scholarly journals Dynamics and Impacting Factors of Ice Regimes in Latvia Inland and Coastal Waters

2016 ◽  
Vol 70 (6) ◽  
pp. 400-408 ◽  
Author(s):  
Māris Kļaviņš ◽  
Zanita Avotniece ◽  
Valērijs Rodinovs
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
North Atlantic ◽  
Sea Water ◽  
Inland Waters ◽  
The North ◽  
The North Atlantic ◽  
Ice Regime ◽  
The Impact

Abstract The sea ice regime is considered to be a sensitive indicator of climate change. This study investigates long-term changes in the ice regimes of the Gulf of Riga along the coast of Latvia in comparison with those of inland waters. The ice regime of the studied region indicates the impact of climate change related to increasing air and sea water temperatures. Ice cover duration on both the sea and inland waters has decreased during recent decades. In addition, long-term records on ice break in the studied region exhibit a pattern of periodic changes in the intensity of ice regime, while trends of the sea ice regime are not consistent between periods of time. Alternating mild and severe winters also occur. The ice regime was shown to be strongly influenced by large-scale atmospheric circulation processes over the North Atlantic, as indicated by close correlation with the North Atlantic Oscillation index.

Preaching and Sermons

2017 ◽  
Author(s):  
Robert H. Ellison
Keyword(s):  
Eighteenth Century ◽  
North Atlantic ◽  
Religious Revival ◽  
Early Nineteenth Century ◽  
Denominational Identity ◽  
The North ◽  
The North Atlantic ◽  
The One ◽  
The Impact

Prompted by the convulsions of the late eighteenth century and inspired by the expansion of evangelicalism across the North Atlantic world, Protestant Dissenters from the 1790s eagerly subscribed to a millennial vision of a world transformed through missionary activism and religious revival. Voluntary societies proliferated in the early nineteenth century to spread the gospel and transform society at home and overseas. In doing so, they engaged many thousands of converts who felt the call to share their experience of personal conversion with others. Though social respectability and business methods became a notable feature of Victorian Nonconformity, the religious populism of the earlier period did not disappear and religious revival remained a key component of Dissenting experience. The impact of this revitalization was mixed. On the one hand, growth was not sustained in the long term and, to some extent, involvement in interdenominational activity undermined denominational identity; on the other hand, Nonconformists gained a social and political prominence they had not enjoyed since the middle of the seventeenth century and their efforts laid the basis for the twentieth-century explosion of evangelicalism in Africa, Asia, and South America.

Tropical cloud-radiative changes contribute to robust DJF jet exit strengthening over Europe under global warming

2021 ◽  
Author(s):  
Nicole Albern ◽  
Aiko Voigt ◽  
Joaquim G. Pinto
Keyword(s):  
Climate Change ◽  
North Atlantic ◽  
Storm Track ◽  
Tropical Pacific ◽  
Jet Stream ◽  
The North ◽  
The North Atlantic ◽  
Stream Response ◽  
The Impact ◽  
North Atlantic Jet

<p>During boreal winter (December to February, DJF), the North Atlantic jet stream and storm track are expected to extend eastward over Europe in response to climate change. This will affect future weather and climate over Europe, for example by steering storms which are associated with strong winds and heavy precipitation towards Europe. The jet stream and storm track responses over Europe are robust across coupled climate models of phases 3, 5, and 6 of the Coupled Model Intercomparison Project (CMIP; Harvey et al., 2020, JGR-A, https://doi.org/10.1029/2020JD032701). We show that the jet stream response is further robust across CMIP5 models of varying complexity ranging from coupled climate models to atmosphere-only General Circulation Models (GCMs) with prescribed sea-surface temperatures (SSTs) and sea-ice cover. In contrast to the jet stream response over Europe, the jet stream response over the North Atlantic is not robust in the coupled climate models and the atmosphere-only GCMs.</p><p>In addition to the CMIP5 simulations, we investigate Amip-like simulations with the atmospheric components of ICON-NWP, and the CMIP5 models MPI-ESM-LR and IPSL-CM5A-LR that apply the cloud-locking method to break the cloud-radiation-circulation coupling and to diagnose the contribution of cloud-radiative changes on the jet stream response to climate change. In the simulations, SSTs are prescribed to isolate the impact of cloud-radiative changes via the atmospheric pathway, i.e., via changes in atmospheric cloud-radiative heating, and global warming is mimicked by a uniform 4K SST increase (cf. Albern et al., 2019, JAMES, https://doi.org/10.1029/2018MS001592 and Voigt et al., 2019, J. Climate, https://doi.org/10.1175/JCLI-D-18-0810.1). In all three models, cloud-radiative changes contribute significantly and robustly to the eastward extension of the North Atlantic jet stream towards Europe. At the same time, cloud-radiative changes contribute to the model uncertainty over the North Atlantic. In addition to the jet stream response, we investigate the impact of cloud-radiative changes on the storm track response in ICON-NWP and discuss similarities and differences between the jet stream and storm track responses over the North Atlantic-European region.</p><p>In ICON-NWP, the impact of cloud-radiative changes on the jet stream response is dominated by tropical cloud-radiative changes while midlatitude and polar cloud-radiative changes have a minor impact. A further division of the tropics into four smaller tropical regions that cover the western tropical Pacific, the eastern tropical Pacific, the tropical Atlantic, and the Indian Ocean shows that cloud-radiative changes over the western tropical Pacific, eastern tropical Pacific, and Indian Ocean all contribute about equally to the eastward extension of the North Atlantic jet stream towards Europe because these regions exhibit substantial upper-tropospheric cloud-radiative heating in response to climate change. At the same time, cloud-radiative changes over the tropical Atlantic hardly contribute to the jet response over Europe because changes in atmospheric cloud-radiative heating under climate change are small in this region. As for the impact of global cloud-radiative changes, we also discuss the impact of the regional cloud-radiative changes on the storm track response over the North Atlantic-European region to climate change.</p>

scholarly journals Atmospheric teleconnection patterns and eddy kinetic energy content: wavelet analysis

2004 ◽  
Vol 11 (3) ◽  
pp. 295-301 ◽  
Author(s):  
V. N. Khokhlov ◽  
A. V. Glushkov ◽  
I. A. Tsenenko
Keyword(s):  
Kinetic Energy ◽  
North Atlantic ◽  
Energy Content ◽  
Southern Oscillation ◽  
Eddy Kinetic Energy ◽  
The North ◽  
The North Atlantic ◽  
The Impact ◽  
The Relationship

Abstract. In this paper, we employ a non-decimated wavelet decomposition to analyse long-term variations of the teleconnection pattern monthly indices (the North Atlantic Oscillation and the Southern Oscillation) and the relationship of these variations with eddy kinetic energy contents (KE) in the atmosphere of mid-latitudes and tropics. Major advantage of using this tool is to isolate short- and long-term components of fluctuations. Such analysis allows revealing basic periodic behaviours for the North Atlantic Oscillations (NAO) indices such as the 4-8-year and the natural change of dominant phase. The main results can be posed as follows. First, if the phases of North Atlantic and Southern Oscillations vary synchronously with the 4-8-year period then the relationship between the variations of the NAO indices and the KE contents is the most appreciable. Second, if the NAO phase tends to abrupt changes then the impact of these variations on the eddy kinetic energy contents in both mid-latitudes and tropics is more significant than for the durational dominance of certain phase.

scholarly journals The Impact of Natural and Anthropogenic Climate Change on Western North Pacific Tropical Cyclone Tracks*

2015 ◽  
Vol 28 (5) ◽  
pp. 1806-1823 ◽  
Author(s):  
Angela J. Colbert ◽  
Brian J. Soden ◽  
Ben P. Kirtman
Keyword(s):  
Climate Change ◽  
North Atlantic ◽  
North Pacific ◽  
Western North Pacific ◽  
Large Scale ◽  
Anthropogenic Climate Change ◽  
The North ◽  
Steering Flow ◽  
The North Atlantic ◽  
The Impact

Abstract The impact of natural and anthropogenic climate change on tropical cyclone (TC) tracks in the western North Pacific (WNP) is examined using a beta and advection model (BAM) to isolate the influence of changes in the large-scale steering flow from changes in genesis location. The BAM captures many of the observed changes in TC tracks due to El Niño–Southern Oscillation (ENSO), while little change is noted for the Pacific decadal oscillation and all-India monsoon rainfall in either observations or BAM simulations. Analysis with the BAM suggests that the observed shifts in the average track between the phases of ENSO are primarily due to changes in the large-scale steering flow, with changes in genesis location playing a secondary role. Potential changes in TC tracks over the WNP due to anthropogenic climate change are also assessed. Ensemble mean projections are downscaled from 17 CMIP3 models and 26 CMIP5 models. Statistically significant decreases [~(4%–6%)] in westward moving TCs and increases [~(5%–7%)] in recurving ocean TCs are found. These correspond to projected decreases of 3–5 TCs per decade over the Philippines and increases of 1–3 TCs per decade over the central WNP. The projected changes are primarily caused by a reduction in the easterlies. This slows the storm movement, allowing more time for the beta drift to carry the storm northward and recurve. A previous study found similar results in the North Atlantic. Taken together, these results suggest that a weakening of the mean atmospheric circulation in response to anthropogenic warming will lead to fewer landfalling storms over the North Atlantic and WNP.

scholarly journals Marine biological shifts and climate

2014 ◽  
Vol 281 (1783) ◽  
pp. 20133350 ◽  
Author(s):  
Grégory Beaugrand ◽  
Eric Goberville ◽  
Christophe Luczak ◽  
Richard R Kirby
Keyword(s):  
Climate Change ◽  
North Atlantic ◽  
Significant Proportion ◽  
Calanus Finmarchicus ◽  
The North ◽  
The North Sea ◽  
Community Shifts ◽  
The North Atlantic ◽  
Spatio Temporal

Phenological, biogeographic and community shifts are among the reported responses of marine ecosystems and their species to climate change. However, despite both the profound consequences for ecosystem functioning and services, our understanding of the root causes underlying these biological changes remains rudimentary. Here, we show that a significant proportion of the responses of species and communities to climate change are deterministic at some emergent spatio-temporal scales, enabling testable predictions and more accurate projections of future changes. We propose a theory based on the concept of the ecological niche to connect phenological, biogeographic and long-term community shifts. The theory explains approximately 70% of the phenological and biogeographic shifts of a key zooplankton Calanus finmarchicus in the North Atlantic and approximately 56% of the long-term shifts in copepods observed in the North Sea during the period 1958–2009.

scholarly journals Linearity of the Atmospheric Response to North Atlantic SST and Sea Ice Anomalies

2005 ◽  
Vol 18 (12) ◽  
pp. 1986-2003 ◽  
Author(s):  
Sébastien Conil ◽  
Laurent Z-X. Li
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Geopotential Height ◽  
Winter Season ◽  
Low Frequency ◽  
Temperature Response ◽  
Low Level ◽  
The North ◽  
The North Atlantic

Abstract The observations of the ocean–atmosphere–sea ice have recently revealed that the oceanic surfaces can have a subtle but significant impact on the atmospheric long-term fluctuations. Low-frequency variations and long-term trends of the North Atlantic atmospheric circulation have been partly related to particular SST and sea ice features. In this work, the influence of typical tripolar SST and dipolar sea ice anomalies in the North Atlantic–Arctic on the atmosphere is investigated. A large ensemble of AGCM simulations forced by three different anomalous boundary conditions (SST, sea ice, and SST + sea ice) are used. The linearity of the simulated response in the winter season is particularly assessed. In these experiments, while the winter low-level temperature response is mainly symmetric about the sign of the forcing, the asymmetric part of the geopotential response is substantial. The sea ice forcing maintains a baroclinic response with a strong temperature anomaly in the vicinity of the forcing but with a weak vertical penetration. The SST maintains an NAO-like equivalent barotropic temperature and geopotential height response that extends throughout the troposphere. It is also shown that the combination of the two forcings is mainly linear for the low-level temperature and nonlinear for the geopotential height. While the SST forcing seems to be the main contributor to the total temperature and geopotential height responses, the sea ice forcing appears to introduce significant nonlinear perturbations.

scholarly journals Short-term response to the North Atlantic Oscillation but no long-term effects of climate change on the reproductive success of an alpine bird

2010 ◽  
Vol 152 (3) ◽  
pp. 631-641 ◽  
Author(s):  
Jean-Yves Barnagaud ◽  
Pierre André Crochet ◽  
Yann Magnani ◽  
Ariane Bernard Laurent ◽  
Emmanuel Menoni ◽  
...  
Keyword(s):  
Climate Change ◽  
Reproductive Success ◽  
North Atlantic ◽  
Long Term Effects ◽  
Short Term ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation ◽  
Term Response

Malthus and the North Atlantic Oscillation: A Reply to Kyle Harper

2016 ◽  
Vol 46 (4) ◽  
pp. 563-578
Author(s):  
John L. Brooke
Keyword(s):  
Climate Change ◽  
North Atlantic Oscillation ◽  
Central Asia ◽  
North Atlantic ◽  
Large Scale ◽  
Classical Antiquity ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation ◽  
The Impact

Subsequent to Harper’s review essay centered on Brooke’s Climate Change and the Course of Global History: A Rough Journey, Brooke concedes that he could have focused more attention on the problem of the Malthusian trap. He stresses, nevertheless, that his reservations regarding the concept of Malthusian crises in pre-industrial societies are well placed, given the concept’s prominence in the large-scale environmental histories written during the past several decades. Turning to the impact of climate change in late classical antiquity, Brooke discusses established and new evidence for increasing, sometimes catastrophic, precipitation from the Mediterranean area into central Asia after a.d. 500 and after 1250, as a result of shifts toward the negative mode of the North Atlantic Oscillation. He also surveys the evidence for emerging arguments that this cooling-driven precipitation may have triggered outbreaks of bubonic plague in Central Asia.

Southern control of interhemispheric synergy on marine carbon sequestration during glacial cycles   

2021 ◽  
Author(s):  
Jinlong Du ◽  
Xu Zhang ◽  
Ying Ye ◽  
Christoph Völker ◽  
Jun Tian
Keyword(s):  
Carbon Sequestration ◽  
Southern Ocean ◽  
Sea Ice ◽  
North Atlantic ◽  
Glacial Cycles ◽  
The North ◽  
Carbon Pump ◽  
The North Atlantic ◽  
The Impact ◽  
Biological Carbon Pump

<p>The mechanisms of atmospheric CO2 draw-down by ~90 ppm during glacial cycles have been one of the most contentious questions in the past several decades. Processes in the Southern Ocean (SO) have been suggested to be at the heart, while the North Atlantic (NA) is recently proposed to be critical during glacial periods as well. However, in a full course of glacial cycles, the individual and synergic roles of these two regions remain enigmatic. Using a state-of-the-art biogeochemical model (MITgcm-REcoM2) associated with an interactive CO<sub>2</sub> module, we examined the impact of the onset of individual mechanisms and combinations of them on atmospheric CO<sub>2</sub>. Here we show that SO controls carbon sequestration in both hemispheres. In sensitivity runs with respect to mechanisms happening during glacial inceptions, cooling in SO contributes to a larger portion of CO<sub>2</sub> draw-down than cooling in NA, by shortening the surface water exposure time, while the early sea ice expansion tends to weaken the carbon uptake. The efficiency of surface carbon storage in the North Atlantic depends on the volume of Antarctic bottom water and reaches its maximum when the glacial stratification is well developed during glacial maxima.  SO cooling and sea ice expansion strongly promote the formation of AABW and the full development of the glacial stratification. Furthermore, increased dust deposition during the glacial maxima raises the contribution of the Southern Ocean in the global biological carbon pump, leading to a higher efficiency of the biological carbon pump. And the maximal expanded sea ice suppresses local carbon leakage.</p><p> </p><p> </p><p> </p>

Long-term Changes in Climatic Characteristics in St. Petersburg and their Possible Environmental Consequences

2021 ◽  
Vol 25 (5) ◽  
pp. 65-71
Author(s):  
V.V. Drozdov ◽  
G.T. Frumin ◽  
A.V. Kosenko
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
North Atlantic ◽  
Atmospheric Precipitation ◽  
Environmental Consequences ◽  
The North ◽  
Long Term Changes ◽  
The North Atlantic ◽  
Climatic Characteristics

The review and analysis of the long-term variability of the average annual and average air temperature for winter and summer, as well as the values of the amounts of atmospheric precipitation in St. Petersburg were carried out. The correlation between the dynamics of the values of these indicators and the intensity of atmospheric circulation over the North Atlantic in the form of the NAO1 index (North Atlantic Oscillation) was estimated. The possible environmental consequences of climate change in the region of St. Petersburg are justified.

Sign in / Sign up

Export Citation Format

Share Document