Abstract
The characteristics of tropical cyclones (TCs) in the summer and autumn seasons over the western North Pacific that are associated with different environmental factors that influence TC ...genesis (TCG) were studied. The authors objectively categorized factors into the five TCG factors classified by Ritchie and Holland: monsoon shear line (SL), monsoon confluence region (CR), monsoon gyre (GY), easterly wave (EW), and the Rossby wave energy dispersion from a preexisting TC (PTC). The GY-TCs tended to develop slowly, and the highest rates of occurrence of rapid intensification (RI) were found for the CR-TCs, whereas the GY-TCs rarely experienced RI. The average storm size of the GY-TCs at the time of formation was the largest of the averages among the TC types, while the EW- and PTC-TCs were smaller, although these differences disappeared at the mature time. There were no significant differences in the sea surface temperature (SST) beneath the TCs, but the tropical cyclone heat potential (TCHP) of the PTC-TCs was higher. The PTC-TCs tended to develop as intense TCs and exhibited favorable environmental characteristics, such as high TCHP, high convective available potential energy, and weak vertical shear. The occurrence rate of the PTC-TCs that made landfall in the Philippines was higher than the averages of the other TC types, whereas those of the EW-TCs (PTC-TCs) that made landfall in Japan (China) were lower. These results provide important information for use in disaster prevention.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The flow environment associated with tropical cyclone genesis (TCG) over the western North Pacific was assessed via categorization into five flow patterns: monsoon shear line (SL), monsoon confluence ...region (CR), monsoon gyre (GY), easterly wave (EW), and preexisting tropical cyclone (PTC). Using reanalysis data and an objective algorithm, the authors defined "contribution scores" for the five flow patterns. Each score represents the contribution to TCG from each flow pattern, and scores were calculated for 908 TCG cases from 1979 to 2008 (30 yr). Of the major contribution flow patterns, SL accounted for 42% of TCGs, EW for 18%, CR for 16%, PTC for 11%, and GY for 6%. Seasonal variations in the occurrence frequency of these five patterns were clear, but interannual variations were not as apparent. Tropical cyclones often appear to be generated in conditions with multiple flow patterns. Thus, relationships between multiple flow patterns were investigated by comparing contribution scores. The SL and CR patterns were strongly correlated to each other, which can be explained by the monsoon southwesterly that organizes both patterns. The EW pattern tends to be independent of the other flow patterns. The PTC pattern has a relatively high correlation with CR, but does not have a correlation with SL or EW. Thus, the characteristics of flow patterns for the occurrence frequency of TCG are derived for a longer period than in previous studies, and correlations among flow patterns are also investigated.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Deep moist atmospheric convection is a key element of the weather and climate system for transporting mass, momentum, and thermal energy. It has been challenging to simulate convection realistically ...in global atmospheric models because of the large gap in spatial scales between convection (100 km) and global motions (104 km). We conducted the first ever subkilometer global simulation and described the features of convection. Through a series of grid‐refinement resolution testing, we found that an essential change for convection statistics occurred around 2 km grid spacing. The convection structure, number of convective cells, and distance to the nearest convective cell dramatically changed at this resolution. The convection core was resolved using multiple grids in simulations with grid spacings less than 2.0 km.
Key Points
Subkilometer global simulation is first successfully conductedThe global features of deep moist convection are presentedThe necessary resolution for simulating convection in global models is 2 km
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
This study examined the statistical characteristics of tropical cyclones (TCs) for which the cyclogenesis (TCG) process was modulated by upper tropospheric cold lows (UCLs) over the western North ...Pacific during the 38 years from 1979 to 2016. Among the 965 TCs, 90 TCs (9 %, 2.4 per year) were defined as having TCG influenced by UCLs in the northwest quadrant of the TC region (UL-TCs). Most UL-TCs occurred in the summer, with large variability in the annual occurrence rate of UL-TCs during June to October, ranging from 0 to approximately 30 %. The annual variation was related to the activity of the Tibetan high and the summer temperature anomaly over Japan. The extremely hot summer of 2016 was partly enhanced by the intense Tibetan high, when 4 UL-TCs also occurred. The average location of UL-TCs at the time of TCG and tropical storm formation (TSF) was significantly farther to the north than the average location of TCs not formed under the influence of UCL (N-UL-TCs). Many UL-TCs occurred in lower tropospheric environments associated with the shear line or confluence regions. The UL-TCs tended to move northward, and the occurrence rate of UL-TCs that made landfall in Japan was approximately double that of other countries. The atmospheric environmental parameters around UL-TCs at the time of TCG were more favorable for the development of TCs than those around N-UL-TCs. In contrast, the atmospheric and oceanic environmental parameters around UL-TCs at the time of TSF were less favorable for the development of TCs, such that UL-TCs tended to remain at weak intensity.
Objectives
Erenumab is a human anti‐calcitonin gene‐related peptide receptor monoclonal antibody approved for migraine prevention. Global studies have demonstrated its efficacy in chronic and ...episodic migraine (EM). Here we report the outcomes from a Phase 3 study of erenumab in Japanese patients with chronic migraine (CM) or EM.
Methods
Japanese patients with EM (<15 headache days/month, including ≥4 migraine days/month) or CM (≥15 headache days/month, including ≥8 migraine days/month) were randomized 1:1 to placebo or erenumab 70 mg once monthly for a 24‐week double‐blind treatment phase (DBTP). The primary endpoint of change from baseline in mean monthly migraine days (MMD) over months 4, 5, and 6 of the DBTP was compared between erenumab and placebo groups. Secondary efficacy and safety endpoints were also assessed.
Results
A total of 261 patients were randomized to placebo (n = 131) or erenumab 70 mg (n = 130); all patients were included in the efficacy and safety analyses. The mean (standard deviation) MMD at baseline was 11.84 (5.70) for the placebo group and 12.40 (5.99) for erenumab 70 mg. The mean (standard error) change in MMD was –1.98 (0.38) for the placebo group (n = 131) and –3.60 (0.38) for erenumab 70 mg (n = 130). The difference in MMD reduction between groups was −1.67 (95% CI: –2.56, –0.78, p < 0.001) for EM and –1.57 (95% CI: –3.39, 0.24, p = 0.089) for CM. Adverse events (AEs) were consistent with earlier studies. The most frequent AEs (placebo, erenumab) were nasopharyngitis (28.2% and 26.9%, respectively), back pain (4.6% and 5.4%), and constipation (0.8% and 4.6%).
Conclusion
Treatment with erenumab 70 mg once monthly demonstrated favorable efficacy and safety findings in Japanese patients with EM or CM.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Sintering processes yield a mutual diffusion region at the electrode/solid electrolyte interface, which is considered as a crucial problem for developing large-sized all-solid-state rechargeable ...lithium batteries with high power density. This work focuses on the interface between LiNi1/3Co1/3Mn1/3O2 (NMC) and NASICON-structured Li+ conductive glass ceramics solid electrolyte (Li2OAl2O3SiO2P2O5TiO2GeO2: LATP sheet (AG-01)), and investigates the effects of sintering temperature on interfacial structure and interfacial resistance at the NMC/LATP sheet. Thin films of NMC were fabricated on the LATP sheets at 700 °C or 900 °C as a model system. We found that the thickness of the mutual diffusion region was almost the same, ca. 30 nm, in these two samples, but the NMC film prepared at 900 °C had three orders of magnitude larger interfacial resistance than the NMC film prepared at 700 °C. Around the interface between the NMC film prepared at 900 °C and the LATP sheet, Co in the NMC accumulates as a reduced valence and lithium-free impurity crystalline phase will be also formed. These two problems must contribute to drastic increasing of interfacial resistance. Formation of de-lithiated NMC around the interface and its thermal instability at higher temperature may be considerable reason to induce these problems.
•Sintered electrode-solid electrolyte interface was analyzed by EELS, EDX, and EIS.•Interfacial resistance varies three-order magnitude by the sintering temperature.•Thickness of mutual diffusion region is almost same.•Co in the electrode accumulates around the interface at higher sintering temperature.•Structural disorder in electrode is a key issue.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
This study examines extended boreal summer (May–October) tropical cyclogenesis events (TCGEs) associated with large-scale flow patterns (LFPs) over the western North Pacific (WNP) between 1979–1997 ...and 1998–2012. WNP TCGEs are objectively identified to be associated with five LFPs e.g., monsoon shear line (SL), monsoon confluence region (CR), monsoon gyre (GY), Pacific easterly wave (EW) and preexisting tropical cyclone (PTC). Results show that an apparent decrease in TCGEs from 1998–2012 was due to the significant decrease in TCGEs associated with the PTC pattern and to a somewhat lesser degree, TCGEs associated with the GY pattern. In contrast, TCGEs associated with the SL pattern show a small increase, which seems to contradict the weakened monsoon circulation since 1998 but corresponds well to cyclonic anomalies over the Philippines region. Decreased TCGEs associated with the GY pattern and increased TCGEs associated with the EW pattern are closely related to the strengthening of Pacific easterly waves in response to the Mega La Niña-like pattern that predominated during 1998–2012. Weakened easterly shear over the eastern WNP is not conducive to the development and propagation into the southeastern WNP of Rossby wave trains induced by preexisting TC energy dispersion. Consequently, there is a significant reduction of TCGEs associated with the PTC pattern and a weakening in the contribution of TCGEs associated with the PTC pattern to TCGEs associated with the EW pattern. An increased correlation between TCs associated with the SL/GY/EW patterns and central Pacific (CP)-type ENSO during 1998–2012 is observed. A stable and robust association between TCGEs associated with the CR pattern and tropical North Atlantic sea surface temperature is observed regardless of decadal climate regime shifts. However, there is no significant link between TCGEs associated with the PTC pattern and more CP ENSO events during 1998–2012, but there is a strong association between the Pacific meridional mode and TCGEs associated with the PTC pattern during 1979–1997. More observational analyses and numerical simulations are needed to further investigate the underlying physical mechanism.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Shallow coastal seawater response during the passage of near-landfall intensification (NLI) tropical cyclones (TCs) and non-NLI TCs was examined using oceanic and atmospheric reanalysis data and ...observations. The sea surface temperature ahead of the NLI-TC track is maintained or even increases when NLI-TC is approaching the land. The magnitude of the wind stress, which plays an important role in the NLI process, is related to the zonal surface wind on the right side of the tracks. Coastal mixed layer warming can be explained by Ekman transport under sustained wind stress due to surface wind forcing. The successive deepening of the coastal ocean boundary layer and the increase in warming in the subsurface seawater temperature by an average of 0.3°C, could maintain thermal capacity in a certain degree. This shallow coastal water response could partly explain the NLI progress in the northern South China Sea, indicating the importance of coastal ocean dynamics and air-sea interactions.
This study investigated the atmospheric and oceanic contributions to the genesis of Typhoon Faxai in 2019. Our statistical analysis using the tropical cyclone genesis score (TGS) attributed the ...tropical disturbance that developed into Faxai (Pre-Faxai) to easterly waves (EWs). The EW score evaluated by a grid version of the TGS (Grid-EW) averaged around the occurrence of Pre-Faxai was approximately twice as large as the climatological mean, and it was the second largest value in the past 38 years. The Pre-Faxai area with high Grid-EW scores could be traced back to the eastern North Pacific (ENP) around August 25, 2019. The lower-troposphere environment characterized by high Grid-EW scores was favorable for vortex formation because it provided a containment area for moisture entrained by the developing circulation or lofted by the deep convection therein. The Pre-Faxai area with high Grid-EW scores moved westward due to the background easterly flow over the ENP and then entered the western North Pacific (WNP). The Typhoon Intensity Forecast Scheme (TIFS) showed that the important environments for its genesis were ocean conditions and the vertical wind shear. The oceanic conditions contributed to the development of Pre-Faxai as it traveled over the WNP. The enhancement of vertical wind shear and subsequent suppression of the development of Pre-Faxai were caused by the lower-troposphere easterly winds associated with high EW scores. They were also caused by upper-troposphere westerly winds associated with an upper cold low northwest of Pre-Faxai. When the vertical shear decreased with weakening of the upper cold low, Pre-Faxai reached tropical storm intensity on September 4. Therefore, TGS and TIFS detected Pre-Faxai 10 days before the typhoon arose, which indicates that monitoring environmental factors such as EW and vertical wind shear are important for disaster prevention.
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