Mediterranean Sea climatic indices: monitoring long term variability and climate changes

2018 ◽  
Author(s):  
Roger Proctor
Keyword(s):  
Mediterranean Sea ◽  
Climate Changes ◽  
Climatic Indices

scholarly journals Mediterranean Sea climatic indices: monitoring long term variability and climate changes

2018 ◽  
Author(s):  
Athanasia Iona ◽  
Athanasios Theodorou ◽  
Sarantis Sofianos ◽  
Sylvain Watelet ◽  
Charles Troupin ◽  
...  
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Mediterranean Sea ◽  
Climate Changes ◽  
Salt Content ◽  
Climatic Indices ◽  
In Situ Observations ◽  
The Mediterranean

Abstract. We present a new product composed of a set of thermohaline climatic indices from 1950 to 2015 for the Mediterranean Sea such as decadal temperature and salinity anomalies, their mean values over selected depths, decadal ocean heat and salt content anomalies at selected depth layers as well as their long times series. It is produced from a new high-resolution climatology of temperature and salinity on a 1/8° regular grid based on historical high quality in situ observations. Ocean heat and salt content differences between 1980–2015 and 1950–1979 are compared for evaluation of the climate shift in the Mediterranean Sea. The spatial patterns of heat and salt content shifts demonstrate in greater detail than ever before that the climate changes differently in the several regions of the basin. Long time series of heat and salt content for the period 1950 to 2015 are also provided which indicate that in the Mediterranean Sea there is a net mean volume warming and salting since 1950 with acceleration during the last two decades. The time series also show that the ocean heat content seems to fluctuate on a cycle of about 40 years and seems to follow the Atlantic Multidecadal Oscillation climate cycle indicating that the natural large scale atmospheric variability could be superimposed on to the warming trend. This product is an observations-based estimation of the Mediterranean climatic indices. It relies solely on spatially interpolated data produced from in-situ observations averaged over decades in order to smooth the decadal variability and reveal the long term trends with more accuracy. It can provide a valuable contribution to the modellers' community, next to the satellite-based products and serve as a baseline for the evaluation of climate-change model simulations contributing thus to a better understanding of the complex response of the Mediterranean Sea to the ongoing global climate change. The product is available here: https://doi.org/10.5281/zenodo.1210100.

scholarly journals Mediterranean Sea climatic indices: monitoring long-term variability and climate changes

2018 ◽  
Vol 10 (4) ◽  
pp. 1829-1842 ◽  
Author(s):  
Athanasia Iona ◽  
Athanasios Theodorou ◽  
Sarantis Sofianos ◽  
Sylvain Watelet ◽  
Charles Troupin ◽  
...  
Keyword(s):  
Time Series ◽  
Mediterranean Sea ◽  
Climate Changes ◽  
Salt Content ◽  
Climatic Indices ◽  
Long Time ◽  
In Situ Observations ◽  
The Mediterranean

Abstract. We present a new product composed of a set of thermohaline climatic indices from 1950 to 2015 for the Mediterranean Sea such as decadal temperature and salinity anomalies, their mean values over selected depths, decadal ocean heat and salt content anomalies at selected depth layers as well as their long time series. It is produced from a new high-resolution climatology of temperature and salinity on a 1∕8∘ regular grid based on historical high-quality in situ observations. Ocean heat and salt content differences between 1980–2015 and 1950–1979 are compared for evaluation of the climate shift in the Mediterranean Sea. The two successive periods are chosen according to the standard WMO climate normals. The spatial patterns of heat and salt content shifts demonstrate that the climate changes differently in the several regions of the basin. Long time series of heat and salt content for the period 1950 to 2015 are also provided which indicate that in the Mediterranean Sea there is a net mean volume warming and salinification since 1950 that has accelerated during the last two decades. The time series also show that the ocean heat content seems to fluctuate on a cycle of about 40 years and seems to follow the Atlantic Multidecadal Oscillation climate cycle, indicating that the natural large-scale atmospheric variability could be superimposed onto the warming trend. This product is an observation-based estimation of the Mediterranean climatic indices. It relies solely on spatially interpolated data produced from in situ observations averaged over decades in order to smooth the decadal variability and reveal the long-term trends. It can provide a valuable contribution to the modellers' community, next to the satellite-based products, and serve as a baseline for the evaluation of climate-change model simulations, thus contributing to a better understanding of the complex response of the Mediterranean Sea to the ongoing global climate change. The product is available in netCDF at the following sources: annual and seasonal T∕S anomalies (https://doi.org/10.5281/zenodo.1408832), annual and seasonal T∕S vertical averaged anomalies (https://doi.org/10.5281/zenodo.1408929), annual and seasonal areal density of OHC/OSC anomalies (https://doi.org/10.5281/zenodo.1408877), annual and seasonal linear trends of T∕S, OHC/OSC anomalies (https://doi.org/10.5281/zenodo.1408917), annual and seasonal time series of T∕S, OHC/OSC anomalies (https://doi.org/10.5281/zenodo.1411398), and differences of two 30-year averages of annual and seasonal T∕S, OHC/OSC anomalies (https://doi.org/10.5281/zenodo.1408903).

scholarly journals Long-Term Observations of Beach Variability at Hasaki, Japan

2020 ◽  
Vol 8 (11) ◽  
pp. 871
Author(s):  
Masayuki Banno ◽  
Satoshi Nakamura ◽  
Taichi Kosako ◽  
Yasuyuki Nakagawa ◽  
Shin-ichi Yanagishima ◽  
...  
Keyword(s):  
Morphological Change ◽  
High Frequency ◽  
Climate Changes ◽  
Wave Climate ◽  
Time Interval ◽  
Observation Data ◽  
Beach Profile ◽  
Water Level Variations ◽  
Monthly Variations

Long-term beach observation data for several decades are essential to validate beach morphodynamic models that are used to predict coastal responses to sea-level rise and wave climate changes. At the Hasaki coast, Japan, the beach profile has been measured for 34 years at a daily to weekly time interval. This beach morphological dataset is one of the longest and most high-frequency measurements of the beach morphological change worldwide. The profile data, with more than 6800 records, reflect short- to long-term beach morphological change, showing coastal dune development, foreshore morphological change and longshore bar movement. We investigated the temporal beach variability from the decadal and monthly variations in elevation. Extremely high waves and tidal anomalies from an extratropical cyclone caused a significant change in the long-term bar behavior and foreshore slope. The berm and bar variability were also affected by seasonal wave and water level variations. The variabilities identified here from the long-term observations contribute to our understanding of various coastal phenomena.

scholarly journals Long-term monitoring programme of the hydrological variability in the Mediterranean Sea: a first overview of the HYDROCHANGES network

Ocean Science ◽  
2013 ◽  
Vol 9 (2) ◽  
pp. 301-324 ◽  
Author(s):  
K. Schroeder ◽  
C. Millot ◽  
L. Bengara ◽  
S. Ben Ismail ◽  
M. Bensi ◽  
...  
Keyword(s):  
Time Series ◽  
Mediterranean Sea ◽  
Sampling Interval ◽  
Global Changes ◽  
Hydrological Variability ◽  
Long Term Monitoring ◽  
The Mediterranean ◽  
Set Up ◽  
Term Monitoring

Abstract. The long-term monitoring of basic hydrological parameters (temperature and salinity), collected as time series with adequate temporal resolution (i.e. with a sampling interval allowing the resolution of all important timescales) in key places of the Mediterranean Sea (straits and channels, zones of dense water formation, deep parts of the basins), constitute a priority in the context of global changes. This led CIESM (The Mediterranean Science Commission) to support, since 2002, the HYDROCHANGES programme (http//www.ciesm.org/marine/programs/hydrochanges.htm), a network of autonomous conductivity, temperature, and depth (CTD) sensors, deployed on mainly short and easily manageable subsurface moorings, within the core of a certain water mass. The HYDROCHANGES strategy is twofold and develops on different scales. To get information about long-term changes of hydrological characteristics, long time series are needed. But before these series are long enough they allow the detection of links between them at shorter timescales that may provide extremely valuable information about the functioning of the Mediterranean Sea. The aim of this paper is to present the history of the programme and the current set-up of the network (monitored sites, involved groups) as well as to provide for the first time an overview of all the time series collected under the HYDROCHANGES umbrella, discussing the results obtained thanks to the programme.

How the Desert got a Past: A History of Quaternary Research in Australia’s Deserts

2014 ◽  
Vol 25 (2) ◽  
pp. 172 ◽  
Author(s):  
Mike Smith
Keyword(s):  
Climate Changes ◽  
Conceptual Space ◽  
The Past ◽  
History Of ◽  
The 1960S

This paper examines how the past of desert landscapes has been interpreted since European explorers and scientists first encountered them. It charts the research that created the conceptual space within which archaeologists and Quaternarists now work. Studies from the 1840s–1960s created the notion of a ‘Great Australian Arid Period'. The 1960s studies of Lake Mungo and the Willandra Lakes by Jim Bowler revealed the cyclical nature of palaeolakes, that changed with climate changes in the Pleistocene, and the complexity of desert pasts. SLEADS and other researchers in the 1980s used thermoluminescence techniques that showed further complexities in desert lands beyond the Willandra particularly through new studies in the Strzelecki and Simpson Dunefields, Lake Eyre, Lake Woods and Lake Gregory. Australian deserts are varied and have very different histories. Far from ‘timeless lands', they have carried detailed information about long-term climate changes on continental scales.

scholarly journals Analysis of climate change in Dnipropetrovsk Region

2017 ◽  
pp. 43-51
Author(s):  
V. V. Hrynchak
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Climate Changes ◽  
Absolute Temperature ◽  
Climatic Conditions ◽  
Annual Precipitation ◽  
Temperature And Precipitation ◽  
Weather Observations ◽  
Average Annual Temperature

The decision about writing this article was made after familiarization with the "Brief Climatic Essay of Dnepropetrovsk City (prepared based on observations of 1886 – 1937)" written by the Head of the Dnipropetrovsk Weather Department of the Hydrometeorological Service A. N. Mikhailov. The guide has a very interesting fate: in 1943 it was taken by the Nazis from Dnipropetrovsk and in 1948 it returned from Berlin back to the Ukrainian Hydrometeorological and Environmental Directorate of the USSR, as evidenced by a respective entry on the Essay's second page. Having these invaluable materials and data of long-term weather observations in Dnipro city we decided to analyze climate changes in Dnipropetrovsk region. The article presents two 50-year periods, 1886-1937 and 1961-2015, as examples. Series of observations have a uniform and representative character because they were conducted using the same methodology and results processing. We compared two main characteristics of climate: air temperature and precipitation. The article describes changes of average annual temperature values and absolute temperature values. It specifies the shift of seasons' dates and change of seasons' duration. We studied the changes of annual precipitation and peculiarities of their seasonable distribution. Apart from that peculiarities of monthly rainfall fluctuations and their heterogeneity were specified. Since Dnipro city is located in the center of the region the identified tendencies mainly reflect changes of climatic conditions within the entire Dnipropetrovsk region.

scholarly journals Dissolved Inorganic Nutrients in the Western Mediterranean Sea (2004–2017)

2019 ◽  
Author(s):  
Malek Belgacem ◽  
Jacopo Chiggiato ◽  
Mireno Borghini ◽  
Bruno Pavoni ◽  
Gabriella Cerrati ◽  
...  
Keyword(s):  
Quality Control ◽  
Mediterranean Sea ◽  
Western Mediterranean ◽  
Inorganic Nutrients ◽  
Marginal Seas ◽  
Western Mediterranean Sea ◽  
Dissolved Inorganic Nutrients ◽  
Climate Shifts ◽  
Quality Control Techniques

Abstract. Long-term time-series are a fundamental prerequisite to understand and detect climate shifts and trends. Understanding the complex interplay of changing ocean variables and the biological implication for marine ecosystems requires extensive data collection for monitoring and hypothesis testing and validation of modelling products. In marginal seas, such as Mediterranean Sea, there are still monitoring gaps, both in time and in space. To contribute filling these gaps, an extensive dataset of dissolved inorganic nutrients profiles (nitrate, NO3; phosphate, PO43−; and silicate, SiO2) have been collected between 2004 and 2017 in the Western Mediterranean Sea and subjected to quality control techniques to provide to the scientific community a publicly available, long-term, quality controlled, internally consistent biogeochemical data product. The database includes 870 stations of dissolved inorganic nutrients sampled during 24 cruises, including temperature and salinity. Details of the quality control (primary and secondary quality control) applied are reported. The data are available in PANGAEA (https://doi.org/10.1594/PANGAEA.904172, Belgacem et al. 2019).

Centennial to millennial-scale variability of Holocene climate and environmental dynamics in the western Mediterranean (Lake Sidi Ali, Middle Atlas, Morocco)

2021 ◽  
Author(s):  
Johannes Schmidt ◽  
Cathleen Kertscher ◽  
Markus Reichert ◽  
Helen Ballasus ◽  
Birgit Schneider ◽  
...  
Keyword(s):  
North Atlantic ◽  
Climate Changes ◽  
Western Mediterranean ◽  
Future Climate ◽  
Holocene Climate ◽  
The Holocene ◽  
The North ◽  
Middle Atlas ◽  
Environmental Responses

<p>The Western Mediterranean region including the North African desert margin is considered one of the most sensitive areas to future climate changes. In order to refine long-term scenarios for hydrological and environmental responses to future climate changes in this region, it is important to improve our knowledge about past environmental responses to climatic variability at centennial to millennial timescales. During the last two decades, the recovery and compilation of Holocene records from the subtropical North Atlantic and the Mediterranean Sea have improved our knowledge about millennial-scale variability of the Western Mediterranean palaeoclimate. The variabilities appear to affect regional precipitation patterns and environmental systems in the Western Mediterranean, but the timescales, magnitudes and forcing mechanisms remain poorly known. To compare the changes in Holocene climate variability and geomorphological processes across temporal scales, we analysed a 19.63-m long sediment record from Lake Sidi Ali (33°03’ N, 5°00’ W, 2080 m a.s.l.) in the sub-humid Middle Atlas that spans the last 12,000 years (23 pollen-based radiocarbon dates accompanied with <sup>210</sup>Pb results). We use calibrated XRF core scanning records with an annual to sub-decadal resolution to disentangle the complex interplay between climate changes and environmental dynamics during the Holocene. Data exploration techniques and time series analysis (Redfit, Wavelet) revealed long-term changes in lake behaviour. Three main proxy groups were identified (temperature proxies: 2ky, 1ky and 0.7ky cycles; sediment dynamic proxies: 3.5ky, 1.5ky cycles; hydrological proxies: 1.5ky, 1.2ky, 0.17ky cycles). For example, redox sensitive elements Fe and Mn show 1ky cycles and higher values in the Early Holocene and 1.5ky cycles and lower values in the Mid- to Late Holocene. All groups show specific periodicities throughout the Holocene, demonstrating their particular climatic and geomorphological dependencies. Furthermore, we discuss these periodicities relating to global and hemispheric drivers, such as the North Atlantic Oscillation (NAO), El-Niño Southern Oscillation (ENSO), Innertropical Convergence Zone variability (ITCZ) and North Atlantic cold relapses (Bond events).</p>

scholarly journals Sponge community variation along the Apulian coasts (Otranto Strait) over a pluri-decennial time span. Does water warming drive a sponge diversity increasing in the Mediterranean Sea?

2019 ◽  
Vol 99 (7) ◽  
pp. 1519-1534 ◽  
Author(s):  
Gabriele Costa ◽  
Giorgio Bavestrello ◽  
Valerio Micaroni ◽  
Maurizio Pansini ◽  
Francesca Strano ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Benthic Communities ◽  
Time Span ◽  
Biodiversity Monitoring ◽  
Sponge Diversity ◽  
Community Variation ◽  
The Mediterranean ◽  
Changes Over Time ◽  
Mass Mortalities

AbstractClimate change and heavy anthropic pressures are giving rise to important modifications in the rocky benthic communities of the Mediterranean Sea. In particular, sponge assemblages have been deeply affected due to the susceptibility of some species to dramatic phenomena such as mass mortalities or widespread variations in the abundance of other species. For this reason, long-term biodiversity monitoring of the sponge assemblages is important for understanding the direction of changes over time. We studied the sponge fauna living off Tricase Porto (Otranto Strait) and compared its composition with the results of a study conducted in the same area 50 years ago. The comparison indicated that the sponge diversity of this area has strongly increased in the last 50 years and a large number of the sponges recorded in the old survey are still present in the recent community. This evidence matches with other results obtained from different localities of the Mediterranean Sea indicating an increase of sponge diversity, possibly due to the present water warming. The description of two new Demosponge species, Diplastrella boeroi sp. nov. and Spirastrella angulata sp. nov., is also provided.

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