Climate and atmospheric circulation related to frost-ring formation in Picea mariana trees from the Boreal Plains, interior North America

AbstractThe interannual variability of wintertime North American surface temperature extremes and its generation and maintenance are analyzed in this study. The leading mode of the temperature extreme anomalies, revealed by empirical orthogonal function (EOF) analyses of December–February mean temperature extreme indices over North America, is characterized by an anomalous center of action over western-central Canada. In association with the leading mode of temperature extreme variability, the large-scale atmospheric circulation features an anomalous Pacific–North American (PNA)-like pattern from the preceding fall to winter, which has important implications for seasonal prediction of North American temperature extremes. A positive PNA pattern leads to more warm and fewer cold extremes over western-central Canada. The anomalous circulation over the PNA sector drives thermal advection that contributes to temperature anomalies over North America, as well as a Pacific decadal oscillation (PDO)-like sea surface temperature (SST) anomaly pattern in the midlatitude North Pacific. The PNA-like circulation anomaly tends to be supported by SST warming in the tropical central-eastern Pacific and a positive synoptic-scale eddy vorticity forcing feedback on the large-scale circulation over the PNA sector. The leading extreme mode–associated atmospheric circulation patterns obtained from the observational and reanalysis data, together with the anomalous SST and synoptic eddy activities, are reasonably well simulated in most CMIP5 models and in the multimodel mean. For most models considered, the simulated patterns of atmospheric circulation, SST, and synoptic eddy activities have lower spatial variances than the corresponding observational and reanalysis patterns over the PNA sector, especially over the North Pacific.

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Impacts of Local Soil Moisture Anomalies on the Atmospheric Circulation and on Remote Surface Meteorological Fields during Boreal Summer: A Comprehensive Analysis over North America

Journal of Climate ◽

10.1175/jcli-d-16-0192.1 ◽

2016 ◽

Vol 29 (20) ◽

pp. 7345-7364 ◽

Cited By ~ 37

Author(s):

Randal D. Koster ◽

Yehui Chang ◽

Hailan Wang ◽

Siegfried D. Schubert

Keyword(s):

Soil Moisture ◽

North America ◽

Atmospheric Circulation ◽

General Circulation ◽

Boreal Summer ◽

Near Surface ◽

Local Soil ◽

Lower Mississippi River ◽

Continental Interior ◽

The U.S

Abstract A series of stationary wave model (SWM) experiments are performed in which the boreal summer atmosphere is forced, over a number of locations in the continental United States, with an idealized diabatic heating anomaly that mimics the atmospheric heating associated with a dry land surface. For localized heating within a large portion of the continental interior, regardless of the specific location of this heating, the spatial pattern of the forced atmospheric circulation anomaly (in terms of 250-hPa eddy streamfunction) is largely the same: a high anomaly forms over west-central North America and a low anomaly forms to the east. In supplemental atmospheric general circulation model (AGCM) experiments, similar results are found; imposing soil moisture dryness in the AGCM in different locations within the U.S. interior tends to produce the aforementioned pattern, along with an associated near-surface warming and precipitation deficit in the center of the continent. The SWM-based and AGCM-based patterns generally agree with composites generated using reanalysis and precipitation gauge data. The AGCM experiments also suggest that dry anomalies imposed in the lower Mississippi River valley have remote surface impacts of particularly large spatial extent, and a region along the eastern half of the U.S.–Canadian border is particularly sensitive to dry anomalies in a number of remote areas. Overall, the SWM and AGCM experiments support the idea of a positive feedback loop operating over the continent: dry surface conditions in many interior locations lead to changes in atmospheric circulation that act to enhance further the overall dryness of the continental interior.

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The relationship between atmospheric circulation patterns and extreme temperature events in North America

International Journal of Climatology ◽

10.1002/joc.6610 ◽

2020 ◽

Vol 41 (1) ◽

pp. 92-103 ◽

Cited By ~ 1

Author(s):

Ryan E. Adams ◽

Cameron C. Lee ◽

Erik T. Smith ◽

Scott C. Sheridan

Keyword(s):

North America ◽

Atmospheric Circulation ◽

Extreme Temperature ◽

Extreme Temperature Events ◽

Atmospheric Circulation Patterns ◽

Circulation Patterns ◽

The Relationship

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AMO- and ENSO-Driven Summertime Circulation and Precipitation Variations in North America

Journal of Climate ◽

10.1175/jcli-d-11-00520.1 ◽

2012 ◽

Vol 25 (19) ◽

pp. 6477-6495 ◽

Cited By ~ 49

Author(s):

Qi Hu ◽

Song Feng

Keyword(s):

North America ◽

Atmospheric Circulation ◽

Time Scale ◽

Southern Oscillation ◽

Precipitation Anomaly ◽

Enso Cycle ◽

Interannual Variations ◽

Recent Climate ◽

Precipitation Anomalies ◽

Forced Waves

Abstract Interannual and multidecadal time-scale anomalies in sea surface temperatures (SST) of the North Atlantic and North Pacific Oceans could result in persistent atmospheric circulation and regional precipitation anomalies for years to decades. Understanding the processes that connect such SST forcings with circulation and precipitation anomalies is thus important for understanding climate variations and for improving predictions at interannual–decadal time scales. This study focuses on the interrelationship between the Atlantic multidecadal oscillation (AMO) and El Niño–Southern Oscillation (ENSO) and their resulting interannual to multidecadal time-scale variations in summertime precipitation in North America. Major results show that the ENSO forcing can strongly modify the atmospheric circulation variations driven by the AMO. Moreover, these modifications differ considerably between the subtropics and the mid- and high-latitude regions. In the subtropics, ENSO-driven variations in precipitation are fairly uniform across longitudes so ENSO effects only add interannual variations to the amplitude of the precipitation anomaly pattern driven by the AMO. In the mid- and high latitudes, ENSO-forced waves in the atmosphere strongly modify the circulation anomalies driven by the AMO, resulting in distinctive interannual variations following the ENSO cycle. The role of the AMO is shown by an asymmetry in precipitation during ENSO between the warm and cold phases of the AMO. These results extend the outcomes of the studies of the recent Climate Variability and Predictability (CLIVAR) Drought Working Group from the AMO and ENSO effects on droughts to understanding of the mechanisms and causal processes connecting the individual and combined SST forcing of the AMO and ENSO with the interannual and multidecadal variations in summertime precipitation and droughts in North America.

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

Advances in Meteorology ◽

10.1155/2018/5746191 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 2

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.

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Influence of Changing Atmospheric Circulation on Precipitation δ18O–Temperature Relations in Canada during the Holocene

Quaternary Research ◽

10.1006/qres.1996.0061 ◽

1996 ◽

Vol 46 (3) ◽

pp. 211-218 ◽

Cited By ~ 107

Author(s):

Thomas W.D. Edwards ◽

Brent B. Wolfe ◽

Glen M. Macdonald

Keyword(s):

North America ◽

Atmospheric Circulation ◽

General Circulation ◽

Isotope Composition ◽

Circulation Model ◽

Early Holocene ◽

Temperature Relation ◽

Atmospheric Circulation Patterns ◽

Central Canada ◽

Precipitation Ratio

Postglacial precipitation δ18O history has been reconstructed for two regions of Canada. Long-term shifts in the oxygen-isotope composition of annual precipitation (δ18Op) in southern Ontario appear to have occurred with a consistent isotope–temperature relation throughout the past 11,500 14C yr. The modern isotope–temperature relation in central Canada near present boreal treeline evidently became established between 5000 and 4000 years ago, although the relation during the last glacial maximum and deglaciation may also have been similar to present. In the early Holocene, however, unusually high δ18Op apparently persisted, in spite of low temperature locally, probably associated with high zonal index. A rudimentary sensitivity analysis suggests that a small reduction in distillation of moisture in Pacific air masses traversing the western Cordillera, perhaps accompanied by a higher summer:winter precipitation ratio, could have been responsible for the observed effect. Equivalent isotope–temperature “anomalies” apparently occurred elsewhere in western North America in response to changing early-Holocene atmospheric circulation patterns, suggesting that a time-slice map of δ18Op for North America during this period might provide a useful target for testing and validation of atmospheric general circulation model simulations using isotopic water tracers.

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The Polar Vortex and Extreme Weather: The Beast from the East in Winter 2018

Atmosphere ◽

10.3390/atmos11060664 ◽

2020 ◽

Vol 11 (6) ◽

pp. 664 ◽

Cited By ~ 1

Author(s):

James Overland ◽

Richard Hall ◽

Edward Hanna ◽

Alexey Karpechko ◽

Timo Vihma ◽

...

Keyword(s):

North America ◽

Atmospheric Circulation ◽

Polar Vortex ◽

Extreme Weather ◽

Extreme Weather Events ◽

Late Winter ◽

Public Attention ◽

Cold Surface ◽

Stratospheric Polar Vortex ◽

Weather Events

Public attention has recently focused on high-impact extreme weather events in midlatitudes that originate in the sub-Arctic. We investigate movements of the stratospheric polar vortex (SPV) and related changes in lower atmospheric circulation during the February-March 2018 “Beast from the East” cold winter event that dramatically affected much of Europe and north-central North America. This study demonstrates that the movement of the SPV is a key linkage in late winter subarctic and northern midlatitude extreme weather events. February–March 2018 saw two types of subarctic-midlatitude weather connections. In the first type, the SPV was displaced from the pole to lower latitudes over North America in February and then was found over northern Siberia in March. Mid-February and mid-March are examples of persistent near vertically aligned geopotential height structures of the atmospheric circulation. These structures over North America and Eurasia advected cold Arctic air southward. The second type of cold surface event was associated with a weak regional SPV and a sudden stratospheric warming event over Europe during the second half of February. These late winter linkage events that arise through dynamic instabilities of the SPV are more common in the last decade, but the potential role of enhanced Arctic amplification is uncertain.

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Ice sheet influence on atmospheric circulation explains the patterns of Pleistocene alpine glacier records in North America

Earth and Planetary Science Letters ◽

10.1016/j.epsl.2020.116115 ◽

2020 ◽

Vol 534 ◽

pp. 116115 ◽

Cited By ~ 4

Author(s):

Joseph P. Tulenko ◽

Marcus Lofverstrom ◽

Jason P. Briner

Keyword(s):

North America ◽

Atmospheric Circulation ◽

Ice Sheet ◽

Alpine Glacier

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Orbital control of western North America atmospheric circulation and climate over two glacial cycles

Nature Communications ◽

10.1038/ncomms4805 ◽

2014 ◽

Vol 5 (1) ◽

Cited By ~ 54

Author(s):

Matthew S. Lachniet ◽

Rhawn F. Denniston ◽

Yemane Asmerom ◽

Victor J. Polyak

Keyword(s):

North America ◽

Atmospheric Circulation ◽

Western North America ◽

Glacial Cycles ◽

Orbital Control

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Contributions of Downstream Eddy Development to the Teleconnection between ENSO and the Atmospheric Circulation over the North Atlantic

Journal of Climate ◽

10.1175/jcli-d-11-00377.1 ◽

2012 ◽

Vol 25 (14) ◽

pp. 4993-5010 ◽

Cited By ~ 33

Author(s):

Ying Li ◽

Ngar-Cheung Lau

Keyword(s):

North America ◽

Atmospheric Circulation ◽

North Atlantic ◽

El Niño ◽

North Pacific ◽

El Nino ◽

Storm Track ◽

The North ◽

The North Atlantic ◽

The North Pacific

Abstract The spatiotemporal evolution of various meteorological phenomena associated with El Niño–Southern Oscillation (ENSO) in the North Pacific–North American–North Atlantic sector is examined using both NCEP–NCAR reanalyses and output from a 2000-yr integration of a global coupled climate model. Particular attention is devoted to the implications of downstream eddy developments on the relationship between ENSO and the atmospheric circulation over the North Atlantic. The El Niño–related persistent events are characterized by a strengthened Pacific subtropical jet stream and an equatorward-shifted storm track over the North Pacific. The wave packets that populate the storm tracks travel eastward through downstream development. The barotropic forcing of the embedded synoptic-scale eddies is conducive to the formation of a flow that resembles the negative phase of the North Atlantic Oscillation (NAO). The more frequent and higher persistence of those episodes during El Niño winters contribute to the prevalence of negative NAO conditions. The above processes are further delineated by conducting a case study for the 2009/10 winter season, in which both El Niño and negative NAO conditions prevailed. It is illustrated that the frequent and intense surface cyclone development over North America and the western Atlantic throughout that winter are associated with upper-level troughs propagating across North America, which in turn are linked to downstream evolution of wave packets originating from the Pacific storm track.

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