Surface and free tropospheric sources of methanesulfonic acid over the tropical Pacific Ocean
The production of sulfate aerosols through marine sulfur chemistry is critical to the climate system. However, not all sulfur compounds have been studied in detail. One such compound is methanesulfonic acid (MSA). In this study, we use a one-dimensional chemical transport model to analyze observed vertical profiles of gas-phase MSA during the Pacific Atmospheric Sulfur Experiment (PASE). The observed sharp decrease in MSA from the surface to 600m implies a surface source of 4.0×107 molecules/cm2/s. Evidence suggests that this source is photolytically enhanced. We also find that the observed large increase of MSA from the boundary layer into the lower free troposphere (1000-2000m) results mainly from the degassing of MSA from dehydrated aerosols. We estimate a source of 1.2×107 molecules/cm2/s through this pathway. This source of soluble MSA potentially provides an important precursor for new particle formation in the free troposphere over tropics, affecting the climate system through aerosol-cloud interactions.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1172464
- Report Number(s):
- PNNL-SA-104715
- Journal Information:
- Geophysical Research Letters, 41(14):5239-5245, Journal Name: Geophysical Research Letters, 41(14):5239-5245
- Country of Publication:
- United States
- Language:
- English
Similar Records
Production and loss of methanesulfonate and non-sea salt sulfate in the equatorial Pacific marine boundary layer
Uptake of gas phase sulfur species methanesulfonic acid, dimethylsulfoxide, and dimethyl sulfone by aqueous surfaces