Long-term changes in the mesosphere calculated by a two-dimensional model

We have used the interactive two-dimensional model SOCRATES to investigate the thermal and the chemical response of the mesosphere to the changes in greenhouse gas concentrations observed in the past 50 years (CO2, CH4, water vapor, N2O, CFCs), and to specified changes in gravity wave drag and diffusion in the upper mesosphere. When considering the observed increase in the abundances of greenhouse gases for the past 50 years, a cooling of 3–7 K is calculated in the mesopause region together with a cooling of 4–6 K in the middle mesosphere. Changes in the meridional circulation of the mesosphere damp the pure radiative thermal effect of the greenhouse gases. The largest cooling in the winter upper mesosphere-mesopause region occurs when the observed increase in concentrations of greenhouse gases and the strengthening of the gravity wave drag and diffusion are considered simultaneously. Depending on the adopted strengthening of the gravity wave drag and diffusion, a cooling varying from typically 6–10 K to 10–20 K over the past 50 years is predicted in the extratropical upper mesosphere during wintertime. In summer, however, consistently with observations, the thermal response calculated by the model is insignificant in the vicinity of the mesopause. Although the calculated cooling of the winter mesopause is still less than suggested by some observations, these results lead to the conclusion that the increase in the abundances of greenhouse gases alone may not entirely explain the observed temperature trends in the mesosphere. Long-term changes in the dynamics of the middle atmosphere (and the troposphere), including changes in gravity wave activity may have contributed significantly to the observed long-term changes in thermal structure and chemical composition of the mesospher

An Exploratory Investigation into the Association of Neuroticization, Cognitive Style, and Spirituality to Reported Altered States of Consciousness in Women Experiencing Childbirth

This study examined the relation of altered states of consciousness to neuroticization, spiritual experience, and divergent thinking in a sample of women (N= 102) at late pregnancy and post-delivery. The results suggest that stress associated with imminent childbirth is linked to higher levels of ASCs and that neuroticization and spirituality seem to be implicated in the induction of ASCs

Charge transfer transitions in the photoluminescence spectra of Zn1-xMexO (Me = Mn, Ni, Co) oxide compounds

Crystals of Zn1-xCoxO and Zn1-xNixO are studied by photoluminescence at temperatures of 8 and 90 K. By resolving the spectra into sums of gaussian distributions and using the known positions of donor and acceptor levels of 3d-impurities relative to the edges of the allowed bands, the observed peaks in the photoluminescence spectra are interpreted in terms of radiative recombination through donor and acceptor levels of nickel and cobalt ions. These results are compared with previously observed features of the photoluminescence spectra of Zn1-xMnxO crystals. © 2013 American Institute of Physics

The effect of the solar rotational irradiance variation on the middle and upper atmosphere calculated by a three-dimensional chemistry-climate model

This paper analyzes the effects of the solar rotational (27-day) irradiance variations on the chemical composition and temperature of the stratosphere, mesosphere and lower thermosphere as simulated by the three-dimensional chemistry-climate model HAMMONIA. Different methods are used to analyze the model results, including high resolution spectral and cross-spectral techniques. To force the simulations, an idealized irradiance variation with a constant period of 27 days (apparent solar rotation period) and with constant amplitude is used. While the calculated thermal and chemical responses are very distinct and permanent in the upper atmosphere, the responses in the stratosphere and mesosphere vary considerably in time despite the constant forcing. The responses produced by the model exhibit a non-linear behavior: in general, the response sensitivities (not amplitudes) decrease with increasing amplitude of the forcing. In the extratropics the responses are, in general, seasonally dependent with frequently stronger sensitivities in winter than in summer. Amplitude and phase lag of the ozone response in the tropical stratosphere and lower mesosphere are in satisfactory agreement with available observations. The agreement between the calculated and observed temperature response is generally worse than in the case of ozone

Manifestation of quasi-biennial oscillation in ozone vertical distribution

The quasi-biennial oscillations (QBO) in ozone and temperature vertical distributions are studied on the basis of ozonesonde data of 21 stations. Maximum QBO amplitudes in ozone are noted in the 16-20 kn layer over Resolute (75N), Aspendale (38S) and in the northern mid-latitude band, but in the 20-24 km layer in the northern subtropical band. In the upper layers the QBO effect is less evident. In the tropospheric layer it is difficult to note the QBO-related effect in all the groups of the data. In all the layers where the QBO effect is noted the positive deviations precede, but the negative deviations follow the time of maximum of the easterly equatorial wind at 50 mb level. No essential differences in phase or amplitude characteristics of the ozone QBO were noted for the Aspendale data compared with that for the Northern Hemisphere data. The QBO-effect is not noted in the temperature data in the mid-latitudes. Above Resolute and in subtropics the ozone and temperature effects are roughly in phase each with other, except in the 28-32 km layer over subtropics, where they are opposite each to other

Quasi-biennial oscillation in total ozone: Global behaviour derived from ground-based measurements

The quasi-biennial oscillation (QBO) in total ozone (TO) is studied on the basis of TO measurements at the world ground-ased ozone network during 1972-1988. The TO content is on the whole greater in the tropical belt and smaller in high latitudes during the westerly phase of the QBO of the equatorial stratospheric 50 mb wind than during the easterly phase in all seasons. The appropriate TO difference (westerly category minus easterly category) displays certain space structures changing during a year. There are regions with the peculiar annual evolution of this difference, particularly in the Arctic and Antarctic. Spectral analysis reveals bimodality of TO power spectra in the frequency range of QBO periods, with spectral maxima corresponding to 17-23 months and 28-35 months. The large period oscillations are predominant on the whole. The small period oscillations are likely the consequence of interaction between an annual cycle and QBO

Discerning the Role of Prostaglandins in Ductus Arteriosus Remodeling

The ductus arteriosus (DA) is a fetal pulmonary bypass shunt that constricts and permanently remodels during the transition from fetal to adult circulation. Prostaglandin E2 (PGE2) is potent mediator of numerous physiological responses both in homeostasis and disease state. PGE2 play a vital role in DA maturation and closure, although the exact molecular role is unclear. We attempt to discern the nature of PGE2 involvement in DA maturation and closure. Here we generate a conditional null allele of the prostaglandin E receptor 4 (EP4), which has been previously shown to be responsible for PGE2 signaling in the DA. Utilizing various tissue specific Cre recombinase transgenes, we have shown that EP4 expression on the neural crest derived smooth muscle cells of the DA is critical for proper DA closure. We have also shown that endothelial expression of the PGE2 vasodilatory receptors (EP4 and EP2) is non-essential for DA closure or vascular development. Genome wide expression profiling of the wildtype DA and EP4 deficient DA were used to assess the transcriptional consequences of PGE2/EP4 signaling in the DA. Differentially expressed genes in the wildtype DA indicate that EP4 receptor expression leads to the up-regulation of numerous cytoskeletal genes. The relative minor increase (<2 fold) of numerous cytoskeletal genes may explain why the wildtype and EP4 deficient DA appear morphologically similar in utero but have antithetical fates after birth. Here we also document the existence of a prostaglandin-independent mechanism of DA maturation and closure in mice. Selective mating generated a recombinant inbred (RI) mouse strain that undergoes DA maturation and closure without any contribution from prostaglandin signaling. Single locus inheritance of patent ductus arteriosus (PDA) in common inbred strains (CIS) seemed at odds with the complex inheritance pattern of PDA in larger animals, but the RI strain indicates that DA closure in non-CIS mice is also a complex trait. The study of both prostaglandin-dependent DA closure of CIS mice and prostaglandin-independent DA closure of RI mice provides a mouse model for understanding the complex trait of larger animals

Total ozone and total NO2 latitudinal distribution derived from measurements in the Atlantic Ocean in May 1988

Total ozone and NO2 were measured aboard a ship in the 40S - 40N latitude band in the Atlantic Ocean in the second half of May 1988. The main features of the latitudinal distributions of total NO2 and ozone are similar. There is seen an increase of total ozone and NO2 from the tropical to subtropical latitudes, strongest in the region of the subtropical jet stream. The fine structure has been revealed in the total ozone and NO2 latitudinal distributions, connected most likely with stratosphere-troposphere exchange processes in the tropopause folding zone