Atmospheric Chemistry and Physics最新文献

{"title":"Impact of high-resolution soil erodibility datasets on dust simulations in WRF-Chem with the GOCART scheme","authors":"Leandro Cristian Segado-Moreno,Juan Pedro Montávez,Ginés Garnés-Morales,Eloisa Raluy-López,Pedro Jiménez-Guerrero,Rajesh Kumar","doi":"10.5194/acp-26-12641-2026","DOIUrl":"https://doi.org/10.5194/acp-26-12641-2026","url":null,"abstract":"Abstract. Mineral dust is a major atmospheric aerosol influencing climate, air quality, and human health through radiative and microphysical processes. The Iberian Peninsula is frequently affected by North African dust intrusions, leading to episodic PM10 exceedances that challenge air quality forecasting. However, accurate representation of dust emissions remains limited by uncertainties in soil erodibility, land surface properties, and meteorological forcing. This study evaluates the impact of two high-resolution soil erodibility datasets on dust simulations using WRF-Chem with the GOCART scheme. The first dataset, EROD-HR, integrates fine-resolution topography to improve dust source representation at 0.0625° (about 5 km) globally and 1 km over the Iberian Peninsula. The second dataset, SOILHD, further refines dust source characterization by incorporating high-resolution soil texture (sand, silt, and clay fractions) and removing misclassified bare-soil areas, resulting in a 1 km global resolution. Both datasets aim to better capture the spatial heterogeneity of dust sources. Simulations are conducted for five dust episodes between 2022 and 2025, covering local and long-range transport conditions. Model performance is evaluated against PM10 observations from the SINQLAIR network in the Region of Murcia. Results show improved representation of dust emissions, with better agreement in magnitude and timing of PM10 peaks at inland stations. Improvements are more limited at coastal and anthropogenically influenced sites, although statistical metrics (correlation, bias, RMSE) indicate consistent gains. Overall, high-resolution erodibility datasets enhance dust simulations by reducing biases and improving variability representation, highlighting the importance of detailed land-surface information for regional dust forecasting systems.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"8 1","pages":"12641-12669"},"PeriodicalIF":6.3,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148933398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement report: Impacts of thermodynamic and dynamic processes on the vertical distribution of carbonaceous aerosols: lessons from in-situ observations at the eastern foothills of Liupan Mountains, Loess Plateau","authors":"Shaofeng Qi,Suping Zhao,Ye Yu,Longxiang Dong,Tong Zhang,Guo Zhao,Jianglin Li,Xiang Zhang,Yiting Lv","doi":"10.5194/acp-26-12671-2026","DOIUrl":"https://doi.org/10.5194/acp-26-12671-2026","url":null,"abstract":"The vertical distribution of carbonaceous aerosols critically influences planetary boundary layer structure and regional climate. However, high-resolution vertical data remain scarce over the Chinese Loess Plateau. To address this gap, coordinated observations of carbonaceous aerosols and meteorological variables were conducted in the Loess Plateau using tethered balloon-borne instruments during two field campaigns in July 2023 and 2024. The average near-surface concentrations of equivalent black carbon (eBC) and ultraviolet-absorbing particulate matter (UVPM) in Pingliang were 0.84 and 1.24 µg m −3 , respectively. Vertically, carbonaceous aerosol concentrations generally decreased with height. A comparison of the vertical profiles of eBC, UVPM, V TKE (mechanical turbulence), and potential temperature showed that during the early morning and nighttime, when convective activity was weak, UVPM concentrations in the upper atmosphere were higher than those of eBC. This pattern is primarily attributed to nucleation processes involving gaseous precursors during nighttime. Analysis of the roles of dynamic and thermodynamic processes indicated that thermodynamic processes dominated aerosol vertical transport in the near-surface layer, while enhanced dynamic processes at higher altitudes facilitated horizontal dispersion of pollutants. Air masses from the south of the observation site contributed significantly to UVPM levels. As air mass altitude decreased, the influence of local sources became more pronounced. Overall, this study demonstrated the regulatory mechanism of daytime and nighttime thermodynamic and dynamic impacts on the vertical distribution of air pollutants.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"59 1","pages":"12671-12687"},"PeriodicalIF":6.3,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148933399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling mineral dust emissions from proglacial valleys of the St. Elias Mountains, Canada","authors":"Daniel Bellamy,Martina Klose,Daniel F. Nadeau,Sebastian Engelstaedter,Richard Washington,James King","doi":"10.5194/acp-26-12613-2026","DOIUrl":"https://doi.org/10.5194/acp-26-12613-2026","url":null,"abstract":"Abstract. Proglacial valleys of western Canada and Alaska demonstrate extensive historical and contemporary records of mineral dust emissions. These contributions remain unresolved by current dust emission modelling and unaccounted for in global emission estimates. We developed and evaluated a sub-km implementation of the Weather Research and Forecasting model with Chemistry (WRF-Chem) capable of simulating dust emissions from proglacial valleys of the St. Elias Mountains, Canada. Modelling these dust sources required precise treatment of surface characteristics and wind dynamics to accurately resolve surface erodibility, emission rates and aerosol dispersion within this mountainous terrain. Land-surface inputs were overhauled, with explicit treatment of glaciofluvial deposit heterogeneity and inundation conditions. Simulations covering 5–19 d periods across 2019–2022 were evaluated against in situ meteorological and dust emission measurements, camera stations and surface-based Doppler LiDAR data. A total emission rate of 1.0×104 kg km−2 d−1 was estimated from erodible deposits across 47 d of simulation, providing a first-order estimate of emissions from these valleys during dusty periods. Seasonal-dependent skill in reproducing surface meteorology and in-valley vertical dispersion is demonstrated, modifying dust dispersion. Emission dynamics from a variety of glaciofluvial deposits were successfully reproduced, however the sensitivity of the emission scheme to soil texture is discussed in light of glaciofluvial deposit heterogeneity and dataset scarcity. The successful model implementation under extreme topographic conditions and arguably the most severely constrained deposits (channel width: 0.1–3 km; sidewalls up to +1.7 km) supports the potential of this approach to simulate dust emissions from currently unaccounted for proglacial valleys across northwest North America and other regions.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"11 1","pages":"12613-12639"},"PeriodicalIF":6.3,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148933429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tower- and drone-based BVOC observations in a suburban Tokyo forest: methodological insights and MEGAN comparison","authors":"Yujiro Ichikawa,Katsuhito Yoshida,Shinichi Yonemochi,Kentaro Takagi,Atsuyuki Sorimachi,Kazuhide Matsuda,Toshimasa Ohara","doi":"10.5194/acp-26-12521-2026","DOIUrl":"https://doi.org/10.5194/acp-26-12521-2026","url":null,"abstract":"Abstract. Biogenic volatile organic compounds (BVOCs) substantially influence regional photochemical air pollution, climate, and the carbon cycle. However, observational constraints on BVOC emissions from urban or suburban forests in Asian megacity regions under humid subtropical climates remain limited. In this study, we conducted multi-year intermittent, multi-height BVOC observations at a 30 m flux tower in a suburban Tokyo forest dominated by Quercus serrata. Spatial variability was examined by combining tower measurements with supplemental drone-based sampling. The measurements were compared with estimates from the Model of Emissions of Gases and Aerosols from Nature (MEGAN). Isoprene volume mixing ratios increased during the warm-season observations from May to October, accounting for over 90 % of the measured BVOC composition during peak summer, while monoterpenes remained low with weak vertical gradients. Isoprene exhibited distinct vertical volume mixing ratio gradients peaking within the canopy, with the daily average emission fluxes ranging from −0.05 to 15.30 mgm-2h-1. Drone-based measurements indicated horizontal variability in isoprene volume mixing ratios of approximately 10 %–30 % within 30 m of the tower. Flux estimates derived from tower and drone measurements differed by approximately 30 %, suggesting that small-scale spatial heterogeneity and height differences can affect gradient-based flux estimates. MEGAN generally overestimated the observed fluxes, particularly during the warm-season observations. These results demonstrate the potential of combining tower-based vertical profiling with supplemental drone-based horizontal sampling to evaluate BVOC fluxes and their spatial representativeness. Although the intermittent sampling design limits comprehensive seasonal and interannual interpretations, this study provides methodological insights for future tower- and drone-based BVOC observations and emission model evaluation based on canopy-scale measurements.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"53 1","pages":"12521-12541"},"PeriodicalIF":6.3,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coastal upwelling and tropical warm water intrusions are key drivers of interannual fog variability along the southwestern African coast","authors":"Alexandre Mass,Jan Cermak,Hendrik Andersen","doi":"10.5194/acp-26-12565-2026","DOIUrl":"https://doi.org/10.5194/acp-26-12565-2026","url":null,"abstract":"Abstract. Fog and low clouds (FLCs) are a key source of moisture for ecosystems in the Namib Desert, yet their variability and underlying mechanisms remain poorly quantified. We investigate monthly FLC cover in two fog hotspots: the Angolan Namib (15–17° S) and the Central Namib (22–24° S), using satellite-based observations from 2004 to 2019. Assuming that most fog originates from advected marine low clouds, we apply a cloud-controlling factor framework in which FLC anomalies are modeled as a linear function of spatial anomaly fields in estimated inversion strength (EIS), relative humidity at 700 hPa (R700), sea surface temperature (SST), and the eastward and northward components of the 10 m wind (U10 and V10). Sensitivities of FLCs to these drivers are quantified using a statistical model. Results indicate positive sensitivities to coastal EIS, negative sensitivities to R700, localized negative sensitivities to SST, and a strong influence of onshore circulation, consistent with an advective origin of fog in the Namib region. The statistical models are then used to reconstruct historical FLC anomalies for 1982–2019 using reanalysis data. The reconstructions reveal near-zero trends resulting from opposing influences: increased atmospheric stability enhances FLCs, while SST warming counteracts this. Finally, the reconstructions are used to assess interannual variability and its links to climate modes. Benguela Niño events, associated with tropical water intrusion and SST warming, explain up to half of the interannual FLC variability in the Angolan Namib, with warmer SSTs reducing FLC cover. El Niño conditions also enhance FLC occurrence, but their influence is much weaker.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"9 1","pages":"12565-12589"},"PeriodicalIF":6.3,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A cellular automaton model of tropical oceanic rain clusters with criticality","authors":"Kevin K. W. Cheung,Chee-Kiat Teo,Tieh-Yong Koh","doi":"10.5194/acp-26-12543-2026","DOIUrl":"https://doi.org/10.5194/acp-26-12543-2026","url":null,"abstract":"Abstract. The distributions of the cluster area, A, and total rain rate, R, for tropical oceanic rain clusters from a cellular automaton (CA) are analysed for their scaling exponent ζA, ζR, and β where f(s) ∼ s-ζS; S∈{A,R}; f(s) the probability distribution of S; β is that for rain rate conditioned by rain area. The CA only includes a few simple rules representing a small set of dynamics thought to be important for convective organization. These rules represent large-scale destabilization of the atmosphere under the moisture static energy framework with a slow driving timescale, as well as convective cells interaction through propagating gravity waves with a fast relaxation timescale. The CA exhibits percolation-like criticality, and the ζA is estimated to be near the theoretical 2-dimensional percolation value of 187/91. This agrees well with the ζA estimates over the Indian Ocean warm pool and the tropical Atlantic reported in previous modelling study, implying numerical models behave like percolation. Although other critical exponents of the rain cluster distributions from the CA, namely the ηS (scaling exponent of the characteristic scale) and DS (cluster fractal dimension), S∈A,R, depend on the adjustable parameter of the CA, the ζA is robust to the adjustable parameter. Although the CA cannot account for the observation-based ζA ∼ 5/3 reported elsewhere that is quite universal over all oceans, further tuning of it such as through the convective cells interaction strength or how they interact may allow the CA to produce the observed exponent. Whether such behaviour can arise from a genuinely self-organized mechanism, rather than through parameter tuning, remains a question for future investigation.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"9 1","pages":"12543-12564"},"PeriodicalIF":6.3,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Planetary albedo change exacerbates surface warming: a perspective from cloud-type changes","authors":"Ruixue Li,Jiming Li,Bida Jian,Lijie Zhang,Jiayi Li","doi":"10.5194/acp-26-12591-2026","DOIUrl":"https://doi.org/10.5194/acp-26-12591-2026","url":null,"abstract":"Abstract. Persistent global warming is modulated by cloud changes, yet the specific contributions and associated controlling factors remain inadequately quantified. Using CERES radiation data with a surface energy-balance framework, we quantify the contribution of cloud radiative changes to decadal surface temperature trends over 2002–2023. Cloud changes exert a weak net effect on global mean warming due to near-cancellation between shortwave warming and longwave cooling, but strongly modulate the meridional pattern of zonal-mean warming. Specifically, clouds enhance warming in low- and mid-latitudes while mitigating warming at high latitudes. This pattern is associated with a systematic redistribution of cloud occurrence from low-/mid-level cloud types to high-level optically thin clouds, which reduce planetary albedo and weaken cloud longwave emission. These changes exhibit hemispheric difference. In 30–60° N, the region contributing most to global warming, the decline in the cloud-reflected solar radiation is mainly driven by decreased cloud fraction, linked to elevated sea surface temperatures, aerosol reductions, and mid-tropospheric drying. In 30–60° S, reduced cloud reflectivity resulting from decreased cloud optical thickness and increased liquid droplet radius dominates. However, at high latitudes in both hemispheres, increased mid-/high-clouds and enhanced cloud reflectivity, driven by enhanced moisture, upper-tropospheric static stability and increased cloud optical thickness, lead to greater reflected solar radiation and reduced downwelling longwave radiation, thereby attenuating local warming. Our results establish a direct observational link between cloud-type changes, planetary albedo decline, and contrasting warming across latitude zones, characterizing the cloud-radiative changes in recent climate change.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"47 1","pages":"12591-12612"},"PeriodicalIF":6.3,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upward transport and segregation of ice-nucleating particles in deep convective clouds","authors":"Jonas Schaefer,Sarah Grawe,Hans-Christian Clemen,Stephan Mertes,Johannes Schneider,Bruno Wetzel,Daniel Sauer,Jennifer Wolf,Laura Tomsche,Johanna Mayer,Roland Schrödner,Silvia Henning,Tina Jurkat-Witschas,Christiane Voigt,Helmut Ziereis,Theresa Harlaß,Mira Pöhlker,Frank Stratmann","doi":"10.5194/acp-26-12505-2026","DOIUrl":"https://doi.org/10.5194/acp-26-12505-2026","url":null,"abstract":"Abstract. Ice-nucleating particles (INPs) play a crucial role in Earth's weather and climate by influencing cloud properties and precipitation. However, their abundance in the free troposphere, vertical distribution, and transport mechanisms are not well-characterized. This study presents immersion INP measurements from filter samples collected aboard the High Altitude and LOng range research aircraft (HALO) in the troposphere and the lower stratosphere (up to 14.5 km) over Europe during the CIRRUS-HL (Cirrus in High Latitudes) campaign in summer 2021. By sampling cloud particle residuals and aerosol particles in the inflow and outflow of deep convective clouds (DCCs), and performing offline INP analysis, we shed light on the vertical transport and segregation of INPs in DCCs. INP-temperature spectra of convective inflow included both INPs active at high (T > −15 °C) and low temperatures (T < −20 °C). In contrast the outflow spectra only featured INPs active at low temperatures. We explain the observed INP segregation in the updraft with precipitation scavenging of INPs active at high temperatures. INPs active at lower temperatures (T < −20 °C), however, are efficiently transported upwards into the free troposphere. There, ambient temperatures are below −40 °C, i.e., temperatures far below the temperatures at which these INPs initiate immersion freezing. In the DCC outflow, INP concentrations exceed the upper tropospheric background concentration by at least two orders of magnitude. These INPs are then available for ice formation in mid and upper tropospheric clouds.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"30 1","pages":"12505-12520"},"PeriodicalIF":6.3,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revisiting the critical role of stabilized Criegee intermediates (sCIs) in sulfuric acid formation: coupling mechanistic updates with interpretable machine learning","authors":"Yuhuan Zhu,Qiang Chen,Luyan He,Chunlin Shang,Li Jiang,Donghong Guan,Guirong Yao,Wenkai Guo","doi":"10.5194/acp-26-12479-2026","DOIUrl":"https://doi.org/10.5194/acp-26-12479-2026","url":null,"abstract":"Abstract. Sulfuric acid, formed via gas-phase SO2 oxidation, drives new particle formation and secondary sulfate aerosol under low relative humidity (RH). Beyond the well-established OH-mediated pathway, stabilized Criegee intermediates (sCIs) from alkene ozonolysis provide an additional SO2 oxidation route whose rate (LSO2,sCIs) and fractional contribution (μsCIs) vary markedly across environments. Although prior studies have documented this spatiotemporal heterogeneity, quantifying the individual factor contributions governing these differences remains lacking. Furthermore, because sCI and OH formation share common precursors yet differ mechanistically, μsCIs can alter the sensitivity of total SO2 oxidation (LSO2) to precursor variations, but the magnitude of this influence remains unclear. Here, we updated Criegee-related reactions in MCM v3.3.1 following recent IUPAC recommendations, conducted extensive AtChem box-model simulations, and trained interpretable XGBoost surrogate models to attribute LSO2,sCIs and μsCIs to their controlling factors and examine how μsCIs regimes modulate LSO2 sensitivity. LSO2,sCIs was primarily controlled by RH and isoprene. The dominant drivers of μsCIs differed between day and night: daytime factors included alkene speciation, O3, and the alkene fraction in VOCs; nighttime factors included alkene speciation, RH, and NOx. Under high-μsCIs regimes, positive LSO2responses to O3, VOCs, and alkene fraction were consistently amplified relative to low-μsCIs regimes. Field observation-based modeling of a summer episode in Wuhai supported these regime-dependent patterns. These findings indicate that reducing VOC emissions provides a more effective mechanism for regulating sulfuric acid formation under conditions with active alkene ozonolysis.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"70 1","pages":"12479-12503"},"PeriodicalIF":6.3,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A cross-instrument closure and polarimetric study for improving sub-millimeter polarimeter-radiometer ice cloud microphysics retrievals","authors":"Jie Gong,Yuli Liu,Joseph A. Finlon,Ian S. Adams,Rachael A. Kroodsma,Dong L. Wu,Ralf Bennartz","doi":"10.5194/acp-26-12457-2026","DOIUrl":"https://doi.org/10.5194/acp-26-12457-2026","url":null,"abstract":"Abstract. Ice cloud microphysical properties, such as phase, shape, size and density, introduce significant uncertainties and biases that affect our understanding of how clouds influence weather and climate. The upcoming spaceborne sub-millimeter radiometers are expected to help in reducing the ice microphysics induced uncertainties in observations. Yet our knowledge about ice microphysics in this spectrum is still limited, and comparison/validation work is still sparse. This paper delivers a comprehensive cross-instrument closure study using active, passive remote sensing and in-situ cloud probe measurements collected during the NASA's IMPACTS field campaign. Through combined use of two radars, one lidar and in-situ cloud probe measurements, a comprehensive best reference “truth” is generated, which is then used to validate collocated sub-mm CoSSIR radiance measurements. We found out that only through a realistic vertical hydrometeor type classification that all types of measurements can reach a closure with minimal discrepancies between simulations and observations, which is critical for generating high-quality retrievals for frozen hydrometeors. We further present a comprehensive exploration of the scientific merit of polarimetric measurements in improving frozen hydrometeor microphysics retrievals. For the first time, we can validate previous theoretical predictions that sub-mm polarimetric signals can be used to retrieve ice particle habit and size. Moreover, we find it is possible to differentiate detailed vertical structure of hydrometeor types using both polarimetric and radiance measurements. This paper paves concrete steps in assuring timely delivery of high-quality science products for the sub-mm radiometer missions as well as possibilities of new science products beyond the mission requirements.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"1 1","pages":"12457-12477"},"PeriodicalIF":6.3,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}