The Influence of Wave– and Zonal Mean–Ozone Feedbacks on the Quasi-biennial Oscillation

The effects of wave and zonal mean ozone heating on the evolution of the quasi-biennial oscillation (QBO) are examined using a two-dimensional mechanistic model of the equatorial stratosphere. The model atmosphere is governed by coupled equations for the zonal mean and (linear) wave fields of ozone, temperature, and wind, and is driven by specifying the amplitudes of a Kelvin wave and a Rossby–gravity wave at the lower boundary. Wave–mean flow interactions are accounted for in the model, but not wave–wave interactions. A reference simulation (RS) of the QBO, in which ozone feedbacks are neglected, is carried out and the results compared with Upper Atmosphere Research Satellite observations. The RS is then compared with three model experiments, which examine separately and in combination the effects of wave ozone and zonal mean ozone feedbacks. Wave–ozone feedbacks alone increase the driving by the Kelvin and Rossby–gravity waves by up to 10%, producing stronger zonal wind shear zones and a stronger meridional circulation. Zonal mean–ozone feedbacks (ozone QBO) alone decrease the magnitude of the temperature QBO by up to 15%, which in turn affects the momentum deposition by the wave fields. Overall, the zonal mean–ozone feedbacks increase the magnitude of the meridional circulation by up to 30%. The combined effects of wave–ozone and ozone QBO feedbacks generally produce a larger response then either process alone. Moreover, these combined ozone feedbacks produce a temperature QBO amplitude that is up to 30% larger than simulations without the feedbacks. Correspondingly, significant changes are also observed in the zonal wind and ozone QBOs. When ozone feedbacks are included in the model, the Kelvin and Rossby–gravity wave amplitudes can be reduced by ∼10% and still produce a QBO similar to simulations without ozone

An Ozone-Modified Refractive Index for Vertically Propagating Planetary Waves

[1] An ozone-modified refractive index (OMRI) is derived for vertically propagating planetary waves using a mechanistic model that couples quasigeostrophic potential vorticity and ozone volume mixing ratio. The OMRI clarifies how wave-induced heating due to ozone photochemistry, ozone transport, and Newtonian cooling (NC) combine to affect wave propagation, attenuation, and drag on the zonal mean flow. In the photochemically controlled upper stratosphere, the wave-induced ozone heating (OH) always augments the NC, whereas in the dynamically controlled lower stratosphere, the wave-induced OH may augment or reduce the NC depending on the detailed nature of the wave vertical structure and zonal mean ozone gradients. For a basic state representative of Northern Hemisphere winter, the wave-induced OH can increase the planetary wave drag by more than a factor of two in the photochemically controlled upper stratosphere and decrease it by as much as 25% in the dynamically controlled lower stratosphere. Because the zonal mean ozone distribution appears explicitly in the OMRI, the OMRI can be used as a tool for understanding how changes in stratospheric ozone due to solar variability and chemical depletion affect stratosphere-troposphere communication

An Examination of Anomalously Low Column Ozone in the Southern Hemisphere Midlatitudes During 1997

[1] Observations from both ground-based and satellite instruments show record low column ozone abundance between 20°S and 40°S during 1997. The 1997 monthly averaged column ozone from the Total Ozone Mapping Spectrometer (TOMS) is up to 25 Dobson units (DU) lower than the TOMS climatological mean (1979–1996) and up to 20 DU below the previous record low values. Observations from the Halogen Occultation Experiment show that below average ozone concentrations during 1997 were confined primarily to the lower stratosphere. Residual circulation statistics calculated from the United Kingdom Meteorological Office temperature analyses indicate that circulation anomalies during 1997 can account for ∼5–10 DU/month decrease in column ozone between 20°S and 50°S. At these latitudes during 1997, structural characteristics of the ozone and residual circulation fields both suggest a connection with the equatorial quasi-biennial oscillation

A New Pathway for Communicating the 11-year Solar Cycle Signal to the QBO

[1] The response of the equatorial quasi-biennial oscillation (QBO) to zonal-mean ozone perturbations consistent with the 11-year solar cycle is examined using a 2 1/2 dimensional model of the tropical stratosphere. Unique to this model are wave-ozone feedbacks, which provide a new, nonlinear pathway for communicating solar variability effects to the QBO. Model simulations show that for zonal-mean ozone perturbations representative of solar maximum (minimum), the diabatic heating due to the wave-ozone feedbacks is primarily responsible for driving a slightly stronger (weaker) QBO circulation and producing a slightly shorter (longer) QBO period. These results, which are explained via an analytical analysis of the divergence of Eliassen-palm flux, are in general agreement with observations of quasi-decadal variability of the QBO

Use of satellite data and modeling to asses the influence of stratospheric processes on the troposphere

The research is comprised of the following tasks: use of simple analytical and numerical models of a coupled troposphere-stratosphere system to examine the effects of radiation and ozone on planetary wave dynamics and the tropospheric circulation; use of satellite data obtained from the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) instrument and Solar Backscattered Ultraviolet (SBUV) experiment, in conjunction with National Meteorological Center (NMC) data, to determine the planetary wave vertical structures, dominant wave spectra, ozone spectra, and time variations in diabatic heating rate; and synthesis of the modeling and observational results to provide a better understanding of the effects that stratospheric processes have on tropospheric dynamics

An Analytical Study of Ozone Feedbacks on Kelvin and Rossby–Gravity Waves: Effects on the QBO

An equatorial beta-plane model of the middle atmosphere is used to analytically examine the effects of radiative cooling and ozone heating on the spatial and temporal evolution of the quasi-biennial oscillation (QBO). Under the assumption that the diabatic heating is weak and the background fields of wind, temperature, and ozone are slowly varying, a perturbation analysis yields expressions describing the vertical spatial modulation of Kelvin and Rossby–gravity waves in the presence of ozone. These expressions show that wave-induced changes in the diabatic heating arising from the advection of basic-state ozone reduce the local radiative damping rate by up to 15% below 35 km. In a one-dimensional model of the QBO, eddy ozone heating increases the amplitude of the zonal wind QBO by 1–2 m s−1 and increases the oscillation period by about two months. The significance of these results to the observed QBO is discussed

Ozone Heating and the Destabilization of Traveling Waves During Summer

The effects of ozone heating on the linear stability of lower stratospheric traveling waves of the summertime, extratropical circulation are examined. Based on coupled equations for the quasigeostrophic potential vorticity and ozone volume mixing ratio, it is shown that the diabatic heating arising from ozone advection can offset the damping due to Newtonian cooling, leading to wave amplification and significant changes in the structure and zonally rectified fluxes of the wave fields in both the lower stratosphere and troposphere. The vertical profile of the zonal mean wind plays a crucial role in determining whether the ozone heating destabilizes eastward and/or westward traveling disturbances

Effects of Planetary Wave-breaking on the Seasonal Variation of Total Column Ozone

The effects of planetary wave breaking on the seasonal variation of total column ozone are investigated using a zonally averaged chemical-radiative-transport model of the atmosphere. The planetary wave breaking effects of zonal wavenumbers k=1 and k=2 are significant in the middle latitude stratosphere during Northern Hemisphere (NH) winter, whereas only wave k=1 is important during Southern Hemisphere (SH) winter. The mixing and induced meridional circulation due to the planetary wave breaking increases the seasonal variation of total column ozone in NH (SH) middle latitudes by ∼20% (∼10%)

Trans Collaborations Clinical Check-In (TC3): Initial Validation of a Clinical Measure for Transgender and Gender Diverse Adults Receiving Psychological Services

One key aspect of evidence-based psychological services is monitoring progress to inform treatment decision making, often using a brief self-report measure. However, no such measure exists to support measurement based care given the distinct needs of transgender and gender diverse people (TGD), a group facing large documented health disparities and marginalization in healthcare. The purpose of the present study was to develop and provide initial psychometric validation of a short, behavioral health progress monitoring self-report measure, the Trans Collaborations Clinical Check-in (TC3). TGD communities, providers identified as TGD-affirmative, and relevant academic experts contributed to item and scale development. The final 18 item version was administered to 215 TGD adults (75 transfeminine, 76 transmasculine, 46 nonbinary, 18 unknown; mean age of 30 with a range of 19 to 73), who were recruited for an online study, with other questionnaires assessing negative affect, well-being, gender dysphoria, gender minority stressors, and resilience. Higher scores on the TC3 (indicating better adjustment and comfort with gender) were generally associated with lower depression, anxiety, minority stress, and gender dysphoria and greater life satisfaction, body congruence, and positive aspects of being TGD such as pride in identity and community belongingness. These results support the validity of the TC3 as a brief measure to be used as a clinical tool for TGD people receiving mental health services. Additional research is needed on the reliability and validity of the TC3 across multiple time points to determine utility as a progress monitoring measure. The TC3 should also be further validated with more culturally diverse samples

Apolipoprotein M attenuates anthracycline cardiotoxicity and lysosomal injury

Apolipoprotein M (ApoM) binds sphingosine-1-phosphate (S1P) and is inversely associated with mortality in human heart failure (HF). Here, we show that anthracyclines such as doxorubicin (Dox) reduce circulating ApoM in mice and humans, that ApoM is inversely associated with mortality in patients with anthracycline-induced heart failure, and ApoM heterozygosity in mice increases Dox-induced mortality. In the setting of Dox stress, our studies suggest ApoM can help sustain myocardial autophagic flux in a post-transcriptional manner, attenuate Dox cardiotoxicity, and prevent lysosomal injury