Latitudinal- and height-dependent long-term climatology of propagating quasi-16-day waves in the troposphere and stratosphere

AbstractThe global amplitude of the westward propagating quasi-16-day waves (16DW) with wavenumber 1 (Q16W1), the strongest component of 16DW, are derived from the European Centre for Medium-Range Weather Forecasts ERA-Interim reanalysis temperature and zonal wind data sets from February 1979 to January 2018. In terms of temperature and zonal wind, strong climatologically average amplitudes of Q16W1 appear in the upper stratosphere at mid–high latitudes in both hemispheres, and the wave amplitude is stronger in the Northern Hemisphere (NH) than in the Southern Hemisphere (SH). Multivariate linear regression is separately applied to calculate the responses of the Q16W1 temperature and zonal wind amplitudes to the QBO (quasi-biennial oscillation), ENSO (El Niño-Southern Oscillation), solar activity and linear trends of the Q16W1 amplitude. The QBO signatures of the Q16W1 temperature and zonal wind amplitudes are mainly located in the stratosphere. The Q16W1 has significant QBO responses at low latitudes. In addition, only the temperature amplitude presents a larger QBO signature in its strongest climatological amplitude region. No significant responses to ENSO and solar activity are observed in temperature and zonal wind amplitudes. The linear trends of the monthly mean Q16W1 temperature and zonal wind amplitude are generally positive, especially in the mid-upper stratosphere. The trend is asymmetric about the equator and significantly stronger in the NH than in the SH. The seasonal variation in the trend of the temperature amplitude is studied and illustrated to be stronger in winter and weaker in spring and autumn. Further investigation suggests that the background and local instability trends contribute most of the increasing trend of the Q16W1 amplitude. In winter in both hemispheres, a weakening trend of eastward zonal wind provides more favourable background wind for Q16W1 upward propagation, in autumn and winter in the NH and in spring, autumn and winter in the SH, and the increasing trend of local instability may enhance wave excitation. Graphical Abstract

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Latitudinal- and Height- Dependent Long-Term Climatology of Propagating Quasi-16-day in the Troposphere and Stratosphere

10.21203/rs.3.rs-577454/v1 ◽

2021 ◽

Author(s):

Wentao Tang ◽

Shao Dong ZHANG ◽

Chun Ming HUANG ◽

Kai Ming HUANG ◽

Yun Gong ◽

...

Keyword(s):

Solar Activity ◽

Southern Oscillation ◽

Linear Trend ◽

High Latitudes ◽

Local Instability ◽

Quasi Biennial Oscillation ◽

Data Set ◽

Weather Forecasts ◽

Increasing Trend ◽

Autumn And Winter

Abstract The global amplitude of the westward propagating quasi-16-day wave (16DW) with wavenumber 1 (Q16W1), the strongest component of 16DW, is derived from European Centre for Medium-Range Weather Forecasts ERA-Interim reanalysis temperature data set from February 1979 to January 2018. The strong climatological mean amplitudes of the Q16W1 appear in winter in the upper stratosphere at high latitudes in both hemispheres, and the wave amplitude is stronger in the Northern Hemisphere (NH) than in the Southern Hemisphere (SH). Multivariate linear regression is applied to calculate responses of the Q16W1 amplitude to QBO (quasi-biennial oscillation), ENSO (El Niño-Southern Oscillation), solar activity and the linear trend of the Q16W1 amplitude. The QBO signatures of the Q16W1 amplitude are mainly located in the stratosphere. In addition to the significant QBO response in the low latitude and low stratosphere, the largest QBO response occurs in the region with the strongest Q16W1 climatology amplitude. There no significant responses to ENSO and solar activity are observed. The linear trend of the monthly mean Q16W1 amplitude is generally positive, especially in the mid-high latitudes of the stratosphere. The trend is asymmetric about the equator and significantly stronger in the NH than in the SH. The trend shows obvious seasonal changes, that is, stronger in winter, weaker in spring and autumn. Further investigation suggests that the background and local instability trends contribute most of the increasing trend of the Q16W1 amplitude. In winter in both hemispheres, the weakening trend of eastward zonal wind provide more favourable background wind for Q16W1 upward propagation, in autumn and winter in the NH and in spring, autumn and winter in the SH, the increasing trend of local instability may enhance the wave excitation.

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Impact of Solar Activity on Global Atmospheric Circulation Based on SD-WACCM-X Simulations from 2002 to 2019

Atmosphere ◽

10.3390/atmos12111526 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1526

Author(s):

Chen-Ke-Min Teng ◽

Sheng-Yang Gu ◽

Yusong Qin ◽

Xiankang Dou

Keyword(s):

Solar Activity ◽

Atmospheric Circulation ◽

Southern Oscillation ◽

Upper Atmosphere ◽

Lower Atmosphere ◽

High Solar Activity ◽

Low Latitude ◽

Quasi Biennial Oscillation ◽

Global Atmospheric Circulation ◽

The Impact

In this study, a global atmospheric model, Specified Dynamics Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension (SD-WACCM-X), and the residual circulation principle were used to study the global atmospheric circulation from the lower to upper atmosphere (~500 km) from 2002 to 2019. Our analysis shows that the atmospheric circulation is clearly influenced by solar activity, especially in the upper atmosphere, which is mainly characterized by an enhanced atmospheric circulation in years with high solar activity. The atmospheric circulation in the upper atmosphere also exhibits an ~11 year period, and its variation is highly correlated with the temporal variation in the F10.7 solar index during the same time series, with a maximum correlation coefficient of up to more than 0.9. In the middle and lower atmosphere, the impact of solar activity on the atmospheric circulation is not as obvious as in the upper atmosphere due to some atmospheric activities such as the Quasi-Biennial Oscillation (QBO), El Niño–Southern Oscillation (ENSO), sudden stratospheric warming (SSW), volcanic forcing, and so on. By comparing the atmospheric circulation in different latitudinal regions between years with high and low solar activity, we found the atmospheric circulation in mid- and high-latitude regions is more affected by solar activity than in low-latitude and equatorial regions. In addition, clear seasonal variation in atmospheric circulation was detected in the global atmosphere, excluding the regions near 10−4 hPa and the lower atmosphere, which is mainly characterized by a flow from the summer hemisphere to the winter hemisphere. In the middle and low atmosphere, the atmospheric circulation shows a quasi-biennial oscillatory variation in the low-latitude and equatorial regions. This work provides a referable study of global atmospheric circulation and demonstrates the impacts of solar activity on global atmospheric circulation.

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The Long-term structural effect of Coronal index solar activity on the ENSO and QBO Time series data using Fractal Dimension

Punjab University Journal of Mathematics ◽

10.52280/pujm.2021.530205 ◽

2021 ◽

pp. 149-163

Author(s):

Muhammad Fahim Akhter

Keyword(s):

Time Series ◽

Fractal Dimension ◽

Solar Activity ◽

Long Memory ◽

Time Series Data ◽

Southern Oscillation ◽

Research Work ◽

Inverse Correlation ◽

Series Data ◽

Quasi Biennial Oscillation

The study concentrated on the fractal dimension of solar activity and climatic parameters. We analyzed comparatively for each parameter numerically. All values are estimated by Box Counting technique of fractal dimension. According to the theme of study, we used a monthly dataset of Coronal Mass Ejection (Coronal Index (CI)), ElNino Southern Oscillation (ENSO) and Quasi-Biennial Oscillation (QBO) from 1954 to 2016. The time seriesof ENSO and QBO are distributed according to the CORONAL INDEX (CI) cycles (19, 20, 21, 22, 23, and 24) to understand their relationship in the perspective of persistence or anti-persistence.The fractal dimension(D) represents the complexity and Hurst exponent(H) indicates the long memory dependence of the selected time series, with scaling constant (a, c). The results obtained indicate the persistence (1 < D < 1.5) for CORONAL INDEX (CI) with distributed ENSO and QBO cycles. The fractional Brownian motion (fBm) is also found long memory dependence(1¿H¿ 0.5) and locally lowpass signal for all studied cycles observed.A linear relationship implies between Hurst coefficient and fractal dimension for a statistical assumption (H + D = 2).The fractal scaling instrument is established between the global indices (ENSO & QBO) and solar activity (particularly CORONAL INDEX (CI)) cycles,the inverse correlation with ENSO and direct with QBO are observed. The results obtained in this research work may help to describe the solar-terrestrial relationship

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Variability of temperature and ozone in the upper troposphere and lower stratosphere from multi-satellite observations and reanalysis data

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-6659-2019 ◽

2019 ◽

Vol 19 (10) ◽

pp. 6659-6679 ◽

Cited By ~ 16

Author(s):

Ming Shangguan ◽

Wuke Wang ◽

Shuanggen Jin

Keyword(s):

Lower Stratosphere ◽

Climate Model ◽

Southern Oscillation ◽

Satellite System ◽

Reanalysis Data ◽

Data Sets ◽

Positive Temperature ◽

Quasi Biennial Oscillation ◽

Model Simulations ◽

Upper Troposphere

Abstract. Temperature and ozone changes in the upper troposphere and lower stratosphere (UTLS) are important components of climate change. In this paper, variability and trends of temperature and ozone in the UTLS are investigated for the period 2002–2017 using high-quality, high vertical resolution Global Navigation Satellite System radio occultation (GNSS RO) data and improved merged satellite data sets. As part of the Stratosphere-troposphere Processes And their Role in Climate (SPARC) Reanalysis Intercomparison Project (S-RIP), three reanalysis data sets, including the ERA-I, MERRA2 and the recently released ERA5, are evaluated for their representation of temperature and ozone in the UTLS. The recent temperature and ozone trends are updated with a multiple linear regression (MLR) method and related to sea surface temperature (SST) changes based on model simulations made with NCAR's Whole Atmosphere Community Climate Model (WACCM). All reanalysis temperatures show good agreement with the GNSS RO measurements in both absolute value and annual cycle. Interannual variations in temperature related to Quasi-Biennial Oscillation (QBO) and the El Niño–Southern Oscillation (ENSO) processes are well represented by all reanalyses. However, evident biases can be seen in reanalyses for the linear trends of temperature since they are affected by discontinuities in assimilated observations and methods. Such biases can be corrected and the estimated trends can be significantly improved. ERA5 is significantly improved compared to ERA-I and shows the best agreement with the GNSS RO temperature. The MLR results indicate a significant warming of 0.2–0.3 K per decade in most areas of the troposphere, with a stronger increase of 0.4–0.5 K per decade at midlatitudes of both hemispheres. In contrast, the stratospheric temperature decreases at a rate of 0.1–0.3 K per decade, which is most significant in the Southern Hemisphere (SH). Positive temperature trends of 0.1–0.3 K per decade are seen in the tropical lower stratosphere (100–50 hPa). Negative trends of ozone are found in the Northern Hemisphere (NH) at 150–50 hPa, while positive trends are evident in the tropical lower stratosphere. Asymmetric trends of ozone can be found in the midlatitudes of two hemispheres in the middle stratosphere, with significant ozone decrease in the NH and increase in ozone in the SH. Large biases exist in reanalyses, and it is still challenging to do trend analysis based on reanalysis ozone data. According to single-factor-controlled model simulations with WACCM, the temperature increase in the troposphere and the ozone decrease in the NH stratosphere are mainly connected to the increase in SST and subsequent changes of atmospheric circulations. Both the increase in SSTs and the decrease in ozone in the NH contribute to the temperature decrease in the NH stratosphere. The increase in temperature in the lower stratospheric tropics may be related to an increase in ozone in that region, while warming SSTs contribute to a cooling in that area.

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Southern Hemisphere Summer Mesopause Responses to El Niño–Southern Oscillation

Journal of Climate ◽

10.1175/jcli-d-15-0816.1 ◽

2016 ◽

Vol 29 (17) ◽

pp. 6319-6328 ◽

Cited By ~ 14

Author(s):

Tao Li ◽

Natalia Calvo ◽

Jia Yue ◽

James M. Russell ◽

Anne K. Smith ◽

...

Keyword(s):

Southern Hemisphere ◽

Zonal Wind ◽

El Niño ◽

El Nino ◽

Southern Oscillation ◽

Onset Time ◽

Polar Vortex ◽

Quasi Biennial Oscillation ◽

Stratospheric Polar Vortex ◽

Enso Events

Abstract In the Southern Hemisphere (SH) polar region, satellite observations reveal a significant upper-mesosphere cooling and a lower-thermosphere warming during warm ENSO events in December. An opposite pattern is observed in the tropical mesopause region. The observed upper-mesosphere cooling agrees with a climate model simulation. Analysis of the simulation suggests that enhanced planetary wave (PW) dissipation in the Northern Hemisphere (NH) high-latitude stratosphere during El Niño strengthens the Brewer–Dobson circulation and cools the equatorial stratosphere. This increases the magnitude of the SH stratosphere meridional temperature gradient and thus causes the anomalous stratospheric easterly zonal wind and early breakdown of the SH stratospheric polar vortex. The resulting perturbation to gravity wave (GW) filtering causes anomalous SH mesospheric eastward GW forcing and polar upwelling and cooling. In addition, constructive inference of ENSO and quasi-biennial oscillation (QBO) could lead to stronger stratospheric easterly zonal wind anomalies at the SH high latitudes in November and December and early breakdown of the SH stratospheric polar vortex during warm ENSO events in the easterly QBO phase (defined by the equatorial zonal wind at ~25 hPa). This would in turn cause much more SH mesospheric eastward GW forcing and much colder polar temperatures, and hence it would induce an early onset time of SH summer polar mesospheric clouds (PMCs). The opposite mechanism occurs during cold ENSO events in the westerly QBO phase. This implies that ENSO together with QBO could significantly modulate the breakdown time of SH stratospheric polar vortex and the onset time of SH PMC.

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Variations in Stratospheric Gravity Waves Derived from Temperature Observations of Multi-GNSS Radio Occultation Missions

Remote Sensing ◽

10.3390/rs13234835 ◽

2021 ◽

Vol 13 (23) ◽

pp. 4835

Author(s):

Jia Luo ◽

Jialiang Hou ◽

Xiaohua Xu

Keyword(s):

Solar Activity ◽

Gravity Wave ◽

Radio Occultation ◽

Southern Oscillation ◽

Temporal Distribution ◽

Satellite System ◽

High Latitudes ◽

Quasi Biennial Oscillation ◽

Global Navigation Satellite ◽

Almost All

The spatial–temporal distribution of the global gravity wave (GW) potential energy (Ep) at the lower stratosphere of 20–35 km is studied using the dry temperature profiles from multi- Global Navigation Satellite System (GNSS) radio occultation (RO) missions, including CHAMP, COSMIC, GRACE, and METOP-A/B/C, during the 14 years from 2007 to 2020, based on which the linear trends of the GW Ep and the responses of GW Ep to solar activity, quasi biennial oscillation (QBO), and El Niño-Southern Oscillation (ENSO) are analyzed using the multivariate linear regression (MLR) method. It is found that the signs and the magnitudes of the trends of GW Ep during each month vary at different altitude ranges and over different latitudes. At 25–35 km of the middle and high latitudes, GW Ep values generally show significant negative trends in almost all months, and the values of the negative trends become smaller in the regions closer to the poles. The distribution of the deseasonalized trends in the monthly zonal-mean GW Ep demonstrates that the GW activities are generally declining from 2007 to 2020 over the globe. The responses of GW Ep to solar activity are found to be mostly positive at 20–35 km over the globe, and the comparison between the distribution pattern of the deseasonalized trends in the GW activities and that of the responses of GWs to solar activity indicates that the sharp decline in solar activity from 2015 to 2017 might contribute to the overall attenuation of gravity wave activity during the 14 years. Significant negative responses of GW Ep to QBO are found at 30–35 km over 30° S–25° N, and the negative responses extend to the mid and high latitudes in the southern hemisphere at 20–30 km. The responses of GW Ep to QBO change to be significantly positive at 20–30 km over 15° S–15° N, which demonstrates that the zonal wind field should be the main factor affecting the GW activities at 20–30 km over the tropics. The responses of GW Ep at 20–35 km to ENSO are found to be positive over 15° S–15° N, while at 30–35 km over 15° N–30° N and at 20–35 km near 50° N, significant negative responses of GW Ep to ENSO exist.

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On the Prediction of Solar Cycles

Solar Physics ◽

10.1007/s11207-020-01760-7 ◽

2021 ◽

Vol 296 (1) ◽

Author(s):

V. Courtillot ◽

F. Lopes ◽

J. L. Le Mouël

Keyword(s):

Solar Activity ◽

Solar Cycle ◽

Transfer Function ◽

Singular Spectrum Analysis ◽

Activity Cycle ◽

Solar Activity Cycle ◽

Planetary Motion ◽

Data Sets ◽

Solar Cycles ◽

Jovian Planets

AbstractThis article deals with the prediction of the upcoming solar activity cycle, Solar Cycle 25. We propose that astronomical ephemeris, specifically taken from the catalogs of aphelia of the four Jovian planets, could be drivers of variations in solar activity, represented by the series of sunspot numbers (SSN) from 1749 to 2020. We use singular spectrum analysis (SSA) to associate components with similar periods in the ephemeris and SSN. We determine the transfer function between the two data sets. We improve the match in successive steps: first with Jupiter only, then with the four Jovian planets and finally including commensurable periods of pairs and pairs of pairs of the Jovian planets (following Mörth and Schlamminger in Planetary Motion, Sunspots and Climate, Solar-Terrestrial Influences on Weather and Climate, 193, 1979). The transfer function can be applied to the ephemeris to predict future cycles. We test this with success using the “hindcast prediction” of Solar Cycles 21 to 24, using only data preceding these cycles, and by analyzing separately two 130 and 140 year-long halves of the original series. We conclude with a prediction of Solar Cycle 25 that can be compared to a dozen predictions by other authors: the maximum would occur in 2026.2 (± 1 yr) and reach an amplitude of 97.6 (± 7.8), similar to that of Solar Cycle 24, therefore sketching a new “Modern minimum”, following the Dalton and Gleissberg minima.

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Seasonal prediction of the boreal winter stratosphere

Climate Dynamics ◽

10.1007/s00382-021-05787-9 ◽

2021 ◽

Author(s):

Alice Portal ◽

Paolo Ruggieri ◽

Froila M. Palmeiro ◽

Javier García-Serrano ◽

Daniela I. V. Domeisen ◽

...

Keyword(s):

Southern Oscillation ◽

Polar Vortex ◽

Seasonal Prediction ◽

Wave Activity ◽

Boreal Winter ◽

Quasi Biennial Oscillation ◽

Stratospheric Polar Vortex ◽

Eddy Heat Flux ◽

Prediction Systems ◽

Model Database

AbstractThe predictability of the Northern Hemisphere stratosphere and its underlying dynamics are investigated in five state-of-the-art seasonal prediction systems from the Copernicus Climate Change Service (C3S) multi-model database. Special attention is devoted to the connection between the stratospheric polar vortex (SPV) and lower-stratosphere wave activity (LSWA). We find that in winter (December to February) dynamical forecasts initialised on the first of November are considerably more skilful than empirical forecasts based on October anomalies. Moreover, the coupling of the SPV with mid-latitude LSWA (i.e., meridional eddy heat flux) is generally well reproduced by the forecast systems, allowing for the identification of a robust link between the predictability of wave activity above the tropopause and the SPV skill. Our results highlight the importance of November-to-February LSWA, in particular in the Eurasian sector, for forecasts of the winter stratosphere. Finally, the role of potential sources of seasonal stratospheric predictability is considered: we find that the C3S multi-model overestimates the stratospheric response to El Niño–Southern Oscillation (ENSO) and underestimates the influence of the Quasi–Biennial Oscillation (QBO).

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Seasonal variation of patulous Eustachian tube diagnoses using climatic and national health insurance data

The Journal of Laryngology & Otology ◽

10.1017/s0022215121001596 ◽

2021 ◽

pp. 1-7

Author(s):

S Lee ◽

S-W Choi ◽

J Kim ◽

H M Lee ◽

S-J Oh ◽

...

Keyword(s):

Relative Risk ◽

Eustachian Tube ◽

Climatic Factors ◽

Data Sets ◽

National Data ◽

Health Insurance Data ◽

Number Of Patients ◽

Autumn And Winter ◽

Insurance Data ◽

Patulous Eustachian Tube

Abstract Objectives This study aimed to analyse if there were any associations between patulous Eustachian tube occurrence and climatic factors and seasonality. Methods The correlation between the monthly average number of patients diagnosed with patulous Eustachian tube and climatic factors in Seoul, Korea, from January 2010 to December 2016, was statistically analysed using national data sets. Results The relative risk for patulous Eustachian tube occurrence according to season was significantly higher in summer and autumn, and lower in winter than in spring (relative risk (95 per cent confidence interval): 1.334 (1.267–1.404), 1.219 (1.157–1.285) and 0.889 (0.840–0.941) for summer, autumn and winter, respectively). Temperature, atmospheric pressure and relative humidity had a moderate positive (r = 0.648), negative (r = –0.601) and positive (r = 0.492) correlation with the number of patulous Eustachian tube cases, respectively. Conclusion The number of patulous Eustachian tube cases was highest in summer and increased in proportion to changes in temperature and humidity, which could be due to physiological changes caused by climatic factors or diet trends.

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Interannual variability of the boreal summer tropical UTLS in observations and CCMVal-2 simulations

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-8695-2016 ◽

2016 ◽

Vol 16 (13) ◽

pp. 8695-8714 ◽

Cited By ~ 5

Author(s):

Markus Kunze ◽

Peter Braesicke ◽

Ulrike Langematz ◽

Gabriele Stiller

Keyword(s):

Climate Models ◽

Southern Oscillation ◽

Asian Summer Monsoon ◽

Multiple Linear Regression Model ◽

Transport Processes ◽

Boreal Summer ◽

Temperature Pattern ◽

The Tibetan Plateau ◽

Quasi Biennial Oscillation ◽

Mixing Ratios

Abstract. During boreal summer the upper troposphere/lower stratosphere (UTLS) in the Northern Hemisphere shows a distinct maximum in water vapour (H2O) mixing ratios and a coincident minimum in ozone (O3) mixing ratios, both confined within the Asian monsoon anticyclone (AMA). This well-known feature has been related to transport processes emerging above the convective systems during the Asian summer monsoon (ASM), further modified by the dynamics of the AMA. We compare the ability of chemistry–climate models (CCMs) to reproduce the climatological characteristics and variability of H2O, O3, and temperature in the UTLS during the boreal summer with MIPAS satellite observations and ERA-Interim reanalyses. By using a multiple linear regression model the main driving factors, the strength of the ASM, the quasi-biennial oscillation (QBO), and the El Niño–Southern Oscillation (ENSO), are separated. The regression patterns related to ENSO show a coherent, zonally asymmetric signal for temperatures and H2O mixing ratios for ERA-Interim and the CCMs and suggest a weakening of the ASM during ENSO warm events. The QBO modulation of the lower-stratospheric temperature near the Equator is well represented as a zonally symmetric pattern in the CCMs. Changes in H2O and O3 mixing ratios are consistent with the QBO-induced temperature and circulation anomalies but less zonally symmetric than the temperature pattern. Regarding the ASM, the results of the regression analysis show for ERA-Interim and the CCMs enhanced H2O and reduced O3 mixing ratios within the AMA for stronger ASM seasons. The CCM results can further confirm earlier studies which emphasize the importance of the Tibetan Plateau/southern slope of the Himalayas as the main source region for H2O in the AMA. The results suggest that H2O is transported towards higher latitudes at the north-eastern edge of the AMA rather than towards low equatorial latitudes to be fed into the tropical pipe.

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