Refractory black carbon (rBC) is a primary aerosol species, produced through incomplete combustion, that absorbs sunlight and contributes to positive radiative forcing. The overall climate effect of rBC depends on its spatial distribution and atmospheric lifetime, both of which are impacted by the efficiency with which rBC is transported or removed by convective systems. These processes are poorly constrained by observations. It is especially interesting to investigate rBC transport efficiency through the Asian Summer Monsoon (ASM) since this meteorological pattern delivers vast quantities of boundary layer air from Asia, where rBC emissions are high to the upper troposphere/lower stratosphere (UT/LS) where the lifetime of rBC is expected to be long. Here, we present in situ observations of rBC made during the Asian Summer Monsoon Chemistry and Climate Impact Project of summer, 2022. We use observed relationships between rBC and CO in ASM outflow to show that rBC is removed nearly completely (>98%) from uplifted air and that rBC concentrations in ASM outflow are statistically indistinguishable from the UT/LS background. We compare observed rBC and CO concentrations to those expected based on two chemical transport models and find that the models reproduce CO to within a factor of 2 at all altitudes whereas rBC is overpredicted by a factor of 20-100 at altitudes associated with ASM outflow. We find that the rBC particles in recently convected air have thinner coatings than those found in the UTLS background, suggesting transport of a small number of rBC particles that are negligible for concentration.

The eastern Tien Shan hosts substantial mid-latitude glaciers, but in situ glacier mass balance records are extremely sparse. Haxilegen Glacier No. 51 (eastern Tien Shan, China) is one of the very few well-measured glaciers, and comprehensive glaciological measurements were implemented from 1999 to 2011 and re-established in 2017. Mass balance of Haxilegen Glacier No. 51 (1999-2015) has recently been reported, but the mass balance record has not extended to the period before 1999. Here, we used a 1:50,000-scale topographic map and long-range terrestrial laser scanning (TLS) data to calculate the area, volume, and mass changes for Haxilegen Glacier No. 51 from 1964 to 2018. Haxilegen Glacier No. 51 lost 0.34 km(2) (at a rate of 0.006 km(2) a(-1) or 0.42% a(-1)) of its area during the period 1964-2018. The glacier experienced clearly negative surface elevation changes and geodetic mass balance. Thinning occurred almost across the entire glacier surface, with a mean value of -0.43 +/- 0.12 m a(-1). The calculated average geodetic mass balance was -0.36 +/- 0.12 m w.e. a(-1). Without considering the error bounds of mass balance estimates, glacier mass loss over the past 50 years was in line with the observed and modeled mass balance (-0.37 +/- 0.22 m w.e. a(-1)) that was published for short time intervals since 1999 but was slightly less negative than glacier mass loss in the entire eastern Tien Shan. Our results indicate that Riegl VZ (R)-6000 TLS can be widely used for mass balance measurements of unmonitored individual glaciers.

High-precision measuring of glacier evolution remains a challenge as the available global and regional remote sensing techniques cannot satisfactorily capture the local-scale processes of most small- and medium-sized mountain glaciers. In this study, we use a high-precision local remote sensing technique, long-range terrestrial laser scanning (TLS), to measure the evolution of Urumqi Glacier No. 1 at an annual scale. We found that the dense point clouds derived from the TLS survey can be used to reconstruct glacier surface terrain, with certain details, such as depressions, debris-covered areas, and supra-glacial drainages can be distinguished. The glacier experienced pronounced thickness thinning and continuous retreat over the last four mass-balance years (2015 - 2019). The mean surface slope of Urumqi Glacier No. 1 gradually steepened, which may increase the removal of glacier mass. The glacier was deeply incised by two very prominent primary supra-glacial rivers, and those rivers presented a widening trend. Extensive networks of supra-glacial channels had a significant impact on accelerated glacier mass loss. High-precision measuring is of vital importance to understanding the annual evolution of this type of glacier.

Fragmented surfaces and harsh environments have always been the main obstacles hindering observation works of glaciers in central Tibetan Plateau (TP). The advent of Terrestrial Laser Scanner (TLS) technology offers a potential revolution in this context. While TLS has been effectively applied to smaller glaciers in the Alps and Tianshan, this study extends its use to the large and topographically complex Ganglongjiama (GLJM) glacier in the Tanggula Mountains. Over a 5-year period, TLS, with a precision of up to 0.012 m, has documented an accelerated melting trend, with the terminus retreating by 13.305 m and a total mass loss of 2.580 m water equivalent. The research also underscores the role of supraglacial channels and lakes in intensifying surface melting and glacier front instability. Despite challenges in data acquisition due to occlusions and logistical constraints at high altitudes, this first TLS survey of a TP glacier provides invaluable insights into glacier dynamics. Future research could integrate TLS with Unmanned Aerial Vehicle-Structure-from-Motion (UAV-SfM) data fusion to achieve more comprehensive coverage and improve the temporal resolution of observations for a detailed analysis of glacier features.