Challenging HYSPLIT trajectories in the equatorial Free Troposphere during PASE: Visualizing In-situ Tracers of Continental Sources and Convective Influence
Abstract
Variations in tropospheric gas and aerosol properties measured during the Pacific Atmospheric Sulfur Experiment (PASE) over the Central Equatorial Pacific are indicative of both their sources and their processing during transport. Evidence of pollution layers suggesting continental sources, and processes such as vertical mixing and cloud scavenging of aerosol denoting convective influence was found in the data. Because of the potential significance of such observations over the equatorial zone and potential links to marine boundary layer aerosol and cloud condensation nuclei (CCN), 3D - HYSPLIT back trajectories were computed starting along tropospheric flight tracks. Here we report a new approach that employs our in-situ physiochemical data to challenge HYSPLIT back trajectories with the goal of better understanding their performance and their value for assessing the sources and transport of aerosol in this equatorial region. Our improved visualization method provides additional constraints on trajectory reliability through testing their consistency with observed aerosol and gas features. Each trajectory was color-coded with corresponding in-situ tracer values (e.g. CO, O3, heated & volatile aerosol number concentrations, Water Vapor Mixing Ratio) measured at the back trajectory start points along the flight track. For example, well performing trajectories extending back to the continent should reveal highest CO and heated aerosol number concentrations. Our analysis demonstrates that HYSPLIT successfully captured numerous features during PASE associated to Amazon Biomass Burning (more then 10.000 km away) and deep equatorial convection (ITCZ, 4.000 km away). Some events were also supported by CALIPSO profiles and GOES imagery when available.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.A13B0231F
- Keywords:
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- 0305 ATMOSPHERIC COMPOSITION AND STRUCTURE / Aerosols and particles;
- 3364 ATMOSPHERIC PROCESSES / Synoptic-scale meteorology;
- 3374 ATMOSPHERIC PROCESSES / Tropical meteorology;
- 3399 ATMOSPHERIC PROCESSES / General or miscellaneous