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How subtropical marine low cloud cover (LCC) will respond to global warming is a major source of uncertainty in future climate change. Although the estimated inversion strength (EIS) is a good predictive index of LCC, it has a serious limitation when applied to evaluate LCC changes due to warming: The LCC decreases despite increases in EIS in future climate simulations of global climate models (GCMs). In this work, using state-of-the-art GCMs, we show that the recently proposed estimated cloud-top entrainment index (ECTEI) decreases consistently with LCC in warmer sea surface temperature (SST) climates. For the patterned SST warming predicted by coupled GCMs, ECTEI can constrain the subtropical marine LCC feedback to –0.41 ± 0.28% K −1 (90% CI), implying virtually certain positive feedback. ECTEI physically explains the heuristic model for LCC changes based on a linear combination of EIS and SST changes in previous studies in terms of cloud-top entrainment processes.

Essential oils (EOs) from Abies sachalinensis (Sakhalin fir), a conifer species found in Sakhalin Island and Hokkaido in Japan, effectively remove nitrogen dioxide and possess antifungal activity. EOs also exert a relaxing effect and enhance air quality. Underwater shock waves generate instantaneous high pressure that ruptures cell walls, enhancing the performance of steam distillation and oil extraction. In this study, we aimed to increase the yield and quality of A. sachalinensis extracts using shockwaves. Leaves and branches were subjected to shockwave pretreatment or left untreated before EO extraction by steam distillation. EO yield of untreated dried leaves was 2.4 g/kg of dry leaf weight (DW). Upon application of a 3.0 kV, 3.6 kJ shockwave, the yield increased with the number of shockwave cycles. After ten cycles, yield increased 13.6-fold. Pretreatment with shockwaves for 10 cycles resulted in approximately 6- and 13-fold reductions in total energy consumption relative to fresh and dried leaves, respectively. Antioxidant activity increased more than 30-fold in shockwave-pretreated leaves than in untreated dried leaves after 10 cycles. This novel process can significantly reduce the energy used for EO extraction in steam distillation, thereby contributing to the development of a sustainable, low-energy EO production system.

The aromatic perennial plant Alpinia zerumbet (Pers.) Burtt & Smith (Zingiberaceae) is widely distributed in the tropical and sub-tropical regions of Japan, from southern Kyushu to the Ryukyu Islands. Its essential oil has a distinct aroma and antioxidant activity but is expensive due to low extraction efficiencies. Applying underwater shockwave pretreatment to A. zerumbet leaves is expected to enable more effective essential oil extraction during subsequent steam distillation. Thus, we subjected A. zerumbet leaves to shockwave pretreatment and analyzed its effects on the essential oil yield and components. Multiple cracks formed in the cell walls via spalling destruction induced by the shockwaves, creating permeation pathways that improved the passage of water vapor and greatly increased the essential oil yield. Moreover, the pretreatment increased the antioxidant activity of the essential oil and its water extract. Underwater shockwave processing selectively and effectively destroyed the fiber and/or cell structures of the leaves, resulting in efficient essential oil extraction. This novel process has the potential for application to many extraction processes, such as the extraction of compounds from medicinal plants. The dynamic control of instantaneous high pressures based on underwater shockwaves could pave the way for a new field of industrial technology.

International audience; We investigate the dependence of radiative feedback on the pattern of sea-surface temperature (SST) change in 14 Atmospheric General Circulation Models (AGCMs) forced with observed variations in SST and sea-ice over the historical record from 1871 to near-present. We find that over 1871-1980, the Earth warmed with feedbacks largely consistent and strongly correlated with long-term climate sensitivity feedbacks (diagnosed from corresponding atmosphere-ocean GCM abrupt-4xCO2 simulations). Post 1980, however, the Earth warmed with unusual trends in tropical Pacific SSTs (enhanced warming in the west, cooling in the east) and cooling in the Southern Ocean that drove climate feedback to be uncorrelated with—and indicating much lower climate sensitivity than—that expected for long-term CO2 increase. We show that these conclusions are not strongly dependent on the Atmospheric Model Intercomparison Project (AMIP) II SST data set used to force the AGCMs, though the magnitude of feedback post 1980 is generally smaller in nine AGCMs forced with alternative HadISST1 SST boundary conditions. We quantify a "pattern effect" (defined as the difference between historical and long-term CO2 feedback) equal to 0.48 ± 0.47 [5%-95%] W m-2 K-1 for the time-period 1871-2010 when the AGCMs are forced with HadISST1 SSTs, or 0.70 ± 0.47 [5%-95%] W m-2 K-1 when forced with AMIP II SSTs. Assessed changes in the Earth's historical energy budget agree with the AGCM feedback estimates. Furthermore satellite observations of changes in top-of-atmosphere radiative fluxes since 1985 suggest that the pattern effect was particularly strong over recent decades but may be waning post 2014.

The development of the climate model MRI-ESM2 (Meteorological Research Institute Earth System Model version 2), which is planned for use in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) simulations, involved significant improvements to the representation of clouds from the previous version MRI-CGCM3 (Meteorological Research Institute Coupled Global Climate Model version 3), which was used in the CMIP5 simulations. In particular, the serious lack of reflection of solar radiation over the Southern Ocean in MRI-CGCM3 was drastically improved in MRI-ESM2. The score of the spatial pattern of radiative fluxes at the top of the atmosphere for MRI-ESM2 is better than for any CMIP5 model. In this paper, we set out comprehensively the various modifications related to clouds that contribute to the improved cloud representation and the main impacts on the climate of each modification. The modifications cover various schemes and processes including the cloud scheme, turbulence scheme, cloud microphysics processes, interaction between cloud and convection schemes, resolution issues, cloud radiation processes, interaction with the aerosol model, and numerics. In addition, the new stratocumulus parameterization, which contributes considerably to increased low-cloud cover and reduced radiation bias over the Southern Ocean, and the improved cloud ice fall scheme, which alleviates the time-step dependency of cloud ice content, are described in detail.

The relationship between improvements in the radiation bias over the Southern Ocean and the alleviation of the double‐intertropical convergence zone (ITCZ) problem in the actual updates of our climate models is investigated. The radiation bias in MRI‐CGCM3 that was used for CMIP5 simulations, particularly over the Southern Ocean, is significantly reduced in MRI‐ESM2 that is used for CMIP6 simulations. Each modification that contributed to the reduction of the radiation bias was progressively reverted to the corresponding older treatment in order to examine their individual impacts on the ITCZ representation. Results show the double‐ITCZ problem worsens almost monotonically when the excessive shortwave insolation over the Southern Ocean increases. The contribution of the atmosphere is about one third of the impact on the total northward energy transport and the corresponding response of the Hadley cell is related to the change in the double‐ITCZ. However, our results also imply that the ITCZ bias cannot be completely resolved by the improvements of radiative flux alone and that there are other causes of the problem.

Background and Aims Plasma potassium levels are impacted by decreased kidney function and are known to be associated with increased mortality, adverse cardiovascular events and adverse kidney events. However, the prognostic implication of urinary potassium is unclear. Method We conducted an observational study of 1102 patients with chronic kidney disease (CKD) who were hospitalized between 2010 and 2018. The expected primary outcomes were all-cause mortality, adverse cardiovascular events and CKD progression. CKD progression was defined as a 30% increase in serum creatinine, the initiation of maintenance dialysis or the need for kidney transplantation. The Cox proportional hazards model was used to analyse the association between urinary potassium excretion and adverse clinical outcomes after adjustment for potential confounders. Results At baseline, 66% of the patients were men, with a median age of 72 years (interquartile range or IQR, 64–79 years); 61% of the patients were diabetic, and 54% of them were hypertensive. The median values for estimated glomerular filtration rate (eGFR) was 12 mL/min/1.73m2 (IQR, 8–18), serum potassium 4.5 mmol/L (IQR, 4.1–5.1) and urinary potassium/creatinine ratio (UK/Cr) 27 mmol/gCr (IQR, 20–38). Over a median follow-up period of 2.6 years (IQR 0.2–4.5), the number of all-cause deaths was 87. There were 171 cases of cardiovascular events and 860 cases of CKD progression. After adjusting for the eGFR, serum potassium level, proteinuria, renin–angiotensin system inhibitors, diuretics and other potential confounders, UK/Cr was found to be neither significantly associated with all-cause mortality nor with adverse cardiovascular events. However, a low UK/Cr was associated with an increased risk of CKD progression (adjusted hazard ratio [95% confidence interval] for the first, second and third quartiles, compared with the fourth quartile, were as follows: 2.09 [1.43-3.06], 1.33 [0.96-1.86] and 1.05 [0.75-1.46]) Conclusion A low UK/Cr might be an independent risk factor for poor renal outcome.

Background and Aims Tolvaptan (TV) slows down the increase in total kidney volume (TKV) in patients with autosomal dominant polycystic kidney disease (ADPKD). The efficacy of TV in patients with moderate-to-severe renal dysfunction (RD) in ADPKD remains unknown. Method This was a single-centre retrospective study involving 27 patients with ADPKD who took TV and visited our hospital in the past six years. The participants were divided into two groups: the normal-to-mild RD (estimated glomerular filtration rate (eGFR) ≥ 45mL/min/1.73m2) group and the moderate-to-severe RD (eGFR < 45mL/min/1.73m2) group. Treatment effects were evaluated using ΔTKV, which was calculated as post-/pre-treatment annual TKV change. Continuous variables are presented using the median [interquartile range]. Results The moderate-to-severe RD group comprised 11 patients. Baseline characteristics of the normal-to-mild vs. moderate-to-severe RD group were as follows: eGFR, 56 [50–69] vs. 29 [24–38] mL/min/1.73m2; age, 48 [39–55] vs. 49 [43–58] years; male gender, 57% vs. 36%; body mass index (BMI) , 26 [23–28] vs. 24 [22–27] kg/m2; TKV 1700 [1084–2574] vs. 1827 [1331–2424] mL; family history of ADPKD, 100% vs. 82%; history of cerebral aneurysm, 19% vs. 36%; hypertension, 81% vs. 82%; hyperuricemia, 13% vs. 27%; dyslipidaemia, 19% vs. 18%; diabetes, 6.1% vs. 9.1% and systolic blood pressure (sBP) on admission 138 [129–144] vs. 131 [128-137] mmHg. No significant differences were noted in all these parameters, except for renal function. The starting dose of TV was 60 mg/day in all cases (0.9 [0.7–1.0] vs. 0.9 [0.8–1.1] mg/kg; P = 0.35). Urine volume (7.5 [5.7–9.6] vs. 4.0 [3.3–4.7] L/day; P = 0.006) and urinary sodium excretion (163 [126–226] vs. 89 [81–120] mEq/day; P = 0.003) were higher in the normal-to-mild RD group. Between the groups, there were no differences in urine protein (0.12 [0.0–0.3] vs. 0.16 [0.08–0.29] g/day; P = 0.31) and ΔeGFR (98% [88–123] vs. 106% [102–112]; P = 0.45), which was calculated as post-/pre-treatment annual eGFR change. Although both groups experienced the therapeutic effects of TV, the efficacy was poorer in the moderate-to-severe RD group (ΔTKV, 82% [76–85] vs. 96% [86–97]; P = 0.001). Conclusion The efficacy of TV patients with moderate-to-severe RD in ADPKD might be modest.

Background: While the suicide rate in Japan has recently declined, it is still high from a global perspective. Recently, suicides related to unemployment caused by COVID-19 have increased. In addition, because of increases in karoshi and industrial accidents, mental health measures for workers have become an urgent issue. We previously conducted a study that tested whether screening for mood disorders, which were strongly associated with suicide-related behavior, helps prevent suicide in small and medium-size enterprise workers, where mental health support was insufficient. The current study builds on 2 the previous study’s findings that mental illness screening helps identify mood disorders and may provide a primary prevention method for suicide. Methods: A total of 1,411 consenting workers were surveyed using the Mini-International Neuropsychiatric Interview (MINI). A representative module of each disease item was extracted and analyzed. The Center for Epidemiological Studies-Depression (CES-D), Bipolar Spectrum Diagnostic Scale (BSDS), Liebowitz Social Anxiety Scale (LSAS-J), and the Sheehan Disability Scale (SDISS) were used as secondary assessments. We compared individuals with depression, bipolar disorder, dysthymia, and mood disorders with a control group. In addition, we conducted multivariate analyses to investigate items that identified individuals with depression, mood dysregulation, bipolar disorder, or all-inclusive mood disorders. Results The adjusted odds ratios in the anxiety disorders groups were 3.2 for panic disorder, 2.6 for social anxiety disorder, 2.1 for agoraphobia, and 1.8 for generalized anxiety disorder; 2.1 for obsessive compulsive disorders; and 2.8 for the bulimia nervosa group. These results show a significant correlation with mental illnesses that are referred to as neuroses in a conventional diagnosis. Conclusion: The study found that screening for anxiety disorders, obsessive-compulsive disorders and eating disorders contributes to preventing mood disorders among workers. We hope that our findings will indirectly contribute to preventing workers’ suicides.

The representations of clouds in climate model MRI-ESM2 (Yukimoto et al. 2019, JMSJ) used in CMIP6 simulations are significantly improved from the previous version MRI-CGCM3 used in CMIP5 simulatio...

The effective radiative forcing (ERF) of anthropogenic gases and aerosols under present-day conditions relative to preindustrial conditions is estimated using the Meteorological Research Institute Earth System Model version 2.0 (MRI-ESM2.0) as part of the Radiative Forcing Model Intercomparison Project (RFMIP) and Aerosol and Chemistry Model Intercomparison Project (AerChemMIP), endorsed by the sixth phase of the Coupled Model Intercomparison Project (CMIP6). The global mean total anthropogenic net ERF estimate at the top of the atmosphere is 1.96 W m−2 and is composed primarily of positive forcings due to carbon dioxide (1.85 W m−2), methane (0.71 W m−2), and halocarbons (0.30 W m−2) and negative forcing due to the total aerosols (− 1.22 W m−2). The total aerosol ERF consists of 23% from aerosol-radiation interactions (− 0.32 W m−2), 71% from aerosol-cloud interactions (− 0.98 W m−2), and slightly from surface albedo changes caused by aerosols (0.08 W m−2). The ERFs due to aerosol-radiation interactions consist of opposing contributions from light-absorbing black carbon (BC) (0.25 W m−2) and from light-scattering sulfate (− 0.48 W m−2) and organic aerosols (− 0.07 W m−2) and are pronounced over emission source regions. The ERFs due to aerosol-cloud interactions (ERFaci) are prominent over the source and downwind regions, caused by increases in the number concentrations of cloud condensation nuclei and cloud droplets in low-level clouds. Concurrently, increases in the number concentration of ice crystals in high-level clouds (temperatures < –38 °C), primarily induced by anthropogenic BC aerosols, particularly over tropical convective regions, cause both substantial negative shortwave and positive longwave ERFaci values in MRI-ESM2.0. These distinct forcings largely cancel each other; however, significant longwave radiative heating of the atmosphere caused by high-level ice clouds suggests the importance of further studies on the interactions of aerosols with ice clouds. Total anthropogenic net ERFs are almost entirely positive over the Arctic due to contributions from the surface albedo reductions caused by BC. In the Arctic, BC provides the second largest contribution to the positive ERFs after carbon dioxide, suggesting a possible important role of BC in Arctic surface warming.

This paper reports on a new index for low cloud cover (LCC), the estimated cloud-top entrainment index (ECTEI), which is a modification of estimated inversion strength (EIS) and takes into account a cloud-top entrainment (CTE) criterion. Shipboard cloud observation data confirm that the index is strongly correlated with LCC. It is argued here that changes in LCC cannot be fully determined from changes in EIS only, but can be better determined from changes in both EIS and sea surface temperature (SST) based on the ECTEI. Furthermore, it is argued that various proposed predictors of LCC change, including the moist static energy vertical gradient, SST, and midlevel clouds, can be better understood from the perspective of the ECTEI.

In this study, the changes in the occurrence of marine fog over the summer North Pacific in warmer sea surface temperature (SST) or increased CO2 climates were investigated based on atmospheric mod...

The development of the climate model MRI-ESM2, which is planned for use in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) simulations, involved significant improvements to the representation of clouds from the previous version MRI-CGCM3, which was used in the CMIP5 simulations. In particular, the serious lack of reflection of solar radiation over the Southern Ocean in MRI-CGCM3 was drastically improved in MRI-ESM2. The score of the spatial pattern of radiative fluxes at the top of the atmosphere for MRI-ESM2 is better than for any CMIP5 model. In this paper, we set out comprehensively the various modifications related to clouds that contribute to the improved cloud representation, and the main impacts on the climate of each modification. The modifications cover various schemes and processes including the cloud scheme, turbulence scheme, cloud microphysics processes, interaction between cloud and convection schemes, resolution issues, cloud radiation processes, interaction with the aerosol model, and numerics. In addition, the new stratocumulus parameterization, which contributes considerably to increased low cloud cover and reduced radiation bias over the Southern Ocean, and the improved cloud ice fall scheme, which alleviates the time-step dependency of cloud ice content, are described in detail.

Changes in marine fog in a warmer climate are investigated through simulations using the atmospheric component of a global climate model, with both observed and perturbed sea surface temperature forcing. Global changes in marine fog occurrence in different seasons are compared. We show that the changes in marine fog occurrence correspond well to changes in horizontal temperature advection near the surface in a warmer climate. Therefore, the changes in marine fog can be well explained by large-scale circulation changes. Regarding changes in the characteristics of marine fog, we show that the in-cloud liquid water content of marine fog is consistently increased in a warmer climate, for a given horizontal surface temperature advection. It is also confirmed that the contribution of changes in marine fog to cloud feedback is not negligible, but is small.

Future responses of cloud regimes are analyzed for five CMIP5 models forced with observed SSTs and subject to a patterned SST perturbation. Correlations between cloud properties in the control climate and changes in the warmer climate are investigated for each of a set of cloud regimes defined using a clustering methodology. The only significant (negative) correlation found is in the in-regime net cloud radiative effect for the stratocumulus regime. All models overestimate the in-regime albedo of the stratocumulus regime. Reasons for this bias and its relevance to the future response are investigated. A detailed evaluation of the models’ daily-mean contributions to the albedo from stratocumulus clouds with different cloud cover fractions reveals that all models systematically underestimate the relative occurrence of overcast cases but overestimate those of broken clouds. In the warmer climate the relative occurrence of overcast cases tends to decrease while that of broken clouds increases. This suggests a decrease in the climatological in-regime albedo with increasing temperature (a positive feedback); this is opposite to the feedback suggested by the analysis of the bulk in-regime albedo. Furthermore we find that the inter-model difference in the sign of the in-cloud albedo feedback is consistent with the difference in sign of the in-cloud liquid water path response, and there is a strong positive correlation between the in-regime liquid water path in the control climate and its response to warming. We therefore conclude that further breakdown of the in-regime properties into cloud cover and in-cloud properties is necessary to better understand the behavior of the stratocumulus regime. Since cloud water is a physical property and is independent of a model’s radiative assumptions, it could potentially provide a useful emergent constraint on cloud feedback.

International audience; Results are presented of the GASS/EUCLIPSE single-column model intercomparison study on the subtropical marine low-level cloud transition. A central goal is to establish the performance of state-of-the-art boundary-layer schemes for weather and climate models for this cloud regime, using large-eddy simulations of the same scenes as a reference. A novelty is that the comparison covers four different cases instead of one, in order to broaden the covered parameter space. Three cases are situated in the North-Eastern Pacific, while one reflects conditions in the North-Eastern Atlantic. A set of variables is considered that reflects key aspects of the transition process, making use of simple metrics to establish the model performance. Using this method, some longstanding problems in low-level cloud representation are identified. Considerable spread exists among models concerning the cloud amount, its vertical structure, and the associated impact on radiative transfer. The sign and amplitude of these biases differ somewhat per case, depending on how far the transition has progressed. After cloud breakup the ensemble median exhibits the well-known "too few too bright" problem. The boundary-layer deepening rate and its state of decoupling are both underestimated, while the representation of the thin capping cloud layer appears complicated by a lack of vertical resolution. Encouragingly, some models are successful in representing the full set of variables, in particular, the vertical structure and diurnal cycle of the cloud layer in transition. An intriguing result is that the median of the model ensemble performs best, inspiring a new approach in subgrid parameterization.

Upper-tropospheric ice cloud measurements from the Superconducting Submillimeter Limb Emission Sounder (SMILES) on the International Space Station (ISS) are used to study the diurnal cycle of upper-tropospheric ice cloud in the tropics and midlatitudes (40°S–40°N) and to quantitatively evaluate ice cloud diurnal variability simulated by 10 climate models. Over land, the SMILES-observed diurnal cycle has a maximum around 1800 local solar time (LST), while the model-simulated diurnal cycles have phases differing from the observed cycle by −4 to 12 h. Over ocean, the observations show much smaller diurnal cycle amplitudes than over land with a peak at 1200 LST, while the modeled diurnal cycle phases are widely distributed throughout the 24-h period. Most models show smaller diurnal cycle amplitudes over ocean than over land, which is in agreement with the observations. However, there is a large spread of modeled diurnal cycle amplitudes ranging from 20% to more than 300% of the observed over both land and ocean. Empirical orthogonal function (EOF) analysis on the observed and model-simulated variations of ice clouds finds that the first EOF modes over land from both observation and model simulations explain more than 70% of the ice cloud diurnal variations and they have similar spatial and temporal patterns. Over ocean, the first EOF from observation explains 26.4% of the variance, while the first EOF from most models explains more than 70%. The modeled spatial and temporal patterns of the leading EOFs over ocean show large differences from observations, indicating that the physical mechanisms governing the diurnal cycle of oceanic ice clouds are more complicated and not well simulated by the current climate models.

We investigate the sensitivity of cloud feedbacks to the use of convective parametrizations by repeating the CMIP5/CFMIP-2 AMIP/AMIP + 4K uniform sea surface temperature perturbation experiments with 10 climate models which have had their convective parametrizations turned off. Previous studies have suggested that differences between parametrized convection schemes are a leading source of inter-model spread in cloud feedbacks. We find however that ‘ConvOff’ models with convection switched off have a similar overall range of cloud feedbacks compared with the standard configurations. Furthermore, applying a simple bias correction method to allow for differences in present-day global cloud radiative effects substantially reduces the differences between the cloud feedbacks with and without parametrized convection in the individual models. We conclude that, while parametrized convection influences the strength of the cloud feedbacks substantially in some models, other processes must also contribute substantially to the overall inter-model spread. The positive shortwave cloud feedbacks seen in the models in subtropical regimes associated with shallow clouds are still present in the ConvOff experiments. Inter-model spread in shortwave cloud feedback increases slightly in regimes associated with trade cumulus in the ConvOff experiments but is quite similar in the most stable subtropical regimes associated with stratocumulus clouds. Inter-model spread in longwave cloud feedbacks in strongly precipitating regions of the tropics is substantially reduced in the ConvOff experiments however, indicating a considerable local contribution from differences in the details of convective parametrizations. In both standard and ConvOff experiments, models with less mid-level cloud and less moist static energy near the top of the boundary layer tend to have more positive tropical cloud feedbacks. The role of non-convective processes in contributing to inter-model spread in cloud feedback is discussed.