Comprehensive effects of interdecadal change of sea surface temperature increase in the Indo-Pacific Ocean on the warming-wetting of the Qinghai-Tibet Plateau.

The correlation characteristics between anomalous changes in summer precipitation on the Qinghai-Tibet Plateau (QTP) and the high-impact areas of global sea-surface temperature (SST) are mainly studied in this paper. The results show that the interdecadal change of the regional "warming-wetting" in China is especially prominent in the northern part of the main body of the QTP, which is therefore identified as the high-value area of precipitation variability. Investigations have revealed that the high-value areas of summer precipitation variability in the northern QTP are significantly correlated with four high-value areas of SST variability, namely the western North Pacific, the western Central Pacific, the Southwest Pacific, and the central Indian Ocean.

Atmospheric transport drives regional interactions of ozone pollution in China.

In recent years, ozone pollution becomes a serious environmental issue in China. A good understanding of source-receptor relationships of ozone transport from aboard and inside China is beneficial to mitigating ozone pollution there. To date, these issues have not been comprehensively assessed, especially for highly polluted regions in the central and eastern China (CEC), including the North China Plain (NCP), Twain-Hu region (THR), Yangtze River Delta (YRD), Pearl River Delta (PRD), and Sichuan Basin (SCB).

Distinct impacts of vapor transport from the tropical oceans on the regional glacier retreat over the Qinghai-Tibet Plateau.

An influence of precipitation on the glacier changes over the Qinghai-Tibet Plateau (QTP) is investigated in this paper. The results show that the glacial loss rates of glaciers in the QTP are significantly correlated with the interannual changes of precipitation and low cloud cover. The water vapor, importing with the warm and wet airflows from the Asian Monsoon regions, significantly influence the precipitation in the southern and northern glacier areas of the QTP in the summer monsoon season.

Anomalous surface O changes in North China Plain during the northwestward movement of a landing typhoon.

As high impact weather in a large scale, typhoon movement from the northwest Pacific into inland regions influencing ambient O changes is unclear, especially in North China Plain (NCP). A landing Typhoon Ampil during July 17-24, 2018 was studied herein to characterize the surface O anomalies during its movement over NCP. Landing typhoons present large negative O anomalies at the center of the typhoon and positive O anomalies 600-1700 km away from the center.

Impact of "blocking" structure in the troposphere on the wintertime persistent heavy air pollution in northern China.

In the winters of 2012-2018, a total of 25 'ultra-long' (≥6 days), wide-ranging pollution events occurred in northern China. The results showed that the atmospheric circulation pattern corresponding to 62.5% of the persistent 'most serious' and 'more serious' air pollution events in northern China were the blocking structures, and that 43.

Land-surface processes and summer-cloud-precipitation characteristics in the Tibetan Plateau and their effects on downstream weather: a review and perspective.

Correct understanding of the land-surface processes and cloud-precipitation processes in the Tibetan Plateau (TP) is an important prerequisite for the study and forecast of the downstream activities of weather systems and one of the key points for understanding the global atmospheric movement. In order to show the achievements that have been made, this paper reviews the progress on the observations for the atmospheric boundary layer, land-surface heat fluxes, cloud-precipitation distributions and vertical structures by using ground- and space-based multiplatform, multisensor instruments and the effect of the cloud system in the TP on the downstream weather. The results show that the form drag related to the topography, land-atmosphere momentum and scalar fluxes is an important part of the parameterization process.

Drivers of improved PM air quality in China from 2013 to 2017.

From 2013 to 2017, with the implementation of the toughest-ever clean air policy in China, significant declines in fine particle (PM) concentrations occurred nationwide. Here we estimate the drivers of the improved PM air quality and the associated health benefits in China from 2013 to 2017 based on a measure-specific integrated evaluation approach, which combines a bottom-up emission inventory, a chemical transport model, and epidemiological exposure-response functions. The estimated national population-weighted annual mean PM concentrations decreased from 61.

Lidar data assimilation method based on CRTM and WRF-Chem models and its application in PM forecasts in Beijing.

A three-dimensional variational (3DVAR) lidar data assimilation method is developed based on the Community Radiative Transfer Model (CRTM) and Weather Research and Forecasting model coupled to Chemistry (WRF-Chem) model. A 3DVAR data assimilation (DA) system using lidar extinction coefficient observation data is established, and variables from the Model for Simulating Aerosol Interactions and Chemistry (MOSAIC) mechanism of the WRF-Chem model are employed. Hourly lidar extinction coefficient data from 12:00 to 18:00 UTC on March 13, 2018 at four stations in Beijing are assimilated into the initial field of the WRF-Chem model; subsequently, a 24 h PM concentration forecast is made.

Spatio-temporal variations in SO and NO emissions caused by heating over the Beijing-Tianjin-Hebei Region constrained by an adaptive nudging method with OMI data.

The Beijing-Tianjin-Hebei (BTH) region in China suffers from heavy air pollution, especially in heating period. SO and NO are two of the key primary gaseous pollutants emitted by coal burning. The increase in air pollution caused by heating in the south-central part of the BTH region is higher than that in the northern part.

The characteristics of abnormal wintertime pollution events in the Jing-Jin-Ji region and its relationships with meteorological factors.

Despite the implementation of strict air pollution control measures in recent years, severe haze events were still encountered in the Beijing-Tianjin-Hebei (Jing-Jin-Ji) region during the winter 2016. In this work, seasonal differences in correlations between air pollution and geographic terrain, atmospheric dynamical and thermal structures, and PBL height over the Jing-Jin-Ji region in history and recent years were investigated and a comprehensive model of atmospheric factors affecting winter air pollution formation was proposed. We found that the distribution of PM concentration closely correlated with the topography feature of China and the difference in haze pollution intensity between winter and other seasons was the most significant in the Jing-Jin-Ji region.

Numerical simulations of the effects of regional topography on haze pollution in Beijing.

In addition to weather conditions and pollutant emissions, the degree to which topography influences the occurrence and development of haze pollution in downtown Beijing and the mechanisms that may be involved remain open questions. A series of atmospheric chemistry simulations are executed by using the online-coupled Weather Research and Forecasting with Chemistry (WRF-Chem) model for November-December 2015 with different hypothetical topographic height scenarios. The simulation results show that topography exerts an important influence on haze pollution in downtown Beijing, particularly the typical development of haze pollution.

[Variations in Aerosol Optical Depth over Three Northeastern Provinces of China, in 2003-2014].

Based on the MODIS-Aqua aerosol optical depth (AOD) products from 2003 to 2014, Nighttime Lights Time data from DMSP satellites and basic meteorological data, the AOD spatial distributions of interannual and seasonal variations over three northeastern provinces of China(Liaoning, Jilin, Heilongjiang) were analyzed. It was found that there was a northeast-southwest area of high annual average AOD composed of Dalian, Shenyang, Changchun, Harbin and other cities, the 12-year average AOD value was 0.4-0.

On the mechanisms of the recurvature of super typhoon Megi.

Tropical cyclones (TC) are one of the most threatening natural hazards to human beings. Although significant improvements have been made in the track prediction of TCs during the past several decades, considerable uncertainties still exist, especially for recurving tracks. In this study, we explore the physical mechanisms that drove the large recurvature of super typhoon Megi through numerical sensitivity experiments using a regional atmospheric model.

Does warmer China land attract more super typhoons?

Accurate prediction of where and when typhoons (or named hurricanes which form over the North Atlantic Ocean) will make landfall is critical to protecting human lives and properties. Although the traditional method of typhoon track prediction based on the steering flow theory has been proven to be an effective way in most situations, it slipped up in some cases. Our analysis of the long-term Chinese typhoon records reveals that typhoons, especially super typhoons (those with maximum sustained surface winds of greater than 51 ms(-1)), have a trend to make landfalls toward warmer land in China over the past 50 years (1960-2009).