Abstract
We used observations and model simulation to examine the atmospheric pulses that dominate the far field in the hours after the January 2022 Tonga eruption. We analyzed radiance observations ...taken from the
Himawari-8
geostationary satellite and showed that both a Lamb wave front with the expected horizontal phase speed ∼315 m s
−1
and a distinct front with phase speed ∼245 m s
−1
can be detected. The slower phase speed is consistent with that expected for the global internal resonant mode that had been proposed by Pekeris in 1937 and in other idealized theoretical studies over the past century, but which had never been detected in the atmosphere. A simulation of the eruption aftermath was performed with a high-resolution atmospheric general circulation model. A hot anomaly over the volcano location was introduced instantaneously to the model fields and the model was integrated for another 12 h. This produced a simulated wave pulse that, in the far field, agreed reasonably well with barograph observations of the Lamb wave. The model results also showed the presence of the slower pulse and that this disturbance had a vertical structure with a 180° phase shift in the stratosphere, in agreement with the theoretical prediction for the internal resonant mode. An implication is that the continuously ringing Lamb wave global normal modes that have been seen in analyses of long observational records ought to have lower-frequency internal Pekeris mode counterparts, a prediction that we confirm though analysis of 67 years of hourly global reanalysis data.
Significance Statement
Our demonstration that both a surface-trapped Lamb wave and a slower horizontal phase speed internal Pekeris wave can be realized as normal modes of the global atmosphere resolves a very long-standing and fundamental issue in dynamical meteorology. Our result also has broader implications. The 2022 Tonga eruption produced a surprisingly large ocean tsunami even in a remote ocean basin, and it is possible that the slower atmospheric Pekeris mode can play a role in exciting the remarkable ocean response. Also the spectral peaks seen in atmospheric variability corresponding to the Pekeris normal mode provide features for comparison with global model simulations of the atmosphere, along with the Lamb modes detected in earlier studies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This work focuses on characterizing the structural and surface properties of Ti X Ce1-X O2 (TiO2−CeO2) mixed oxides using XRD, XPS, BET, H2-TPR, and NH3-TPD techniques. The Ti X Ce1-X O2 mixed oxides ...synthesized by the urea coprecipitation method showed unimodal nanoporous structure with pore sizes increasing from 3.7 nm for X = 0.9 to 5.3 nm for X = 0.1. Concomitant with their higher surface area and pore volume, the mixed oxides were nanocrystalline, about 4.0 nm in crystallite size when X = 0.9, and 4.8−5.4 nm when X = 0.1− 0.3, which are significantly smaller than TiO2 and CeO2 single oxides prepared by the same method (8.1 to 8.4 nm). A dominant anatase phase was detected by XRD when X was 0.9 or higher while a cubic fluorite phase was dominant when X was 0.3 or lower. Lattice parameters were changed by incorporating Ce into TiO2, and Ti into CeO2, respectively. This change indicates distortion of structure and was attributed to reduction of Ti4+ to Ti3+, and Ce4+ to Ce3+. XPS (Ce 3d, Ti 2p, O 1s) and H2-TPR revealed that the oxidation state of surface cations decreased, and oxygen deficiency of the surface was significantly enhanced by introducing Ce into TiO2, and Ti into CeO2. The structural and surface modification by introducing Ce into TiO2 increased the reducibility of mixed oxides in H2-TPR. NH3-TPD showed that increasing Ti content in Ti X Ce1-X O2 enhanced surface acidity. Furthermore, H2O and N2 formation from NH3 was detected by mass spectrometry, which was attributed to the oxidation activity of the Ti X Ce1-X O2 mixed oxides. The highest NH3 oxidation activity was observed when X = 0.9. The present study clearly established that the structural (crystal phase, crystal size, nanoporosity, pore size) and surface properties (reducibility, oxygen deficiency, acidity, oxidation activity) of the Ti X Ce1-X O2 mixed oxides can be tailored by controlling their composition by the urea coprecipitation procedure.
Previous studies conducted have reported higher mortality and heart failure readmission rates in heart failure patients with selenium deficiency. However, these studies included patients with ...advanced heart failure, which may have confounded the relationship between selenium deficiency and heart failure pathology. This study aimed to explore the clinical characteristics and outcomes of heart failure patients with selenium deficiency who were newly diagnosed and hospitalized for heart failure in Japan. A total of 256 patients, who were admitted to our hospital for the first time due to heart failure, were included in this study. The patients were divided into two groups: a low selenium group (LS group, n=132) and a normal selenium group (NS group, n=124). Clinical features and outcomes were compared between the two groups, including 1-y mortality and readmissions due to heart failure. Among the patients admitted with heart failure, 51.6% exhibited selenium deficiency. The LS group showed a higher proportion of females (65.4% vs. 46.4%, p=0.003) and lower albumin levels (3.2±0.5 g/dL vs. 3.5±0.5 g/dL, p<0.001) compared to the NS group. The LS group had a significantly higher readmission rate for heart failure (31.8% vs. 17.7%, p=0.009). Multivariate analysis revealed heart failure patients with low selenium as an independent factor for readmission due to heart failure. Newly diagnosed heart failure patients with low selenium demonstrated a high readmission rate for heart failure.
Abstract
Gravity wave characteristics in the middle- to high-latitude Southern Hemisphere are analyzed using simulation data over 3 yr from a high-resolution middle-atmosphere general circulation ...model without using any gravity wave parameterizations. Gravity waves have large amplitudes in winter and are mainly distributed in the region surrounding the polar vortex in the middle and upper stratosphere, while the gravity wave energy is generally weak in summer. The wave energy distribution in winter is not zonally uniform, but it is large leeward of the southern Andes and Antarctic Peninsula. Linear theory in the three-dimensional framework indicates that orographic gravity waves are advected leeward significantly by the mean wind component perpendicular to the wavenumber vector. Results of ray-tracing and cross-correlation analyses are consistent with this theoretical expectation. The leeward energy propagation extends to several thousand kilometers, which explains part of the gravity wave distribution around the polar vortex in winter. This result indicates that orographic gravity waves can affect the mean winds at horizontal locations that are far distant from the source mountains. Another interesting feature is a significant downward energy flux in winter, which is observed in the lower stratosphere to the south of the southern Andes. The frequency of the downward energy flux is positively correlated with the gravity wave energy over the southern Andes. Partial reflection from a rapid increase in static stability around 10 hPa and/or gravity wave generation through nonlinear processes are possible mechanisms to explain the downward energy flux.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This article describes the new Earth system model (ESM), the Model for Interdisciplinary Research on Climate, Earth System version 2 for Long-term simulations (MIROC-ES2L), using a state-of-the-art ...climate model as the physical core. This model embeds a terrestrial biogeochemical component with explicit carbon–nitrogen interaction to account for soil nutrient control on plant growth and the land carbon sink. The model's ocean biogeochemical component is largely updated to simulate the biogeochemical cycles of carbon, nitrogen, phosphorus, iron, and oxygen such that oceanic primary productivity can be controlled by multiple nutrient limitations. The ocean nitrogen cycle is coupled with the land component via river discharge processes, and external inputs of iron from pyrogenic and lithogenic sources are considered. Comparison of a historical simulation with observation studies showed that the model could reproduce the transient global climate change and carbon cycle as well as the observed large-scale spatial patterns of the land carbon cycle and upper-ocean biogeochemistry. The model demonstrated historical human perturbation of the nitrogen cycle through land use and agriculture and simulated the resultant impact on the terrestrial carbon cycle. Sensitivity analyses under preindustrial conditions revealed that the simulated ocean biogeochemistry could be altered regionally (and substantially) by nutrient input from the atmosphere and rivers. Based on an idealized experiment in which CO2 was prescribed to increase at a rate of 1 % yr−1, the transient climate response (TCR) is estimated to be 1.5 K, i.e., approximately 70 % of that from our previous ESM used in the Coupled Model Intercomparison Project Phase 5 (CMIP5). The cumulative airborne fraction (AF) is also reduced by 15 % because of the intensified land carbon sink, which results in an airborne fraction close to the multimodel mean of the CMIP5 ESMs. The transient climate response to cumulative carbon emissions (TCRE) is 1.3 K EgC−1, i.e., slightly smaller than the average of the CMIP5 ESMs, which suggests that “optimistic” future climate projections will be made by the model. This model and the simulation results contribute to CMIP6. The MIROC-ES2L could further improve our understanding of climate–biogeochemical interaction mechanisms, projections of future environmental changes, and exploration of our future options regarding sustainable development by evolving the processes of climate, biogeochemistry, and human activities in a holistic and interactive manner.
The sixth version of the Model for Interdisciplinary Research on Climate
(MIROC), called MIROC6, was cooperatively developed by a Japanese modeling
community. In the present paper, simulated mean ...climate, internal
climate variability, and climate sensitivity in MIROC6 are evaluated and
briefly summarized in comparison with the previous version of our climate
model (MIROC5) and observations. The results show that the overall
reproducibility of mean climate and internal climate variability in MIROC6
is better than that in MIROC5. The tropical climate systems (e.g.,
summertime precipitation in the western Pacific and the eastward-propagating
Madden–Julian oscillation) and the midlatitude atmospheric circulation
(e.g., the westerlies, the polar night jet, and troposphere–stratosphere
interactions) are significantly improved in MIROC6. These improvements can
be attributed to the newly implemented parameterization for shallow
convective processes and to the inclusion of the stratosphere. While there
are significant differences in climates and variabilities between the two
models, the effective climate sensitivity of 2.6 K remains the same because
the differences in radiative forcing and climate feedback tend to offset
each other. With an aim towards contributing to the sixth phase of the
Coupled Model Intercomparison Project, designated simulations tackling a
wide range of climate science issues, as well as seasonal to decadal climate
predictions and future climate projections, are currently ongoing using
MIROC6.
A new version of the atmosphere–ocean general circulation model cooperatively produced by the Japanese research community, known as the Model for Interdisciplinary Research on Climate (MIROC), has ...recently been developed. A century-long control experiment was performed using the new version (MIROC5) with the standard resolution of the T85 atmosphere and 1° ocean models. The climatological mean state and variability are then compared with observations and those in a previous version (MIROC3.2) with two different resolutions (medres, hires), coarser and finer than the resolution of MIROC5.
A few aspects of the mean fields in MIROC5 are similar to or slightly worse than MIROC3.2, but otherwise the climatological features are considerably better. In particular, improvements are found in precipitation, zonal mean atmospheric fields, equatorial ocean subsurface fields, and the simulation of El Niño–Southern Oscillation. The difference between MIROC5 and the previous model is larger than that between the two MIROC3.2 versions, indicating a greater effect of updating parameterization schemes on the model climate than increasing the model resolution. The mean cloud property obtained from the sophisticated prognostic schemes in MIROC5 shows good agreement with satellite measurements. MIROC5 reveals an equilibrium climate sensitivity of 2.6 K, which is lower than that in MIROC3.2 by 1 K. This is probably due to the negative feedback of low clouds to the increasing concentration of CO₂, which is opposite to that in MIROC3.2.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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•Chemistry of common solid sorbents utilized in industrial natural gas desulfurization is reviewed.•The higher oxidation state of oxide-based sorbents, such as CuO and Fe2O3, ...contribute to their suitable performance in natural gas desulfurization.•Higher oxidation state, Cu+2, influences efficient H2S removal more than lower oxidation state, Cu+1 and Cu0.•The environmental and safety aspect of the spent Fe2O3 sorbent is discussed in terms of pyrophoricity/self-heating property.
The chemistry on sorptive H2S removal in industrial natural gas desulfurization was reviewed on mechanistic aspects of H2S adsorption/sorption over the surface of activated carbon, zeolite/molecular sieve, zinc oxide, copper oxide, and iron oxide as representative industrial common sorbents. H2S removal of natural gas underwent through weak chemisorption over the surface of activated carbon and zeolite/molecular sieve and dissociative chemisorption over the surface of ZnO, CuO, and Fe2O3 at ambient or relatively low temperature. Dissociative chemisorption over the oxides concomitantly occurred with lattice oxygen replacement by sulfur migration into bulk of oxides, which contributes to higher H2S removal capacity. The infrared spectroscopy and X-ray photoelectron spectroscopy studies elucidated the influence of the presence of impurities, such as CO2 or H2O on H2S removal over each surface. The advantages and disadvantages of industrially preferred H2S removal sorbents, CuO and Fe2O3, were highlighted especially on the role of oxidation state. At last, the discussion of spent sulfided sorbents was extended to the environmental and safety aspect.
•No studies have shown the clinical features of acute myocardial infarction (AMI) in welfare recipients in Japan.•We investigated the clinical characteristics of AMI patients receiving welfare.•AMI ...patients receiving welfare have poor management of lifestyle-related diseases.•AMI patients receiving welfare had poor cardiac function in the chronic phase.
An increase in the rate of relative poverty and the number of welfare recipients is a serious social problem in Japan. A recent overseas survey demonstrated that lack of health insurance was associated with increased in-hospital mortality in patients with ST-segment elevation myocardial infarction (STEMI). The aim of this study is to investigate the clinical features of STEMI patients who receive welfare public assistance in Japan.
We enrolled 525 STEMI patients who were hospitalized in our hospital from 2010 to 2019. We divided patients into groups of patients receiving welfare public assistance (WPA group, N = 67) and groups of patients not receiving welfare public assistance (non-WPA group, N = 458). Patient characteristics, clinical outcome, and cardiac function on transthoracic echocardiography were compared.
WPA group were younger than non-WPA group (61.2 ± 10.9 years VS 64.5 ± 13.3 years, p = 0.03). The prevalence of smoking was higher in WPA group compared to non-WPA group (91.0% VS 81.1% p = 0.04) and high-density lipoprotein cholesterol value of WPA group was lower than in non-WPA group (43.2 ± 9.9 mg/dl vs 47.1 ± 12.8 mg/dl, p = 0.005).
Ventricular arrhythmia on admission was significantly more frequent in WPA group (11.9% VS 4.8%, p = 0.02). In acute and chronic phase, left ventricular ejection fraction in WPA group was lower than non-WPA group (in acute phase 46.6 ± 10.7% vs 53.3 ± 8.6% p = 0.001, in chronic phase 48.7 ± 10.1% vs 55.3 ± 9.4%, p = 0.008).
STEMI patients receiving welfare public assistance had poorer control of coronary risk, increased risk of fatal arrhythmia, and reduced systolic function than those not receiving welfare public assistance. It is necessary to have a system that can strengthen lifestyle management, such as diet and smoking cessation for the purpose of improving the prognosis of welfare recipients after AMI.
Tide gauge data indicated that ocean waves were generated by the eruption of the Hunga Tonga-Hunga Ha’apai volcano on January 15, 2022. These high-amplitude waves reached the Japanese coast earlier ...than expected for free ocean waves. These fluctuations in sea level were reasonably reproduced by an ocean model, with realistic bottom topography forced by sea-level pressure perturbations well reproduced by atmospheric general circulation models. While early arrival times are associated with atmospheric Lamb waves, the amplitude of the sea level changes cannot be fully explained by the resonance mechanism associated with sea-level pressure fluctuations of Lamb and Pekeris waves alone. Rather, resonance due to atmospheric waves in conjunction with the amplification effects caused by a steep continental slope is required in order to reproduce sea level fluctuations along the Japanese coast. In particular, the deep Northwest Pacific Basin to the east of Japan is important for strengthening the amplitude of the meteorological tsunami.
•Sea level fluctuations due to the 2022 volcanic eruption in Tonga was reproduced.•Meteorological tsunamis were generated by Lamb and Pekeris waves.•Meteorological tsunamis by Pekeris waves are amplified due to Proudman resonance.•Meteorological tsunamis are amplified by entering the sharp continental slope.
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