scholarly journals The Challenges of Forecasting Small, But Mighty, Polar Lows

Eos ◽  
2021 ◽  
Vol 102 ◽  
Author(s):  
Marta Moreno Ib��ez
Keyword(s):  
Ocean Circulation ◽  
High Latitude ◽  
Coastal Communities ◽  
Economic Activities ◽  
Polar Lows

These intense maritime storms pose threats to high-latitude coastal communities and economic activities and may influence climate and ocean circulation.

scholarly journals The oceanographic contribution of James Croll

2021 ◽  
pp. 1-7
Author(s):  
Alastair DAWSON
Keyword(s):  
Ocean Circulation ◽  
High Latitude ◽  
First Principles ◽  
Heat Supply ◽  
Real Data ◽  
Ocean Currents ◽  
Ice Ages ◽  
Scientific Exploration ◽  
The Many

ABSTRACT The research of James Croll on the nature of Ice Ages led him into a detailed investigation of ocean currents. By the early 1870s he had calculated from first principles the quantities of heat delivered by ocean currents to high latitude areas and he understood how this heat supply may have altered drastically during ice ages. The publication of his many papers on ocean currents as well as his book, Climate and Time, coincided with Challenger expedition that, in 1872, embarked on a 4-year voyage of scientific exploration of the world's oceans. The expedition was crucially important for Croll since it enabled him to test his theories of ocean circulation using real data. His novel theories of ocean circulation based on this information conflicted with the established views popularly advocated by William Carpenter but they ultimately prevailed. In the many writings of Croll on ocean currents, we encounter, as with other areas of his research, numerous remarkable ideas many decades ahead their time.

scholarly journals Paleocene-Eocene volcanic segmentation of the Norwegian-Greenland seaway reorganized high-latitude ocean circulation

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Jussi Hovikoski ◽  
Michael B. W. Fyhn ◽  
Henrik Nøhr-Hansen ◽  
John R. Hopper ◽  
Steven Andrews ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
High Latitude ◽  
Seismic Reflection ◽  
Arctic Region ◽  
Climatic Conditions ◽  
The Arctic ◽  
Early Eocene ◽  
Subaerial Exposure ◽  
Thermal Maximum ◽  
Volcanic Facies

AbstractThe paleoenvironmental and paleogeographic development of the Norwegian–Greenland seaway remains poorly understood, despite its importance for the oceanographic and climatic conditions of the Paleocene–Eocene greenhouse world. Here we present analyses of the sedimentological and paleontological characteristics of Paleocene–Eocene deposits (between 63 and 47 million years old) in northeast Greenland, and investigate key unconformities and volcanic facies observed through seismic reflection imaging in offshore basins. We identify Paleocene–Eocene uplift that culminated in widespread regression, volcanism, and subaerial exposure during the Ypresian. We reconstruct the paleogeography of the northeast Atlantic–Arctic region and propose that this uplift led to fragmentation of the Norwegian–Greenland seaway during this period. We suggest that the seaway became severely restricted between about 56 and 53 million years ago, effectively isolating the Arctic from the Atlantic ocean during the Paleocene–Eocene thermal maximum and the early Eocene.

scholarly journals Coastal Nutrition Status of the Country Reviewed from Social Culture and Islamic Perspective

2020 ◽  
Vol 7 (2) ◽  
pp. 17
Author(s):  
Eliska Eliska ◽  
Nurhayati Nurhayati ◽  
Petti Sitti Fatimah
Keyword(s):  
Nutritional Status ◽  
Quantitative Research ◽  
Sampling Method ◽  
Total Population ◽  
Coastal Communities ◽  
Nutrition Status ◽  
School Age Children ◽  
Economic Activities ◽  
Social Culture ◽  
Daily Work

Coastal communities are people who live and carry out socio-economic activities that depend on coastal resources, one of which is fishermen. The cultural identity of coastal communities as a whole is formed from the culture of fishermen who are directly related to the management of coastal and marine resources. Nutritional problems arise not only from health problems but also influenced by social culture and religion. The design of this study uses quantitative research with a Cross Sectional.The sample is the total population selected by the purposive sampling method, which is 71 students from five schools. The instrument in this study used a questionnaire. Techniques and data processing are carried out by using a computer program to present data in the form of frequency and then the results are presented in the table. It is known that there is a relationship between nutritional status and socio-culture in coastal communities because the nutritional status of school-age children is below the threshold of 25.4%, and 12.7% is very thin. This happens because most parents of students have daily work as fishermen so that the lack of income from parents causes children's nutritional intake to decrease, while seen from the cultural tribes of the coastal community there are more Javanese tribes which result in low nutritional status due to lack of variety in food intake.

scholarly journals High-latitude ocean ventilation and its role in Earth's climate transitions

2017 ◽  
Vol 375 (2102) ◽  
pp. 20160324 ◽  
Author(s):  
Alberto C. Naveira Garabato ◽  
Graeme A.  MacGilchrist ◽  
Peter J. Brown ◽  
D. Gwyn Evans ◽  
Andrew J. S. Meijers ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
High Latitude ◽  
Climate System ◽  
High Latitudes ◽  
Overturning Circulation ◽  
Ocean Ventilation ◽  
Earth’S Climate ◽  
Warming World ◽  
Climate Transitions

The processes regulating ocean ventilation at high latitudes are re-examined based on a range of observations spanning all scales of ocean circulation, from the centimetre scales of turbulence to the basin scales of gyres. It is argued that high-latitude ocean ventilation is controlled by mechanisms that differ in fundamental ways from those that set the overturning circulation. This is contrary to the assumption of broad equivalence between the two that is commonly adopted in interpreting the role of the high-latitude oceans in Earth's climate transitions. Illustrations of how recognizing this distinction may change our view of the ocean's role in the climate system are offered. This article is part of the themed issue ‘Ocean ventilation and deoxygenation in a warming world’.

The impact of insolation, greenhouse gas forcing and ocean circulation changes on glacial inception

The Holocene ◽  
2011 ◽  
Vol 21 (5) ◽  
pp. 803-817 ◽  
Author(s):  
G. Vettoretti ◽  
W.R. Peltier
Keyword(s):  
Snow Cover ◽  
Greenhouse Gas ◽  
Ocean Circulation ◽  
High Latitude ◽  
Goodness Of Fit ◽  
Decadal Variability ◽  
Snow Accumulation ◽  
High Northern Latitude ◽  
The Future ◽  
The Impact

In this study we employ the NCAR CCSM3 coupled model to investigate the onset of high northern latitude perennial snow cover. Two periods of Earth’s insolation history, that of the pre-industrial period and that of 116 ka before present (BP), are used as benchmarks in an investigation of the influences of interglacial greenhouse gas (GHG) concentration and insolation upon the occurrence of permanent summer snow cover. An additional two experiments at 10 ka and 51 ka into the future (AP) using a typical interglacial GHG level are used to investigate the length of the current interglacial. Results from this set of multicentury sensitivity experiments demonstrate the relative importance of forcings due to insolation and atmospheric greenhouse gases at the millennial scale, and of Atlantic ocean overturning strength (AMOC) at the century scale. We find that while areas of perennial snow cover are sensitive to GHG concentrations, they are much more sensitive to the contemporaneous insolation regime. The goodness of fit of the climatology of the control model to the modern observed climatology is found to influence the modeling results. While there is a strong correlation between AMOC decadal variability and high latitude surface temperature in our control climates, we find little change in AMOC strength during our simulations of 116 ka BP climate nor do we find significant correlation between high latitude snow accumulation and the AMOC. Both the 10 ka AP and 51 ka AP future simulations produce inception events which are much stronger than that of the equivalent pre-industrial simulation. The simulation of inception at 10 ka into the future suggests a maximum duration of the current interglacial of approximately 20 ka in the absence of modern anthropogenic forcing.

scholarly journals Between the sea and the land: the livelihood of estuarine people in southeastern Brazil

2007 ◽  
Vol 10 (1) ◽  
pp. 121-136 ◽  
Author(s):  
Natalia anazaki ◽  
Fabio de Castro ◽  
Vivian Gladys Oliveira ◽  
Nivaldo Peroni
Keyword(s):  
Agricultural Practices ◽  
Forest Products ◽  
Coastal Communities ◽  
Southeastern Brazil ◽  
Small Scale ◽  
Brazilian Coast ◽  
Economic Activities ◽  
Central Focus ◽  
External Pressures ◽  
Estuarine Region

The central focus of this study is to characterize and compare the livelihood strategies of two coastal communities from the estuarine region of Ribeira Valley (São Paulo State, Southeastern Brazil), analyzing the interplay among four economic activities: small-scale agriculture, fishing, tourism-related jobs, and extraction of non-timber vegetal resources. The local people of these communities are mostly Caiçara, the native inhabitants of southeastern Brazilian coast, in an Atlantic forest area. The miscegenation of Amerindians, European colonizers, and African Brazilians gave rise to the Caiçara people, whose subsistence was originally based on small-scale itinerant agriculture, small-scale fishery, and some extraction of forest products. Their livelihoods activities changed through time: agricultural practices were gradually abandoned, while fishing grew in importance. Recently, tourism-related jobs and the extraction of non-timber vegetal resources acquired a key role in the estuarine Caiçara livelihood. After an historical overview, we focus our analysis on the local factors and external pressures affecting the combination of these activities.

Livelihood Diversification Through Tourism: Identity, Well-Being, and Potential in Rural Coastal Communities

2022 ◽  
Author(s):  
Albert Nsom Kimbu ◽  
Irma Booyens ◽  
Anke Winchenbach
Keyword(s):  
Rural Communities ◽  
Rural Livelihoods ◽  
Well Being ◽  
Coastal Communities ◽  
Small Scale ◽  
Livelihood Diversification ◽  
Way Of Life ◽  
Economic Activities ◽  
Resource Decline

Traditional rural livelihoods are disappearing due to natural resource decline, climate pressure and, also modernization. This study explores livelihood diversification from primary economic activities into tourism employment in rural communities. We examine the developmental role of tourism in areas where traditional activities, in this case fishing, have declined and tourism is growing. This article presents the findings of two case studies: the coastal communities of Padstow (UK) and Paternoster (South Africa). The approach is qualitative and draws on sustainable livelihoods and social well-being notions to examine how affected people “cope with change” with respect to tourism diversification, and individual and community well-being. While the socioeconomic and sociopolitical contexts in the two research sites differ, the findings show that narratives about belonging and identity feature prominently with respect to fishing livelihoods in both cases. Small-scale fishing, perceived as a way of life for fishers, is under threat in both areas, yet there is limited evidence of concerted efforts to plan and manage the potential diversification processes into tourism. Nonetheless, we observe that tourism does provide some opportunities for fishing-dependent communities and outline some avenues for stronger collaboration, particularly by focusing on culinary tourism.

Characteristics and variability of ocean ventilation in the high-latitude North Atlantic in an eddy-permitting ocean model

2021 ◽  
Author(s):  
Helen L. Johnson ◽  
Graeme MacGilchrist ◽  
David P. Marshall ◽  
Camille Lique ◽  
Matthew Thomas ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
Mixed Layer ◽  
North Atlantic ◽  
High Latitude ◽  
Circulation Model ◽  
Open Ocean ◽  
Labrador Sea ◽  
Surface Mixed Layer ◽  
Atmospheric Forcing ◽  
Boundary Current

<p>A substantial fraction of the deep ocean is ventilated in the high latitude North Atlantic. As a result, the region plays a crucial role in transient climate change through the uptake of carbon dioxide and heat. We investigate the nature of ventilation in the high latitude North Atlantic in an eddy-permitting numerical ocean circulation model using a set of comprehensive Lagrangian trajectory experiments. Backwards-in-time trajectories from a model-defined ‘North Atlantic Deep Water’ (NADW) reveal the times and locations of subduction from the surface mixed layer at high temporal and spatial resolution. The major fraction (∼60%) of NADW ventilation results from subduction directly into the Labrador Sea boundary current, with a smaller fraction (∼25%) arising from open ocean deep convection in the Labrador Sea. There is a notable absence of ventilation arising from subduction in the Greenland–Iceland–Norwegian Seas, due to the re-entrainment of those waters as they move southward. Temporal variability in ventilation arises both from changes in subduction — driven by large-scale atmospheric forcing — and from year-to-year changes in the subsurface retention of newly subducted water, the result of an inter-annual equivalent of Stommel’s mixed layer demon. This interannual demon operates most effectively in the open ocean where newly subducted water is slow to escape its region of subduction. Thus, while subduction in the boundary current dominates NADW ventilation, processes in the open ocean set the variability, mediating the translation of inter-annual variations in atmospheric forcing to the ocean interior.</p>

Late cretaceous ocean circulation in the south Atlantic and Pacific oceans

2019 ◽  
Author(s):  
◽  
Shannon Haynes
Keyword(s):  
Indian Ocean ◽  
Ocean Circulation ◽  
Late Cretaceous ◽  
North Atlantic ◽  
High Latitude ◽  
Climate Model ◽  
South Atlantic ◽  
Regional Studies ◽  
Circulation Patterns ◽  
Insight Into

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Cooling during the last 15 million years of the Cretaceous is widely believed to have resulted in a reorganization of ocean circulation, with cooler periods being associated with deep ocean convection in high latitude regions (e.g., Robinson et al., 2010; MacLeod et al., 2011; Robinson and Vance, 2012; Jung et al., 2013). Understanding the relationship between climate change and sub-surface ocean circulation patterns, and gaining further insight into how circulation dynamics were influenced by the unique Cretaceous paleobathymetry is crucial to furthering our understanding of global climate dynamics during the Late Cretaceous. To provide further insight into Late Cretaceous ocean circulation we used neodymium isotopes as a tool to infer past ocean circulation patterns. Neodymium was extracted from fossilized fish teeth and bone fragments from bulk rock samples at 26 different sites (4 Pacific, 12 South Atlantic, 3 North Atlantic, 3 proto-Indian Ocean). We present two regional studies that focus on Campanian (84-72 Ma) and Maastrichtian (72-66 Ma) circulation patterns in the Pacific (Chapter 2) and South Atlantic (Chapter 3) Oceans. These chapters argue that, by the end of the Cretaceous, climate had cooled enough to support high latitude convection but also that circulation patterns were tightly controlled by bathymetry. To investigate the global implications of these two regional studies we also present preliminary neodymium isotopic data from several sites in the North Atlantic and proto-Indian Ocean (Chapter 4). Further, neodymium isotopic trends were compared to climate model simulations as well as to previously published neodymium, carbon, and oxygen isotopic records.

scholarly journals Interhemispheric Asymmetry of Warming in an Eddy-Permitting Coupled Sector Model

2015 ◽  
Vol 28 (18) ◽  
pp. 7385-7406 ◽  
Author(s):  
David K. Hutchinson ◽  
Matthew H. England ◽  
Andrew M. Hogg ◽  
Kate Snow
Keyword(s):  
Sea Ice ◽  
Heat Transport ◽  
Ocean Circulation ◽  
High Latitude ◽  
Climate Model ◽  
Mean Flow ◽  
Surface Warming ◽  
Sector Model ◽  
Air Temperatures ◽  
Wide Sector

Abstract Climate model projections and observations show a faster rate of warming in the Northern Hemisphere (NH) than the Southern Hemisphere (SH). This asymmetry is partly due to faster rates of warming over the land than the ocean, and partly due to the ocean circulation redistributing heat toward the NH. This study examines the interhemispheric warming asymmetry in an intermediate complexity coupled climate model with eddy-permitting (0.25°) ocean resolution, and results are compared with a similar model with coarse (1°) ocean resolution. The models use a pole-to-pole 60° wide sector domain in the ocean and a 120° wide sector in the atmosphere, with Atlantic-like bathymetry and a simple land model. There is a larger high-latitude ocean temperature asymmetry in the 0.25° model compared with the 1° model, both in equilibrated control runs and in response to greenhouse warming. The larger warming asymmetry is caused by greater melting of NH sea ice in the 0.25° model, associated with faster, less viscous boundary currents transporting heat northward. The SH sea ice and heat transport response is relatively insensitive to the resolution change, since the eddy heat transport differences between the models are small compared with the mean flow heat transport. When a wind shift and intensification is applied in these warming scenarios, the warming asymmetry is further enhanced, with greater upwelling of cool water in the Southern Ocean and enhanced warming in the NH. Surface air temperatures show a substantial but lesser degree of high-latitude warming asymmetry, reflecting the sea surface warming patterns over the ocean but warming more symmetrically over the land regions.

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