Publications by authors named "Thomas C Hill"
Article Synopsis
- Sea spray aerosol (SSA) particles significantly affect climate by scattering solar radiation and aiding in cloud formation, with their composition influenced by oceanic biological processes, especially during phytoplankton blooms.
- A mesocosm study using natural seawater revealed that two distinct phytoplankton blooms led to different SSA chemical compositions; the first bloom produced organic-rich SSA, while the second did not.
- The research highlights the complexity of SSA composition influence, showing that it is governed not only by phytoplankton abundance (measured by chlorophyll-a) but also by microbial degradation processes affecting the organic material produced during these blooms.
Ice nucleating particles (INPs) are vital for ice initiation in, and precipitation from, mixed-phase clouds. A source of INPs from oceans within sea spray aerosol (SSA) emissions has been suggested in previous studies but remained unconfirmed. Here, we show that INPs are emitted using real wave breaking in a laboratory flume to produce SSA.
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- - The study investigates the role of ice nucleation-active (INA) bacteria in cloud processes and how they may influence glaciation and precipitation, highlighting uncertainty in their environmental impact.
- - Two quantitative PCR tests were developed to measure the abundance of INA bacteria in environmental samples, successfully identifying new bacterial clades related to well-known species like Pseudomonas and Pantoea.
- - Results showed high concentrations of ina genes in cultivated crops but lower amounts in natural vegetation; however, a biological source was found to be a major contributor to ice-nucleating particles in fresh snow, while a thunderstorm hail sample indicated a significant presence of INA bacteria.
Unlabelled: Apical perfusion artifacts seen on a high-sensitivity camera warranted a practice performance assessment to evaluate contributions from soft-tissue attenuation, patient positioning, and image processing techniques.
Methods: Cardiac perfusion studies (n = 534) spanning 5 mo were retrospectively reviewed. Images were acquired with the patient in the upright position, and attenuation correction was used.