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This study used radar observations and a high‐resolution numerical simulation to explore the interactions between an mesoscale convective system (MCS), cold pool outflows, and atmospheric bores in a non‐uniform baroclinic environment. The bores were generated by a nocturnal MCS that occurred on 2–3 June 2017 over the southern North China Plain. The goal of this investigation is to determine how the structure of bores varied within this non‐uniform environment and whether and how the bores would maintain the MCS and alter its structure. To the southwest of the MCS, where there was large CAPE and a well‐mixed boundary layer, discrete convection initiation occurred behind a single radar fine line (RFL) maintaining the propagation of the MCS. To the southeast of the MCS, multiple RFLs were found suggesting the generation of an undular bore in an environment containing an intense nocturnal stable boundary layer with dry upper layers and little CAPE. Hydraulic and nonlinear theory were applied to the simulation of the MCS revealing that the differences in the bore evolution depended on both the characteristics of the cold pool and the variations in the ambient environment. Thus, the characteristics of the ambient environment and the associated differences in bore structure impacted the maintenance and organization of the MCS. This study implies the importance of an accurate representation of the low‐level ambient environment and the microphysics and kinematics within the MCS to accurately simulate and forecast cold pools, the generation and evolution of bores, and their impact on nocturnal MCSs. Convective storms that occur during the day are often maintained by the lifting of low‐level air by storm outflows. At night when a low‐level stable layer forms, these outflows can generate an atmospheric bore, which is a type of gravity wave response. Investigations at numerous locations worldwide have demonstrated that bores contribute to the initiation and maintenance of nocturnal convective systems. However, relatively few studies have concentrated on how a non‐uniform nocturnal environment can change the structure of bores and their impact on convection. This study examines how bores and convection interact over the southern North China Plain (SNCP) where the nocturnal environment during warm season is often non‐uniform. These environmental variations impacted the generation and evolution of the bores altering the storm structure. The bores over the SNCP also had a unique generation mechanism forming when a strong downdraft penetrated into a moist layer. This study shows that an accurate representation of both the ambient environment and the storm microphysics and kinematics are likely necessary to improve the forecast accuracy of the nocturnal convective systems, particularly over regions with a non‐uniform environment, such as the SNCP. Atmospheric bores are generated within a nocturnal mesoscale convective system in a non‐uniform environmentThe mesoscale variations in the environment ahead of the mesoscale convective system (MCS) modify the structure of the bores, which impact the organization of the MCSThe intrusion of the convective downdraft into the nocturnal boundary layer plays a critical role in generating bores over the southern North China Plain Atmospheric bores are generated within a nocturnal mesoscale convective system in a non‐uniform environment The mesoscale variations in the environment ahead of the mesoscale convective system (MCS) modify the structure of the bores, which impact the organization of the MCS The intrusion of the convective downdraft into the nocturnal boundary layer plays a critical role in generating bores over the southern North China Plain

This first multi‐year investigation focuses on bores over the southern North China Plain during the 2015–2019 warm seasons. Bore structure depended on location with undular bores tending to occur close to the coast and non‐undular bores to the west near elevated terrain. Bores were most likely to occur during June and July when convection is active. While bore frequency over the Southern Great Plains (SGP) of U.S. is linked to the region's nocturnal low‐level jet, the bores herein were sensitive to the synoptic regime with ∼80% occurring during 4‐to‐5‐day periods under three different synoptic regimes. The bores had shorter durations than their SGP counterparts and a far wider range in their direction of propagation. Overall, these findings find regional differences in bores' frequency, movement, and structure serving an impetus for future investigations of nocturnal mesoscale convective systems and bores over China and other locations worldwide. Mesoscale convective systems (MCSs) contribute to beneficial rainfall and the increase of extreme rainfall observed in present warming climate. MCSs are generally considered to be a result of lifting of the environmental air by the MCS's diabatically generated cold pool. Recent studies have shown that nocturnal MCSs can also generate bores that cause significant lifting (of ∼1 km) in the lower troposphere, destabilizing large areas (>10,000 km2) surrounding the MCS. Past studies of bores have generally concentrated on nocturnal convection over the Southern Great Plains (SGP) in the United States. This study provides the first systematic investigation of the generation, characteristics, and evolution of bores over China. While similarities were found with their SGP counterparts, the documentation of significant differences raises the impetus for future investigations focused on advancing the understanding and prediction of bore dynamics over other locations and their relationship to nocturnal mesoscale convective systems. This climatological study examines the frequency, structure, and movement of bores over the southern North China PlainNocturnal mesoscale convective systems over China generate bores but with significant differences from that over the central United StatesThis study raises the impetus for future investigations of bores' dynamics and bores over other regions This climatological study examines the frequency, structure, and movement of bores over the southern North China Plain Nocturnal mesoscale convective systems over China generate bores but with significant differences from that over the central United States This study raises the impetus for future investigations of bores' dynamics and bores over other regions

A coupled earth system model (ESM) has been developed at the Nanjing University of Information Science and Technology (NUIST) by using version 5.3 of the European Centre Hamburg Model (ECHAM), version 3.4 of the Nucleus for European Modelling of the Ocean (NEMO), and version 4.1 of the Los Alamos sea ice model (CICE). The model is referred to as NUIST ESM1 (NESM1). Comprehensive and quantitative metrics are used to assess the model’s major modes of climate variability most relevant to subseasonal-to-interannual climate prediction. The model’s assessment is placed in a multi-model framework. The model yields a realistic annual mean and annual cycle of equatorial SST, and a reasonably realistic precipitation climatology, but has difficulty in capturing the spring-fall asymmetry and monsoon precipitation domains. The ENSO mode is reproduced well with respect to its spatial structure, power spectrum, phase locking to the annual cycle, and spatial structures of the central Pacific (CP)-ENSO and eastern Pacific (EP)-ENSO; however, the equatorial SST variability, biennial component of ENSO, and the amplitude of CP-ENSO are overestimated. The model captures realistic intraseasonal variability patterns, the vertical-zonal structures of the first two leading predictable modes of Madden-Julian Oscillation (MJO), and its eastward propagation; but the simulated MJO speed is significantly slower than observed. Compared with the T42 version, the high resolution version (T159) demonstrates improved simulation with respect to the climatology, interannual variance, monsoon-ENSO lead-lag correlation, spatial structures of the leading mode of the Asian-Australian monsoon rainfall variability, and the eastward propagation of the MJO.

Aromatic‐substituted derivatives of 1,3,2‐diazaphospholidin‐4‐ones 2a–gwere readily prepared from 1,3‐diaryl glycinamides 1by the reaction with hexaethylphosphoric triamide. Their chemical transformation was selectively effected with different thionation reagents to afford thionated products at the phosphorus atom to give 3a–gand at the carbonyl group to give 4a. An oxidation reaction at phosphorus to produce 5awas effected with 10% hydrogen peroxide. Preliminary bioassays revealed that some of the title compounds, 2a–gand 3a–gpossess selective herbicidal activity against rape. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:497–500, 2001

1,2 and 1,3 bis-ylides derived from corresponding bis-phosphonium salts reacted with substituted benzaldehydes to give 19 dienes with E,E-selectivity.

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