Distinct impacts of ENSO on haze pollution in Beijing-Tianjin-Hebei region between early and late winters

The Beijing-Tianjin-Hebei (BTH) region has encountered increasingly severe and frequent haze pollution during recent decades. This study reveals that the El Niño–Southern Oscillation (ENSO) has distinctive impacts on interannual variations of haze pollution over BTH in early and late winters. The impact of ENSO on the haze pollution over the BTH is strong in early winter, but weak in late winter. In early winter, ENSO-related sea surface temperature anomalies generate double-cell Walker circulation anomalies, with upward motion anomalies over the tropical central-eastern Pacific and tropical Indian Ocean, and downward motion anomalies over tropical western Pacific. The ascending motion and enhanced atmospheric heating anomalies over the tropical Indian Ocean trigger atmospheric teleconnection propagating from North Indian Ocean to East Asia, and result in generation of an anticyclonic anomaly over northeast Asia. The associated southerly anomalies to the west side lead to more serious haze pollution via reducing surface wind speed and increasing low-level humidity and thermal inversion. Strong contribution of the Indian Ocean heating anomalies to the formation of the anticyclonic anomaly over northeast Asia in early winter can be confirmed by atmospheric model numerical experiments. In late winter, vertical motion and precipitation anomalies are weak over tropical Indian Ocean related to ENSO. As such, ENSO cannot induce clear anticyclonic anomaly over northeast Asia via atmospheric teleconnection, and thus has a weak impact on the haze pollution over BTH. Further analysis shows that stronger ENSO-induced atmospheric heating anomalies over tropical Indian Ocean in early winter is partially due to higher mean SST and precipitation there.

Psychological insights on discussing societal disruption and collapse

As the impacts of climate change grow in number and severity, so climate distress is increasing around the world and becoming a major issue for psychologists, as both individuals and professionals. Increasing numbers of people assess that the damage that is forthcoming because of existing trajectories of atmospheric heating will lead to massive disruption and ultimate collapse of societies around the world. Some such people have been grouping together to share ideas on the implications for the rest of their lives. Many are using the concept and framework of “Deep Adaptation” to organise their sense making and actions. Their existence and ideas have led to strong criticisms from some commentators and scientists, who argue it is not correct or helpful to discuss collapse risk and readiness. This paper explores the reasons why publicly discussing anticipation of collapse has become helpful, and how criticisms of it are likely involving forms of ‘experiential avoidance’. The problematic objectification of people for ‘doomism’ is explained, as well as the antecedents of authoritarianism that may be emerging in the criticisms of Deep Adaptation. Therefore, a case is made for how psychotherapists and psychologists can help people, including scholars, understand how their aversion to the topic of collapse — and the emotions associated with it — could be preventing dialogue and wise action at this crucial time for humanity.

Microclimatic comparison of lichen heaths and shrubs: shrubification generates atmospheric heating but subsurface cooling during the growing season

Lichen heaths are declining in abundance in alpine and Arctic areas partly due to an increasing competition with shrubs. This shift in vegetation types might have important consequences for the microclimate and climate on a larger scale. The aim of our study is to measure the difference in microclimatic conditions between lichen heaths and shrub vegetation during the growing season. With a paired plot design, we measured the net radiation, soil heat flux, soil temperature and soil moisture on an alpine mountain area in southern Norway during the summer of 2018 and 2019. We determined that the daily net radiation of lichens was on average 3.15 MJ (26 %) lower than for shrubs during the growing season. This was mainly due to a higher albedo of the lichen heaths but also due to a larger longwave radiation loss. Subsequently, we estimate that a shift from a lichen heath to shrub vegetation leads to an average increase in atmospheric heating of 3.35 MJ d−1 during the growing season. Surprisingly, the soil heat flux and soil temperature were higher below lichens than below shrubs during days with high air temperatures. This implies that the relatively high albedo of lichens does not lead to a cooler soil compared to shrubs during the growing season. We predict that the thicker litter layer, the presence of soil shading and a higher evapotranspiration rate at shrub vegetation are far more important factors in explaining the variation in soil temperature between lichens and shrubs. Our study shows that a shift from lichen heaths to shrub vegetation in alpine and Arctic areas will lead to atmospheric heating, but it has a cooling effect on the subsurface during the growing season, especially when air temperatures are relatively high.

On the thermal atmosphere evaporation of hot neptune GJ 436b

В данной работе с помощью одномерной самосогласованной аэрономической модели были получены высотные профили температуры, скорости и плотности для горячего нептуна GJ 436b. Мы проследили расширение газовой оболочки под действием нагрева от жесткого излучения родительской звезды от тонкого атмосферного слоя 1.02R 0 до 5R 0 . Используемая модель учитывает вклад надтепловых частиц, что значительно уточняет функцию нагрева атмосферы. Установлено, что формируется структура атмосферы с двумя характерными шкалами высоты, отвечающими относительно плотной атмосфере и более разреженной короне. Также был посчитан темп оттока атмосферы, составивший около 1.6 × 10 9 г с -1 , что ниже результатов, полученных авторами других расчетов. In this work the height profiles of temperature, velocity, and density were obtained for the hot neptune GJ 436b, using a one-dimensional self-consistent aeronomic model. We traced the expansion of the gas envelope affected by heating from the extreme radiation of the host star from the thin atmospheric layer 1.02R 0 up to 5R 0 . The model used takes into account the contribution of suprathermal particles, which significantly refines the atmospheric heating function. It was found that the structure of the atmosphere is being formed with two characteristic altitude scales corresponding to a relatively dense atmosphere and a more rarefied corona. The atmospheric mass loss rate was also calculated, it was found to be about 1.6 × 10 9 g s -1 , which is lower than the results obtained by the authors of other calculations.

Aerosol-induced atmospheric heating rate decreases over South and East Asia as a result of changing content and composition

Aerosol emissions from human activities are extensive and changing rapidly over Asia. Model simulations and satellite observations indicate a dipole pattern in aerosol emissions and loading between South Asia and East Asia, two of the most heavily polluted regions of the world. We examine the previously unexplored diverging trends in the existing dipole pattern of aerosols between East and South Asia using the high quality, two-decade long ground-based time series of observations of aerosol properties from the Aerosol Robotic Network (AERONET), from satellites (Moderate Resolution Imaging Spectroradiometer (MODIS) and Ozone Monitoring Instrument (OMI)), and from model simulations (Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2). The data cover the period since 2001 for Kanpur (South Asia) and Beijing (East Asia), two locations taken as being broadly representative of the respective regions. Since 2010 a dipole in aerosol optical depth (AOD) is maintained, but the trend is reversed—the decrease in AOD over Beijing (East Asia) is rapid since 2010, being 17% less in current decade compared to first decade of twenty-first century, while the AOD over South Asia increased by 12% during the same period. Furthermore, we find that the aerosol composition is also changing over time. The single scattering albedo (SSA), a measure of aerosol’s absorption capacity and related to aerosol composition, is slightly higher over Beijing than Kanpur, and has increased from 0.91 in 2002 to 0.93 in 2017 over Beijing and from 0.89 to 0.92 during the same period over Kanpur, confirming that aerosols in this region have on an average become more scattering in nature. These changes have led to a notable decrease in aerosol-induced atmospheric heating rate (HR) over both regions between the two decades, decreasing considerably more over East Asia (− 31%) than over South Asia (− 9%). The annual mean HR is lower now, it is still large (≥ 0.6 K per day), which has significant climate implications. The seasonal trends in AOD, SSA and HR are more pronounced than their respective annual trends over both regions. The seasonal trends are caused mainly by the increase/decrease in anthropogenic aerosol emissions (sulfate, black carbon and organic carbon) while the natural aerosols (dust and sea salt) did not change significantly over South and East Asia during the last two decades. The MERRA-2 model is able to simulate the observed trends in AODs well but not the magnitude, while it also did not simulate the SSA values or trends well. These robust findings based on observations of key aerosol parameters and previously unrecognized diverging trends over South and East Asia need to be accounted for in current state-of-the-art climate models to ensure accurate quantification of the complex and evolving impact of aerosols on the regional climate over Asia.

The decline of alpine lichen heaths generates atmospheric heating but subsurface cooling during the growing season

Lichen heaths are declining in abundance in alpine and arctic areas partly due to an increasing competition with shrubs. This shift in vegetation types might have important consequences for the microclimate and climate on a larger scale. The aim of our study is to measure the difference in microclimatic conditions between lichen heaths and shrub vegetation during the growing season. With a paired plot design, we measured the net radiation, soil heat flux, soil temperature, and soil moisture on an alpine mountain area in south Norway during the summer of 2018 and 2019. We determined that the daily net radiation of lichens was on average 3.15 MJ (26 %) lower than for shrubs during the growing season. This was mainly due to a higher albedo of the lichen heaths, but also due to a larger longwave radiation loss. Subsequently, we estimate that a shift from a lichen heath to shrub vegetation leads to an average increase in atmospheric heating of 3.35 MJ per day during the growing season. Surprisingly, the soil heat flux and soil temperature were higher below lichens than below shrubs during days with high air temperatures. This implies that the relatively high albedo of lichens does not lead to a cooler soil compared to shrubs during the growing season. We hypothesize that the thicker litter layer, the presence of soil shading, and a higher evapotranspiration rate at shrub vegetation are far more important factors in explaining the variation in soil temperature between lichens and shrubs. Our study shows that a shift from lichen heaths to shrub vegetation in alpine and arctic areas will lead to atmospheric heating, but has a cooling effect on the subsurface during the growing season, especially when air temperatures are relatively high.