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.
Ligand enrichment assessment based on benchmarking data sets has become a necessity for the rational selection of the best‐suited approach for prospective data mining of drug‐like molecules. Up to ...now, a variety of benchmarking data sets had been generated and frequently used. Among them, MUBD‐HDACs from our prior research efforts was regarded as one of five state‐of‐the‐art benchmarks in 2017 by Frontiers in Pharmacology. This benchmarking set was generated by one of our unique de‐biasing algorithms. It also rendered quite a few other cases of successful applications in recent years, thus is expected to have more impact in modern drug discovery. To make our algorithm amenable to more users, we developed a Python GUI application called MUBD‐DecoyMaker 2.0. Moreover, it has two new additional functional modules, i. e. “Detect 2D Bias” and “Quality Control”. This new GUI version had been proved to be easy to use while generate benchmarking data sets of the same quality. MUBD‐DecoyMaker 2.0 is freely available at https://github.com/jwxia2014/MUBD‐DecoyMaker2.0, along with its manual and testcase.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Long-term changes in the East Asian summer monsoon (EASM) lifecycle since 1979 are analyzed based on observational datasets and historical simulations of the Coupled Model Intercomparison Project ...Phase 6 (CMIP6). According to the observation, the active and break phases of EASM have intensified resulting in a shorter but stronger rainy season, followed by a longer dry spell. This intensification in the active-phase precipitation is accompanied by increased lower tropospheric southwesterly wind and subsequent convergence of water vapor flux. These changes are accompanied by the widely reported westward extension of the North Pacific Subtropical High, which has been associated with the warming climate. CMIP6 models generally underestimated the observed intensification of the EASM lifecycle and the monsoon precipitation. However, some of the models did simulate the intensified EASM lifecycle similar to that observed. The result highlights the reasonable performance on EASM shown in some CMIP6 models and those simulations lend support to a dynamically-driven intensification of the EASM lifecycle in the warmer climate.
The climate anomalies leading to the May 2015 floods in Texas and Oklahoma were analyzed in the context of El Niño teleconnection in a warmer climate. A developing El Niño tends to increase ...late‐spring precipitation in the southern Great Plains, and this effect has intensified since 1980. Anthropogenic global warming contributed to the physical processes that caused the persistent precipitation in May 2015: Warming in the tropical Pacific acted to strengthen the teleconnection toward North America, modification of zonal wave 5 circulation that deepened the stationary trough west of Texas, and enhanced Great Plains low‐level southerlies increasing moisture supply from the Gulf of Mexico. Attribution analysis using the Coupled Model Intercomparison Project Phase 5 single‐forcing experiments and the Community Earth System Model Large Ensemble Project indicated a significant increase in the El Niño‐induced precipitation anomalies over Texas and Oklahoma when increases in the anthropogenic greenhouse gases were taken into account.
Key Points
Increased GHG affects the May 2015 floods in Texas
Climate warming intensifies the El Niño teleconnection and climate impacts
Amplified synoptic waves and strengthened LLJ are part of climate trends
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The Pacific Decadal Oscillation (PDO), the leading mode of Pacific decadal sea surface temperature variability, arises mainly from combinations of regional air-sea interaction within the North ...Pacific Ocean and remote forcing, such as from the tropical Pacific and the Atlantic. Because of such a combination of mechanisms, a question remains as to how much PDO variability originates from these regions. To better understand PDO variability, the equatorial Pacific and the Atlantic impacts on the PDO are examined using several 3-dimensional partial ocean data assimilation experiments conducted with two global climate models: the CESM1.0 and MIROC3.2m. In these partial assimilation experiments, the climate models are constrained by observed temperature and salinity anomalies, one solely in the Atlantic basin and the other solely in the equatorial Pacific basin, but are allowed to evolve freely in other regions. These experiments demonstrate that, in addition to the tropical Pacific’s role in driving PDO variability, the Atlantic can affect PDO variability by modulating the tropical Pacific climate through two proposed processes. One is the equatorial pathway, in which tropical Atlantic sea surface temperature (SST) variability causes an El Niño-like SST response in the equatorial Pacific through the reorganization of the global Walker circulation. The other is the north tropical pathway, where low-frequency SST variability associated with the Atlantic Multidecadal Oscillation induces a Matsuno-Gill type atmospheric response in the tropical Atlantic-Pacific sectors north of the equator. These results provide a quantitative assessment suggesting that 12–29% of PDO variance originates from the Atlantic Ocean and 40–44% from the tropical Pacific. The remaining 27–48% of the variance is inferred to arise from other processes such as regional ocean-atmosphere interactions in the North Pacific and possibly teleconnections from the Indian Ocean.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
High‐amplitude ridges can enforce heat‐trapping systems that persist through an entire season, contributing to drought events. However, the impacts of day‐to‐day weather system changes at the meso‐ ...and synoptic‐scale are also important, albeit less well studied. We identify five weather types (WTs) from 500‐hPa geopotential height anomalies. These categories include WT4, which represents ridges and associated dry and warm anomalies, and WT3, which characterizes troughs and associated wetter‐ and colder‐than‐normal conditions and is the largest contributor to precipitation in the western U.S. While no discernable trend is evident for WT4 conditions, WT3 conditions have undergone a distinctive decrease in frequency at both annual and seasonal scales, thus a general drying trend across the west during this time period may be more significantly associated with fewer troughs rather than more ridges. Attribution analysis reveals that this decrease in wetter and colder weather is a likely result of anthropogenic forcing.
Plain Language Summary
While it is well known that large, persistent areas of high pressure can trap heat in a region for an entire season, contributing to droughts, the impacts of day‐to‐day weather system changes at smaller scales have remained less studied. In this study, we learned that dry‐ and hot‐weather‐inducing ridge conditions did not significantly change during a period of generalized drying between 1980 and 2018. What did change during those years was the pattern of troughs, which are associated with wetter‐ and colder‐than‐normal conditions; these conditions became less common during those years. This trend is likely to have occurred in response to human‐caused factors.
Key Points
No discernable trend is evident for dry‐ and warm‐weather‐inducing ridge conditions
Trough conditions‐the largest contributor to annual precipitation in the western U.S.‐have undergone a distinctive decrease in frequency
The decreasing trend in western troughs is likely to have occurred in response to external forcing rather than natural forcing alone
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
Explosive cyclones (ECs), defined as extratropical cyclones that experience normalized pressure drops of at least 24 hPa in 24 h, are impactful weather events in the North Atlantic sector, ...but year-to-year changes in the frequency and impacts of these storms are sizeable. To analyze the sources of this interannual variability, we track cases of ECs and dissect them into two spatial groups: those that formed near the east coast of North America (coastal) and those in the north central Atlantic (high latitude). The frequency of high-latitude ECs is strongly correlated with the North Atlantic Oscillation, a well-known feature, whereas coastal EC frequency is statistically linked with an atmospheric wave train emanating from the North Pacific in the last 30 years. This wave train pattern of alternating high and low pressure is associated with heightened upper-level divergence and Eady growth rates along the east coast of North America, likely resulting in a stronger correspondence between the atmospheric wave train and coastal EC frequency. Using coupled model experiments, we show that the tropical and North Pacific oceans are an important factor for this atmospheric wave train and the subsequent enhancement of seasonal baroclinicity in the North Atlantic.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
9.
The 2011 Great Flood in Thailand Promchote, Parichart; Wang, S.-Y. Simon; Johnson, Paul G.
Journal of climate,
01/2016, Volume:
29, Issue:
1
Journal Article
Peer reviewed
Open access
Severe flooding occurred in Thailand during the 2011 summer season, which resulted in more than 800 deaths and affected 13.6 million people. The unprecedented nature of this flood in the Chao Phraya ...River basin (CPRB) was examined and compared with historical flood years. Climate diagnostics were conducted to understand the meteorological conditions and climate forcing that led to the magnitude and duration of this flood. Neither the monsoon rainfall nor the tropical cyclone frequency anomalies alone was sufficient to cause the 2011 flooding event. Instead, a series of abnormal conditions collectively contributed to the intensity of the 2011 flood: anomalously high rainfall in the premonsoon season, especially during March; record-high soil moisture content throughout the year; elevated sea level height in the Gulf of Thailand, which constrained drainage; and other water management factors. In the context of climate change, the substantially increased premonsoon rainfall in CPRB after 1980 and the continual sea level rise in the river outlet have both played a role. The rainfall increase is associated with a strengthening of the premonsoon northeasterly winds that come from East Asia. Attribution analysis using phase 5 of the Coupled Model Intercomparison Project historical experiments pointed to anthropogenic greenhouse gases as the main external climate forcing leading to the rainfall increase. Together, these findings suggest increasing odds for potential flooding of similar intensity to that of the 2011 flood.
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BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Southern Japan suffered from a succession of extreme events in summer 2018. Climatological 10‐day precipitation in southern Japan depict the three‐phase lifecycle of the East Asian summer monsoon ...(EASM) and the corresponding timing of the 2018 consecutive extreme events (indicated in the bottom). The sequential yet contrasting extreme events in Japan therefore reflect an amplified EASM projected in a warmer climate.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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