scholarly journals Continentality and Oceanity in the Mid and High Latitudes of the Northern Hemisphere and Their Links to Atmospheric Circulation

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Edvinas Stonevicius ◽  
Gintautas Stankunavicius ◽  
Egidijus Rimkus
Keyword(s):  
North America ◽  
Atmospheric Circulation ◽  
Northern Hemisphere ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Climatic Conditions ◽  
High Latitudes ◽  
Teleconnection Patterns ◽  
The Pacific ◽  
The Impact

The climate continentality or oceanity is one of the main characteristics of the local climatic conditions, which varies with global and regional climate change. This paper analyzes indexes of continentality and oceanity, as well as their variations in the middle and high latitudes of the Northern Hemisphere in the period 1950–2015. Climatology and changes in continentality and oceanity are examined using Conrad’s Continentality Index (CCI) and Kerner’s Oceanity Index (KOI). The impact of Northern Hemisphere teleconnection patterns on continentality/oceanity conditions was also evaluated. According to CCI, continentality is more significant in Northeast Siberia and lower along the Pacific coast of North America as well as in coastal areas in the northern part of the Atlantic Ocean. However, according to KOI, areas of high continentality do not precisely correspond with those of low oceanity, appearing to the south and west of those identified by CCI. The spatial patterns of changes in continentality thus seem to be different. According to CCI, a statistically significant increase in continentality has only been found in Northeast Siberia. In contrast, in the western part of North America and the majority of Asia, continentality has weakened. According to KOI, the climate has become increasingly continental in Northern Europe and the majority of North America and East Asia. Oceanity has increased in the Canadian Arctic Archipelago and in some parts of the Mediterranean region. Changes in continentality were primarily related to the increased temperature of the coldest month as a consequence of changes in atmospheric circulation: the positive phase of North Atlantic Oscillation (NAO) and East Atlantic (EA) patterns has dominated in winter in recent decades. Trends in oceanity may be connected with the diminishing extent of seasonal sea ice and an associated increase in sea surface temperature.

scholarly journals Northern Hemisphere Stationary Waves in a Changing Climate

2019 ◽  
Vol 5 (4) ◽  
pp. 372-389 ◽  
Author(s):  
Robert C. J. Wills ◽  
Rachel H. White ◽  
Xavier J. Levine
Keyword(s):  
Climate Change ◽  
Atmospheric Circulation ◽  
Northern Hemisphere ◽  
Climate Models ◽  
Regional Climate ◽  
Stationary Wave ◽  
Future Research ◽  
Stationary Waves ◽  
The Pacific ◽  
Longitudinal Variations

Abstract Purpose of Review Stationary waves are planetary-scale longitudinal variations in the time-averaged atmospheric circulation. Here, we consider the projected response of Northern Hemisphere stationary waves to climate change in winter and summer. We discuss how the response varies across different metrics, identify robust responses, and review proposed mechanisms. Recent Findings Climate models project shifts in the prevailing wind patterns, with corresponding impacts on regional precipitation, temperature, and extreme events. Recent work has improved our understanding of the links between stationary waves and regional climate and identified robust stationary wave responses to climate change, which include an increased zonal lengthscale in winter, a poleward shift of the wintertime circulation over the Pacific, a weakening of monsoonal circulations, and an overall weakening of stationary wave circulations, particularly their divergent component and quasi-stationary disturbances. Summary Numerous factors influence Northern Hemisphere stationary waves, and mechanistic theories exist for only a few aspects of the stationary wave response to climate change. Idealized studies have proven useful for understanding the climate responses of particular atmospheric circulation features and should be a continued focus of future research.

scholarly journals Storyline approach to the construction of regional climate change information

2019 ◽  
Vol 475 (2225) ◽  
pp. 20190013 ◽  
Author(s):  
Theodore G. Shepherd
Keyword(s):  
Climate Change ◽  
Atmospheric Circulation ◽  
Regional Climate ◽  
Regional Scale ◽  
Regional Climate Change ◽  
Climate Impacts ◽  
Climate Projections ◽  
Ethical Implications ◽  
Climate Change Information ◽  
The Impact

Climate science seeks to make statements of confidence about what has happened, and what will happen (conditional on scenario). The approach is effective for the global, thermodynamic aspects of climate change, but is ineffective when it comes to aspects of climate change related to atmospheric circulation, which are highly uncertain. Yet, atmospheric circulation strongly mediates climate impacts at the regional scale. In this way, the confidence framework, which focuses on avoiding type 1 errors (false alarms), raises the prospect of committing type 2 errors (missed warnings). This has ethical implications. At the regional scale, however, where information on climate change has to be combined with many other factors affecting vulnerability and exposure—most of which are highly uncertain—the societally relevant question is not ‘What will happen?’ but rather ‘What is the impact of particular actions under an uncertain regional climate change?’ This reframing of the question can cut the Gordian knot of regional climate change information, provided one distinguishes between epistemic and aleatoric uncertainties—something that is generally not done in climate projections. It is argued that the storyline approach to climate change—the identification of physically self-consistent, plausible pathways—has the potential to accomplish precisely this.

Interpreting Results from the NARCCAP and NA-CORDEX Ensembles in the Context of Uncertainty in Regional Climate Change Projections

2018 ◽  
Vol 99 (10) ◽  
pp. 2093-2106 ◽  
Author(s):  
Ambarish V. Karmalkar
Keyword(s):  
Climate Change ◽  
North America ◽  
General Circulation ◽  
Climate Models ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Internal Variability ◽  
General Circulation Models ◽  
Eastern United States ◽  
The Impact

AbstractTwo ensembles of dynamically downscaled climate simulations for North America—the North American Regional Climate Change Assessment Program (NARCCAP) and the Coordinated Regional Climate Downscaling Experiment (CORDEX) featuring simulations for North America (NA-CORDEX)—are analyzed to assess the impact of using a small set of global general circulation models (GCMs) and regional climate models (RCMs) on representing uncertainty in regional projections. Selecting GCMs for downscaling based on their equilibrium climate sensitivities is a reasonable strategy, but there are regions where the uncertainty is not fully captured. For instance, the six NA-CORDEX GCMs fail to span the full ranges produced by models in phase 5 of the Coupled Model Intercomparison Project (CMIP5) in summer temperature projections in the western and winter precipitation projections in the eastern United States. Similarly, the four NARCCAP GCMs are overall poor at spanning the full CMIP3 ranges in seasonal temperatures. For the Southeast, the NA-CORDEX GCMs capture the uncertainty in summer but not in winter projections, highlighting one consequence of downscaling a subset of GCMs. Ranges produced by the RCMs are often wider than their driving GCMs but are sensitive to the experimental design. For example, the downscaled projections of summer precipitation are of opposite polarity in two RCM ensembles in some regions. Additionally, the ability of the RCMs to simulate observed temperature trends is affected by the internal variability characteristics of both the RCMs and driving GCMs, and is not systematically related to their historical performance. This has implications for adequately sampling the impact of internal variability on regional trends and for using model performance to identify credible projections. These findings suggest that a multimodel perspective on uncertainties in regional projections is integral to the interpretation of RCM results.

Different Climatic Effects of the Arctic and Antarctic ice Covers on Land Surface Temperature in the Northern Hemisphere: Application of Liang-Kleeman Information Flow Method and CAM4.0

2021 ◽  
Author(s):  
Shunyu Jiang ◽  
Haibo HU ◽  
William Perrie ◽  
Ning Zhang ◽  
Haokun Bai ◽  
...  
Keyword(s):  
North America ◽  
East Asia ◽  
Atmospheric Circulation ◽  
Northern Hemisphere ◽  
Information Flow ◽  
Air Temperature ◽  
The Arctic ◽  
High Latitudes ◽  
Flow Method ◽  
The Antarctic

Abstract Ice covers in high latitudes play important role in the global atmospheric circulation and abnormal temperature distribution. The observations have revealed the differences in the interannual variability of the Arctic and Antarctic ice covers, but their respective climate effect is not clear. The Liang-Kleeman information flow method is used to reveal the causal relationships from the sea ices of the Arctic and Antarctic to the global air temperature. The results point out that changes of the Arctic or Antarctic sea ices both have significant impacts on the global air temperature. Especially for the air temperature in East Asia and North America, the interannual variation of the Antarctic sea ice has an even stronger impact than the Arctic ice covers. This causality is further proved by the General Atmospheric Circulation Model (CAM4.0). In the numerical experiments, the ice covers in Arctic and Antarctic are changed individually or simultaneously as the forcing fields, and then the respective climate effects are analyzed. The results show that both the Arctic and Antarctic ice cover variations can change the intensity of atmospheric baroclinic disturbance in mid-high latitudes of individual hemisphere, generating wave energy transmission across the equator in the meridional direction, and eventually causing air temperature anomalies in both hemispheres. Furthermore, the Antarctic ice covers are closer to the mid-high latitude atmospheric jets in the southern hemisphere. Therefore, the changes of Antarctic ice covers lead to a larger atmospheric wave-activity flux response, and quickly spread to the northern hemisphere, causing more significant temperature anomalies over the East Asia and North America.

scholarly journals Compensation between Resolved Wave Driving and Parameterized Orographic Gravity Wave Driving of the Brewer–Dobson Circulation and Its Response to Climate Change

2014 ◽  
Vol 27 (14) ◽  
pp. 5601-5610 ◽  
Author(s):  
Michael Sigmond ◽  
Theodore G. Shepherd
Keyword(s):  
Climate Change ◽  
Gravity Wave ◽  
Northern Hemisphere ◽  
Rossby Wave ◽  
Climate Model ◽  
Wave Drag ◽  
High Latitudes ◽  
Remarkable Degree ◽  
The Impact

Abstract Following recent findings, the interaction between resolved (Rossby) wave drag and parameterized orographic gravity wave drag (OGWD) is investigated, in terms of their driving of the Brewer–Dobson circulation (BDC), in a comprehensive climate model. To this end, the parameter that effectively determines the strength of OGWD in present-day and doubled CO2 simulations is varied. The authors focus on the Northern Hemisphere during winter when the largest response of the BDC to climate change is predicted to occur. It is found that increases in OGWD are to a remarkable degree compensated by a reduction in midlatitude resolved wave drag, thereby reducing the impact of changes in OGWD on the BDC. This compensation is also found for the response to climate change: changes in the OGWD contribution to the BDC response to climate change are compensated by opposite changes in the resolved wave drag contribution to the BDC response to climate change, thereby reducing the impact of changes in OGWD on the BDC response to climate change. By contrast, compensation does not occur at northern high latitudes, where resolved wave driving and the associated downwelling increase with increasing OGWD, both for the present-day climate and the response to climate change. These findings raise confidence in the credibility of climate model projections of the strengthened BDC.

Fossil flower of Staphylea L. from the Miocene amber of Mexico: New evidence of the Boreotropical Flora in low-latitude North America

2017 ◽  
Vol 108 (4) ◽  
pp. 471-478 ◽  
Author(s):  
Ana L. Hernández-Damián ◽  
Sergio R. S. Cevallos-Ferriz ◽  
Alma R. Huerta-Vergara
Keyword(s):  
North America ◽  
Northern Hemisphere ◽  
Fossil Record ◽  
First Record ◽  
High Latitudes ◽  
Low Latitude ◽  
Southern Mexico ◽  
Apparent Lack ◽  
History Of ◽  
New Evidence

ABSTRACTA new flower preserved in amber in sediments of Simojovel de Allende, México, is identified as an extinct member of Staphyleaceae, a family of angiosperms consisting of only three genera (Staphylea, Turpinia and Euscaphis), which has a large and abundant fossil record and is today distributed over the Northern Hemisphere. Staphylea ochoterenae sp. nov. is the first record of a flower for this group, which is small, pedicelled, pentamer, bisexual, with sepals and petals with similar size, dorsifixed anthers and superior ovary. Furthermore, the presence of stamens with pubescent filaments allows close comparison with extant flowers of Staphylea bulmada and S. forresti, species currently growing in Asia. However, their different number of style (one vs. three) and the apparent lack of a floral disc distinguish them from S. ochoterenae. The presence of Staphyleaceae in southern Mexico ca. 23 to 15My ago is evidence of the long history of integration of vegetation in low-latitude North America, in which some lineages, such as Staphylea, could move southwards from high latitudes of the Northern Hemisphere, as part of the Boreotropical Flora. In Mexico it grew in association with tropical elements, as suggested by the fossil record of the area.

scholarly journals Climate Change Controls Phosphorus Transport from the Watershed into Lake Kinneret (Israel)

2021 ◽  
Author(s):  
Moshe Gophen
Keyword(s):  
Climate Change ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Lake Kinneret ◽  
Phosphorus Transport ◽  
Efficient Management ◽  
Hula Valley ◽  
Reclamation Project ◽  
The Impact

AbstractPart of the Kinneret watershed, the Hula Valley, was modified from wetlands – shallow lake for agricultural cultivation. Enhancement of nutrient fluxes into Lake Kinneret was predicted. Therefore, a reclamation project was implemented and eco-tourism partly replaced agriculture. Since the mid-1980s, regional climate change has been documented. Statistical evaluation of long-term records of TP (Total Phosphorus) concentrations in headwaters and potential resources in the Hula Valley was carried out to identify efficient management design targets. Significant correlation between major headwater river discharge and TP concentration was indicated, whilst the impact of external fertilizer loads and 50,000 winter migratory cranes was probably negligible. Nevertheless, confirmed severe bdamage to agricultural crops carried out by cranes led to their maximal deportation and optimization of their feeding policy. Consequently, the continuation of the present management is recommended.

scholarly journals AI-Based Campus Energy Use Prediction for Assessing the Effects of Climate Change

2020 ◽  
Vol 12 (8) ◽  
pp. 3223 ◽  
Author(s):  
Soheil Fathi ◽  
Ravi S. Srinivasan ◽  
Charles J. Kibert ◽  
Ruth L. Steiner ◽  
Emre Demirezen
Keyword(s):  
Climate Change ◽  
Energy Use ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Developed Countries ◽  
Energy Performance ◽  
Energy Needs ◽  
Energy Use Prediction ◽  
Campus Energy ◽  
The Impact

In developed countries, buildings are involved in almost 50% of total energy use and 30% of global annual greenhouse gas emissions. The operational energy needs of buildings are highly dependent on various building physical, operational, and functional characteristics, as well as meteorological and temporal properties. Besides physics-based energy modeling of buildings, Artificial Intelligence (AI) has the capability to provide faster and higher accuracy estimates, given buildings’ historic energy consumption data. Looking beyond individual building levels, forecasting building energy performance can help city and community managers have a better understanding of their future energy needs, and to plan for satisfying them more efficiently. Focusing at an urban scale, this research develops a campus energy use prediction tool for predicting the effects of long-term climate change on the energy performance of buildings using AI techniques. The tool comprises four steps: Data Collection, AI Development, Model Validation, and Model Implementation, and can predict the energy use of campus buildings with 90% accuracy. We have relied on energy use data of buildings situated in the University of Florida, Gainesville, Florida (FL). To study the impact of climate change, we have used climate properties of three future weather files of Gainesville, FL, developed by the North American Regional Climate Change Assessment Program (NARCCAP), represented based on their impact: median (year 2063), hottest (2057), and coldest (2041).

The Impact of Regional Climate Change on the Marine Ecosystem of the Western Antarctic Peninsula

2012 ◽  
pp. 91-120 ◽  
Author(s):  
Andrew Clarke ◽  
David K. A. Barnes ◽  
Thomas J. Bracegirdle ◽  
Hugh W. Ducklow ◽  
John C. King ◽  
...  
Keyword(s):  
Climate Change ◽  
Antarctic Peninsula ◽  
Regional Climate ◽  
Marine Ecosystem ◽  
Regional Climate Change ◽  
Western Antarctic Peninsula ◽  
The Impact

Future Change of Northern Hemisphere Summer Tropical–Extratropical Teleconnection in CMIP5 Models*

2014 ◽  
Vol 27 (10) ◽  
pp. 3643-3664 ◽  
Author(s):  
June-Yi Lee ◽  
Bin Wang ◽  
Kyong-Hwan Seo ◽  
Jong-Seong Kug ◽  
Yong-Sang Choi ◽  
...  
Keyword(s):  
North America ◽  
Northern Hemisphere ◽  
Summer Monsoon ◽  
North Pacific ◽  
Western North Pacific ◽  
Cmip5 Models ◽  
Boreal Summer ◽  
Moderate Increase ◽  
Coupled Models ◽  
Teleconnection Patterns

Abstract Two dominant global-scale teleconnections in the Northern Hemisphere (NH) extratropics during boreal summer season (June–August) have been identified: the western North Pacific–North America (WPNA) and circumglobal teleconnection (CGT) patterns. These teleconnection patterns are of critical importance for the NH summer seasonal climate prediction. Here, how these teleconnections will change under anthropogenic global warming is investigated using representative concentration pathway 4.5 (RCP4.5) experiments by 20 coupled models that participated in phase 5 of the Coupled Model Intercomparison Project (CMIP5). The six best models are selected based on their performance in simulation of the two teleconnection patterns and climatological means and variances of atmospheric circulation, precipitation, and sea surface temperature. The selected models capture the CGT and its relationship with the Indian summer monsoon (ISM) reasonably well. The models can also capture the WPNA circulation pattern but with striking deficiencies in reproducing its associated rainfall anomalies due to poor simulation of the western North Pacific summer monsoon rainfall. The following changes are anticipated in the latter half of twenty-first century under the RCP4.5 scenario: 1) significant weakening of year-to-year variability of the upper-level circulation due to increased atmospheric stability, although the moderate increase in convective heating over the tropics may act to strengthen the variability; 2) intensification of the WPNA pattern and major spectral peaks, particularly over the eastern Pacific–North America and North Atlantic–Europe sectors, which is attributed to the strengthening of its relationship with the preceding mature phase of El Niño–Southern Oscillation (ENSO); and 3) weakening of the CGT due to atmospheric stabilization and decreasing relationship with ISM as well as weakening of the ISM–ENSO relationship.

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