The international journal of Aerosol and Air Quality Research (AAQR) covers all aspects of aerosol science and technology, atmospheric science and air quality related issues.

It has been confirmed that the karst rocky desertification (KRD) has severely changed the interactions between atmosphere and terrestrial ecosystem which would cause a significant effect on regional climate system. In this study, the Weather and Research Forecasting model was applied to investigate the biogeophysical impact on temperature and precipitation change by land use/land cover change data with different KRD conditions in 1993, 2003, and 2013 in Southwest China. The results showed that an improving trend of KRD has been found in Southwest China, especially in east Sichuan, Chungking, southwest Yunnan, and south Guangxi. The 2-m air temperature decreased by 0~− 1 °C in general with this improving trend. The possible reason was the decreasing KRD accompanied by the decreasing albedo, causing the increasing net shortwave radiation and the increasing net radiation. Meanwhile, the increasing evaporation strengthened the latent heat flux and weakened the sensible heat flux so that decreased temperature was addressed in forest areas. The effect of KRD change transferred to the upper troposphere through atmosphere vertical convection, which made the subtropical high to be strengthened and westerly extended. Therefore, the upward moisture flux at the surface (QFX) was weakened in the central part of Guangxi, southern Guizhou, which led to the decrease of the precipitation. Moreover, the southwest monsoon was strengthened, which caused the increasing water vapor flux and led to the heavy rainfall in the west of Yunnan.

Glacier inventories are critical for monitoring glacier response to climate change, providing constraints for glacier modeling studies and for assessing the impacts of glacier retreat on ecosystems and human societies. In the Bhutanese Himalaya, an up-to-date glacier inventory and a systematic analysis of decadal-scale glacier changes is lacking. Here, we present three glacier inventories (1976, 1998, and 2024) for this region. Manual mapping of glacier outlines from multi-source satellite imagery and the Copernicus digital elevation model (DEM) are used to derive a glacier inventory with associated topographic attributes. We found that 1871 glaciers existed in this region in 1976, covering an area of 2297.07 ± 117.15 km². By 1998 this number had reduced to 1803 glaciers, covering 2106.99 ± 90.60 km². In 2024, only 1697 glaciers remained, covering 1584.18 ± 36.37 km². A total of 89 (1976–1998) and 435 (1998–2024) glaciers became extinct in the Bhutanese Himalaya during these two time periods, and glacier area decrease accelerated from ~0.38% yr⁻¹ to ~0.95% yr⁻¹. Lake-terminating glaciers retreated almost three times faster (~32.2 m yr⁻¹) than land-terminating (~10.4 m yr⁻¹) glaciers during the observation period. Debris-covered glacier area increased from 112.79 ± 11.50 km² in 1976 to 128.89 ± 10.50 km² in 2024. Glaciers on the South Bhutanese Himalaya (draining into Bhutan) experienced faster glacier retreat than the glaciers of the North Bhutanese Himalaya (draining into the Tibetan Autonomous Region). ERA5-Land reanalysis data show that summer decadal average temperature in this region increased by 0.003 °C yr⁻¹ between 1976 and 1998 and 0.020 °C yr⁻¹ between 1998 and 2024, with the increase in warming rate coinciding with accelerated glacier retreat after 1998. Our updated glacier inventories will be useful for assessments of global sea level change, mountain hazards, and water resources.

Glacier inventories provide baseline data for understanding and evaluating past, current, and future changes in glacier extent in response to climate changes. We present a multi-year, manually mapped glacier inventory for sub-Antarctic Heard Island, a remote glacier-covered volcano in the southern Indian Ocean. Glacier outlines are presented for 1947, 1988, and 2019, derived from large-scale topographical maps (1:50 000), cloud-free medium-resolution SPOT, and high-resolution Pléiades satellite ortho-images. ASTER and Pléiades digital surface elevation models for 2000 and 2019 were also used to determine topographic parameters for individual glaciers. Heard Island glacier area reduced from 289.4 ± 6.1 km² in 1947 to 260.3 ± 6.3 km² in 1988, further decreasing to 225.7 ± 4.2 km² in 2019. The rate of annual glacier area loss between the two observation periods (1947–1988 and 1988–2019) almost doubled from −0.25 % to −0.43 % yr⁻¹. Glaciers on the eastern slopes of Heard Island experienced much higher retreat rates than glaciers elsewhere on the island. The maximum retreat observed between 1947 and 2019 was ∼5.8 km for the east-facing Stephenson Glacier, where collapse of the terminus led to the formation of a large lagoon during recent decades. Surface debris cover on Heard Island glaciers increased from 7.0 % ± 6 % (18.1 km²) in 1988 to 12.8 % ± 5.5 % (29.0 km²) in 2019. We also observed an upward shift (4.2 m yr⁻¹) in the maximum elevation of debris cover from 285 ± 20 m a.s.l. (above sea level) to 605 ± 20 m a.s.l. during this time. Direct climate observations from Heard Island are scarce, but climate reanalysis data show that the decline in glaciers is associated with a rising temperature of 0.7 °C over the last seven decades. Our inventory dataset will be freely available in the Global Land Ice Measurements from Space (GLIMS) glacier database to facilitate further analysis and modelling of Heard Island glaciers.

Glacial landforms record valuable information about past climates, but quantitative reconstructions depend on robust estimates of glacier characteristics, particularly the equilibrium-line altitude. Traditional approaches rely on global mean or median values of equilibrium-line altitude ratios (Accumulation Area Ratio, Toe-to-Headwall Altitude Ratio, and Area-Altitude Balance Ratio) to calculate equilibrium-line altitude. However, these ratios vary across glacier types and climatic regimes, meaning that use of a single value can introduce substantial errors. Here we present empirically-constrained global estimates of equilibrium-line altitude ratios for approximately 215,000 glaciers derived from numerical modeling. We find that the Accumulation Area Ratio provides the most reliable approximation of the equilibrium-line altitude, particularly when adjusted for glacier type. Explicitly accounting for climatic setting, glacier size, slope and aspect when selecting equilibrium-line altitude ratios further improves accuracy of past climate reconstructions. Our work provides insights into global glacier characteristics and establishes a stronger basis for reconstructing past climates.