Analysis of Field of View for a Moon-Based Earth Observation Multispectral Camera.

A Moon-based Earth observation multispectral camera provides a unique perspective for observing large-scale Earth phenomena. This study focuses on the analysis of the field of view (FOV) for such a sensor. Unlike space-borne sensors, the analysis of the FOV for a Moon-based sensor takes into account not only Earth's maximum apparent diameter as seen from the lunar surface but also the Earth's and the solar trajectory in the lunar sky, as well as the pointing accuracy and pointing adjustment temporal intervals of the turntable.

Unveiling the Indian Ocean forcing on winter eastern warming - western cooling pattern over North America.

While the tropical Pacific teleconnection to North America has been studied extensively, the impact of the Indian Ocean on North American climate has received less attention. Here, through observational analysis and hierarchy atmospheric model simulations with different complexity, we find that the Indian Ocean plays a crucial role in North American winter climate through a teleconnection termed the Indian Ocean - North America pattern. We show that in the warm Indian Ocean phase, this teleconnection contributes to anomalously cold winters along the west coast of the United States through advection with increased mountain snowfall, while simultaneously leading to warmer conditions over the Great Lakes region.

Effects of relative humidity on atmospheric organosulfur species derived from photooxidation and nocturnal chemistry in a forest environment.

The molecular composition of organic aerosols in ambient PM was investigated at the northern foothills of Qinling Mountain region in central China during the summer of 2022. The molecular characteristics of organic matter were analyzed using ultrahigh performance liquid chromatography coupled with high-resolution Orbitrap mass spectrometry. The number of molecular formula assignments was dominated by organosulfur species (OrgS, on average 28-47% in total).

A novel reaction between ammonia and Criegee intermediates can form amines and suppress oligomers from isoprene.

Isoprene and ammonia (NH) are essential precursors for organic and inorganic aerosol in the atmosphere, but their molecular interactions are unclear. The fundamental role of NH in secondary organic aerosol (SOA) formation from ozonolysis of isoprene was investigated based on chamber experiments. The molecular information was determined based on high-resolution orbitrap mass spectrometry.

A long-term high-resolution dataset of grasslands grazing intensity in China.

Grazing is a significant anthropogenic disturbance to grasslands, impacting their function and composition, and affecting carbon budgets and greenhouse gas emissions. However, accurate evaluations of grazing impacts are limited by the absence of long-term high-resolution grazing intensity data (i.e.

High summer background O levels in the desert of northwest China.

Generally speaking, the precursors of ozone (O), nitrogen oxides and volatile organic compounds are very low in desert areas due to the lack of anthropogenic emissions and natural emissions, and thus O concentrations are relatively low. However, high summer background concentrations of about 100 µg/m or 60 ppb were found in the Alxa Desert in the highland of northwest China based on continuous summer observations from 2019 to 2021, which was higher than the most of natural background areas or clean areas in world for summer O background concentrations. The high O background concentrations were related to surface features and altitude.

Interpreting hourly mass concentrations of PM chemical components with an optimal deep-learning model.

PM constitutes a complex and diverse mixture that significantly impacts the environment, human health, and climate change. However, existing observation and numerical simulation techniques have limitations, such as a lack of data, high acquisition costs, and multiple uncertainties. These limitations hinder the acquisition of comprehensive information on PM chemical composition and effectively implement refined air pollution protection and control strategies.

A Satellite-Based Indicator for Diagnosing Particulate Nitrate Sensitivity to Precursor Emissions: Application to East Asia, Europe, and North America.

Particulate nitrate is a major component of fine particulate matter (PM) and a key target for improving air quality. Its formation is varyingly sensitive to emissions of nitrogen oxides (NO ≡ NO + NO), ammonia (NH), and volatile organic compounds (VOCs). Diagnosing the dominant sensitivity is critical for effective pollution control.

[Spatiotemporal Characterization and Driving Factors of Fine Particulate Matter and Its Chemical Components in the Huaihe River Basin].

According to the data sets of fine particulate matter （PM） and its components in 35 cities in the Huaihe River Basin from 2015 to 2021, the temporal and spatial distribution patterns of pollutants were analyzed. The influence of meteorological factors on PM concentrations was examined using a random forest model. The original series of PM, sulfate （SO）, nitrate （NO）, ammonium salt （NH）, organic matter （OM）, and black carbon （BC） were rebuilt using KZ （Kolmogorov-Zurbenko） filtering and multiple linear regression （MLR） to quantify the effects of meteorological conditions.

Early emergence and determinants of human-induced Walker circulation weakening.

The Walker circulation is projected to slow down in response to greenhouse gas warming. However, detecting the impact of human activities on changes in the Walker circulation is challenging due to the significant influence of internal variability. Here, based on ensembles of multiple climate models from the Coupled Model Intercomparison Project Phase 6 (CMIP6), we show evidence that the emergence of the human-induced weakening of Walker circulation tends to occur earlier in the middle-upper troposphere than at the surface.

Surface and canopy urban heat island disparities across 2064 urban clusters in China.

The vast majority of urban heat island (UHI) studies are now derived from surface temperatures, substituting for the original air temperature-based definition. The disparities in hourly surface-canopy UHI effects (SUHI, CUHI) and the contrasting mechanisms are currently poorly understood. Here, we use high-resolution hourly LST and air temperature data from 2064 urban clusters in China to estimate SUHI and CUHI intensities and their driving mechanisms during the summer and winter of 2022.

Characteristics of Nocturnal Boundary Layer over a Subtropical Forest: Implications for the Dispersion and Fate of Atmospheric Species.

The nocturnal boundary layer (NBL) significantly influences the dispersion and fate of atmospheric species at night. Subtropical forests are crucial in carbon and water exchange between the biosphere and the atmosphere. However, the NBL characteristics and their impact on atmospheric species over these forests remain unknown.

An updated modeling framework to simulate Los Angeles air quality - Part 1: Model development, evaluation, and source apportionment.

This study describes a modeling framework, model evaluation, and source apportionment to understand the causes of Los Angeles (LA) air pollution. A few major updates are applied to the Community Multiscale Air Quality (CMAQ) model with a high spatial resolution (1 km × 1 km). The updates include dynamic traffic emissions based on real-time, on-road information and recent emission factors and secondary organic aerosol (SOA) schemes to represent volatile chemical products (VCPs).

Improved Standard Addition Method for Measuring Stable Isotopic Compositions and Its Application to Sulfur Isotope Composition.

The standard addition method (SAM) is widely used to measure the isotopic compositions of natural samples, particularly those with a complex matrix. However, traditional SAM has limitations for isotope systems with significant variations in isotope composition due to its reliance on approximation in calculation and the requirement for estimates of analyte isotopic compositions and accurate concentrations. To overcome the issues, our work proposes an improved SAM that explicitly calculates isotope ratio (i.

Warm Arctic-Cold Eurasia pattern helps predict spring wildfire burned area in West Siberia.

Extreme wildfires have devastating impacts on multiple fronts, and associated carbon greatly heats the earth's climate. Whether and how to predict wildfires becomes a critical question. In this study, we find that the preceding-winter "warm Arctic-cold Eurasia" (WACE) pattern significantly enlarges the spring burned area in West Siberia.

Compound hot drought events in the Mei-yu region: Influences from polar and tropical regions.

In the Mei-yu region, there has been noticeable increase in the occurrence of compound hot drought (CHD) events in recent years. However, the underlying causes of these occurrences remain poorly understood. To address this knowledge gap, we conducted a comprehensive study utilizing observational datasets, reanalysis datasets, and four numerical experiments to investigate the associated physical mechanisms.

Carbon dioxide fertilization enhanced carbon sink offset by climate change and land use in Amazonia on a centennial scale.

The Amazon, the Earth's largest tropical forest, plays a critical role in the global carbon cycle, acting as a significant carbon sink. Recent studies, however, indicate a decline in its carbon sequestration capacity due to climate variability, intensive deforestation, and fires. This study aims to examine the impacts of these factors on the carbon dynamics of the Amazon over a centennial scale based on dynamic global vegetation models (DGVMs) of Trendy-v11.

Projecting future excess deaths associated with extreme precipitation events in China under changing climate: an integrated modelling study.

Background: Climate-change-induced extreme precipitation events have attracted global attention; however, the associated excess deaths burden has been insufficiently explored and remains unclear.

Methods: We first defined an extreme precipitation event for each county when the daily total precipitation exceeded the county-specific 99·5th percentile of the daily precipitation from 1986 to 2005; then we estimated the associations between extreme precipitation events and cause-specific deaths in 280 Chinese counties using a two-stage time-series model. Second, we projected the excess deaths related to extreme precipitation events by combining the bias-corrected multi-model precipitation predictions derived under different combined emission-population scenarios of three representative concentration pathways (RCPs; RCP2·6, RCP4·5, and RCP8·5) and three shared socioeconomic pathways (SSP2, a business-as-usual scenario) populations (S1, low fertility rate; S2, medium fertility rate; and S3, high fertility rate).