Anthropogenic warming induced intensification of summer monsoon frontal precipitation over East Asia.

Summer monsoon frontal rainfall in East Asia (EA) is crucial for water resources and flood hazards in densely populated areas. Recent studies have documented the increasing intensity of summer frontal rainfall over recent decades. However, the extent of ongoing climate change on the intensification of the EA frontal precipitation system remains uncertain. Using an objective method for detecting frontal systems, we found a 17 ± 3% increase in observed frontal rainfall intensity during 1958 to 2015. Climate model simulations with and without greenhouse gases suggest that anthropogenic warming plays a key role in the intensification of EA summer frontal precipitation by 5.8% from 1991 to 2015. The analysis highlights that enhanced water vapor convergence and reinforced western North Pacific subtropical High collectively increased moisture transport to the region, resulting in intensified EA frontal precipitation. The results lend support to the anthropogenic warming-induced enhancement of the EA frontal precipitation and its persistence in the future.

A novel statistical-dynamical method for a seasonal forecast of particular matter in South Korea.

Societal concerns about air quality in East Asia are still growing despite country-level efforts to reduce air pollution emissions. In coping with this growing concern, the government and the public demand a longer­lead forecast of air quality to ensure sufficient response time until society prepares for countermeasures such as a temporary reduction of specific emission sources. Here we propose a novel method that produces skillful seasonal forecasting of wintertime (December to February) PM10 concentration over South Korea. The method is based on the idea that climate condition and air quality have co-variability in the seasonal time scales and that the state-of-art seasonal prediction model will benefit air quality forecasting. More specifically, a linear regression model is constructed to link observed winter PM10 concentration and climate variables where the predicted climate variables were furnished from NCEP CFSv2 forecast initialized during autumn. In this case, climate variables were selected as predictors of the model because they are not only physically related to air quality but also 'predictable' in CFS hindcast. Through analysis of retrospective forecasts of 20 winters for the period 2001-2020, we found this model shows statistically significant skill for the seasonal forecast of wintertime PM10 concentration.

Abrupt shift to hotter and drier climate over inner East Asia beyond the tipping point.

Unprecedented heatwave-drought concurrences in the past two decades have been reported over inner East Asia. Tree-ring-based reconstructions of heatwaves and soil moisture for the past 260 years reveal an abrupt shift to hotter and drier climate over this region. Enhanced land-atmosphere coupling, associated with persistent soil moisture deficit, appears to intensify surface warming and anticyclonic circulation anomalies, fueling heatwaves that exacerbate soil drying. Our analysis demonstrates that the magnitude of the warm and dry anomalies compounding in the recent two decades is unprecedented over the quarter of a millennium, and this trend clearly exceeds the natural variability range. The "hockey stick"-like change warns that the warming and drying concurrence is potentially irreversible beyond a tipping point in the East Asian climate system.

Weakening of the stratospheric polar vortex by Arctic sea-ice loss.

Successive cold winters of severely low temperatures in recent years have had critical social and economic impacts on the mid-latitude continents in the Northern Hemisphere. Although these cold winters are thought to be partly driven by dramatic losses of Arctic sea-ice, the mechanism that links sea-ice loss to cold winters remains a subject of debate. Here, by conducting observational analyses and model experiments, we show how Arctic sea-ice loss and cold winters in extra-polar regions are dynamically connected through the polar stratosphere. We find that decreased sea-ice cover during early winter months (November-December), especially over the Barents-Kara seas, enhances the upward propagation of planetary-scale waves with wavenumbers of 1 and 2, subsequently weakening the stratospheric polar vortex in mid-winter (January-February). The weakened polar vortex preferentially induces a negative phase of Arctic Oscillation at the surface, resulting in low temperatures in mid-latitudes.

Association of metabolic syndrome and benign prostate enlargement in young korean males.

PURPOSE: This study was designed to evaluate the association of metabolic syndrome and benign prostate enlargement in young Korean males. We analyzed the clinical data associated with metabolic syndrome and prostate volume in the study population. MATERIALS AND METHODS: We retrospectively analyzed the clinical data obtained from 1,506 young men under the age of 60 who visited the health promotion center in our institution for routine checkups. The patients were interviewed with a questionnaire including the International Prostate Symptom Score (IPSS) and were evaluated by medical history, blood chemistry, digital rectal examination, and prostate volume via transrectal ultrasonography. The presence of metabolic syndrome was determined according to the modified National Cholesterol Education Program Expert Panel on Detection, Evalution, And Treatment of High Blood Cholesterol in Adults criteria. We divided the subjects into two groups: those with metabolic syndrome and those without. Logistic regression analysis was carried out to determine which metabolic components were associated with an increased risk of benign prostate enlargement. RESULTS: Significant differences in prostate volume were noted between the groups. The prostate volumes were significantly larger in the metabolic syndrome group than in the non-metabolic syndrome group in all subgroups divided by age (in decades). However, no significant differences in IPSS or voiding or storage subscore were noted. In the multivariate regression analysis, only diabetes and obesity were identified as risk factors for benign prostate enlargement among the metabolic components. CONCLUSIONS: Metabolic syndrome and prostate volume were significantly related, even in young males. Diabetes and obesity were identified as significant risk factors for benign prostate enlargement in young males under the age of 60.