point ◽

The North Atlantic ◽

Phase Variability ◽

Degree Of Association

Low -frequency variability is a good starting point for modelling the climate system and understanding mechanisms that can give us some indication of future climate evolution. this work aims to better understand the degree of association between the atmospheric circulation and precipitation over europe and the iberian Peninsula. to achieve this goal, the standard precipitation anomalies in europe and the anomalies of sea level pressure (sLP) in the north atlantic region during the twentieth century were subjected to Multi -Channel singular spectrum analysis (Mssa). this procedure allows us to measure the degree of association between the sLP and precipitation fields. the identification of common oscillations between the two climatic fields led not only to the confirmation of the physical meaning of these oscillations, but also to the identification of the dynamical evolution of the ocean -atmosphere system in the north atlantic. two oscillations, statistically significant, common to both the precipitation field and sLP field were isolated with periods of about 8 years and 5.3 years. the 8 -year oscillation is the most significant and robust of the two climatic fields and exhibits a classic naO pattern, with an out -of -phase variability between northern and southern parts of the domain. furthermore, it is characterized by a westward propagation of the climate signal and a perfect out -of -phase variability between the precipitation and sLP. the 8 -year oscillation is also very significant in the iberian Peninsula and is associated with dry winters and wet winters, whose sequence was identified for the twentieth century. the 5.3 -year oscillation is related to the east atlantic Pattern that exhibits another dipolar structure, with an out -of -phase variability between southwest and northwest europe. the regularity of the 8 year oscillation can be anticipated with a degree of certainty, thus permitting a prediction of the occurrence of wet and dry years and allowing for a better management of water resources.

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The North Atlantic Oscillations: Cycle Times for the NAO, the AMO and the AMOC

Climate ◽

10.3390/cli7030043 ◽

2019 ◽

Vol 7 (3) ◽

pp. 43 ◽

Cited By ~ 4

Author(s):

Knut Lehre Seip ◽

Øyvind Grøn ◽

Hui Wang

Keyword(s):

Time Series ◽

North Atlantic ◽

North Atlantic Ocean ◽

Atlantic Multidecadal Oscillation ◽

Meridional Overturning Circulation ◽

Cycle Times ◽

The North ◽

In Series ◽

The North Atlantic ◽

The North Atlantic Oscillation

We show that oceanic cycle lengths persist across oceanic cyclic time-series by comparing cycles in series that come from “sister” measurements in the North Atlantic Ocean. These are the North Atlantic oscillation (NAO), the Atlantic multidecadal oscillation (AMO) and the Atlantic meridional overturning circulation (AMOC). The raw NAO series, which is an extremely noisy series in its raw format, showed cycles at 7, 13, 20, 26 and 34 years that were common with, or overlapped, the other two series, and across increasing degrees of smoothing of the NAO series. At the 1960 midpoint of the hiatus period 1943–1975, NAO was leading time-series to AMOC and AMO and AMO was a leading time-series to AMOC, but in 1975, at the end of the hiatus period, the leading relations were reversed.

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Taurine Is a Major Carbon and Energy Source for Marine Prokaryotes in the North Atlantic Ocean off the Iberian Peninsula

Microbial Ecology ◽

10.1007/s00248-019-01320-y ◽

2019 ◽

Vol 78 (2) ◽

pp. 299-312 ◽

Cited By ~ 9

Author(s):

Elisabeth L. Clifford ◽

Marta M. Varela ◽

Daniele De Corte ◽

Antonio Bode ◽

Victor Ortiz ◽

...

Keyword(s):

Energy Source ◽

Atlantic Ocean ◽

Iberian Peninsula ◽

North Atlantic ◽

North Atlantic Ocean ◽

The North ◽

The North Atlantic

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Heinrich event 4 characterized by terrestrial proxies in southwestern Europe

Climate of the Past ◽

10.5194/cp-9-1053-2013 ◽

2013 ◽

Vol 9 (3) ◽

pp. 1053-1064 ◽

Cited By ~ 19

Author(s):

J. M. López-García ◽

H.-A. Blain ◽

M. Bennàsar ◽

M. Sanz ◽

J. Daura

Keyword(s):

Iberian Peninsula ◽

North Atlantic ◽

Deep Sea ◽

North Atlantic Ocean ◽

The North ◽

Heinrich Event ◽

The North Atlantic ◽

Small Vertebrate ◽

Vertebrate Assemblage ◽

First Time

Abstract. Heinrich event 4 (H4) is well documented in the North Atlantic Ocean as a cooling event that occurred between 39 and 40 Ka. Deep-sea cores around the Iberian Peninsula coastline have been analysed to characterize the H4 event, but there are no data on the terrestrial response to this event. Here we present for the first time an analysis of terrestrial proxies for characterizing the H4 event, using the small-vertebrate assemblage (comprising small mammals, squamates and amphibians) from Terrassa Riera dels Canyars, an archaeo-palaeontological deposit located on the seaboard of the northeastern Iberian Peninsula. This assemblage shows that the H4 event is characterized in northeastern Iberia by harsher and drier terrestrial conditions than today. Our results were compared with other proxies such as pollen, charcoal, phytolith, avifauna and large-mammal data available for this site, as well as with the general H4 event fluctuations and with other sites where H4 and the previous and subsequent Heinrich events (H5 and H3) have been detected in the Mediterranean and Atlantic regions of the Iberian Peninsula. We conclude that the terrestrial proxies follow the same patterns as the climatic and environmental conditions detected by the deep-sea cores at the Iberian margins.

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The Petrology of Mesozoic Alkaline Intrusives of Central Newfoundland

Canadian Journal of Earth Sciences ◽

10.1139/e74-114 ◽

1974 ◽

Vol 11 (9) ◽

pp. 1208-1219 ◽

Cited By ~ 26

Author(s):

D. F. Strong ◽

A. Harris

Keyword(s):

High Pressure ◽

North Atlantic ◽

Strong Evidence ◽

North Atlantic Ocean ◽

Immiscible Liquid ◽

Host Matrix ◽

The North ◽

Pressure Fractionation ◽

Silicate Liquids ◽

The North Atlantic

Lamprophyre dikes occur as northeast-striking swarms and in radiating patterns around alkaline stocks. They range in age from Jurassic to Cretaceous and are interpreted as the result of the rifting associated with formation of the North Atlantic Ocean. They show strong evidence of coexisting immiscible silicate liquids, with leucocratic globules in a darker host matrix. The globules are richer in CO2 and Na2O than the host and these liquids are not similar in composition to those of other immiscible liquid pairs. The whole suite is interpreted to have resulted from high pressure eclogite fractionation followed by volatile build-up due to lower pressure fractionation of olivine, titanaugite, plagioclase, biotite, and/or kaersutite.

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The role of consecutive extratropical cyclones Daniel, Elsa, and Fabien on drought busting during December 2019 in the Minho-Limia-Sil Hydrographic demarcation

10.5194/egusphere-egu21-13586 ◽

2021 ◽

Author(s):

Milica Stojanovic ◽

Ana Gonçalves ◽

Rogert Sorí ◽

Marta Vázquez ◽

Margarida L.R. Liberato

Keyword(s):

Atlantic Ocean ◽

Iberian Peninsula ◽

North Atlantic ◽

North Atlantic Ocean ◽

Extratropical Cyclones ◽

Intense Rainfall ◽

Hydrological Conditions ◽

The North ◽

The North Atlantic

Three consecutive extratropical cyclones named Daniel, Elsa, and Fabien affected the northwest of the Iberian Peninsula during December 2019. In this region is located the Mi&#241;o-Limia-Sil Hydrographic Demarcation (MLSHD), which includes part of Galicia, in Spain and the north of Portugal. The water resources of the MLSHD are of great importance for the socio-economic framework of both countries, particularly for the agricultural and livestock activities, tourism, and the production of electrical energy from renewable sources like the eolic and the hydroelectric. In this study was analysed the synoptic characteristics of these extratropical cyclones, particularly during the life cycle close to the Iberian Peninsula, when the greatest damages associated with strong winds and intense rainfall occurred. The storm Daniel was formed from a secondary low located to the west and close to the Iberian Peninsula during the afternoon of December 15. Nevertheless, Elsa was formed in the Gulf of Mexico and Fabian in the north Atlantic Ocean, then both crossed the north Atlantic Ocean to finally affect with intense rainfall that caused floods in the MLSHD from 18 to 21 December 2019. The moisture supplies from the tropical north Atlantic Ocean, revealed by the integrated water vapour transport favoured the intensification of all these systems. The consecutive impact of these systems provided great amounts of rainfall to the MLSHD, causing positive anomalies of the total accumulated rainfall for this month. An assessment of drought conditions through the SPI and the SPEI on time scales of 1, 3, 6, and 12 months exposed the role of these systems on drought busting in the MLSHD. Therefore, despite the negative impacts, these systems favoured a recovery of the hydrological conditions of the Demarcation. Our results confirm the importance of studying for a long study period the role of extratropical cyclones on hydrological conditions of the MLSHD.Acknowledgements: This study is supported by Funda&#231;&#227;o para a Ci&#234;ncia e a Tecnologia, Portugal (FCT), under project WEx-Atlantic (PTDC/CTA-MET/29233/2017).

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