Latest articles in this journal
Atmosphere, Volume 13; https://doi.org/10.3390/atmos13122077
Sanjiang Plain is the most extensive marsh distribution region in China. Marshes in this region can protect biodiversity, regulate climate, and provide habitats for wild animals and plants. The normalized difference vegetation index (NDVI) is a crucial indicator of vegetation coverage, which may reflect ecosystem structure and functional features. Clarifying the spatiotemporal change of marsh coverage and its climatic drivers is vital for observing and predicting vegetation change in Sanjiang Plain. Using meteorological dataand MODIS NDVI data from 2000 to 2020, we analyzed the spatiotemporal variation in marsh vegetation coverage and climatic change effects in Sanjiang Plain. We found that the growing season vegetation NDVI of marsh increased significantly at a rate of 0.011/decade, indicating that the marsh vegetation growth has obviously improved during the past 21 years. Furthermore, we found that the increase of minimum (Tmin) and maximum (Tmax) temperature in July can significantly promote the marsh plant growth, and increasing nighttime Tmin has a stronger impact on promoting the growth than increasing daytime Tmax in this month. In addition, the increase of daytime Tmax in August can promote the marsh vegetation growth, whereas the increasing precipitation in August was unfavorable for the growth in Sanjiang Plain.
Atmosphere, Volume 13; https://doi.org/10.3390/atmos13122076
Climate change is one of the biggest threats to human living and health in the 21st century. Whilst a large number of papers have been published addressing the health impact of climate change, there is a lack of comprehensive bibliometric analysis in the crosscutting field. This study evaluated the global scientific output of research in the field of climate change and health between 1990 and 2020, based on the Web of Science Core Collection database. Research themes were identified using a social network analysis technique based on author keywords. Research trends were assessed by the change in overall publication number and the percentage of publications in each research theme. Articles were further categorized by the availability of funding and author affiliation to compare the difference between developed and developing countries. Results showed that the research output in the field of climate change and health has increased dramatically in the past 30 years, mainly dominated by researchers in developed countries. The percentage of research receiving funding was found to be the lowest in those published by developing countries only and the highest in those published by the collaboration of developed and developing countries. A total of nine major research themes was identified. Research related to ‘risk assessment and adaptation’, ‘sustainable development’ and ‘infectious diseases’ were relatively underfunded. A significant research trend was observed between 2006 and 2020, with increased attention on research themes related to ‘risk assessment and adaptation’, ‘sustainable development’, ‘extreme events’ and ‘air pollution’, and reduced attention on research themes related to ‘ocean’, ‘infectious disease’ and ‘phenology’. The shift of the research trend was mainly driven by research in developed countries. Suggestions, recommendations and future priorities identified by experts in the field of atmospheric sciences, epidemiology, public health, climate change, environmental sciences, and policy development are also provided to guide future research. It is important to shift our focus from single health aspects to an integrated system (such as One Health framework, which considers environmental health, animal health and human health as a whole), with future research focusing more on the systemic impact of climate change in order to achieve better, more effective and efficient risk governance. More funding should be mobilized to support the research capacity building in developing countries and to support climate change adaptation strategies for sustainable development.
Atmosphere, Volume 13; https://doi.org/10.3390/atmos13122071
Uniform grid data are widely used in climate science and related interdisciplinary fields. Such data usually describe the hydrometeorological states averaged over uniform latitude–longitude grids. While these data have larger grid areas in the tropics than other high-latitude regions, less attention has been paid to the areal weights of these grid data. Here, we revisited two methods available for processing these uniform grid data, including weighted sample statistics and grid interpolation. The former directly considers the grid area differences using geodetic weights; the latter converts the uniform grids to equal-area grids for conventional data analysis. When applied to global temperature and precipitation data, we found larger differences between weighted and unweighted samples and smaller differences between weighted and interpolated samples, highlighting the importance of areal weights in grid data analysis. Given the different results from various methods, we call for explicit clarification of the grid data processing methods to improve reproducibility in climate research.
Atmosphere, Volume 13; https://doi.org/10.3390/atmos13122075
The Central Plains Economic Region (CPER) is one of the most polluted regions in China. Air pollution has caused visibility degradation due to the light extinction of fine particles (PM2.5). However, the source of light extinction and visibility degradation is still unclear. In this study, the nested air quality prediction model system coupled with an online tracer-tagging module has been used to quantify the contribution of emission sectors and regions to visibility degradation. The light extinction coefficients were well reproduced over CPER. The results showed that resident-related emissions, traffic and industry were the main sectors of visibility degradation over CPER, contributing 55~62%, 10~28%, and 9~19%, respectively. The contribution of local emissions and regional transport was also investigated, and the results showed that regional transport dominated the light extinction (56~68%), among which transport within Henan province contributes significantly (12~45%). Sensitivity tests showed that the reduction in the resident-related sector was more effective than that of the industry sector. Emission control of 40% in resident-related, industry, and traffic sectors over the whole region can achieve the goal of good visibility. This study will provide scientific suggestions for the control strategies development to mitigate visibility degradation over CPER.
Atmosphere, Volume 13; https://doi.org/10.3390/atmos13122074
This study focused on the elimination of chlorobenzene by dual adsorption/catalytic oxidation over activated carbon fibers (ACFs) loaded with transition metal oxides (TMOs). The TMOs were successfully loaded on the ACFs by the incipient wetness impregnation method, which has the advantages of easy preparation, low cost, and size uniformity. The removal effects for chlorobenzene (CB) were investigated on pristine ACFs and [email protected] in a fix-bed reactor. The adsorption/catalytic oxidation experiments result demonstrated that ACFs can be used as a very efficient adsorbent for the removal of low-concentration CB at the low temperature of 120 °C; the breakthrough time of CB over pristine ACFs can reach 15 h at an inlet concentration of 5000 ppmv and space velocity of 20,000 h−1. As the bed temperature rose above 175 °C, the CB removal mainly contributed to the catalytic oxidation of MnO2; a preferable CB removal ratio was achieved at higher temperatures in the presence of more MnO2. Therefore, CB can be effectively removed by the dual adsorbent/catalyst of MnO2@ACF at the full temperature range below 300 °C.
Atmosphere, Volume 13; https://doi.org/10.3390/atmos13122073
Synoptic eddies (with a period of two to eight days) are active in the South China Sea-Philippine Sea (SCS-PS) and control weather variations. In addition, the intensity and frequency of synoptic eddies may change along with variations in sea surface temperatures (SST). This paper presented the influence of SST in the northwest Indian Ocean on synoptic eddies in the lower troposphere over the SCS-PS in June. Our statistical analysis showed a significant negative correlation between the SST in the northwest Indian Ocean and the synoptic scale eddy kinetic energy (EKE) in the SCS-PS. By analyzing the EKE budget of synoptic eddies, we found that the variation in the synoptic scale EKE over the SCS-PS is mainly due to the change in the monthly zonal wind gradient, which affects the barotropic energy conversion between the monthly mean flow and the synoptic eddies. Additionally, the northwest Indian Ocean SST modulates the monthly flow over the SCS-PS by alternating the strength of the Walker circulation in the west Pacific and Indian Ocean. Finally, the influence of SST in the northwest Indian Ocean on EKE in the SCS-PS was reproduced using the simplified atmospheric general circulation model, SPEEDY.
Atmosphere, Volume 13; https://doi.org/10.3390/atmos13122072
The evaporation duct is a particular type of atmospheric structure that always appears on the open ocean. Predicting the evaporation duct height (EDH) accurately and in a timely manner is of great significance for the practical application of marine wireless communication equipment. Understanding the characteristics of EDH time series is an essential prerequisite for establishing an appropriate prediction model. Moreover, the sampling timescales of EDH data may influence the dynamic characteristics of the EDH time series as well. In this study, EDH time series datasets at three timescales, hourly, daily, and monthly, were constructed as the case study. Statistical methods, namely the augmented Dickey–Fuller test and Ljung–Box test, were adopted to verify the stationary and white noise characteristics of the EDH time series. Then, rescaled range analysis was applied to calculate the Hurst exponent to study the fractal characteristics of the EDH time series. An extensive analysis and discussion of the chaotic dynamics of the EDH time series are provided. From the perspective of nonlinear dynamics, the phase space was constructed from the time delay
and embedding dimension m, which were calculated from the mutual information method and the Grassberger–Procaccia algorithm, respectively. The maximum Lyapunov exponent was also calculated by the small data volume method to explore the existence of chaos in the EDH time series. According to our analysis, the EDH time series are stationary and have a non-white noise characteristic. The Hurst exponents for all three timescales were greater than 0.5, indicating the predictability of the EDH time series. The phase space diagrams exhibited strange attractors in a well-defined region for all the timescales, suggesting that the evolution of the EDH time series can possibly be explained by deterministic chaos. All of the maximum Lyapunov exponents were positive, confirming the chaos in the EDH time series. Further, stronger chaotic characteristics were found for the finer-resolution time series than the coarser-resolution time series. This study provides a new perspective for scholars to understand the fluctuation principles of the evaporation duct at different timescales. The findings from this study also lay a theoretical and scientific foundation for the future application of chaotic prediction methods in the research on the evaporation duct.
Atmosphere, Volume 13; https://doi.org/10.3390/atmos13122070
Variable resolution configuration is a defining feature of the NCAR MPAS (Model for Prediction Across Scales) model, which allows us to smoothly vary the horizontal resolution for taking a closer look at an area of interest. In this study, we aimed to analyze the impact of variable resolution on intrinsic predictability using bred vectors. Thus, the breeding cycles of the MPAS model with and without variable resolution configuration were implemented and tested with two different rescaling intervals of 6 h and 1 day. Rescaling within our breeding cycles were centered by the nature run, thus we could deal with the intrinsic predictability limited only by the initial error growth. We confirmed reasonable estimates of fast-growing errors by bred vectors at two different scales of convective and synoptic systems. We then found that the variable resolution configuration gave consistent improvement of intrinsic predictability not only over the high-resolution area but also outside. A quantitative analysis showed that an improvement with the variable resolution could be found in general for most vertical levels for both rescaling interval experiments. Additionally, we present the computational cost and experience of performing the variable resolution model which would help users in their decisions on this setting.
Atmosphere, Volume 13; https://doi.org/10.3390/atmos13122069
Climate change is a global issue. Its impacts are recognized at different scales ranging from global to regional to local. Climate change particularly changes in temperature and precipitation has been observed differently in different ecological regions in Nepal Himalaya. The study area comprises five villages of three ecological regions in the Gandaki River Basin (GRB) of Nepal. Based on the observed climate data of a 30-year period from 1990 to 2020, the changes in temperature and precipitation of each ecological region are analyzed using the Mann–Kendall trend test and Sen’s slope. The temperature trend was found to be increasing at the rate of 0.0254 °C per year (°C/a) between 1990 and 2020 in the Mountain region, by 0.0921 °C/a in the Hill region and 0.0042 °C/a in the Tarai region. The precipitation trend in the Mountain region is decreasing by −13.126 mm per year (mm/a), by −9.3998 mm/a in the Hill region and by −5.0247 mm/a in the Tarai region. Household questionnaire surveys, key informant interviews and focus group discussions were carried out to assess the perception of climate change and its impact. The farmers of the three ecological regions have perceived increasing temperature trends, but perceived variability in precipitation trends. Both snowfall and rainfall have varied. Snowfall has drastically decreased. Drought has increased. Extreme disaster events and impacts from such climate-induced events are experienced by 67.9% of respondents. A major impact of climate change is reported on cultivated crops with damage caused by increased insect and rodent pests. The impact of climate change is varied by ecological region. The comparative study of observed data and household data shows the need for a micro-level study so that a real situation can be captured and would be very much useful for policy formulation to combat climate change at a local scale.
Atmosphere, Volume 13; https://doi.org/10.3390/atmos13122068
The OI135.6 nm radiation intensity and the associated change with solar activity are very complex, and this is particularly the case during November 2020. In this paper, we investigated the OI135.6 nm radiation intensity in the low-latitude ionosphere during a quiet geomagnetic period. The Ionospheric Photometer (IPM) instrument onboard the FY-3(D) meteorological satellite was employed to measure the OI135.6 nm night airglow at 02:00 LT (local time) and its response to the solar activity. The results showed there is a statistically significant correlation between the intensity of the equatorial ionospheric anomaly (EIA) and solar activity after midnight. The EIA at 02:00 LT and before midnight shared the same climatological characteristics—strong in equinoxes and weak in solstices. In November 2020, when the F10.7 flux significantly increased, the OI135.6 nm radiation intensity in the EIA region recorded a 100–200% increase compared to the previous month, which was much higher than in the same period in the preceding two years. A similar phenomenon was observed at the same time by the Global-scale Observations of Limb and Disk (GOLD), which makes continuous observations of ionospheric structure variation in global patterns. Data analysis suggests that the EIA at 02:00 LT was due to the attenuation of the EIA before midnight after the disappearance of the eastward electric field. The magnetic latitude of the EIA crest (hereafter denoted by
) indicates a range-and-seasonal rule of hemispherical asymmetry: closer to the geomagnetic equator in equinoxes and farther away from the geomagnetic equator in solstices. Further studies are needed.