Biological consequences of global warming: does sea surface temperature affect cetacean distribution in the western Ligurian Sea?

2008 ◽  
Vol 88 (6) ◽  
pp. 1145-1152 ◽  
Author(s):  
A. Azzellino ◽  
S.A. Gaspari ◽  
S. Airoldi ◽  
C. Lanfredi
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Global Climate ◽  
Sperm Whale ◽  
Sea Surface ◽  
Distribution Data ◽  
Physeter Macrocephalus ◽  
Ligurian Sea ◽  
Stenella Coeruleoalba ◽  
Cetacean Distribution

The aim of this study was to assess if sea surface temperature does affect cetacean distribution in the western Ligurian Sea. Relationships with temperature were investigated for: striped dolphin (Stenella coeruleoalba), fin whale (Balaenoptera physalus) and sperm whale (Physeter macrocephalus). Remotely sensed sea surface temperature (SST) data were studied. A series of 20 monthly images (i.e. June to September monthly images from 1996 to 2000) was considered. Concurrently, distribution data collected during shipboard summer surveys, and covering an area of about 20,000 km2 in the western Ligurian Sea, were analysed. The relationship between the three species presence and SST was investigated by using a grid of 3 × 3 nautical mile cell units. For every cell the SST mean, standard deviation, coefficient of variance and the deviation from the monthly average were calculated. Finally, binary logistic regression functions allowed to assess significant (P < 0.05) relationships with temperature in these species. These logistic models, were able to predict 60–78% of the species presence(1)/absence(0) cells, and suggest the need for further investigations spanning longer time periods to assess how the global climate change has been changing and will change in the future cetacean distribution in the western Ligurian Sea.

scholarly journals A Process-Oriented Approach to Identify Evolutions of Sea Surface Temperature Anomalies with a Time-Series of a Raster Dataset

2021 ◽  
Vol 10 (8) ◽  
pp. 500
Author(s):  
Lianwei Li ◽  
Yangfeng Xu ◽  
Cunjin Xue ◽  
Yuxuan Fu ◽  
Yuanyu Zhang
Keyword(s):  
Time Series ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Global Climate ◽  
Sea Surface ◽  
Temperature Anomalies ◽  
Global Climate Changes ◽  
Space And Time ◽  
Novel Approach ◽  
Sea Surface Temperature Anomalies

It is important to consider where, when, and how the evolution of sea surface temperature anomalies (SSTA) plays significant roles in regional or global climate changes. In the comparison of where and when, there is a great challenge in clearly describing how SSTA evolves in space and time. In light of the evolution from generation, through development, and to the dissipation of SSTA, this paper proposes a novel approach to identifying an evolution of SSTA in space and time from a time-series of a raster dataset. This method, called PoAIES, includes three key steps. Firstly, a cluster-based method is enhanced to explore spatiotemporal clusters of SSTA, and each cluster of SSTA at a time snapshot is taken as a snapshot object of SSTA. Secondly, the spatiotemporal topologies of snapshot objects of SSTA at successive time snapshots are used to link snapshot objects of SSTA into an evolution object of SSTA, which is called a process object. Here, a linking threshold is automatically determined according to the overlapped areas of the snapshot objects, and only those snapshot objects that meet the specified linking threshold are linked together into a process object. Thirdly, we use a graph-based model to represent a process object of SSTA. A node represents a snapshot object of SSTA, and an edge represents an evolution between two snapshot objects. Using a number of child nodes from an edge’s parent node and a number of parent nodes from the edge’s child node, a type of edge (an evolution relationship) is identified, which shows its development, splitting, merging, or splitting/merging. Finally, an experiment on a simulated dataset is used to demonstrate the effectiveness and the advantages of PoAIES, and a real dataset of satellite-SSTA is used to verify the rationality of PoAIES with the help of ENSO’s relevant knowledge, which may provide new references for global change research.

scholarly journals The PRISM4 (mid-Piacenzian) paleoenvironmental reconstruction

2016 ◽  
Vol 12 (7) ◽  
pp. 1519-1538 ◽  
Author(s):  
Harry Dowsett ◽  
Aisling Dolan ◽  
David Rowley ◽  
Robert Moucha ◽  
Alessandro M. Forte ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Land Surface ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Sea Surface ◽  
Paleoenvironmental Reconstruction ◽  
Dynamic Topography ◽  
Intercomparison Project

Abstract. The mid-Piacenzian is known as a period of relative warmth when compared to the present day. A comprehensive understanding of conditions during the Piacenzian serves as both a conceptual model and a source for boundary conditions as well as means of verification of global climate model experiments. In this paper we present the PRISM4 reconstruction, a paleoenvironmental reconstruction of the mid-Piacenzian ( ∼  3 Ma) containing data for paleogeography, land and sea ice, sea-surface temperature, vegetation, soils, and lakes. Our retrodicted paleogeography takes into account glacial isostatic adjustments and changes in dynamic topography. Soils and lakes, both significant as land surface features, are introduced to the PRISM reconstruction for the first time. Sea-surface temperature and vegetation reconstructions are unchanged but now have confidence assessments. The PRISM4 reconstruction is being used as boundary condition data for the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) experiments.

scholarly journals A new global gridded sea surface temperature data product based on multisource data

2021 ◽  
Vol 13 (5) ◽  
pp. 2111-2134
Author(s):  
Mengmeng Cao ◽  
Kebiao Mao ◽  
Yibo Yan ◽  
Jiancheng Shi ◽  
Han Wang ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Global Climate ◽  
Observation Time ◽  
Sea Surface ◽  
In Situ Sensors ◽  
Time Correction ◽  
Accuracy Assessments ◽  
Observation Times

Abstract. Sea surface temperature (SST) is an important geophysical parameter that is essential for studying global climate change. Although sea surface temperature can currently be obtained through a variety of sensors (MODIS, AVHRR, AMSR-E, AMSR2, WindSat, in situ sensors), the temperature values obtained by different sensors come from different ocean depths and different observation times, so different temperature products lack consistency. In addition, different thermal infrared temperature products have many invalid values due to the influence of clouds, and passive microwave temperature products have very low resolutions. These factors greatly limit the applications of ocean temperature products in practice. To overcome these shortcomings, this paper first took MODIS SST products as a reference benchmark and constructed a temperature depth and observation time correction model to correct the influences of the different sampling depths and observation times obtained by different sensors. Then, we built a reconstructed spatial model to overcome the effects of clouds, rainfall, and land interference that makes full use of the complementarities and advantages of SST data from different sensors. We applied these two models to generate a unique global 0.041∘ gridded monthly SST product covering the years 2002–2019. In this dataset, approximately 25 % of the invalid pixels in the original MODIS monthly images were effectively removed, and the accuracies of these reconstructed pixels were improved by more than 0.65 ∘C compared to the accuracies of the original pixels. The accuracy assessments indicate that the reconstructed dataset exhibits significant improvements and can be used for mesoscale ocean phenomenon analyses. The product will be of great use in research related to global change, disaster prevention, and mitigation and is available at https://doi.org/10.5281/zenodo.4419804 (Cao et al., 2021a).

scholarly journals The PRISM4 (mid-Piacenzian) palaeoenvironmental reconstruction

2016 ◽  
Author(s):  
Harry Dowsett ◽  
Aisling Dolan ◽  
David Rowley ◽  
Matthew Pound ◽  
Ulrich Salzmann ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Land Surface ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Sea Surface ◽  
Dynamic Topography ◽  
Palaeoenvironmental Reconstruction ◽  
Intercomparison Project

Abstract. The mid-Piacenzian is known as a period of relative warmth when compared to the present day. A comprehensive understanding of conditions during the Piacenzian serves as both a conceptual model and a source for boundary conditions and means of verification of global climate model experiments. In this paper we present the PRISM4 reconstruction, a palaeoenvironmental reconstruction of the mid-Piacenzian (~ 3 Ma) containing data for palaeogeography, land and sea-ice, sea-surface temperature, vegetation, soils and lakes. Our retrodicted palaeogeography takes into account glacial isostatic adjustments and changes in dynamic topography. Soils and lakes, both significant as land surface features, are introduced to the PRISM reconstruction for the first time. Sea-surface temperature and vegetation reconstructions are unchanged but now have confidence assessments. The PRISM4 reconstruction is being used as boundary condition data for the Pliocene Model Intercomparison Project, Phase 2 (PlioMIP2) experiments.

scholarly journals DINEOF reconstruction of clouded images including error maps – application to the Sea-Surface Temperature around Corsican Island

Ocean Science ◽  
2006 ◽  
Vol 2 (2) ◽  
pp. 183-199 ◽  
Author(s):  
J.-M. Beckers ◽  
A. Barth ◽  
A. Alvera-Azcárate
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Empirical Orthogonal Functions ◽  
Sea Surface ◽  
Optimal Interpolation ◽  
Orthogonal Functions ◽  
Ligurian Sea ◽  
Additional Information ◽  
Error Covariance ◽  
Data Coverage

Abstract. We present an extension to the Data INterpolating Empirical Orthogonal Functions (DINEOF) technique which allows not only to fill in clouded images but also to provide an estimation of the error covariance of the reconstruction. This additional information is obtained by an analogy with optimal interpolation. It is shown that the error fields can be obtained with a clever rearrangement of calculations at a cost comparable to that of the interpolation itself. The method is presented on the reconstruction of sea-surface temperature in the Ligurian Sea and around the Corsican Island (Mediterranean Sea), including the calculation of inter-annual variability of average surface values and their expected errors. The application shows that the error fields are not only able to reflect the data-coverage structure but also the covariances of the physical fields.

Orbital-scale climatic record in the North China across the Pliocene-Pleistocene transition

2021 ◽  
Author(s):  
Ze Zhang ◽  
Zhixiang Wang ◽  
Chunju Huang
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Transition Period ◽  
Global Climate ◽  
East Asian ◽  
High Amplitude ◽  
Sea Surface ◽  
Equatorial Atlantic ◽  
East Asian Climate ◽  
Sst Gradient

&lt;p&gt;The Pliocene - Pleistocene period (3.6-1.8 Ma) was a significant global cooling time, from very warm, equable climates to high-amplitude glacial-interglacial cycles. The origin of glaciers in the Northern Hemisphere, and the mechanisms by which glacial cycles have expanded since the late Pliocene, remain a subject of ongoing discussion. The studies of the Pliocene orbital scale climate evolution mainly are focused on marine sediments and loess-paleosoil sequences, however, there are few records of continental lacustrine facies during this period. Here we present a 37.6 m high-resolution Sanmen lacustrine sequences during the Pliocene-Pleistocene transition period that indicates the astronomically controlling East Asian climate transition and the Sanmen paloelake evolution. The Rb/Sr series evolution was divided into two parts for astronomical analysis based on the obvious changes observed in curve shape and Evolutionary spectral analysis through the section: 7.4-19 and 19-45 m. Based on evaluation of average accumulation rates from paleomagnetic results, the dominated ~99-cm cycles in the 7.4 to 19 m intervals represent ~41 kyr obliquity cycles. The 19 to 45 m intervals show obvious cycles at ~232-cm, interpreting as ~100 kyr eccentricity. Astronomical tuning combined with paleomagnetic results has been used to establish the 3.83-2.32 Ma high-precision astronomical scale. Rb/Sr series reveals that ~100 kyr eccentricity was the dominant control on lake expansion for Sanmen paleolake evolutionary before 2.75 Ma, after that, dominant obliquity control. Based on re-established the meridional sea surface temperature (SST) gradient between polar Atlantic borehole ODP 982 and the equatorial Atlantic borehole ODP 662, results show that the meridional sea surface temperature gradients increased significantly at 2.75 Ma, with cyclicity changing from the dominant ~140 kyr and ~95 kyr cycles to ~41 kyr at 2.75 Ma, and is coeval with our Rb/Sr record in the Weihe Basin. Crossspectral analysis show that the Rb/Sr and meridional SST gradient are strongly coherent and almost in-phase at these primary orbital periods in the past between 3.83-2.32 Ma. Thus, we conclude that the reorganization of the East Asian climate system at ~2.75 Ma, which coincided with the expansion of Arctic ice sheet, was a response to a dramatic cooling of the global climate and obliquity-driven changes in meridional SST gradients.&lt;/p&gt;

Seasonal variation of striped dolphins, fin- and sperm whales' abundance in the Ligurian Sea (Mediterranean Sea)

2007 ◽  
Vol 87 (1) ◽  
pp. 345-352 ◽  
Author(s):  
Sophie Laran ◽  
Violaine Drouot-Dulau
Keyword(s):  
Relative Abundance ◽  
Sperm Whale ◽  
Line Transect ◽  
Physeter Macrocephalus ◽  
Monthly Basis ◽  
Ligurian Sea ◽  
Stenella Coeruleoalba ◽  
Abundance Indices ◽  
Fin Whales ◽  
Acoustic Sampling

In order to investigate seasonal changes in cetacean relative abundance, a series of surveys were conducted between the French mainland and Corsica. From February 2001 to February 2004, thirty similar transects were conducted monthly, using the same dedicated boat and a consistent sampling protocol, including visual observation and passive acoustic sampling. A total effort of 5759 km was sampled, conducted at the same speed and in good sighting conditions. Relative abundances of striped dolphins (Stenella coeruleoalba) and fin whales (Balaenoptera physalus) were determined using standard line-transect methodology. The relative abundance of striped dolphins peaked in May and September (>1.3×10-2 ind.km-1), while a consistent minimum value (<0.6×10-2 ind.km-1) was obtained from December to April. A maximum relative abundance of fin whales occurred in August with 5.6×10-2 ind.km-1 and decreased to almost zero from November to January. For sperm whale (Physeter macrocephalus), a long diver species, frequency and abundance indices were determined using acoustic sampling. The highest acoustic relative abundance was observed from August to October, with more than 2×10-2 ind.km-1. Environmental parameters (sea surface temperature and chlorophyll) were computed for the sampling area from remote sensing imagery and pooled on a monthly basis, to correlate with relative abundance indices of the three species.

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