Late Twenty-First-Century Changes in the Midlatitude Atmospheric Circulation in the CESM Large Ensemble

Peings, Yannick; Cattiaux, Julien; Vavrus, Stephen J.; Magnúsdóttir, Guðrún

doi:10.1175/jcli-d-16-0340.1

Cited by 44 publications

(61 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is opposite to expectations from the influence of AA alone (Francis and Vavrus 2012, Zappa et al 2018. Nevertheless, changes are highly sector-dependent (Peings et al 2017), the North American sector being the sole region to exhibit AA-expected changes (i.e. weakened westerly flow and increased waviness) , Peings et al 2017.…”

Section: Introductionmentioning

confidence: 75%

“…The large UTW signal projected by GCMs due to increased upper-level latent heat release in the tropics (Santer et al 2017), as well as weaker and wider Hadley cells in winter (Seo et al 2014), may counterbalance its effect on the mid-latitude atmospheric circulation (Deser et al 2015, Blackport and Kushner 2017, Oudar et al 2017, McCusker et al 2017, Zappa and Shepherd 2017, 2018. In fact, in the zonal average, 21st century climate projections from the Coupled Model Intercomparison Project phase 5 (CMIP5) and from the Community Earth System Model Large Ensemble (CESM-LENS) show unchanged or slightly decreased mid-latitude waviness and frequency of blocking events, as well as reinforced westerlies at the core of the jet (Barnes and Polvani 2015, Peings et al 2017. This is opposite to expectations from the influence of AA alone (Francis and Vavrus 2012, Zappa et al 2018.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Projected squeezing of the wintertime North-Atlantic jet

Peings

Cattiaux

Vavrus

et al. 2018

Environ. Res. Lett.

Self Cite

View full text Add to dashboard Cite

Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence.Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Figure 1. (a) CMIP5 ensemble mean of future versus present-day changes in 700 hPa zonal wind. (b) Cross-section of zonal wind changes averaged over the North Atlantic sector (50°W/40°E). (c) Latitude versus time change in 700 hPa zonal wind over the North Atlantic sector (50°W/40°E). (d)-(f) are the corresponding fields in CESM-LENS. Season is ONDJFM. Shading indicates anomalies that are significant at the 95% confidence level. Climatology is shown in green contours: 3 m s −1 interval on (a) and (d), 5 m s −1 interval on (b) and (e), sector zonal average in right panels of (c) and (f).Figure 2. (a) Timeseries of the ONDJFM zonal index over the North Atlantic sector (50°W/40°E) in CMIP5 (green) and CESM-LENS (orange). Solid line is the ensemble mean, the envelope shows ±1 standard deviation spread between the models/members. The right panel shows the future versus present-day relative changes in %, with the ±1 standard deviation spread. A star indicates that the change is significant at the 90% confidence level. (b) Same as (a) but for sinuosity (relative future versus present-day changes are given, in %). (c) Same as (a) but for the blocking index. (d) Same as (a) but for the jet width index (future versus present-day changes are given in degree of latitude). ZON is computed from monthly data downloaded for the whole period. SIN, BLO and JWI are computed from daily data downloaded for two time slices. 2 Environ. Res. Lett. 14 (2019) 049602 Y Peings et alFigure 3. (a) CMIP5 ensemble mean of future versus present-day changes in ONDJFM zonal mean temperature. Shading indicates anomalies that are significant at the 95% confidence level. (b) Timeseries of ONDJFM UTW in CMIP5 (green) and CESM-LENS (orange). Solid line is the ensemble mean, the envelope shows ±1 standard deviation spread between the models/members. The right panel barplot shows the future versus present-day changes, with the ±1 standard deviation spread. A star indicates that the change is significant at the 90% confidence level. (c) Same as (b) but for AA. (d) Same as (b) but for RUTAW. 3 Environ. Res. Lett. 14 (2019) 049602 Y Peings et alFigure 4. Scatterplots of ONDJFM future versus present-day changes in CMIP5 (numbers, see list in table S1) and CESM-LENS (grey dots) for: (a) BLO versus UPTG; (b) SIN versus UPTG; (c) ZON versus RUTAW; (d) JWI versus RUTAW. Results from three regression analyses are shown. The red solid lines and upper-left correlation coefficients (red) are for a standard regression analysis on CMIP5. The black solid lines and upper-centre correlation coefficients (black) are for an error-in-variable regression analysis on CMIP5, using the CESM-LENS spread as errors on variables X and Y. The solid black curves gives a confidence interval for uncertainties due to both sampling error and internal ...

show abstract

Section: Introductionmentioning

confidence: 75%

Section: Introductionmentioning

confidence: 99%

Projected squeezing of the wintertime North-Atlantic jet

Peings

Cattiaux

Vavrus

et al. 2018

Environ. Res. Lett.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In particular, it is possible, though unlikely due to the rarity of blocking events, that larger blocks increase the time‐mean width of the jet. Furthermore, the strength and latitude of the jet, and w and λ are interconnected (Barnes & Polvani, ; Barnes & Screen, ; Kidston & Vallis, ; Peings et al, , ; Ronalds et al, ). To quantitatively separate the effects of these parameters on each other, controlled experiments using linear response functions can be used (Hassanzadeh & Kuang, , , , ; Khodkar et al, ; Ma et al, ); this is left for future work.…”

Section: Summary and Discussionmentioning

confidence: 99%

“…As a result, there has been significant interest in understanding how blocking events might change with climate change (Davini et al, 2012;Matsueda & Endo, 2017;Masato et al, 2013;Woollings et al, 2018). Most studies so far have focused on changes in the frequency of blocking events and the resulting weather extremes (e.g., Ayarzagüena & Screen, 2016;Barnes & Polvani, 2015;Barnes & Screen, 2015;Barnes et al, 2014;Cohen et al, 2014;Coumou et al, 2018;Francis & Vavrus, 2012;Hassanzadeh & Kuang, 2015;Hassanzadeh et al, 2014;Horton et al, 2015;Liu et al, 2012;Peings et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Size of the Atmospheric Blocking Events: Scaling Law and Response to Climate Change

Nabizadeh

Hassanzadeh

Yang

et al. 2019

Geophysical Research Letters

View full text Add to dashboard Cite

Understanding the response of atmospheric blocking events to climate change has been of great interest in recent years. However, potential changes in the blocking area (size), which can affect the spatiotemporal characteristics of the resulting extreme events, have not received much attention. Using two large‐ensemble, fully coupled general circulation model (GCM) simulations, we show that the size of blocking events increases with climate change, particularly in the Northern Hemisphere (by as much as 17%). Using a two‐layer quasi‐geostrophic model and a dimensional analysis technique, we derive a scaling law for the size of blocking events, which shows that area mostly scales with width of the jet times the Kuo scale (i.e., the length of stationary Rossby waves). The scaling law is validated in a range of idealized GCM simulations. Predictions of this scaling law agree well with changes in blocking events' size under climate change in fully coupled GCMs in winters but not in summers.

show abstract

“…Projections outside the autumn tend to be more complex, with some studies suggesting limited changes (Barnes & Polvani, 2013), while others identify equatorial movements and strengthening of atmospheric circulation (Simpson et al, 2014). In the end, several regional processes spanning the Northern Hemisphere affect atmospheric circulation at the midlatitudes, resulting in complex dynamics that are difficult to model and predict across all seasons (Peings, Cattiaux, Vavrus, & Magnusdottir, 2017).…”

mentioning

confidence: 99%

Projected changes in wind assistance under climate change for nocturnally migrating bird populations

Sorte

Horton

Nilsson

et al. 2018

Global Change Biology

View full text Add to dashboard Cite

Current climate models and observations indicate that atmospheric circulation is being affected by global climate change. To assess how these changes may affect nocturnally migrating bird populations, we need to determine how current patterns of wind assistance at migration altitudes will be enhanced or reduced under future atmospheric conditions. Here, we use information compiled from 143 weather surveillance radars stations within the contiguous United States to estimate the daily altitude, density, and direction of nocturnal migration during the spring and autumn. We intersected this information with wind projections to estimate how wind assistance is expected to change during this century at current migration altitudes. The prevailing westerlies at midlatitudes are projected to increase in strength during spring migration and decrease in strength to a lesser degree during autumn migration. Southerly winds will increase in strength across the continent during both spring and autumn migration, with the strongest gains occurring in the center of the continent. Wind assistance is projected to increase across the central (0.44 m/s; 10.1%) and eastern portions of the continent (0.32 m/s; 9.6%) during spring migration, and wind assistance is projected to decrease within the central (0.32 m/s; 19.3%) and eastern portions of the continent (0.17 m/s; 6.6%) during autumn migration. Thus, across a broad portion of the continent where migration intensity is greatest, the efficiency of nocturnal migration is projected to increase in the spring and decrease in the autumn, potentially affecting time and energy expenditures for many migratory bird species. These findings highlight the importance of placing climate change projections within a relevant ecological context informed through empirical observations, and the need to consider the possibility that climate change may generate both positive and negative implications for natural systems.

show abstract

Late Twenty-First-Century Changes in the Midlatitude Atmospheric Circulation in the CESM Large Ensemble

Cited by 44 publications

References 54 publications

Projected squeezing of the wintertime North-Atlantic jet

Projected squeezing of the wintertime North-Atlantic jet

Size of the Atmospheric Blocking Events: Scaling Law and Response to Climate Change

Projected changes in wind assistance under climate change for nocturnally migrating bird populations

Contact Info

Product

Resources

About