This study investigated the impact of assimilating satellite data into atmospheric reanalyses on trends in ocean surface winds and waves. Two experiments were performed using a numerical wave model ...forced by near-surface winds: one derived from the Japanese 55-year Reanalysis (JRA-55; experiment A) and the other derived from JRA-55 using assimilated conventional observations only (JRA-55C; experiment B). The results showed that the satellite data assimilation reduced upward trends of the annual mean of wave energy flux (WEF) in the midlatitude North Pacific and southern ocean (30°–60°S), south of Australia, from 1959 to 2012. It was also found that the assimilation of scatterometer winds reduced the near-surface wind speed in the midlatitude North Pacific after the mid-1990s, which resulted in the reduced trend in WEF from 1959 to 2012. By contrast, assimilation of the satellite radiances for 1973–94 increased near-surface wind speed in the southern ocean, south of Australia, whereas the assimilation of the scatterometer winds after the mid-1990s reduced wind speed. The latter led to the reduced trend in WEF south of Australia from 1959 to 2012.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Since the mid‐1990s, ocean wave reanalysis and in situ wave observations have revealed marked downward trends in wave height, exceeding −0.1 m per decade in the midlatitude North Pacific. The wave ...period in the tropical Pacific is also on a downward trend, exceeding −0.4 s per decade during this period. These changes in wave climate in the Pacific are attributable to recently strengthened trade winds and La Niña‐like conditions in the tropical Pacific. The downward trend in significant wave height in the midlatitude North Pacific is due to strengthening of the negative phase of the Pacific‐North American teleconnection. Numerical experimentations with a wave model also showed that the downward trend in the wave period in the eastern equatorial Pacific was induced not only by increased wind waves due to strengthened trade winds but also by weakened propagating swells from the midlatitude North Pacific.
Key Points
Wave height in the midlatitude North Pacific is decreasing for 1996 to 2012Wave period in the tropical Pacific is decreasing for 1996 to 2012Recent tropical Pacific climate change is the cause of the wave climate change
The climatology and long‐term trend of wave energy resources around Japan were estimated from in situ wave data measured at 25 observation points during 1980 to 2009. The climatological annual mean ...wave energy around Japan was estimated to be 6.4 kW m−1, and the long‐term trend was 0.27 kW m−1/30‐yr. Our results indicate that the long‐term trend in wave energy varies among areas and seasons. There is a marked increasing trend in wave energy in the southern half of the east coast of Japan. Increased average wave period and height contributed to this trend on the east coast. We also found an increasing trend in surface wind speeds east of Japan. These results suggest that more frequent swells have been generating greater wave energy off Japan's east coast during the last decade.
Key Points
The climatology and long‐term trend of wave energy around Japan are estimated
There is a marked increasing trend in wave energy along the east coast of Japan
The increasing trend is due to the increased occurrence of swells
It has been widely believed that the tropical Pacific trade winds weakened in the last century and would further decrease under a warmer climate in the 21st century. Recent high-quality observations, ...however, suggest that the tropical Pacific winds have actually strengthened in the past two decades. Precise causes of the recent Pacific climate shift are uncertain. Here we explore how the enhanced tropical Indian Ocean warming in recent decades favors stronger trade winds in the western Pacific via the atmosphere and hence is likely to have contributed to the La Niña-like state (with enhanced east–west Walker circulation) through the Pacific ocean–atmosphere interactions. Further analysis, based on 163 climate model simulations with centennial historical and projected external radiative forcing, suggests that the Indian Ocean warming relative to the Pacific’s could play an important role in modulating the Pacific climate changes in the 20th and 21st centuries.
A
bstract
We study 1
/N
corrections to a Wilson loop in holographic duality. Extending the AdS/CFT correspondence beyond the large
N
limit is an important but a subtle issue, as it needs quantum ...gravity corrections in the gravity side. To find a physical property of the quantum corrected geometry of near-horizon black 0-branes previously obtained by Hyakutake, we evaluate a Euclidean string worldsheet hanging down in the geometry, which corresponds to a rectangular Wilson loop in the SU(
N
) quantum mechanics with 16 supercharges at a finite temperature with finite
N
. We find that the potential energy defined by the Wilson loop increases due to the 1
/N
correction, therefore the quantum gravity correction weakens the gravitational attraction.
Background: The safety and feasibility of using 1-month dual antiplatelet therapy (DAPT) followed by P2Y12inhibitor monotherapy for patients after percutaneous coronary intervention (PCI) with ...thin-strut biodegradable polymer drug-eluting stents (BP-DES) in daily clinical practice remain uncertain.Methods and Results: The REIWA region-wide registry is a prospective study conducted in 1 PCI center and 9 local hospitals in northern Japan. A total of 1,202 patients who successfully underwent final PCI using BP-DES (Synergy: n=400; Ultimaster: n=401; Orsiro: n=401), were enrolled in the registry, and received 1-month DAPT followed by P2Y12inhibitor (prasugrel 3.75 mg/day or clopidogrel 75 mg/day) monotherapy. The primary endpoint was a composite of cardiovascular and bleeding events at 12 months, including cardiovascular death, myocardial infarction (MI), definite stent thrombosis (ST), ischemic or hemorrhagic stroke, and Thrombolysis in Myocardial Infarction (TIMI) major or minor bleeding. Based on the results of a previous study, we set the performance goal at 5.0%. Over the 1-year follow-up, the primary endpoint occurred in 3.08% of patients, which was lower than the predefined performance goal (Pnon-inferiority<0.0001). Notably, definite ST occurred in only 1 patient (0.08%) within 1 year (at 258 days). No differences were observed in the primary endpoint between stent types.Conclusions: The REIWA region-wide registry suggests that 1-month DAPT followed by P2Y12inhibitor monotherapy is safe and feasible for Japanese patients with BP-DES.
Metallaphotoredox-catalyzed allylation represents an emerging synthetic methodology that enables allylic substitution using nucleophilic radical species. The C–H allylation of N-aryl ...tetrahydroisoquinolines is an innovative example in this area and allows access to synthetically useful precursors for the further derivatization of tetrahydroisoquinolines. However, previous methods have required the use of noble metals, which has hampered their application due to concerns over their sustainability. Here we report the C–H allylation of N-aryl tetrahydroisoquinolines using a cobalt/organophotoredox dual catalyst system. Based on precedent, control experiments and controlled irradiation experiments, a mechanism for the cobalt/photoredox-catalyzed allylation that involves a π-allyl cobalt complex is proposed.
The aim of this study was to evaluate the impact of the size of the isolated surface area and non-ablated left atrial posterior area after extensive encircling pulmonary vein isolation (EEPVI) for ...non-paroxysmal atrial fibrillation (AF) on arrhythmia recurrence. This study included 132 consecutive persistent AF patients who underwent EEPVI guided by Ablation Index (AI). The isolated antral surface area (IASA) excluding the pulmonary veins, the non-ablated left atrial (LA) posterior wall surface area (PWSA), the ratio of IASA to LA surface area (IASA/LA ratio), and the ratio of PWSA to LA surface area (PWSA/LA ratio) were assessed using CARTO3 and the association with AF and atrial tachycardia (AT) recurrence was examined. At a mean follow-up of 13.2 ± 7.3 months, sinus rhythm was maintained in 115 (87%) patients. In the univariate Cox regression analysis, the factors that significantly predicted AT/AF recurrence were a history of heart failure, a higher CHA
2
DS
2
-VASc score, a larger LA diameter, and a larger PWSA/LA ratio. Multivariate Cox regression analysis revealed that the independent predictors of AT/AF recurrence were LA diameter hazard ratio (HR) 1.120 per 1 mm increase; 95% confidence interval (CI) 1.006–1.247;
P
= 0.039 and PWSA/LA ratio (HR 1.218 per 1% increase; 95% CI 1.041–1.425;
P
= 0.014). Receiver operating characteristics curve analysis yielded an optimal cut-off value of 8% for the PWSA/LA ratio. The Kaplan–Meier survival curve showed that patients with a larger PWSA/LA ratio had poorer clinical outcomes (Log-rank
P
= 0.001). A larger PWSA/LA ratio was associated with a high AT/AF recurrence rate in patients with non-paroxysmal atrial fibrillation.
The sympathetic nervous system plays an important role in life-threatening ventricular arrhythmias (VAs). Bilateral cardiac sympathetic denervation (BCSD) is performed for refractory VAs. We sought ...to assess our institutional experience with BCSD in managing treatment-resistant monomorphic ventricular tachycardia (MMVT) in heart failure patients with a reduced ejection fraction (HFrEF).Four patients with HFrEF (EF 30.0 ± 8.2%, New York Heart Association NYHA class IV 1) underwent BCSD for MMVT (VT storm 3, repetitive VT requiring implantable cardioverter defibrillator ICD therapy 1) refractory to antiarrhythmic drugs, catheter ablation and ICD therapy. BCSD was effective for suppressing VT in 3 patients for whom deep sedation was effective for suppressing VT. One patient remained alive after 14 months of follow-up without episodes of VT. One patient died of acute myocardial infarction before discharge and 1 patient died from unknown cause at 3 days post-discharge. In contrast, BCSD was completely ineffective for suppressing VT in a patient with NYHA class IV for whom deep sedation and stellate ganglion block were ineffective. This patient died on the 10th post-CSD day, despite left ventricular assist device implantation. In all cases, BCSD was successfully performed without procedure-related complications.Despite the limited number of cases, our results showed that BCSD in patients with HFrEF suppressed refractory MMVT in acute-phase except for a patient with NYHA class IV; however, the prognoses were not good. BCSD may be a treatment option at an earlier stage of NYHA and a bridge to orthotopic heart transplantation, even if BCSD is effective for suppressing VAs.
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