Atmospheric Research最新文献

{"title":"Evaluating sources and oxidation pathways of nitrate aerosols across altitudes: A year-long study using oxygen isotope anomaly and stable nitrogen isotopic composition from Canton Tower in South China","authors":"Yujing Wang ,&nbsp;Chenglei Pei ,&nbsp;Fobang Liu ,&nbsp;Fan Jiang ,&nbsp;Junwen Liu ,&nbsp;Fang Cao ,&nbsp;Yanlin Zhang","doi":"10.1016/j.atmosres.2025.107930","DOIUrl":"10.1016/j.atmosres.2025.107930","url":null,"abstract":"<div><div>Nitrate aerosol (NO₃⁻) has increasingly contributed to particular matter pollution in many regions worldwide, yet the relative contributions of key sources and oxidation pathways to NO₃⁻ remain poorly understood in South China. In this study, we present a year-long observation of the signatures for oxygen isotope anomaly (Δ¹⁷O) and stable nitrogen isotopic composition (δ¹⁵N) in NO₃⁻ collected at different heights (ground, 118 m, 488 m) from Canton Tower in South China covering the period from October 18, 2018 to August 10, 2019. Δ¹⁷O-δ¹⁵N-derived measurements showed that the main contributors to the oxidation pathways and source of NO₃⁻ in Guangzhou during the sampling campaign were NO₂ + OH (58.1 %) and coal combustion (34.3 %), respectively. Interestingly, there was an obvious vertical change for both the source and oxidation pathways of NO₃⁻ under different NO₃⁻ pollution levels. During periods of slight pollution, there was no significant difference in the oxidation pathways among the three heights, despite the ground-level NO₃⁻ concentration being much higher than at the other two altitudes. In contrast, during severe NO₃⁻ pollution episodes, the contribution of nocturnal chemistry (NO₃ + HC/N₂O₅ + Cl⁻ and N₂O₅ + H₂O) to NO₃⁻ formation reached up to 60.4 % at 118 m and 57.1 % at 488 m, which is 1.4 to 1.5 times higher than the contribution observed at ground level. Taken together, our year-long measurements for the signatures of Δ¹⁷O and δ¹⁵N in NO₃⁻ highlight the important role of nocturnal chemistry and coal combustion in driving NO₃⁻ pollution in the largest city of South China.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"315 ","pages":"Article 107930"},"PeriodicalIF":4.5,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of the 2022 extreme drought over the Yangtze River basin using two satellite-gauge precipitation products","authors":"Linyong Wei ,&nbsp;Shanhu Jiang ,&nbsp;Liliang Ren ,&nbsp;Zulin Hua ,&nbsp;Linqi Zhang ,&nbsp;Zheng Duan","doi":"10.1016/j.atmosres.2025.107929","DOIUrl":"10.1016/j.atmosres.2025.107929","url":null,"abstract":"<div><div>In 2022, the Yangtze River Basin in China experienced an unprecedented extreme drought, induced by high temperatures and precipitation deficits. Accurate monitoring of such extreme drought events is vitally significant for disaster mitigation under global warming. This study evaluated the effectiveness of two satellite-based precipitation products: the latest Integrated Multi-satellitE Retrievals for Global Precipitation Measurement Final Run (IMERG-F) v07B and gauge-adjusted Global Satellite Mapping of Precipitation (GSMaP-G) v8, using the Standardized Precipitation Evapotranspiration Index (SPEI) to monitor the record-breaking drought. The evaluation was implemented based on the China Hydro-Meteorology precipitation (CHM_PRE) dataset with high-density stations. Results showed that the both satellite products presented satisfactory accuracy for the precipitation anomalies and monthly precipitation estimates. IMERG-F generally performed better than GSMaP-G, especially in the upstream region. Although the satellite-based SPEIs were constantly consistent with the CHM_PRE observations (correlation coefficient surpassing 0.9) in the midstream and downstream regions as the timescale increased, they exhibited greater spatial heterogeneity and temporal differentiation at longer timescales. IMERG-F demonstrated strong performance in detecting historical drought events, whereas it displayed worse reliability for the except 1-month drought estimates, as reflected by lower correlation and higher error metrics. During the 2022 extreme drought, IMERG-F-based SPEI had more reliable performance in identifying the stricken area and severity of meteorological drought. Conversely, GSMaP-G was more effective in characterizing the variability of summer agricultural drought and hydrological drought. These findings can provide valuable insights for the use of satellite remote sensing products in monitoring extreme drought events, offering potential to reduce drought risks and improve disaster management strategies.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"315 ","pages":"Article 107929"},"PeriodicalIF":4.5,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subseasonal prediction of weekly precipitation anomalies over Southern China during early summer based on predictability analysis and machine learning","authors":"Yang Lyu ,&nbsp;Xiefei Zhi ,&nbsp;Shoupeng Zhu ,&nbsp;Yi Fan ,&nbsp;Yan Ji","doi":"10.1016/j.atmosres.2025.107927","DOIUrl":"10.1016/j.atmosres.2025.107927","url":null,"abstract":"<div><div>Rainfall in southern China (SC) reaches its annual peak in early summer (May–June), which is often accompanied by the occurrence of rainstorm and flooding disasters. Reliable subseasonal precipitation forecasts play important roles in disaster prevention and mitigation. In this study, the four leading predictable patterns (accounts for 63.24 % of the total variance) of weekly precipitation anomalies (WPA) over Southern China (SC) during early summer and the corresponding signal sources in European Centre for Medium-Range Weather Forecasts (ECMWF) are analyzed. The first and second predictable patterns present uniform and meridional dipole pattern over SC, respectively, while the third and fourth predictable patterns feature with the tripole patterns. Further analysis indicates that the low-level anomalous anticyclone centered over the tropical western Pacific and the lower-level subtropical western North Pacific anomalous anticyclone are the key predictability sources for the first and second predictable patterns, respectively. Although ECMWF shows limited forecast skills in predicting the four leading predictable patterns after 2-week lead time, it can capture the associated large-scale circulation features to a large extent even up to 4-week lead time. Against this backdrop, we develop a dynamical-statistical model (DSM) using random forest to reconstruct these predictable patterns of WPA based on the associated large-scale features in ECMWF. The DSM can extend the forecast skills of WPA up to 4-week lead time over the majority area of SC and increase regional average TCC by ∼0.1 compared to the ensemble mean forecast from ECMWF for 3–4-week lead times. Further analysis indicates that the enhanced TCCs of DSM compared with ECMWF can be largely attributed to the enhancement in predicting the second predictable pattern. The proposed DSM is very promising in subseasonal precipitation forecasts and can also be applied to the routine forecast of other atmospheric and ocean phenomena in the future.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"315 ","pages":"Article 107927"},"PeriodicalIF":4.5,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Passive microwave-based diagnostics of medicanes over the period 2000–2021","authors":"Valentina Di Francesca ,&nbsp;Leo Pio D'Adderio ,&nbsp;Paolo Sanò ,&nbsp;Jean-François Rysman ,&nbsp;Daniele Casella ,&nbsp;Giulia Panegrossi","doi":"10.1016/j.atmosres.2025.107922","DOIUrl":"10.1016/j.atmosres.2025.107922","url":null,"abstract":"<div><div>The Mediterranean Sea is a well-documented region of cyclogenesis where hundreds of cyclones of variable lifetime, intensity and structure form every year. Although they are smaller, weaker and shorter in duration compared to tropical or most of the extratropical cyclones, they are often associated with high impact weather phenomena, due to significant amount of precipitation, strong winds and storm surges, thus affecting the coastal areas in the Mediterranean basin. Recently, there has been a growing interest in Mediterranean cyclones which closely resemble actual tropical cyclones with spiraling rainbands around a calm, a mostly cloud-free “eye”, strong rotation winds around the center, and a warm core (WC). These cyclones are generally referred to as Tropical-Like Cyclones (TLCs) or MEDIterranean hurriCANES (medicanes). This study aims to analyse, through an observational, satellite-based approach, 23 medicanes occurred from 2000 to 2021 in order to carry out a comprehensive passive microwave (PMW)-based characterization of these cyclones. A novel methodology for detecting the “closed eye” feature has been designed and implemented. Moreover, a well-established methodology based on the 54–55 GHz temperature sounding channels is applied to all 23 cyclones to detect the WC and characterize its depth, intensity and symmetry. Finally, the high frequency channels (&gt; 89 GHz) are exploited to retrieve cloud top height and ice water path, and to detect deep moist convection, offering insights on the role of diabatic heating in the WC development. This study applies, for the first time, both known and newly-developed PMW-based techniques and tools over an extensive medicanes' satellite-based data record in order to unveil the thermodynamic and microphysical processes which fuel the WC and to identify the cyclones which undergo a tropical-transition, (i.e., with a WC mainly driven by diabatic processes). In addition, this study evidences how PMW radiometry can contribute to address open questions on the processes that drive medicanes development and evolution, and offer useful insights into the potential classification of these complex systems.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"316 ","pages":"Article 107922"},"PeriodicalIF":4.5,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increasingly frequent and severe dry-to-wet abrupt alteration events are striking the Yangtze River Basin in China","authors":"Zhanrui Huang ,&nbsp;Xiao Chen ,&nbsp;Zhihua Pan ,&nbsp;Riping Gao ,&nbsp;Jingyu Men ,&nbsp;Pengshuai Bi ,&nbsp;Na Huang ,&nbsp;Fangxiao Zhang ,&nbsp;Rongdao Yang","doi":"10.1016/j.atmosres.2025.107926","DOIUrl":"10.1016/j.atmosres.2025.107926","url":null,"abstract":"<div><div>Dry-to-wet abrupt alteration events (DWAA) are characterized by the rapid transition from drought to heavy rainfall, with serious impacts on agricultural production and society in the Yangtze River Basin (YRB). However, a key research gap is the lack of comprehensive DWAA identification methods to accurately capture short-term DWAA features. Here, an improved pentad-scale DWAA index combining standardized soil moisture indexes and standardized precipitation indexes is proposed and the temporal and spatial characteristics of DWAA are identified using ERA5-Land reanalysis data. The results show that, from 1980 to 2022, the average of frequency, duration, strength, and rate of rapid alteration of DWAA in the YRB have significantly increased. Compared with the 1980s, the average duration of DWAA extended from 6.2 pentads to 6.3 pentads in the 2010s, and the average rapid alteration rate increased from 2.8 pentad⁻¹ to 2.9 pentad⁻¹. High occurrence areas of DWAA (20 times) were observed in east and south of the YRB and northwestern Sichuan. These regions also experienced prolonged duration of up to 13 pentads and great strength of 17. Based on the Cumulative Distribution Function and Copula function, the average state of DWAA (50th percentile, duration of 5 pentads, strength of 8.2) had a recurrence period of 1 year, while extreme state events (90th percentile, duration of 9 pentads, strength of 15.1) had a recurrence period of 90 years. These findings can provide an important scientific basis for local governments to improve the regional responding capacity and development of disaster prevention and mitigation policies.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"315 ","pages":"Article 107926"},"PeriodicalIF":4.5,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Liquid cloud drop effective radius over China: A 20-year MODIS-based assessment” [Atmospheric Research 312 (2024) 107750].","authors":"Xiaolin Zhang ,&nbsp;Yuanzhi Wang ,&nbsp;Yele Sun ,&nbsp;Xiaojing Shen ,&nbsp;Huizheng Che ,&nbsp;Thomas Choularton","doi":"10.1016/j.atmosres.2025.107925","DOIUrl":"10.1016/j.atmosres.2025.107925","url":null,"abstract":"","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"315 ","pages":"Article 107925"},"PeriodicalIF":4.5,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143099738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dubai's record precipitation event of 16 April 2024 – A diagnosis","authors":"Kenny Thiam Choy Lim Kam Sian ,&nbsp;Philip Sagero ,&nbsp;Laban Lameck Kebacho ,&nbsp;Victor Ongoma","doi":"10.1016/j.atmosres.2025.107924","DOIUrl":"10.1016/j.atmosres.2025.107924","url":null,"abstract":"<div><div>Understanding climate extremes is crucial for improving forecasting accuracy to minimise the associated loss of lives and property. On 16 April 2024, Dubai, an arid desert region in the United Arab Emirates, recorded unprecedented very heavy precipitation, causing widespread flooding and significant socio-economic impacts. This study investigates the atmospheric conditions that contributed to the event using hourly data from the European Centre for Medium-Range Weather Forecasts' fifth-generation reanalysis. A composite analysis of precipitation and atmospheric conditions during the event is conducted. Findings reveal enhanced convective activities, likely modulated by large-scale flow patterns and strong low-level convergence associated with moisture transport dynamics from the Red Sea, Arabian Sea, and Persian Gulf. Strong cyclonic circulation anomalies in the lower to mid-troposphere supported persistent upward vertical motion, promoting deep convective cloud formation. High convective available potential energy and a pronounced mid-level atmospheric trough were evident, indicators of an unstable atmosphere conducive to deep convection. Strong upper-level subtropical jets further facilitated and sustained the convective processes. The combined atmospheric conditions from the lower to upper troposphere provided conditions highly favourable for deep cloud formation, leading to the extreme precipitation event. This study highlights the importance of understanding factors, such as moisture transport dynamics, low-pressure systems, and upper-level jets, in forecasting extreme precipitation in the UAE region. Improving the knowledge of these circulations is essential for enhancing the accuracy of climate extremes forecasting and monitoring, enabling better preparedness and effective, practical anticipatory measures.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"315 ","pages":"Article 107924"},"PeriodicalIF":4.5,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatiotemporal evolution patterns of flood-causing rainstorm events in China from a 3D perspective","authors":"Jie Wang ,&nbsp;Xiaodan Guan ,&nbsp;Shiguang Miao","doi":"10.1016/j.atmosres.2025.107920","DOIUrl":"10.1016/j.atmosres.2025.107920","url":null,"abstract":"<div><div>Floods induced by rainstorm events (RSEs) are among the most frequent natural disasters and have a significant impact on ecosystems and human society. While most extensive researches have investigated the magnitude, frequency, and risk of floods, understanding the spatiotemporal evolution of contiguous flood-causing rainstorm events remains largely unexplored in China. Here, we collected historical flood disaster data from the Statistical Yearbook, news reports, and government sources and examined the evolution patterns of spatiotemporally contiguous flood-causing RSEs across China from 2000 to 2020, utilizing the connected component three-dimensional algorithm. Our results indicate that floods mostly occur in southern China (SC), followed by northern China (NC), with less frequency in northwestern China (NWC) and the Qinghai-Tibetan Plateau (TP). The flood-causing RSEs tend to occur with longer durations and higher magnitudes in SC and NC, while in NWC and TP, they are primarily characterized by short-term precipitation processes with lower magnitudes. Moreover, the flood-causing RSEs exhibit distinct evolutionary patterns in different subregions. In NWC and TP, RSEs generally move eastward and southeastward, with relatively longer lifespans, traveling longer distances at faster moving speeds, but covering smaller areal extent and lower accumulated rainfall amounts. In contrast, in both SC and NC, flood-causing rainstorm events are mainly moved in two directions, namely westwards and eastwards. These events have shorter average lifespans, and travel shorter moving distances at slower moving speeds, but have a larger areal extent and huge accumulated rainfall amounts. Our findings significantly enhance our understanding of flood-causing rainstorm characteristics in China.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"315 ","pages":"Article 107920"},"PeriodicalIF":4.5,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing Air Pollution Forecasts in Cities by Characterizing the Urban Heat Island Effects on Planetary Boundary Layers","authors":"Leo Matak,&nbsp;Mostafa Momen","doi":"10.1016/j.atmosres.2025.107923","DOIUrl":"10.1016/j.atmosres.2025.107923","url":null,"abstract":"<div><div>Rapid urbanization can cause serious air pollution and human health problems in densely populated cities. Urban areas have complex surface characteristics that can highly impact microclimate and air quality in these environments. Cities are typically warmer than their surroundings due to the Urban Heat Island (UHI) effect caused by anthropogenic activities and unique urban surface properties. However, the UHI impacts on air quality and aerosol forecasts in major cities have not been well understood yet. The objective of this paper is to address this knowledge gap by characterizing the impacts of the UHI on meteorological and aerosol forecasts in cities. To this end, more than 30 days of simulations over two major US cities (Houston and Dallas) are performed using the Weather Research and Forecasting (WRF) model coupled with Chemistry (WRF-Chem). In total, 78 simulations are conducted by varying the Planetary Boundary Layer (PBL) schemes, urban models, and various UHI magnitudes. Our results indicate that the current urban schemes in WRF do not accurately parameterize UHI effects which can highly influence their air pollution and meteorological forecasts. The lack of proper UHI representation causes a more stable atmosphere during nighttime as the model does not account for additional heating that occurs in major cities. This leads to the accumulation of aerosol forecasts on urban surfaces and overestimated particulate matter forecasts. By enhancing the UHI representation, we were able to remarkably improve the default WRF-Chem forecasts of particulate matter and ozone by an average of ∼50 % and ∼12 % in Houston, respectively. Similar improvements were obtained for Dallas, and different PBL and urban schemes. The study underscores the significance of urban-specific models such as the UHI effect for accurate meteorological and aerosol forecasts in cities.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"315 ","pages":"Article 107923"},"PeriodicalIF":4.5,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143099737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Operational satellite cloud products need local adjustment – The Galapagos case of ecoclimatic cloud zonation","authors":"Nazli Turini ,&nbsp;Byron Delgado Maldonado ,&nbsp;Samira Zander ,&nbsp;Steve Darwin Bayas López ,&nbsp;Daniela Ballari ,&nbsp;Rolando Célleri ,&nbsp;Johanna Orellana - Alvear ,&nbsp;Benjamin Schmidt ,&nbsp;Dieter Scherer ,&nbsp;Jörg Bendix","doi":"10.1016/j.atmosres.2025.107918","DOIUrl":"10.1016/j.atmosres.2025.107918","url":null,"abstract":"<div><div>Like many small oceanic islands, the Galapagos archipelago, renowned for its unique geographic location and exceptional endemic biodiversity, faces significant challenges under climate change. In particular, the atmospheric water supply for the ecosystem and the local population is under threat, with clouds and rain playing an important role in ensuring freshwater availability under climate change. Better planning of adaptation measures would require climate data on clouds as a prerequisite for precipitation and rainfall at high spatio-temporal resolution, which are not available in this area. Operational products such as satellite derived cloud and precipitation products or reanalysis data are widely used to compensate for the lack of local data availability but are often poorly suited for regional applications. In the current study, we aim to generate high quality area-wide cloud information to distinguish ecoclimatic cloud zones that may require different adaptation measures to climate change. To address this issue, we have developed a new physical rule-based cloud mask retrieval specifically tailored for the Galapagos Archipelago, based on data from the third generation GOES-16 Advanced Baseline Imager (ABI) geostationary satellite. The new Galapagos Rainfall Retrieval (GRR) cloudmask was tested against independent observational data and compared to both the operational GOES-16 ACM (ABI Clear sky Mask) and the MODIS cloudmask benchmark cloud mask. Our test results confirm that the GRR-cloudmask (Probability of Detection POD = 0.94, Critical Success Index CSI = 0.92–0.93) clearly outperforms the operational ACM-cloudmask (POD = 0.56–0.68, CSI = 0.55–0.67). Area-wide tests against the MODIS cloud mask showed a CSI of 0.72 and a POD of 0.74 for the ACM, which is superior to the GOES-16 ACM-cloudmask. We produced cloud frequency maps for all months and day slots and analysed cloud frequency using ancillary meteorological data. In general, the cool season (Jun-Dec) / night shows much higher cloud frequencies than the warm season (Jan-May) / daytime. However, regional cloud patterns differ along a west-to-east and south-to-north gradient, depending on complex interactions of forcing parameters such as exposure to the main circulation, sea surface temperature zones, altitude and land cover. A k-mean cluster analysis resulted in nine ecoclimatic cloud zones over land, which are much more differentiated than the widely used four-zone classification. The results will help to develop more site-specific climate change adaptation planning for the iconic Galapagos National Park.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"315 ","pages":"Article 107918"},"PeriodicalIF":4.5,"publicationDate":"2025-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143099725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}