Examining the stratospheric response to the solar cycle in a coupled WACCM simulation with an internally generated QBO

Kren, Andrew C.; Marsh, Daniel R.; Smith, Anne K.; Pilewskie, P.

doi:10.5194/acp-14-4843-2014

Cited by 15 publications

(18 citation statements)

References 59 publications

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“…Using the same length of data as in Labitzke and Kunze (), we randomly subsample periods of 68 years and correlate the vortex strength, but at no point do we find any statistically significant relationship. Kren et al () performed a similar analysis, but using the WACCM model and randomly subsampling 40 year periods (as opposed to the 68 year periods used here). In their study, they did find occasions where a statistically significant correlation existed in both QBO‐E and W phases, although the correlations were of either sign.…”

Section: Analysis Of the Solar Signalssupporting

confidence: 56%

“…In their study, they did find occasions where a statistically significant correlation existed in both QBO‐E and W phases, although the correlations were of either sign. Repeating our analysis, but using the shorter period from Kren et al (), we find similar results over a few randomly sampled periods, i.e. a strong solar‐vortex correlation could appear by chance in a 40 year period.…”

Section: Analysis Of the Solar Signalsmentioning

confidence: 99%

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Solar signals in CMIP‐5 simulations: the stratospheric pathway

Mitchell

Misios

Gray

et al. 2015

Quart J Royal Meteoro Soc

147

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The 11 year solar-cycle component of climate variability is assessed in historical simulations of models taken from the Coupled Model Intercomparison Project, phase 5 (CMIP-5).Multiple linear regression is applied to estimate the zonal temperature, wind and annular mode responses to a typical solar cycle, with a focus on both the stratosphere and the stratospheric influence on the surface over the period ∼1850-2005. The analysis is performed on all CMIP-5 models but focuses on the 13 CMIP-5 models that resolve the stratosphere (high-top models) and compares the simulated solar cycle signature with reanalysis data. The 11 year solar cycle component of climate variability is found to be weaker in terms of magnitude and latitudinal gradient around the stratopause in the models than in the reanalysis. The peak in temperature in the lower equatorial stratosphere (∼70 hPa) reported in some studies is found in the models to depend on the length of the analysis period, with the last 30 years yielding the strongest response.A modification of the Polar Jet Oscillation (PJO) in response to the 11 year solar cycle is not robust across all models, but is more apparent in models with high spectral resolution in the short-wave region. The PJO evolution is slower in these models, leading to a stronger response during February, whereas observations indicate it to be weaker. In early winter, the magnitude of the modelled response is more consistent with observations when only data from 1979-2005 are considered. The observed North Pacific high-pressure surface response during the solar maximum is only simulated in some models, for which there are no distinguishing model characteristics. The lagged North Atlantic surface response is reproduced in both high-and low-top models, but is more prevalent in the former. In both cases, the magnitude of the response is generally lower than in observations.

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Section: Analysis Of the Solar Signalssupporting

confidence: 56%

Section: Analysis Of the Solar Signalsmentioning

confidence: 99%

Solar signals in CMIP‐5 simulations: the stratospheric pathway

Mitchell

Misios

Gray

et al. 2015

Quart J Royal Meteoro Soc

147

View full text Add to dashboard Cite

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“…Marsh et al [2007] used a set of perpetual WACCM 3 simulations under fixed solar maximum and solar minimum conditions to study the solar cycle influences on chemical species. Kren et al [2014] used WACCM simulations from 1850 to 2005 and demonstrated that the solar cycle responses deduced from the model vary depending on the length of data set and interval of years selected, indicating that solar cycle influences are challenging to reliably extract from time-varying simulations due to variations of volcanic activity and greenhouse gases. Kren et al [2014] used WACCM simulations from 1850 to 2005 and demonstrated that the solar cycle responses deduced from the model vary depending on the length of data set and interval of years selected, indicating that solar cycle influences are challenging to reliably extract from time-varying simulations due to variations of volcanic activity and greenhouse gases.…”

Section: Analysis Methodsmentioning

confidence: 99%

The 11 year solar cycle signature on wave‐driven dynamics in WACCM

2016

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This study describes the influence of the 11 year solar cycle on gravity waves and the wave‐driven circulation, using an ensemble of six simulations of the period from 1955 to 2005 along with fixed solar maximum and minimum simulations of the Whole Atmospheric Community Climate Model (WACCM). Solar cycle signals are estimated by calculating the difference between solar maximum and minimum conditions. Simulations under both time‐varying and fixed solar inputs show statistically significant responses in temperatures and winds in the Southern Hemisphere (SH) during austral winter and spring. At solar maximum, the monthly mean, zonal mean temperature in the SH from July to October is cooler (~1–3 K) in the stratosphere and warmer (~1–4 K) in the mesosphere and the lower thermosphere (MLT). In solar maximum years, the SH polar vortex is more stable and its eastward speed is about 5–8 m s−1 greater than during solar minimum. The increase in the eastward wind propagates downward and poleward from July to October in the SH. Because of increase in the eastward wind, the propagation of eastward gravity waves to the MLT is reduced. This results in a net westward response in gravity wave drag, peaking at ~10 m s−1 d−1 in the SH high‐latitude MLT. These changes in gravity wave drag modify the wave‐induced residual circulation, and this contributes to the warming of ~1–4 K in the MLT.

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“…Recently, a number of modeling works have been conducted by such GCMs. [Shindell et al, 1999;Schmidt and Brasseur, 2006;Schmidt et al, 2010;Marsh et al, 2007;Smith and Matthes, 2008;Frame and Gary, 2010;Cnossen et al, 2011;Chiodo et al, 2012;Kren et al, 2014, Cullens et al, 2015. These GCMs include, for example, the Whole Atmosphere Community Climate Model (WACCM) and the Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA), to study the atmospheric response to SC in the MLT region.…”

Section: Introductionmentioning

confidence: 99%

Temperature responses to the 11 year solar cycle in the mesosphere from the 31 year (1979–2010) extended Canadian Middle Atmosphere Model simulations and a comparison with the 14 year (2002–2015) TIMED/SABER observations

Gan

Fomichev

et al. 2017

JGR Space Physics

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A recent 31 year simulation (1979–2010) by extended Canadian Middle Atmosphere Model (eCMAM30) and the 14 year (2002–2015) observation by the Thermosphere Ionosphere Mesosphere and Dynamics/Sounding of the Atmosphere using Broadband Emssion Radiometry (TIMED/SABER) are utilized to investigate the temperature response to the 11 year solar cycle on the mesosphere. Overall, the zonal mean responses tend to increase with height, and the amplitudes are on the order of 1–2 K/100 solar flux unit (1 sfu = 10−22 W m−2 Hz−1) below 80 km and 2–4 K/100 sfu in the mesopause region (80–100 km) from the eCMAM30, comparatively weaker than those from the SABER except in the midlatitude lower mesosphere. A pretty good consistence takes place at around 75–80 km with a response of ~1.5 K/100 sfu within 10°S/N. Also, a symmetric pattern of the responses about the equator agrees reasonably well between the two. It is noteworthy that the eCMAM30 displays an alternate structure with the upper stratospheric cooling and the lower mesospheric warming at midlatitudes of the winter hemisphere, in favor of the long‐term Rayleigh lidar observation reported by the previous studies. Through diagnosing multiple dynamical parameters, it is manifested that this localized feature is induced by the anomalous residual circulation as a consequence of the wave‐mean flow interaction during the solar maximum year.

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Examining the stratospheric response to the solar cycle in a coupled WACCM simulation with an internally generated QBO

Cited by 15 publications

References 59 publications

Solar signals in CMIP‐5 simulations: the stratospheric pathway

Solar signals in CMIP‐5 simulations: the stratospheric pathway

The 11 year solar cycle signature on wave‐driven dynamics in WACCM

Temperature responses to the 11 year solar cycle in the mesosphere from the 31 year (1979–2010) extended Canadian Middle Atmosphere Model simulations and a comparison with the 14 year (2002–2015) TIMED/SABER observations

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