The middle atmospheric response to short and long term solar UV variations: analysis of observations and 2D model results

Fleming, Eric L.; Chandra, Sushil; Jackman, Charles H.; Considine, David B.; Douglass, Anne R.

doi:10.1016/0021-9169(94)e0013-d

Cited by 120 publications

(117 citation statements)

References 56 publications

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“…Chemistry-climate models suggest strong responses in stratospheric and mesospheric OH and H 2 O mixing ratios caused by solar irradiance variability (Fleming et al, 1995;Egorova et al, 2005;Rozanov et al, 2006;Gruzdev et al, 2009). The response was also found in the observed data.…”

Section: Introductionsupporting

confidence: 68%

Signature of the 27-day solar rotation cycle in mesospheric OH and H<sub>2</sub>O observed by the Aura Microwave Limb Sounder

et al. 2012

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Abstract. The mesospheric hydroxyl radical (OH) is mainly produced by the water vapor (H 2 O) photolysis and could be considered as a proxy for the influence of the solar irradiance variability on the mesosphere. We analyze the tropical mean response of the mesospheric OH and H 2 O data as observed by the Aura Microwave Limb Sounder (MLS) to 27-day solar variability. The analysis is performed for two time periods corresponding to the different phases of the 11-yr cycle: from December 2004 to December 2005 (the period of "high activity" with a pronounced 27-day solar cycle) and from August 2008 to August 2009 ("solar minimum" period with a vague 27-day solar cycle). We demonstrate, for the first time, that in the mesosphere the daily time series of OH concentrations correlate well with the solar irradiance (correlation coefficients up to 0.79) at zero time-lag. At the same time H 2 O anticorrelates (correlation coefficients up to −0.74) with the solar irradiance at non-zero time-lag. We found that the response of OH and H 2 O to the 27-day variability of the solar irradiance is strong for the period of the high solar activity and negligible for the solar minimum conditions. It allows us to suggest that the 27-day cycle in the solar irradiance and in OH and H 2 O are physically connected.

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Section: Introductionsupporting

confidence: 68%

Signature of the 27-day solar rotation cycle in mesospheric OH and H<sub>2</sub>O observed by the Aura Microwave Limb Sounder

et al. 2012

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“…Modelling studies have shown good agreement with observations for the 27-day cycle (Brasseur, 1993;Fleming et al, 1995;Williams et al, 2001), which has similar spectral changes in UV flux than the Schwabe cycle. For the 11-year cycle, even though ozone column amounts are correctly simulated (e.g.…”

Section: Introductionsupporting

confidence: 55%

Solar cycle variations of stratospheric ozone and temperature in simulations of a coupled chemistry-climate model

2007

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Abstract.The results from three 45-year simulations of a coupled chemistry climate model are analysed for solar cycle influences on ozone and temperature. The simulations include UV forcing at the top of the atmosphere, which includes a generic 27-day solar rotation effect as well as the observed monthly values of the solar fluxes. The results are analysed for the 27-day and 11-year cycles in temperature and ozone. In accordance with previous results, the 27-day cycle results are in good qualitative agreement with observations, particularly for ozone. However, the results show significant variations, typically a factor of two or more in sensitivity to solar flux, depending on the solar cycle.In the lower and middle stratosphere we show good agreement also between the modelled and observed 11-year cycle results for the ozone vertical profile averaged over low latitudes. In particular, the minimum in solar response near 20 hPa is well simulated. In comparison, experiments of the model with fixed solar phase (solar maximum/solar mean) and climatological sea surface temperatures lead to a poorer simulation of the solar response in the ozone vertical profile, indicating the need for variable phase simulations in solar sensitivity experiments. The role of sea surface temperatures and tropical upwelling in simulating the ozone minimum response are also discussed.

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“…Beig et al (2012) show corresponding results at the Equator from the 3-D chemistry-climate Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA), which show hints of negative ozone responses between 65 and 75 km, and steady values of ∼ 5 % (100 sfu) −1 between 80 and 95 km. The 2-D models of Brasseur (1993) and Fleming et al (1995) show larger negative ozone responses in the mesosphere and attribute the negative values to temperature-ozone feedback. …”

Section: Ozonementioning

confidence: 92%

Ozone and temperature decadal responses to solar variability in the mesosphere and lower thermosphere, based on measurements from SABER on TIMED

et al. 2016

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Abstract. We have derived ozone and temperature responses to solar variability over a solar cycle, from June 2002 through June 2014, 50 to 100 km, 48 • S to 48 • N, based on data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the ThermosphereIonosphere-Mesosphere-Energetics and Dynamics (TIMED) satellite. Results with this extent of coverage in the mesosphere and lower thermosphere have not been available previously. A multiple regression is applied to obtain responses as a function of the solar 10.7 cm flux (solar flux units, sfu). Positive responses mean that they are larger at solar maximum than at solar minimum of the solar cycle. From ∼ 80 to 100 km, both ozone and temperature responses are positive for all latitudes and are larger than those at lower altitudes. From ∼ 80 to 100 km, ozone responses can exceed 10 % (100 sfu) −1 , and temperature responses can approach 4 • K. From 50 to ∼ 80 km, the ozone responses at low latitudes (∼ ±35 • ) are mostly negative and can approach ∼ negative 3 % (100 sfu) −1 . However, they are mostly positive at midlatitudes in this region and can approach ∼ 2 % (100 sfu) −1 . In contrast to ozone, from ∼ 50 to 80 km, the temperature responses at low latitudes remain positive, with values up to ∼ 2.5 K (100 sfu) −1 , but are weakly negative at midlatitudes. Consequently, there is a systematic and robust relation between the phases of the ozone and temperature responses. They are positively correlated (in phase) from ∼ 80 to 100 km for all latitudes and negatively correlated (out of phase) from ∼ 50 to 80 km, also for all latitudes. The negative correlation from 50 to 80 km is maintained even though the ozone and temperature responses can change signs as a function of altitude and latitude, because the corresponding temperature responses change signs in step with ozone. This is consistent with the idea that dynamics have the larger influence between ∼ 80 and 100 km, while photochemistry is more in control from ∼ 50 to 75 km. The correlation coefficients between the solar 10.7 cm flux and the ozone and temperature themselves from 2012 to 2014 are positive (negative) in regions where the responses are positive (negative). This supports our results since the correlations are independent of the multiple regression used to derive the responses. We also compare with previous results.

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The middle atmospheric response to short and long term solar UV variations: analysis of observations and 2D model results

Cited by 120 publications

References 56 publications

Signature of the 27-day solar rotation cycle in mesospheric OH and H<sub>2</sub>O observed by the Aura Microwave Limb Sounder

Signature of the 27-day solar rotation cycle in mesospheric OH and H<sub>2</sub>O observed by the Aura Microwave Limb Sounder

Solar cycle variations of stratospheric ozone and temperature in simulations of a coupled chemistry-climate model

Ozone and temperature decadal responses to solar variability in the mesosphere and lower thermosphere, based on measurements from SABER on TIMED

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The middle atmospheric response to short and long term solar UV variations: analysis of observations and 2D model results

Cited by 120 publications

References 56 publications

Signature of the 27-day solar rotation cycle in mesospheric OH and H&lt;sub&gt;2&lt;/sub&gt;O observed by the Aura Microwave Limb Sounder

Signature of the 27-day solar rotation cycle in mesospheric OH and H&lt;sub&gt;2&lt;/sub&gt;O observed by the Aura Microwave Limb Sounder

Solar cycle variations of stratospheric ozone and temperature in simulations of a coupled chemistry-climate model

Ozone and temperature decadal responses to solar variability in the mesosphere and lower thermosphere, based on measurements from SABER on TIMED

Contact Info

Product

Resources

About

Signature of the 27-day solar rotation cycle in mesospheric OH and H<sub>2</sub>O observed by the Aura Microwave Limb Sounder

Signature of the 27-day solar rotation cycle in mesospheric OH and H<sub>2</sub>O observed by the Aura Microwave Limb Sounder