National Aeronautics and Space Administration

GACP Projects

Integration of Long-Term Oceanic Aerosol Records from Univ. of Miami Network Stations with NASA Satellite Products

J. M. Prospero , PI
D. L. Savoie, Co-PI
H. Maring, Co-PI

Background
The University of Miami Aerosol Group (UMAG) has a long history of operating oceanic aerosol sampling stations, beginning in 1965. In the early 1980's, UMAG began to install networks of stations in various ocean regions. For much of the period between the early 1980's until late 1996 we had about 30 stations in continuous operation. Aerosols are collected by high-volume filter samplers. All samples are analyzed for the major aerosol species: nss-SO₄=, NO₃-, NH₄+, sea-salt components. A large subset of the samples are also analyzed for methanesulfonate (MSA). Another large subset of samples is analyzed for mineral dust either through the analysis for Al (and/or other trace elements) or by ashing the filter at 500(C (after extracting water soluble species) and weighing the ash. Samples from many sites are analyzed for 7Be and 210Pb. Most station are located at coastal sites. At some sites, in order to minimize the impact from local aerosol sources, the samplers are controlled by a wind sensor system which activates the pumps only when the wind is blowing from the open-ocean sector and when the wind velocity is greater than 1 m/s. At some stations the filters are changed every day thereby allowing us to associated aerosol properties with specific synoptic situations. At some stations that normally operated on a weekly protocol, the protocol was occasionally changed to a daily schedule - for example, during the NASA PEM-West and GLOBE field programs. A large subset of sites collect unsectored (continuous) samples on a weekly cycle. Over the duration of the UMAG activities, we have carried out operations at 50 different sites and collected and analyzed over 30,000 individual filter samples. Some stations have continuous records that extend over more than 10 years.

Proposed Program
Objective: Provide long-term aerosol data records that can be used for the interpretation and validation of remotely-sensed data.

Activities:

1. Provide a detailed survey of the types of aerosol data in the UMAG archive for each of the 50 stations and the time periods for which data are available.
2. Provide a descriptive summary of the data from the UM sites, including graphs of the times series from each station.
   • In consultation with the NASA Aerosol Radiative Forcing Science Team, select a subset (about 25) of those sites to survey and summarize.
   • Give preference to sites were intensive field campaigns have taken place
   • Emphasize stations in the North Atlantic and North Pacific Oceans.
3. In response to specific queries from scientists involved in this NASA activity, to examine the aerosol data in detail to ascertain if they would be suitable for use in a satellite validation, algorithm development, and related activities.
   • Includes, but is not be limited to, comparison of coincident complimentary data (e.g., aerosol number size distributions)
4. If specific data sets are selected, to do a detailed check of data quality.
5. Provide aerosol data sets to Team users in a format that is mutually acceptable.
6. Provide aliquots of archived filter samples to persons interested in making additional measurements of aerosol properties.
7. Participate in the meetings and activities of the Aerosol Radiative Forcing Science Team.
8. Interact with the users of the data in the interpretation of the data in terms of our understanding of the temporal and spatial distribution of aerosols and the associated meteorological/climatological controlling situations.
9. Participate in writing summary reports or scientific papers that might derive from the above activities.
10. Participate in the planning of future aerosol/radiation/remote sensing activities.

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