scholarly journals Rapid climatic variability in the west Mediterranean during the last 25 000 years from high resolution pollen data

2009 ◽  
Vol 5 (3) ◽  
pp. 503-521 ◽  
Author(s):  
N. Combourieu Nebout ◽  
O. Peyron ◽  
I. Dormoy ◽  
S. Desprat ◽  
C. Beaudouin ◽  
...  
Keyword(s):  
High Resolution ◽  
North Atlantic ◽  
Climate Reconstruction ◽  
Mediterranean Vegetation ◽  
Pollen Record ◽  
Alboran Sea ◽  
Climatic Fluctuations ◽  
The Holocene ◽  
The Mediterranean ◽  
Alborán Sea

Abstract. High-temporal resolution pollen record from the Alboran Sea ODP Site 976, pollen-based quantitative climate reconstruction and biomisation show that changes of Mediterranean vegetation have been clearly modulated by short and long term variability during the last 25 000 years. The reliability of the quantitative climate reconstruction from marine pollen spectra has been tested using 22 marine core-top samples from the Mediterranean. The ODP Site 976 pollen record and climatic reconstruction confirm that Mediterranean environments have a rapid response to the climatic fluctuations during the last Termination. The western Mediterranean vegetation response appears nearly synchronous with North Atlantic variability during the last deglaciation as well as during the Holocene. High-resolution analyses of the ODP Site 976 pollen record show a cooling trend during the Bölling/Allerød period. In addition, this period is marked by two warm episodes bracketing a cooling event that represent the Bölling-Older Dryas-Allerød succession. During the Holocene, recurrent declines of the forest cover over the Alboran Sea borderlands indicate climate events that correlate well with several events of increased Mediterranean dryness observed on the continent and with Mediterranean Sea cooling episodes detected by alkenone-based sea surface temperature reconstructions. These events clearly reflect the response of the Mediterranean vegetation to the North Atlantic Holocene cold events.

scholarly journals Rapid climatic variability in the west Mediterranean during the last 25 000 years from high resolution pollen data

2009 ◽  
Vol 5 (1) ◽  
pp. 671-707 ◽  
Author(s):  
N. Combourieu Nebout ◽  
O. Peyron ◽  
I. Dormoy
Keyword(s):  
High Resolution ◽  
North Atlantic ◽  
Climatic Variability ◽  
Mediterranean Vegetation ◽  
High Temporal Resolution ◽  
Pollen Record ◽  
Alboran Sea ◽  
The West ◽  
Climatic Fluctuations ◽  
Alborán Sea

Abstract. High-temporal resolution pollen record of Alboran Sea ODP Site 976 and pollen-based quantitative climate reconstruction shows that changes of Mediterranean vegetation have been clearly modulated by short and long term variability during the last 25 000 years. The western Mediterranean vegetation response appears nearly synchronous with North Atlantic variability during the last deglaciation as well as during the Holocene. High-resolution analyses of the ODP 976 pollen record allows to separate the Bölling/Alleröd period in two warm episodes that surround a cooling representative of the climatic succession of the Bölling, Older Dryas and Alleröd. A cooling trend is observed from Bölling to Alleröd. The ODP pollen record confirms that Mediterranean environments show rapid responses to the climatic fluctuations during the last termination, in particular that of all the climate oscillations associated with the successive steps of the deglaciation in the North Atlantic have been observed in the west Mediterranean region. Recurrent Holocene declines of the forest cover on the Alboran Sea borderlands indicate repetitive climate events that correlate well with several events of increased Mediterranean dryness observed on the continent and with alkenone SST showing Mediterranean Sea cooling. These events reflect clearly the response of to Mediterranean vegetation to North Atlantic Holocene cold events.

Cd and Mn in the Alboran Sea and adjacent North Atlantic: geochemical implications for the Mediterranean

Nature ◽  
1985 ◽  
Vol 313 (6003) ◽  
pp. 565-567 ◽  
Author(s):  
P. J. Statham ◽  
J. D. Burton ◽  
D. J. Hydes
Keyword(s):  
North Atlantic ◽  
Alboran Sea ◽  
The Mediterranean ◽  
Alborán Sea

scholarly journals Holocene hydrography evolution in the Alboran Sea: a multi-record and multi-proxy comparison

2019 ◽  
Vol 15 (3) ◽  
pp. 927-942 ◽  
Author(s):  
Albert Català ◽  
Isabel Cacho ◽  
Jaime Frigola ◽  
Leopoldo D. Pena ◽  
Fabrizio Lirer
Keyword(s):  
North Atlantic ◽  
Climatic Variability ◽  
Planktonic Foraminifera ◽  
Warming Trend ◽  
Western Mediterranean ◽  
Alboran Sea ◽  
The Holocene ◽  
Sst Variability ◽  
Peak Structure ◽  
Alborán Sea

Abstract. A new high-resolution deglacial and Holocene sea surface temperature (SST) reconstruction is presented for the Alboran Sea (western Mediterranean), based on Mg∕Ca ratios measured in the planktonic foraminifera Globigerina bulloides. This new record is evaluated by comparison with other Mg∕Ca SST records and previously published alkenone SST reconstructions from the same region for both the Holocene and glacial periods. In all cases there is a high degree of coherence between the different Mg∕Ca SST records but strong discrepancies when compared to the alkenone SST records. We argue that these discrepancies are due to differences in the proxy response during deglaciation which we hypothesize to reflect a resilience strategy of G. bulloides, changing its main growth season, and consequently Mg∕Ca records a shorter deglacial warming than alkenones. In contrast, short-term Holocene SST variability is larger in the Mg∕Ca SST than in the alkenone SST records. We propose that the larger Mg∕Ca SST variability is a result of spring temperatures variability, while the smoothed alkenone SST variability represents averaged annual temperatures. The Mg∕Ca SST record differentiates the Holocene into three periods: (1) the warmest SST values occurred during the Early Holocene (11.7–9 cal. kyr BP), (2) a continuous cooling trend occurred during the Middle Holocene that culminated in the coldest Holocene SST having a double cold peak structure centred at around 4.2 cal. kyr BP, and (3) the Late Holocene (4.2 cal. kyr BP to present) did not follow any clear cooling/warming trend although millennial-scale oscillations were enhanced. This SST evolution is discussed in the context of the changing properties in the Atlantic inflow water associated with North Atlantic circulation conditions and also with local hydrographical and atmospheric changes. We propose that a tight link between North Atlantic circulation patterns and the inflow of surface waters into the Mediterranean played a major role in controlling Holocene climatic variability of this region.

First record of Sphoeroides spengleri (Osteichthyes: Tetraodontidae) in the Mediterranean Sea

2004 ◽  
Vol 84 (5) ◽  
pp. 1089-1090 ◽  
Author(s):  
J.A. Reina-Hervás ◽  
J.E. García Raso ◽  
M.E. Manjón-Cabeza
Keyword(s):  
Alien Species ◽  
Mediterranean Sea ◽  
First Record ◽  
Western Mediterranean ◽  
Alboran Sea ◽  
Total Length ◽  
The Mediterranean ◽  
Alborán Sea

The capture of a specimen of Sphoeroides spengleri (Osteichthyes: Tetraodontidae), 17 December 2000 and 29·7 mm total length, from the Málaga coast (Alborán Sea, western Mediterranean) represents the first record of a new alien species for Mediterranean waters.

North Atlantic Oscillation-related impacts on precipitation over the Italian Peninsula during the 1979-2020 period

2021 ◽  
Author(s):  
Paula Lorenzo Sánchez ◽  
Leonardo Aragão
Keyword(s):  
High Resolution ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Mediterranean Region ◽  
Italian Peninsula ◽  
The North ◽  
Nao Index ◽  
The North Atlantic ◽  
The Mediterranean ◽  
Resolution Dataset

<p>The North Atlantic Oscillation (NAO) has been widely recognized as one of the main patterns of atmospheric variability over the northern hemisphere, helping to understand variations on the North Atlantic Jet (NAJ) position and its influence on storm-tracks, atmospheric blocking and Rossby Wave breaking. Among several relevant teleconnection patterns identified through different timescales, the most prominent ones are found for northern Europe during winter months, when positive (negative) phases of NAO are related to wetter (drier) conditions. Although it is not well defined yet, an opposite connection is observed for the Mediterranean region, where negative NAO values are often associated with high precipitation. Therefore, the main goal of this study is to identify which regions and periods of the year are the most susceptible to abundant NAO-related precipitation throughout the Italian Peninsula. For doing so, the last 42 years period (1979-2020) was analysed using the Fifth Generation ECMWF Atmospheric ReAnalysis of the Global Climate (ERA5). The NAO index was calculated using the Mean Sea Level Pressure (MSLP) extracted from the nearest gridpoints to Reykjavik, Ponta Delgada, Lisbon and Gibraltar, with a time resolution of one hour and horizontal spatial resolution of 0.25ºx0.25º. Both NAO index and MSLP time series were validated for different timescales (hourly, daily, monthly and seasonal) using the Automated Surface Observing System data and the Climatic Research Unit (CRU) high-resolution dataset (based on measured data). High correlations, ranging from 0.92 to 0.98, were found for all stations, timescales and evaluated parameters. To quantify the influence of NAO over the Mediterranean region, the monthly averaged ERA5 ‘total precipitation’ data over the Italian Peninsula [35-48º N; 5-20º E] were used. As expected, the results concerning NAO x Precipitation presented the best correlations when analysed monthly, confirming some of the already known NAO signatures over the Italian Peninsula: higher correlations during winter and over the Tyrrhenian coast, and lower correlations during summer and over the Apennines, the Adriatic Sea and the Ionian Sea. On the other hand, the precipitation over the Alps and the Tunisian coast presented a remarkable signature of positive NAO values that, despite a lower statistical significance (85-90%), is in agreement with recent findings of observational studies. In addition, significant negative correlations were identified for the spring and autumn months over the Tyrrhenian area. Among those, the high correlations found during May are particularly interesting, as they follow the behaviour described in recent studies performed using the same high-resolution dataset (ERA5), which have identified an increased number of cyclones over the Mediterranean during this month. This connection suggests that NAO could also be used to explore the potential penetration of the North Atlantic depressions into the Mediterranean Basin. </p><p>Keywords: NAO; Teleconnections; ERA5; ReAnalysis; Mediterranean; Climatology.</p>

scholarly journals Characterization of the submesoscale energy cascade in the Alboran Sea thermocline from spectral analysis of high-resolution MCS data

2016 ◽  
Vol 43 (12) ◽  
pp. 6461-6468 ◽  
Author(s):  
Valenti Sallares ◽  
Jhon F. Mojica ◽  
Berta Biescas ◽  
Dirk Klaeschen ◽  
Eulàlia Gràcia
Keyword(s):  
Spectral Analysis ◽  
High Resolution ◽  
Energy Cascade ◽  
Alboran Sea ◽  
Alborán Sea

Denudation response of the Mediterranean Alpine Ranges to the Quaternary glacial cycles

2021 ◽  
Author(s):  
Pierre-Henri Blard ◽  
Stéphane Molliex ◽  
Apolline Mariotti ◽  
Julien Charreau ◽  
Gwenaël Jouet ◽  
...  
Keyword(s):  
High Resolution ◽  
Southern Alps ◽  
Special Focus ◽  
Glacial Cycles ◽  
Climatic Fluctuations ◽  
Denudation Rates ◽  
Original Dataset ◽  
Climatic Transition ◽  
The Mediterranean ◽  
Glacier Flow

<p>It is important to better understand how climatic fluctuations modified denudation, in particular during the large amplitude glacial cycles of the Quaternary, not only because denudation is thought to be a long-term climate pacer, but also because available denudation records are contradictory and sometimes underconstrained. To make progress on this question, we present here a compilation of <sup>10</sup>Be-derived denudation rates from 6 boreholes and cores drilled in offshore sediments from two alpine massifs of the Mediterranean Sea: Southern Alps (Var River) and Corsica (Golo River). This original dataset of 60 <sup>10</sup>Be samples from well-dated sedimentary archives documents at high resolution (1 kyr in some sections) the denudation variability over the last 3 million years of the alpine reliefs, with a special focus on the last five 100 kyr glacial cycles. Our new record brings two main results:</p><p>1) At the million years timescale, the appearance of the Quaternary glaciations at the Plio-Pleistocene transition (2.6 Ma) had a negligible impact on the mean <sup>10</sup>Be-derived denudation rates of Mediterranean Alpine reliefs. This observation is in good agreement with other <sup>10</sup>Be-denudation rates records from Asia (Tianshan and Himalaya) that report a limited impact of the Pleistocene climatic transition (Puchol et al., 2017; Charreau et al., 2020; Lenard et al., 2020), but at odds with other regions of the American Cordilleras, where tectonic may have played a role (Stock et al., 2004; Granger and Schaller, 2014).</p><p>2) At the glacial-interglacial cycles timescale, our high resolution <sup>10</sup>Be data over the last 500 kys reveal that glacial maxima enhanced denudation compared to interglacial periods. However, this impact is variable in space and time, different denudation responses being observed between Southern Alps and Corsica. This contrasted behavior appears to be controlled by the velocity of paleoglaciers. Glacier flow being determined by the combined impact of paleoclimate and basin reliefs, this mechanism is responsible for a non-linear response of denudation to glacier fluctuations. This may explain why glaciations had regionally variable impacts on denudation (Mariotti et al., 2021).</p><p><strong>References</strong></p><p>Charreau, J. et al. (2020) Basin Research. doi: 10.1111/bre.12511; Granger, D. E. and Schaller, M. (2014) Elements, doi: 10.2113/gselements.10.5.369; Lenard, S. J. P. et al. (2020) Nature Geoscience, doi: 10.1038/s41561-020-0585-2; Mariotti, A. et al. (2021) Nature Geoscience, doi: 10.1038/s41561-020-00672-2; Puchol, N. et al. (2017) Bulletin of the Geological Society of America, doi: 10.1130/B31475.1; Stock, G. M., et al. (2004) Geology, doi: 10.1130/G20197.1.</p>

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