Tianle Yuan UMBC GESTAR II NASA Goddard Space Flight Center Tianle Yuan MODISVIIRS STM 2023 5123 Tianle Yuan MODISVIIRS STM 2023 2 Acknowledgement Coauthors Hua Song ID: 1042659
Download Presentation The PPT/PDF document "` 5/1/23 1 Strong Aerosol Indirect Forci..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
1. `5/1/231Strong Aerosol Indirect Forcing from Increasing Low-cloud Coverage Tianle Yuan UMBC - GESTAR IINASA Goddard Space Flight CenterTianle Yuan @ MODIS/VIIRS STM 2023
2. 5/1/23Tianle Yuan @ MODIS/VIIRS STM 20232Acknowledgement:Co-authors: Hua Song1, Chenxi Wang2,3 ,Robert Wood4, Lazaros Oreopoulos3, Steven Platnick3, Hongbin Yu3, Kerry Meyer3, Eric Wilcox5 1 SSAI, 2UMBC, 3GSFC, 4U. of Wash. ,5DRIFunding from the NASA TerraAquaNPP / MEaSUREs programs
3. 5/1/23Tianle Yuan @ MODIS/VIIRS STM 20233Introduction: Ship-tracksConover (1966)Anomalous cloud linesExcellent ‘opportunistic experiments’ for aerosol indirect effectsChristensen et al., 2022
4. 5/1/23Tianle Yuan @ MODIS/VIIRS STM 20234Detection : ML methodYuan et al (2019 & 2022)Automatic detection of ship-tracks at both day and night time
5. 5/1/23Tianle Yuan @ MODIS/VIIRS STM 20235Analysis method: Aerosol-cloud interactionsDetection and analysisStudy ACI
6. 5/2/23Tianle Yuan @ MODIS/VIIRS STM 20236Ship-track distributionYuan et al. (2022)First global climatology map of ship-tracks
7. 5/1/23Tianle Yuan @ MODIS/VIIRS STM 20237Results: PDFs of bulk changesYuan et al. (2022b)PDFs of changes in cloud properties; high variance
8. 5/1/23Tianle Yuan @ MODIS/VIIRS STM 20238Observation-based AIF estimation: methodMeasurement-basedCloud albedo susceptibility Scene albedo susceptibility
9. 5/1/23Tianle Yuan @ MODIS/VIIRS STM 20239dlnLWP/dlnNd systematically depends on background Reff, Nd, and above cloud top RH. Similar to Toll et al. (2019) and refs. in Bellouin et al. (2020). Drier air above clouds, more polluted and non-precipitating low clouds tend to reduce LWP in response to ship-emitted aerosols.Such behaviors are often explained by the competing effects of entrainment drying and aerosol-precipitation interactions.A Few Curious Connections: Aerosol- ML - clouds
10. 5/1/23Tianle Yuan @ MODIS/VIIRS STM 202310A Few Curious Connections: Aerosol- ML - cloudsCF strongly increases inside ship-tracks once clouds are clean and likely precipitating and the sensitivity is an exponential function of background Re. Minimum CF change under relatively polluted background clouds (e.g. Reff < 14 µm or Nd > 60 cm-3). The sensitivity is quantitatively similar to what is reported in Possner et al. (2018).Rosenfeld et al. (2006); Christensen and Stephens (2011); Goren and Rosenfeld (2012); Wang et al., (2011); Christensen et al. (2020); Possner et al. (2018); Gryspeerdt et al. (2016); Rosenfeld et al. (2019) etc.
11. 5/1/23Tianle Yuan C-C@Fort Collins 202211CF change is proportional to the background cloud droplet size and precipitation frequency.CF changes and precipitation
12. 5/1/23Tianle Yuan @ MODIS/VIIRS STM 202312Forcing from three effects: CF effect is strongCF adjustment amounts to at least 59% of the Twomey effect, could be larger.LWP adjustment is close to zero when averaged over global ocean.The CF-effect may be a key driver for the uncertainty in total indirect forcing in low clouds.
13. 5/1/23Tianle Yuan @ MODIS/VIIRS STM 202313Sensitivity: A large variation for CF effect Table: Forcing Using Different Explanatory Variables (W/m2)Explanatory variable(s)Cf Effect/TwomeyNd only59%Nd and Cf202%Nd and RH59%Nd and SST130%Nd and EIS68%Nd, CF, and RH193%Nd, EIS, and RH73%
14. 5/2/23Tianle Yuan @ MODIS/VIIRS STM 202314Changes: Impact from shipping fuel regulationEmission control areasGlobal regulationYuan et al. (2022)Forcing?
15. 5/1/23Tianle Yuan @ MODIS/VIIRS STM 202315ConclusionsCF effect is strong and LWP effect is overall weakForcing from CF adjustment could be as large as the Twomey effect 59% to 202% of the forcing from the Twomey effect is possiblePrecipitation-mediated processes are likely importantReducing the uncertainty of AIF due to CF effect is critical.