Atmospheric Heating Research Articles

Assessment of Atmospheric and Surface Energy Budgets Using Observation-Based Data Products

AbstractAccurate diagnosis of regional atmospheric and surface energy budgets is critical for understanding the spatial distribution of heat uptake associated with the Earth’s energy imbalance (EEI). This contribution discusses frameworks and methods for consistent evaluation of key quantities of those budgets using observationally constrained data sets. It thereby touches upon assumptions made in data products which have implications for these evaluations. We evaluate 2001–2020 average regional total (TE) and dry static energy (DSE) budgets using satellite-based and reanalysis data. For the first time, a consistent framework is applied to the ensemble of the 5th generation European Reanalysis (ERA5), version 2 of modern-era retrospective analysis for research and applications (MERRA-2), and the Japanese 55-year Reanalysis (JRA55). Uncertainties of the computed budgets are assessed through inter-product spread and evaluation of physical constraints. Furthermore, we use the TE budget to infer fields of net surface energy flux. Results indicate biases < 1 W/m2 on the global, < 5 W/m2 on the continental, and ~ 15 W/m2 on the regional scale. Inferred net surface energy fluxes exhibit reduced large-scale biases compared to surface flux data based on remote sensing and models. We use the DSE budget to infer atmospheric diabatic heating from condensational processes. Comparison to observation-based precipitation data indicates larger uncertainties (10–15 Wm−2 globally) in the DSE budget compared to the TE budget, which is reflected by increased spread in reanalysis-based fields. Continued validation efforts of atmospheric energy budgets are needed to document progress in new and upcoming observational products, and to understand their limitations when performing EEI research.

Field evidence of brown carbon absorption enhancement linked to organic nitrogen formation in Indo-Gangetic Plain

Atmospheric brown carbon (BrC), a short-lived climate forcer, absorbs solar radiation and is a substantial contributor to the warming of the Earth's atmosphere. BrC composition, its absorption properties, and their evolution are poorly represented in climate models, especially during atmospheric aqueous events such as fog and clouds. These aqueous events, especially fog, are quite prevalent during wintertime in Indo-Gangetic Plain (IGP) and involve several stages (e.g., activation, formation, and dissipation, etc.), resulting in a large variation of relative humidity (RH) in the atmosphere. The huge RH variability allowed us to examine the evolution of water-soluble brown carbon (WS-BrC) diurnally and as a function of aerosol liquid water content (ALWC) and RH in this study. We explored links between the evolution of WS-BrC mass absorption efficiency at 365 nm (MAEWS-BrC-365) and chemical characteristics, viz., low-volatility organics and water-soluble organic nitrogen (WSON) to water-soluble organic carbon (WSOC) ratio (org-N/C), in the field (at Kanpur in central IGP) for the first time worldwide. We observed that WSON formation governed enhancement in MAEWS-BrC-365 diurnally (except during the afternoon) in the IGP. During the afternoon, the WS-BrC photochemical bleaching dwarfed the absorption enhancement caused by WSON formation. Further, both MAEWS-BrC-365 and org-N/C ratio increased with a decrease in ALWC and RH in this study, signifying that evaporation of fog droplets or bulk aerosol particles accelerated the formation of nitrogen-containing organic chromophores, resulting in the enhancement of WS-BrC absorptivity. The direct radiative forcing of WS-BrC relative to that of elemental carbon (EC) was ∼19 % during wintertime in Kanpur, and ∼ 40 % of this contribution was in the UV-region. These findings highlight the importance of further examining the links between the evolution of BrC absorption behavior and chemical composition in the field and incorporating it in the BrC framework of climate models to constrain the predictions.

Unraveling the Indian monsoon’s role in fueling the unprecedented 2022 Marine Heatwave in the Western North Pacific

An unprecedented marine heatwave (MHW) event occurred in the middle-high latitudes of the western North Pacific during the summer of 2022. We demonstrate that excessive precipitation thousands of kilometers away fuels this extreme MHW event in July 2022. In the upper atmosphere, a persistent atmospheric blocking system, forming over the MHW region, reduces cloud cover and increases shortwave radiation at the ocean surface, leading to high sea surface temperatures. Atmospheric perturbations induced by latent heat release from the extreme precipitation in the Indian summer monsoon region enhance this atmospheric blocking through the propagation of quasi-stationary Rossby waves. Our hypothesis is verified by using a numerical model that is forced with the observed atmospheric anomalous diabatic heating. This study sheds light on how a subtropical extreme event can fuel another extreme event at middle-high latitudes through an atmospheric teleconnection.

Methanogenesis in sediments of a tropical coastal wetland: a culture-dependent method

Introduction: Methanogenic archaea (MA), participate in the anaerobic mineralization of organic matter in mangrove sediments, their activity is related to atmospheric warming due to the production of methane; several environmental variables can influence the presence of MA and methane production in these sediments. Objective: To analyze, through culture-dependent techniques, viable methanogenic archaea (VMA) in the sediments, and the production of methane from acetate in different climatic periods in the mangrove El Morro-La Mancha, Veracruz, Gulf of Mexico. Methods: From May to November 2019, following a salinity transect, sediment samples from El Morro-La Mancha mangrove were collected at three locations, in three different climatic seasons, dry (May), rainy (October) and northern (November) (N = 9). VMA in the sediments was quantified using the Most Probable Number (MPN) technique with acetate and methanol as substrates. The influence of sulfate on methane production was analyzed from acetate in microcosm by gas chromatography and the chemical variables of salinity, pH, Eh, carbohydrates, organic content, and carbonates in the sediments were evaluated. Results: The abundance of VMA was 102 to 108 MPN/g of wet sediment, higher than that reported in other studies, this abundance was higher when methanol (104-108 MPN/g sediment) was used as substrate, compared to acetate (102-105 MPN/g sediment); methane production in the microcosms increased in sulfate-free conditions (29.78-929.75 nmol CH4/month) and in the sediments of the rainy season. Conclusion: The influence of the chemical conditions of the mangrove sediments on the methanogenic dynamics is highlighted, determining that in the rainy season, the decrease in salinity, more electronegative Eh, and the increase in organic fractions favored the methanogenesis. Objetive: To analyze, through culture-dependent techniques, the abundance of MA and the production of methane in different climatic periods in the mangrove El Morro-La Mancha, Veracruz, Gulf of Mexico. Methods: From May to November 2019, following a salinity transect, sediment samples from El Morro-La Mancha mangrove were collected at three sampling locations, in three different climatic seasons, dry (May), rainy (October) and northern (November) (n=9). The methanogenic abundance in the sediments was quantified using the Most Probable Number (MPN) technique with acetate and methanol as substrates; methane production was analyzed from acetate by gas chromatography and the chemical variables of salinity, pH, Eh, carbohydrates, organic content and carbonates in the sediments were evaluated. Results: The abundance of MA was 102 to 108 cells/g of wet sediment, higher to that reported in other studies, this abundance was higher when methanol (104 - 108 cells/g sediment) was used as substrate, compared to acetate (102 - 105 cells/sediment); methane production increased in rains with 13% compared to dry. Conclusion: Highlighted the influence of the chemical conditions of the mangrove sediments on the methanogenic dynamics, determining that in the rainy season, the decrease in salinity, Eh more electronegative and the increase in organic fractions favored both methanogenic abundance as methane production.

Improved simulations of biomass burning aerosol optical properties and lifetimes in the NASA GEOS Model during the ORACLES-I campaign

Abstract. In order to improve aerosol representation in the NASA Goddard Earth Observing System (GEOS) model, we evaluated simulations of the transport and properties of aerosols from southern African biomass burning sources that were observed during the first deployment of the NASA ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) field campaign in September 2016. An example case study of 24 September was analyzed in detail, during which aircraft-based in situ and remote sensing observations showed the presence of a multi-layered smoke plume structure with significant vertical variation in single scattering albedo (SSA). Our baseline GEOS simulations were not able to represent the observed SSA variation or the observed organic aerosol-to-black-carbon ratio (OA : BC). Analyzing the simulated smoke age suggests that the higher-altitude, less absorbing smoke plume was younger (∼4 d), while the lower-altitude and more absorbing smoke plume was older (∼7 d). We hypothesize a chemical or microphysical loss process exists to explain the change in aerosol absorption as the smoke plume ages, and we apply a simple loss rate to the model hydrophilic biomass burning OA to simulate this process. We also utilized the ORACLES airborne observations to better constrain the simulation of aerosol optical properties, adjusting the assumed particle size, hygroscopic growth, and absorption. Our final GEOS model simulation with additional OA loss and updated optics showed better performance in simulating aerosol optical depth (AOD) and SSA compared to independent ground- and space-based retrievals for the entire month of September 2016, including the Ozone Monitoring Instrument (OMI) Aerosol Index. In terms of radiative implications of our model adjustments, the final GEOS simulation suggested a decreased atmospheric warming of about 10 % (∼2 W m−2) over the southeastern Atlantic region and above the stratocumulus cloud decks compared to the model baseline simulations. These results improve the representation of the smoke age, transport, and optical properties in Earth system models.

High-resolution observations and numerical simulations provide insight into solar atmospheric heating

High-resolution observations and numerical simulations provide insight into solar atmospheric heating

Model Biases in the Atmosphere‐Ocean Partitioning of Poleward Heat Transport Are Persistent Across Three CMIP Generations

AbstractThe observed partitioning of poleward heat transport between atmospheric and oceanic heat transports (AHT and OHT) is compared to that in coupled climate models. Model ensemble mean poleward OHT is biased low in both hemispheres, with the largest biases in the Southern Hemisphere extratropics. Poleward AHT is biased high in the Northern Hemisphere, especially in the vicinity of the peak AHT near 40°N. The significant model biases are persistent across three model generations (CMIP3, CMIP5, CMIP6) and are insensitive to the satellite radiation and atmospheric reanalyzes products used to derive observational estimates of AHT and OHT. Model biases in heat transport partitioning are consistent with biases in the spatial structure of energy input to the ocean and atmosphere. Specifically, larger than observed model evaporation in the tropics adds excess energy to the atmosphere that drives enhanced poleward AHT at the expense of weaker OHT.

A mechanism for reconciling the synchronisation of Heinrich events and Dansgaard-Oeschger cycles

The evolution of the northern hemispheric climate during the last glacial period was beset by quasi-episodic iceberg discharge events from the Laurentide ice sheet, known as Heinrich events (HEs). The paleo record places most HEs into the cold stadial of the Dansgaard-Oeschger cycle. However, not every Dansgaard-Oeschger cycle is associated with a HE, revealing a complex interplay between the two modes of glacial variability. Here, using a coupled ice sheet-solid earth model, we introduce a mechanism that explains the synchronicity of HEs and Dansgaard-Oeschger cycles. Unlike earlier studies, our mechanism does not require a trigger during the stadial. Instead, the atmospheric warming signal during the interstadial of the Dansgaard-Oeschger cycle causes enhanced ice stream thickening that leads to the HE during the late interstadial. We demonstrate that this mechanism reproduces the key HE characteristics and provides an explanation for synchronous HEs from different regions of the Laurentide ice sheet.

Extremes of summer Arctic sea ice reduction investigated with a rare event algorithm

Various studies identified possible drivers of extremes of Arctic sea ice reduction, such as observed in the summers of 2007 and 2012, including preconditioning, local feedback mechanisms, oceanic heat transport and the synoptic- and large-scale atmospheric circulations. However, a robust quantitative statistical analysis of extremes of sea ice reduction is hindered by the small number of events that can be sampled in observations and numerical simulations with computationally expensive climate models. Recent studies tackled the problem of sampling climate extremes by using rare event algorithms, i.e., computational techniques developed in statistical physics to reduce the computational cost required to sample rare events in numerical simulations. Here we apply a rare event algorithm to ensemble simulations with the intermediate complexity coupled climate model PlaSim-LSG to investigate extreme negative summer pan-Arctic sea ice area anomalies under pre-industrial greenhouse gas conditions. Owing to the algorithm, we estimate return times of extremes orders of magnitude larger than feasible with direct sampling, and we compute statistically significant composite maps of dynamical quantities conditional on the occurrence of these extremes. We find that extremely low sea ice summers in PlaSim-LSG are associated with preconditioning through the winter sea ice-ocean state, with enhanced downward longwave radiation due to an anomalously moist and warm spring Arctic atmosphere and with enhanced downward sensible heat fluxes during the spring-summer transition. As a consequence of these three processes, the sea ice-albedo feedback becomes active in spring and leads to an amplification of pre-existing sea ice area anomalies during summer.

Horizontally polarized kink oscillations supported by solar coronal loops in an asymmetric environment

Context. Kink oscillations are ubiquitously observed in solar coronal loops, and understanding them is crucial in the contexts of coronal seismology and atmospheric heating. Aims. We studied kink modes supported by a straight coronal loop embedded in an asymmetric environment using 3D magnetohydrodynamic simulations. Methods. We implemented the asymmetric effect by setting different exterior densities below and above the loop interior and initiated the simulation using a kink-like velocity perturbation perpendicular to the loop plane, mimicking the frequently measured horizontally polarized kink modes. Results. We find that the external velocity fields show fan-blade structures propagating in the azimuthal direction as a result of the successive excitation of higher azimuthal Fourier modes. Resonant absorption and phase-mixing can still occur despite an asymmetric environment, leading to the development of small-scale structures at loop boundaries. These small-scale structures nonetheless develop asymmetrically at the upper and lower boundaries due to the different gradients of the Alfvén speed. Conclusions. These findings enrich our understanding of kink modes in coronal loops embedded within an asymmetric environment, providing insights that will be helpful for future high-resolution observations.

‘Consequences of this Climate’: Disabling Environmental Effects in Beckett's Late Work

This article analyses the change in the representation of disability in Beckett's work from medical impairments in the 1940s and 1950s to bodies that are limited by environmental conditions from the 1960s onwards. I suggest the term ‘disability effects’ to describe the condition of characters who are limited or harmed by the harsh environments of Beckett's imagination. A ‘disability effect’ arises from the interaction between a harmful environment and a human body through conditions such as confinement, toxic atmosphere, or extreme heat. While the social model of disability is useful for reading disability in the earlier works, it does not adequately account for the environmental pressures that lead to disability effects. Instead, the ecological–enactive model developed by Toro et al. provides a better framework that allows for a variety of subjective responses to the restrictions imposed by the Beckett's narrative ecologies. The representation of disability in Beckett's later work thus places at the centre of attention harmed bodies that are marginalised in too many discourses around the Anthropocene or held up as a warning sign for the terrible consequences of inaction, and can be read as a critique of ableist attitudes, which are also common in environmental movements. As climate change has become a present reality rather than a future danger to be averted, a rapidly changing environment is generating a range of disability and disability effects affecting whole populations and amplifying the shortcomings of the ableist social model that views disability as an exception that must be accommodated by an abled society. Beckett's work can help us come to terms with the continuity of adverse conditions, while leaving a space for the variability of personal adaptations.

Monitoring climate change in the marine Arctic

Changes in the temperature regime of the marine Arctic and the influencing factors are considered based on the current knowledge of the causes of climate change and the use of new data sources. In the Arctic, the warming is developing due to such factors as the increase in the transfer of heat and moisture from the low latitudes. This, in turn, drives the feedbacks in the Arctic climate system, increasing the flow of long-wave radiation to the surface due to rising atmospheric water vapor concentrations and slowing down the growth of the sea ice thickness in winter. The increase in the atmospheric heat transfer to the Arctic is associated with changes in atmospheric circulation, in particular, under the influence of ocean surface temperature anomalies, especially in the low latitudes since the bulk of the heat influx from the from solar radiation and anthropogenic forcing is accumulated here. Analyzing the causes of warming in the Arctic in the 1930s and 40s led researchers to the conclusion that the water influx from the North Atlantic is a factor to consider. Therefore, the influx of warm and salty water is also an important influence on the formation of the climate of the marine Arctic today, which should be taken into account when monitoring the temperature and ice regime of this area. Based on the analysis of the characteristics of climate variability in the marine Arctic and its causes, the article examines representative indicators of climate change in the temperature and ice regime of the marine Arctic and the factors influencing them in the present period.

Shaking up Assumptions: Earthquakes Have Rarely Triggered Andean Glacier Lake Outburst Floods

AbstractAs the world’s glaciers recede in response to a warming atmosphere, a change in the magnitude and frequency of related hazards is expected. Among the most destructive hazards are glacier lake outburst floods (GLOFs), and their future evolution is concerning for local populations and sustainable development policy. Central to this is a better understanding of triggers. There is a long‐standing assumption that earthquakes are a major GLOF trigger, and seismic activity is consistently included as a key hazard assessment criterion. Here, we provide the first empirical evidence that this assumption is largely incorrect. Focusing on the Tropical Andes, we show that, of 59 earthquakes (1900–2021) the effects of which intersect with known glacier lakes, only one has triggered GLOFs. We argue that, to help develop climate resilient protocols, the focus for future assessments should be on understanding other key GLOF drivers, such as thawing permafrost and underlying structural geology.

Spatio-temporal variability of small-scale leads based on helicopter maps of winter sea ice surface temperatures

Observations of sea ice surface temperature provide crucial information for studying Arctic climate, particularly during winter. We examined 1 m resolution surface temperature maps from 35 helicopter flights between October 2, 2019, and April 23, 2020, recorded during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC). The seasonal cycle of the average surface temperature spanned from 265.6 K on October 2, 2019, to 231.8 K on January 28, 2020. The surface temperature was affected by atmospheric changes and varied across scales. Leads in sea ice (cracks of open water) were of particular interest because they allow greater heat exchange between ocean and atmosphere than thick, snow-covered ice. Leads were classified by a temperature threshold. The lead area fraction varied between 0% and 4% with higher variability on the local (5–10 km) than regional scale (20–40 km). On the regional scale, it remained stable at 0–1% until mid-January, increasing afterward to 4%. Variability in the lead area is caused by sea ice dynamics (opening and closing of leads), as well as thermodynamics with ice growth (lead closing). We identified lead orientation distributions, which varied between different flights but mostly showed one prominent orientation peak. The lead width distribution followed a power law with a negative exponent of 2.63, which is in the range of exponents identified in other studies, demonstrating the comparability to other data sets and extending the existing power law relationship to smaller scales down to 3 m. The appearance of many more narrow leads than wide leads is important, as narrow leads are not resolved by current thermal infrared satellite observations. Such small-scale lead statistics are essential for Arctic climate investigations because the ocean–atmosphere heat exchange does not scale linearly with lead width and is larger for narrower leads.

The relationship between childhood trauma andinternet addiction in adolescents: Ameta-analysis.

Many studies have explored the relationship between childhood trauma and internet addiction from different theoretical perspectives; however, the results have been inconsistent. The purpose of this meta-analysis was to examine the relationship between childhood trauma and internet addiction. The PubMed, Web of Science, Embase, CNKI, Wanfang and VIP electronic databases were searched to identify studies examining the correlation between childhood trauma and adolescent internet addiction. The databases were searched from inception to December 31, 2022. Two researchers independently screened the literature, extracted the data, and evaluated the risk of bias of the included studies. Then, Stata 17.0 software was used to perform meta-analysis. This study was registered on PROSPERO (CRD42023388699). A total of 19 studies involving 21,398 adolescents were included in this meta-analysis. The random effects model was used for pooled analysis, and the results revealed a strong positive association between childhood trauma and internet addiction (r = 0.395, 95% CI [0.345, 0.442]). The relationship between childhood trauma and internet addiction was moderated by sample size, survey area, and internet addiction measurement tools. There were significant differences between the associations based on the various child trauma measurement tools and study quality scores. However, interstudy heterogeneity was not significantly affected by study year, sample source, or participant age. Internet addiction is positively correlated with childhood trauma. Therefore, it is extremely important for parents to provide a good growth environment during childhood to enhance the physical and mental development of adolescents. A warm family atmosphere helps individuals develop a healthy personality, thereby reducing or preventing the occurrence of internet addiction. Due to the limited number and low quality of the included studies, the above conclusions need to be verified by additional high-quality studies.

Synthesis and characterization of luminescent cerium-doped hydroxyapatite

Hydroxyapatite (HAp) biomaterials are intended for use as bone substitutes, target functional agents in theranostics or bioimaging due to affinity for hard tissues, biocompatibility, and bioactivity. This study is devoted to HAp doped with cerium, having distinctive feature to change the oxidation state (3+/4+), which affects the physico-chemical and optical properties of the obtained powders. Cerium-doped HAp nanopowders with Ce content up to 0.5 wt% were obtained through precipitation technique and then were heat treated. The following conditions for heat treating were used: (i) heating in air atmosphere, (ii) hot pressing, (iii) heating in a carbon filling. For characterization, the complex methodology was implemented, including X-ray diffraction (XRD) analysis and high temperature XRD, X-ray absorption near edge structure (XANES) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, inductively coupled plasma atomic emission spectrometry (ICP-AES), transmission electron microscopy (TEM), electron paramagnetic resonance (EPR) spectroscopy, and, finally, photoluminescence (PL) spectroscopy. It was shown that the monophase cerium-HAp is stable up to a temperature of 1000 °C in the oxidizing atmosphere, above 1000 °C cerium(4+) oxide forms. Using reducing atmosphere during heating prevents the transition of Ce3+ to Ce4+. PL, EPR and XANES studding clarified obviously the Ce3+ content in the materials obtained under different processing conditions. It was shown, that Ce-HAp powders produced by precipitation and hot pressing contain Ce3+ and exhibit luminescence. The significant luminescence of hot pressed Ce-HAps was caused by a higher concentration of Ce3+ ions and incorporation of carbonate ions as a result of the processing.

3D simulations of TRAPPIST-1e with varying CO2, CH4, and haze profiles

ABSTRACT Using a 3D General Circulation Model, the Unified Model, we present results from simulations of a tidally locked TRAPPIST-1e with varying carbon dioxide CO2 and methane CH4 gas concentrations, and their corresponding prescribed spherical haze profiles. Our results show that the presence of CO2 leads to a warmer atmosphere globally due to its greenhouse effect, with the increase of surface temperature on the dayside surface reaching up to ∼14.1 K, and on the nightside up to ∼21.2 K. Increasing presence of CH4 first elevates the surface temperature on the dayside, followed by a decrease due to the balance of tropospheric warming and stratospheric cooling. A thin layer of haze, formed when the partial pressures of CH4 to CO2 (pCH4/pCO2) = 0.1, leads to a dayside warming of ∼4.9 K due to a change in the water vapour H2O distribution. The presence of a haze layer that formed beyond the ratio of 0.1 leads to dayside cooling. The haze reaches an optical threshold thickness when pCH4/pCO2 ∼ 0.4 beyond which the dayside mean surface temperature does not vary much. The planet is more favourable to maintaining liquid water on the surface (mean surface temperature above 273.15 K) when pCO2 is high, pCH4 is low, and the haze layer is thin. The effect of CO2, CH4, and haze on the dayside is similar to that for a rapidly rotating planet. On the contrary, their effect on the nightside depends on the wind structure and the wind speed in the simulation.

Exploring Sensitivity of Phenology to Seasonal Climate Differences in Temperate Grasslands of China Based on Normalized Difference Vegetation Index

The affiliation between vegetation phenology and seasonal climate (start and end times of the growing season, or SOS and EOS) provides a basis for acquiring insight into the dynamic response of terrestrial ecosystems to the effects of climate change. Although climate warming is an important factor affecting the advancement or delay of plant phenology, understanding the sensitivity of phenology to seasonal variation in climate factors (e.g., local air temperature, precipitation) is generally lacking under different climate backgrounds. In this study, we investigated the interannual variability of grassland phenology and its spatial variation in temperate regions of China based on satellite-derived products for the normalized difference vegetation index (NDVI) and weather data acquired from 2001 to 2020. We found that due to differences in local climate conditions, the effects of seasonal warming and precipitation on phenology were divergent or even opposite during the 20 years. The sensitivities of the start of growing season (SOS) to both spring temperature and last-winter precipitation was controlled by mean annual precipitation in terms of spatial variation. The SOS in the semi-humid (200–400 mm) region was most sensitive to spring temperature, advancing 5.24 days for each 1 °C rise in the average spring temperature (p < 0.05), while it was most sensitive to last-winter precipitation in arid regions (<200 mm), with SOS advancing up to 2.23 days for every 1 mm increase in the last-winter precipitation (p < 0.05). The end of growing season (EOS) was sensitive to autumn temperature, being delayed 10.13 days for each 1 °C rise in the average autumn temperature in regions with temperatures between −10 °C and −5 °C (p < 0.05). The uncertainty in the determination of the EOS could conceivably be greater than the determination of the SOS due to the dual effects of pre-autumn climate and growth constraints induced by declining fall temperatures. The effect of atmospheric warming on grassland phenology was lessened with increased atmospheric and soil aridity, suggesting that the interaction of regional drought and climate warming is an important source for local-to-regional differences and uncertainties in grass phenological response.

Accumulation of absorbing aerosols over the Indian Sector of Southern Ocean during the austral summer: Role of thermal inversions

Optical properties of aerosols and their direct radiative effect were analyzed from columnar Aerosol Optical Depth (AOD) and ambient Black Carbon (BC) mass concentration (MB) estimated during Indian Southern Ocean Expeditions (SOEs), conducted in the austral summers of 2016–17 (SOE-IX) and 2017–18 (SOE-X). The aforementioned observations were supplemented with concurrent vertical soundings of the lower atmosphere. Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) data aided in investigating the vertical distribution of aerosols up to 10 km altitude. The relative contribution of BC aerosols emanating from fossil fuel combustion and biomass burning showed the former to be predominant, as the latter is larger and preferentially scavenged during long-range transport to remote marine regions. The highest values of AOD at 500 nm (AOD500; 0.156 ± 0.026) and MB (90.78 ± 40.11 ng m−3) were encountered in the region between 50 and 60°S. Consequently, the atmospheric clear-sky Aerosol Direct Radiative Effect (ADRE; +3.10 ± 0.38 W m−2) and heating rate (HR; 0.087 ± 0.011 K day−1) were also observed to be the highest in the region. Multiple atmospheric inversions were detected between 40 and 69°S. Although a much lower AOD500 (0.070 ± 0.017) prevailed between 60 and 69°S, the average clear-sky ADRE (+1.56 ± 0.49 W m−2) and HR (0.044 ± 0.014 K day−1) were fairly high. The mean MB in the region was high (68.81 ± 28.40 ng m−3) for the pristine ice-covered region. Low-lying inversions prevented the vertical ventilation and dispersal of BC therein. Simulations of BC-induced atmospheric heating rates at three locations in the coastal Antarctic waters indicated a ≈ 3–5-fold increase, corresponding to an increase in ambient BC from 50 to 300 ng m−3.

Three-dimensional cage based on porous Ni–Co–Cu phosphide as efficient and stable bifunctional electrocatalysts for overall water splitting

The development of cheap and high-performance dual electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in an electrolyte is of great importance. Tuning the electronic structure through heteroatom doping and increasing the catalytic sites through designing the morphology of nanostructures are the most popular approaches to enhance electrocatalytic performance. In recent years, with the development of nanotechnology and interface engineering, significant progress has been made in this field, but it is still challenging. Here three-dimensional porous NiCoCu–P cage were synthesized using a quick and easy method with the help of 26-face Cu2O as a sacrificial template, then it was phosphidated by a facile phosphidation heat treatment in N2 atmosphere and then for the electrochemical evaluations, the glassy carbon electrode surface (GCE) surface was modified with it. Taking advantage of these strategies, NiCoCu–P cage offer large surface area, fast electron/mass transfer and open channels for efficient gas release, which show improved electrochemical performance in alkaline environment and achieved an overpotential of −210 mV at 10 mA cm−2 for HER and 240 mV at 50 mA cm−2 for OER. Also, an overall water splitting device is assembled by two symmetric NiCoCu–P cage/carbon cloth as cathode and anode, that can provide a current density of 100 mA cm−2 at a cell voltage of less than 1.6 V.