scholarly journals Pacific contribution to decadal surface temperature trends in the Arctic during the twentieth century

2021 ◽  
Author(s):  
Lea Svendsen ◽  
Noel Keenlyside ◽  
Morven Muilwijk ◽  
Ingo Bethke ◽  
Nour-Eddine Omrani ◽  
...  
Keyword(s):  
Twentieth Century ◽  
Surface Temperature ◽  
Decadal Variability ◽  
The Arctic ◽  
External Forcing ◽  
Arctic Warming ◽  
Temperature Trends ◽  
The Pacific ◽  
Instrumental Records ◽  
Arctic Surface

AbstractInstrumental records suggest multidecadal variability in Arctic surface temperature throughout the twentieth century. This variability is caused by a combination of external forcing and internal variability, but their relative importance remains unclear. Since the early twentieth century Arctic warming has been linked to decadal variability in the Pacific, we hypothesize that the Pacific could impact decadal temperature trends in the Arctic throughout the twentieth century. To investigate this, we compare two ensembles of historical all-forcing twentieth century simulations with the Norwegian Earth System Model (NorESM): (1) a fully coupled ensemble and (2) an ensemble where momentum flux anomalies from reanalysis are prescribed over the Indo-Pacific Ocean to constrain Pacific sea surface temperature variability. We find that the combined effect of tropical and extratropical Pacific decadal variability can explain up to ~ 50% of the observed decadal surface temperature trends in the Arctic. The Pacific-Arctic connection involves both lower tropospheric horizontal advection and subsidence-induced adiabatic heating, mediated by Aleutian Low variations. This link is detected across the twentieth century, but the response in Arctic surface temperature is moderated by external forcing and surface feedbacks. Our results also indicate that increased ocean heat transport from the Atlantic to the Arctic could have compensated for the impact of a cooling Pacific at the turn of the twenty-first century. These results have implications for understanding the present Arctic warming and future climate variations.

scholarly journals The Influence of Changes in Cloud Cover on Recent Surface Temperature Trends in the Arctic

2008 ◽  
Vol 21 (4) ◽  
pp. 705-715 ◽  
Author(s):  
Yinghui Liu ◽  
Jeffrey R. Key ◽  
Xuanji Wang
Keyword(s):  
Surface Temperature ◽  
Cloud Cover ◽  
Temperature Trend ◽  
The Arctic ◽  
Surface Warming ◽  
Weather Forecasts ◽  
Temperature Trends ◽  
Four Seasons ◽  
Sky Conditions ◽  
Arctic Surface

Abstract A method is presented to assess the influence of changes in Arctic cloud cover on the surface temperature trend, allowing for a more robust diagnosis of causes for surface warming or cooling. Seasonal trends in satellite-derived Arctic surface temperature under clear-, cloudy-, and all-sky conditions are examined for the period 1982–2004. The satellite-derived trends are in good agreement with trends in the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis product and surface-based weather station measurements in the Arctic. Surface temperature trends under clear and cloudy conditions have patterns similar to the all-sky trends, though the magnitude of the trends under cloudy conditions is smaller than those under clear-sky conditions, illustrating the negative feedback of clouds on the surface temperature trends. The all-sky surface temperature trend is divided into two parts: the first part is a linear combination of the surface temperature trends under clear and cloudy conditions; the second part is caused by changes in cloud cover as a function of the clear–cloudy surface temperature difference. The relative importance of these two components is different in the four seasons, with the first part more important in spring, summer, and autumn, but with both parts being equally important in winter. The contribution of biases in satellite retrievals is also evaluated.

Long-term predictability of winter teleconnection indices and their relationship to seasonal temperature extremes in Europe

2021 ◽  
Author(s):  
Nina Schuhen ◽  
Nathalie Schaller ◽  
Hannah C. Bloomfield ◽  
David J. Brayshaw ◽  
Jana Sillmann ◽  
...  
Keyword(s):  
Twentieth Century ◽  
Surface Temperature ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Decadal Variability ◽  
Environmental Research ◽  
Seasonal Temperature ◽  
East Atlantic ◽  
Teleconnection Patterns

<p>European winter weather is dominated by several low-frequency teleconnection patterns, the main ones being the North Atlantic Oscillation (NAO), East Atlantic, East Atlantic/Western Russia and Scandinavian patterns. Through predicting these patterns, skillful forecasts of weather parameters like surface temperature can be generated, which in turn are used in a variety of applications (e.g., predictions of energy demand). A previous study (Weisheimer et.al., 2017) found that the NAO was subject to decadal variability during the twentieth century, affecting its long-term predictability. During recent decades, predictions for the NAO index have shown considerable skill, but this is likely to change during future periods of reduced predictability.</p><p>We analyze the century-long ERA-20C reanalysis and ASF-20C seasonal hindcast datasets to find if the other main teleconnection patterns also experience fluctuations in predictability, with potential implications for future skill and development of seasonal forecasting models. By linking the teleconnections to extreme cold and heat wave indices (Russo et al., 2015), we highlight the impact of these large-scale patterns on seasonal surface temperature in Europe during two periods of interest in the middle and end of the century. Our study shows that even though the predictability of the teleconnection patterns themselves fluctuates on a decadal scale, the links to winter surface temperatures are not significantly affected. However, the ability of the seasonal hindcasts to reproduce these patterns is quite limited.</p><p> </p><p>References:</p><p>Russo, S., Sillmann, J., & Fischer, E. M. (2015). Top ten European heatwaves since 1950 and their occurrence in the coming decades. Environmental Research Letters, 10(12), 124003. doi: 10.1088/1748-9326/10/12/124003</p><p>Weisheimer, A., Schaller, N., O’Reilly, C., MacLeod, D. A., & Palmer, T. (2017). Atmospheric seasonal forecasts of the twentieth century:  multi-decadal variability in predictive skill of the winter North Atlantic Oscillation (NAO) and their potential value for extreme event attribution. Quarterly Journal of the Royal Meteorological Society, 143(703), 917-926. doi: 10.1002/qj.29</p>

scholarly journals Unraveling Causes for the Changing Behavior of the Tropical Indian Ocean in the Past Few Decades

2018 ◽  
Vol 31 (6) ◽  
pp. 2377-2388 ◽  
Author(s):  
Lei Zhang ◽  
Weiqing Han ◽  
Frank Sienz
Keyword(s):  
Indian Ocean ◽  
Time Scales ◽  
Climate Models ◽  
Decadal Variability ◽  
Global Climate ◽  
Tropical Indian Ocean ◽  
Volcanic Eruptions ◽  
Warming Trend ◽  
External Forcing ◽  
The Pacific

Observations show that decadal (10–20 yr) to interdecadal (>20 yr) variability of the tropical Indian Ocean (TIO) sea surface temperature (SST) closely follows that of the Pacific until the 1960s. Since then, the TIO SST exhibits a persistent warming trend, whereas the Pacific SST shows large-amplitude fluctuations associated with the interdecadal Pacific oscillation (IPO), and the decadal variability of the TIO SST is out of phase with that of the Pacific after around 1980. Here causes for the changing behavior of the TIO SST are explored, by analyzing multiple observational datasets and the recently available large-ensemble simulations from two climate models. It is found that on interdecadal time scales, the persistent TIO warming trend is caused by emergence of anthropogenic warming overcoming internal variability, while the time of emergence occurs much later in the Pacific. On decadal time scales, two major tropical volcanic eruptions occurred in the 1980s and 1990s causing decadal SST cooling over the TIO during which the IPO was in warm phase, yielding the out-of-phase relation. The more evident fingerprints of external forcing in the TIO compared to the Pacific result from the much weaker TIO internal decadal–interdecadal variability, making the TIO prone to the external forcing. These results imply that the ongoing warming and natural external forcing may make the Indian Ocean more active, playing an increasingly important role in affecting regional and global climate.

Assessment of decadal variability in sea ice in the Community Earth System Model against a long-term regional observational record: implications for the predictability of an ice-free Arctic

2021 ◽  
Author(s):  
Amélie Desmarais ◽  
Bruno Tremblay
Keyword(s):  
Sea Ice ◽  
Decadal Variability ◽  
Earth System Model ◽  
System Model ◽  
The Arctic ◽  
Earth System ◽  
Atlantic Sector ◽  
The Pacific ◽  
Community Earth System Model ◽  
Observational Record

AbstractUncertainties in the timing of a seasonal ice cover in the Arctic Ocean depend on model physics and parameterizations, natural variability at decadal timescales and uncertainties in climate scenarios and forcings. We use the Gridded Monthly Sea-Ice Extent and Concentration, 1850 Onward product to assess the simulated decadal variability from the Community Earth System Model – Large Ensemble (CESM-LE) in the Pacific, Eurasian and Atlantic sector of the Arctic where a longer observational record exists. Results show that sea-ice decadal (8-16 years) variability in CESM-LE is in agreement with the observational record in the Pacific sector of the Arctic, underestimated in the Eurasian sector of the Arctic, specifically in the East-Siberian Sea, and slightly overestimated in the Atlantic sector of the Arctic, specifically in the Greenland Sea. Results also show an increase in variability at decadal timescales in the Eurasian and Pacific sectors during the transition to a seasonally ice-free Arctic, in agreement with the observational record although this increase is delayed by 10-20 years. If the current sea-ice retreat in the Arctic continues to be Pacific-centric, results from the CESM-LE suggest that uncertainty in the timing of an ice-free Arctic associated with natural variability is realistic, but that a seasonal ice cover may occur earlier than projected.

Solar radiation in the Arctic during the Early Twentieth Century Warming period (1921–50)

2020 ◽  
Author(s):  
Rajmund Przybylak ◽  
Pavel Sviashchennikov ◽  
Joanna Uscka-Kowalkowska ◽  
Przemysław Wyszyński
Keyword(s):  
Twentieth Century ◽  
Solar Radiation ◽  
20Th Century ◽  
Solar Irradiance ◽  
Research Work ◽  
The Arctic ◽  
Early 20Th Century ◽  
Solar Forcing ◽  
Arctic Warming ◽  
Early Twentieth Century

<p>The Early Twentieth Century Warming (ETCW) period includes a time when a clear increase in actinometric observations was noted in the Arctic, which is defined for the purpose of the present paper after Atlas Arktiki (Treshnikov ed., 1985). Nevertheless, available information about energy balance, and its components, for the Arctic for the study period is still very limited, and therefore solar forcing cannot be reliably determined. As a result, the literature contains large discrepancies between estimates of solar forcing. For example, reconstructions of the increase of terrestrial solar irradiance (TSI) during the ETCW period range from 0.6 Wm<sup>-2</sup> (CMIP5, Wang et al., 2005), through 1.8 Wm<sup>-2</sup> (Crowley et al., 2003), to 3.6 Wm<sup>-2</sup> (Shapiro et al., 2011). Suo et al. (2013) concluded that the collection and processing of solar data is of paramount and central importance to the ability to take solar forcing into account, especially in modelling work.</p><p>            Having in mind the weaknesses of our knowledge described above, we decided to present in the paper a summary of our research concerning the availability of solar data in the Arctic (including measurements taken during land and marine expeditions). A detailed inventory of data series for the ETCW period (1921–50) also containing all available metadata will be an important part of this work. Based on the gathered data, a preliminary analysis will be presented of the general solar conditions in the Arctic in this time in terms of global, diffuse and direct solar radiation, and their changes from the ETCW period to present times (mainly 1981–2010).</p><p>            The research work in this paper was supported by a grant entitled “Causes of the Early 20th Century Arctic Warming”, funded by the National Science Centre, Poland (grant no. 2015/19/B/ST10/02933).</p><p>References:</p><p>Crowley T.J., Baum S.K., Kim K., Hegerl G.C. and Hyde W.T., 2003. Modeling ocean heat content changes during the last millennium. Geophys. Res. Lett. 30, 1932</p><p>Shapiro A.I., Schmutz W., Rozanov E., Schoell M., Haberreiter M. and co-authors, 2011. A new approach to the long-term reconstruction of the solar irradiance leads to large historical solar forcing. Astron. Astrophys. 529, A67.</p><p>Suo L., Ottera O.H., Bentsen M., Gao Y. and Johannessen O.M., 2013. External forcing of the early 20th century Arctic warming, Tellus A 2013, 65, 20578, http://dx.doi.org/10.3402/tellusa.v65i0.20578</p><p>Treshnikov A.F. (ed.), 1985. Atlas Arktiki. Glavnoye Upravlenye Geodeziy i Kartografiy: Moscow.</p><p>Wang Y.M., Lean J.L. and Sheeley Jr. N.R., 2005. Modeling the sun’s magnetic field and irradiance since 1713. Astroph. J. 625, 522.</p>

scholarly journals Comparison of satellite, thermochron and air temperatures at Summit, Greenland, during the winter of 2008/09

2010 ◽  
Vol 56 (198) ◽  
pp. 735-741 ◽  
Author(s):  
Lora S. Koenig ◽  
Dorothy K. Hall
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Satellite Data ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Seasonal Temperature ◽  
Temperature Trends ◽  
Air Temperatures ◽  
Winter Time ◽  
Arctic Surface

AbstractCurrent trends show a rise in Arctic surface and air temperatures, including over the Greenland ice sheet where rising temperatures will contribute to increased sea-level rise through increased melt. We aim to establish the uncertainties in using satellite-derived surface temperature for measuring Arctic surface temperature, as satellite data are increasingly being used to assess temperature trends. To accomplish this, satellite-derived surface temperature, or land-surface temperature (LST), must be validated and limitations of the satellite data must be assessed quantitatively. During the 2008/09 boreal winter at Summit, Greenland, we employed data from standard US National Oceanic and Atmospheric Administration (NOAA) air-temperature instruments, button-sized temperature sensors called thermochrons and the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite instrument to (1) assess the accuracy and utility of thermochrons in an ice-sheet environment and (2) compare MODIS-derived LSTs with thermochron-derived surface and air temperatures. The thermochron-derived air temperatures were very accurate, within 0.1 ± 0.3°C of the NOAA-derived air temperature, but thermochron-derived surface temperatures were ∼3°C higher than MODIS-derived LSTs. Though surface temperature is largely determined by air temperature, these variables can differ significantly. Furthermore, we show that the winter-time mean air temperature, adjusted to surface temperature, was ∼11°C higher than the winter-time mean MODIS-derived LST. This marked difference occurs largely because satellite-derived LSTs cannot be measured through cloud cover, so caution must be exercised in using time series of satellite LST data to study seasonal temperature trends.

scholarly journals Factors Associated with Decadal Variability in Great Plains Summertime Surface Temperatures

2013 ◽  
Vol 26 (1) ◽  
pp. 343-350 ◽  
Author(s):  
Scott J. Weaver
Keyword(s):  
Surface Temperature ◽  
Great Plains ◽  
Decadal Variability ◽  
Atlantic Multidecadal Oscillation ◽  
Regional Warming ◽  
Factors Associated ◽  
Sst Variability ◽  
The Pacific ◽  
Low Level Jet ◽  
Decadal Climate

Abstract Decadal variability of summertime Great Plains surface temperature is probed from the perspective of the Great Plains low-level jet (GPLLJ). GPLLJ variability modes 2 and 5 are shown to be most influential on the evolution and magnitude of Great Plains surface temperature anomalies over the latter half of the twentieth century, including the development of the summertime warming hole and are further linked to the Pacific decadal oscillation (PDO) and Atlantic multidecadal oscillation (AMO), respectively. The connection between GPLLJ variability and Great Plains surface temperature is strongest when the PDO and AMO are oppositely phased, and in the case of the warming hole, a preference for a positive (negative) PDO (AMO). The influence of remote SST variability on the central U.S. warming hole is broadly consistent with previous modeling studies. However, the pivotal role that GPLLJ variability plays in linking the hemispheric-wide SST variability (through the AMO and PDO) to the regional warming hole is an expanded and clarified perspective. These findings unify the results of recent studies from the U.S. Climate Variability and Predictability (CLIVAR) Drought Working Group and have implications for decadal climate prediction efforts.

scholarly journals Spatial Patterns of Preinstrumental Moisture Variability in the Southern Canadian Cordillera

2005 ◽  
Vol 18 (15) ◽  
pp. 2847-2863 ◽  
Author(s):  
Emma Watson ◽  
Brian H. Luckman
Keyword(s):  
Twentieth Century ◽  
Severity Index ◽  
Drought Severity ◽  
Canadian Cordillera ◽  
Entire Area ◽  
The Pacific ◽  
Dry Conditions ◽  
The Pacific Ocean ◽  
Instrumental Records ◽  
Precipitation Records

Abstract Extreme wet and dry intervals of the last 350 yr in the Canadian Cordillera and adjacent United States are examined using a network of 25 tree-ring-based precipitation and Palmer Drought Severity Index (PDSI) reconstructions. Reconstructed twentieth-century-mapped patterns compare well with patterns based on the instrumental records at both annual and decadal scales. During the most extreme events, dry conditions occurred over the entire area. The longest widespread drought in the last 350 yr occurred from 1917 to 1941. Shorter intervals of more severely dry conditions occurred in the early 1720s, 1750s, 1790s, 1860s–70s, and the 1890s. Many of the driest individual years and most extreme dry periods of <7 yr are reconstructed for the eighteenth century. The longest, wettest periods identified by these reconstructions occurred in the early twentieth century. In agreement with published studies that explore links between instrumental precipitation records from the region and conditions in the Pacific Ocean, the reconstructed records show that drier (wetter)-than-normal conditions are associated with El Niño (La Niña) events and the positive (negative) phase of the Pacific decadal oscillation (PDO).

scholarly journals Early 20th-century Arctic warming intensified by Pacific and Atlantic multidecadal variability

2017 ◽  
Vol 114 (24) ◽  
pp. 6227-6232 ◽  
Author(s):  
Hiroki Tokinaga ◽  
Shang-Ping Xie ◽  
Hitoshi Mukougawa
Keyword(s):  
Phase Shift ◽  
20Th Century ◽  
North Atlantic ◽  
Interdecadal Variability ◽  
The Arctic ◽  
Positive Phase ◽  
Northern Eurasia ◽  
Early 20Th Century ◽  
Arctic Warming ◽  
The Pacific

With amplified warming and record sea ice loss, the Arctic is the canary of global warming. The historical Arctic warming is poorly understood, limiting our confidence in model projections. Specifically, Arctic surface air temperature increased rapidly over the early 20th century, at rates comparable to those of recent decades despite much weaker greenhouse gas forcing. Here, we show that the concurrent phase shift of Pacific and Atlantic interdecadal variability modes is the major driver for the rapid early 20th-century Arctic warming. Atmospheric model simulations successfully reproduce the early Arctic warming when the interdecadal variability of sea surface temperature (SST) is properly prescribed. The early 20th-century Arctic warming is associated with positive SST anomalies over the tropical and North Atlantic and a Pacific SST pattern reminiscent of the positive phase of the Pacific decadal oscillation. Atmospheric circulation changes are important for the early 20th-century Arctic warming. The equatorial Pacific warming deepens the Aleutian low, advecting warm air into the North American Arctic. The extratropical North Atlantic and North Pacific SST warming strengthens surface westerly winds over northern Eurasia, intensifying the warming there. Coupled ocean–atmosphere simulations support the constructive intensification of Arctic warming by a concurrent, negative-to-positive phase shift of the Pacific and Atlantic interdecadal modes. Our results aid attributing the historical Arctic warming and thereby constrain the amplified warming projected for this important region.

Sign in / Sign up

Export Citation Format

Share Document