The prediction of downhill thunderstorms (DSs) remains elusive. We propose an objective method to identify DSs, based on which enhanced and dissipated DSs are discriminated. A radar wind profiler (RWP) mesonet is used to derive divergence and vertical velocity. The mid-troposphere divergence and prevailing westerlies enhance the intensity of DSs, whereas low-level divergence is observed when the DS dissipates. The findings highlight the key role that an RWP mesonet plays in the evolution of DSs.

Weather prediction models simplify the physical processes related to light scattering by clouds consisting of complex ice crystals. Whether these simplifications are the cause for uncertainties in their prediction can be evaluated by comparing them with measurement data. Here we do this for Arctic ice clouds over sea ice using airborne measurements from two case studies. The model performs well for thick ice clouds but not so well for thin ones. This work can be used to improve the model.

I use errors in climate model simulations to derive correction factors for the impacts of greenhouse gases and particles that bring these simulated temperature fields into agreement with an observational reconstruction of the Earth's temperature. On average across eight models, a reduction by about one-half of the particle-induced cooling would be required, causing only 0.24 K of cooling since 1850–1899. The greenhouse gas warming simulated by several highly sensitive models would also reduce.

We present airborne infrared limb sounding GLORIA measurements of ammonia (NH₃) in the upper troposphere of air masses within the Asian monsoon and of those connected with biomass burning. Comparing CAMS (Copernicus Atmosphere Monitoring Service) model data, we find that the model reproduces the measured enhanced NH₃ within the Asian monsoon well but not that within biomass burning plumes, where no enhanced NH₃ is measured in the upper troposphere but considerable amounts are simulated by CAMS.

This study uses the Community Inversion Framework and CHIMERE model to assess the potential of TROPOMI-S5P PAL NO₂ tropospheric column data to estimate NO_x emissions in France (2019–2021). Results show a 3 % decrease in average emissions compared to the 2016 CAMS-REG/INS, lower than the 14 % decrease from CITEPA. The study highlights challenges in capturing emission anomalies due to limited data coverage and error levels but shows promise for local inventory improvements.

Deep convection under various large-scale meteorological patterns (LSMPs) shows distinct precipitation features. In southeastern Texas, mesoscale convective systems (MCSs) contribute significantly to precipitation year-round, while isolated deep convection (IDC) is prominent in summer and fall. Self-organizing maps (SOMs) reveal convection can occur without large-scale lifting or moisture convergence. MCSs and IDC events have distinct life cycles influenced by specific LSMPs.

We investigate the usage of discrete radiocarbon (¹⁴C)-based fossil fuel carbon dioxide (ffCO₂) concentration estimates vs. continuous carbon monoxide (CO)-based ffCO₂ estimates to evaluate the seasonal cycle of ffCO₂ emissions in an urban region with an inverse modeling framework. We find that the CO-based ffCO₂ estimates allow us to reconstruct robust seasonal cycles, which show the distinct COVID-19 drawdown in 2020 and can be used to validate emission inventories.

We assess the uncertainty in continuous fossil fuel carbon dioxide (ffCO₂) estimates derived from carbon monoxide (CO) observations and radiocarbon (¹⁴CO₂) flask measurements from an urban and a rural site. This study provides the basis for using continuous CO-based ffCO₂ observations in atmospheric transport inversion frameworks to derive ffCO₂ emission estimates. We also compare the flask-based CO / ffCO₂ ratios with modeled ratios to validate an emission inventory for central Europe.

Trends of surface ozone were examined across South America. Our findings indicate that ozone trends in major South American cities either increase or remain steady, with no signs of decline. The upward trends can be attributed to chemical regimes that efficiently convert nitric oxide into nitrogen dioxide. Additionally, our results suggest a climate penalty for ozone driven by meteorological conditions that favor wildfire propagation in Chile and extensive heat waves in southern Brazil.

This paper presents detailed plume simulations of nitrogen oxides and carbon dioxide that are emitted from four large industrial facilities world-wide. Results from the high-resolution simulations that include atmospheric chemistry are compared to nitrogen dioxide observations from satellites. We find good performance of the model and show that common assumptions that are used in simplified models need revision. This work is important for the monitoring of emissions using satellite data.

Using particle analysis by laser mass spectrometry, we examine vanadium-containing ship exhaust particles measured on NASA's DC-8 during the Atmospheric Tomography Mission (ATom). Our results reveal ship exhaust particles are sufficiently widespread in the marine atmosphere and experience atmospheric aging. Finally, we use laboratory calibrations to determine the vanadium, sulfate, and organic single-particle mass fractions of vanadium-containing ship exhaust particles.

The Tibetan Plateau (TP), the highest and largest plateau, experiences strong surface solar UV radiation, whose excess can cause harmful influences on local biota. Hence, it is critical to study TP ozone. We find ENSO, the strongest interannual phenomenon, tends to induce tropospheric temperature change and thus modulate tropopause variability, which in turn favours ozone change over the TP. Our results have implications for a better understanding of the interannual variability of TP ozone.

Aiming to inform parameter selection for future observational constraint analyses, we incorporate five candidate meteorological drivers specifically targeting high clouds into a cloud controlling factor framework within a range of spatial domain sizes. We find a discrepancy between optimal domain size for predicting locally and globally aggregated cloud radiative anomalies and identify upper-tropospheric static stability as an important high-cloud controlling factor.

Ethane and propane are volatile organic compounds emitted from human activities which help to form ozone, a pollutant and greenhouse gas, and also affect the chemistry of the lower atmosphere. Atmospheric models tend to do a poor job of reproducing the abundance of these compounds in the atmosphere. By using regional estimates of their emissions, rather than globally consistent estimates, we can significantly improve the simulation of ethane in the model and make some improvement for propane.

The 2022 Hunga Tonga–Hunga Ha’apai (HTHH) volcanic eruption not only triggered broad-spectrum atmospheric waves but also generated unusual tsunamis which can generate atmospheric gravity waves (AGWs). Multiple strong atmospheric waves were observed in the far-field area of the 2022 HTHH volcano eruption in the upper atmosphere by a ground-based airglow imager network. AGWs caused by tsunamis can propagate to the mesopause region; there is a good match between atmospheric waves and tsunamis.

This study aims to provide gridded data on sea-wide concentrations, deposition fluxes, and soluble deposition fluxes with detailed source categories of metals using the modified CMAQ model. We developed a monthly emission inventory of six metals – Fe, Al, V, Ni, Zn, and Cu – from terrestrial anthropogenic, ship, and dust sources in East Asia in 2017. Our results reveal the contribution of each source to the emissions, concentrations, and deposition fluxes of metals in the East Asian seas.

In 2022, Shanghai implemented city-wide static management measures during the high-ozone season in April and May, providing a chance to study ozone pollution control. Despite significant emissions reductions, ozone levels increased by 23 %. Statistically, the number of days with higher ozone diurnal variation types increased during the lockdown period. The uneven decline in VOC and NO₂ emissions led to heightened photochemical processes, resulting in the observed ozone level rise.

Targeted derivatization and non-targeted analysis with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) were used to reveal the molecular composition of carbonyl molecules in PM_2.5, and the important role of carbonyls in increasing the oxidative potential of organic aerosol was found in real samples.

The analysis of the atmospheric CO₂ record from the Zotino Tall Tower Observatory (ZOTTO) in central Siberia shows significant increases in the length and amplitude of the CO₂ uptake and release in the 2010–2021 period. The trend shows a stronger increase in carbon release amplitude compared to the uptake, suggesting that, despite enhanced growing season uptake, during this period climate warming did not elevate the annual net CO₂ uptake as cold-season respirations also responded to the warming.

Using an updated soil reactive nitrogen emission scheme in the Unified Inputs for Weather Research and Forecasting coupled with Chemistry (UI-WRF-Chem) model, we investigate the role of soil NO and HONO (Nr) emissions in air quality and temperature in North China. Contributions of soil Nr emissions to O₃ and secondary pollutants are revealed, exceeding effects of soil NO_x or HONO emission. Soil Nr emissions play an important role in mitigating O₃ pollution and addressing climate change.

We investigated aerosol composition and sources and the interaction between secondary organic aerosol (SOA) and clouds at a regional mountain site in southeastern China. Clouds efficiently scavenge more oxidized SOA; however, cloud evaporation leads to the production of less oxidized SOA. The unexpectedly high presence of nitrate in aerosol particles indicates that nitrate formed in polluted areas has undergone interactions with clouds, significantly influencing the regional background site.

The study examines how the volatility of semi-volatile organic compounds affects secondary organic aerosol (SOA) formation and climate. Our simulations show that uncertainties in these volatilities influence aerosol mass and climate impacts. Accurate representation of these compounds in climate models is crucial for predicting global climate patterns.

The water solubility of secondary organic aerosols (SOAs) is a crucial factor in determining their hygroscopicity and climatic impact. Stable carbon isotope and mass spectrometry techniques were combined to assess the water solubility of SOAs with different aging degrees in a coastal megacity in China. This work revealed a much higher water-soluble fraction of aged SOA compared to fresh SOA, indicating that the aging degree of SOA has considerable impacts on its water solubility.

We focus on the interactions among TLEs, lightning, and the ionospheric electric field. The SNR of the Schumann resonance at the first and second modes dropped during the TLEs. A significant enhancement of the energy in ULF occurred. Distinct lightning whistler waves were found in the VLF band. Our results indicate that the observations of electric fields from the satellite could possibly be utilized to monitor lower-atmospheric lightning and its impact on the space environment.