Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Related Publications
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

This dataset contains trace element concentrations from 2014 and 2015 in aerosols. 

Aerosol samples, integrated over a 24-hour period, were collected using a high-volume aerosol sampler (model 5170-VBL, Tisch Environmental, 1.2 m3 min-1) which pulls air through 12 replicate acid-washed 47 mm nitrocellulose filter disks (Whatman 41).

Instantaneous aerosol leaches (UHP-soluble) were conducted by the method described in Buck et al. (2010). Total aerosol digestions were conducted using a microwave digestion scheme described in Morton et al. (2013). All samples were analyzed on the Thermo Scientific Element 2 HR-ICP-MS.

These data were published in:

Ebling, A. M., & Landing, W. M. (2017). Trace elements in the sea surface microlayer: rapid responses to changes in aerosol deposition. Elem Sci Anth, 5(0), 42. doi: 10.1525/elementa.237

Data went through internal lab QAQC process. The spreadsheet uses BDL for below detection limit.

BCO-DMO Processing Notes:
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions
- nd (no data) was entered into all blank cells and NA cells.
- re-formatted date from m/d/yyyy HH:MM to yyyy-mm-ddTHHMM
- replaced spaces with underscores

Description from NSF award abstract:
Dust and mineral aerosols are a significant source of micro and macronutrients to oligotrophic ocean surface waters. Evidence is growing that heterotrophic microbes may play key roles in processing deposited minerals and nutrients. Yet it is not known which components of dust stimulate the heterotrophic bacteria, which cellular mechanisms are responsible for the utilization of those components and how the activity of these bacteria affect the availability and utilization of dust-derived minerals and nutrients by marine autotrophs. Knowledge of these factors is key to understanding how dust deposition impacts carbon cycles and for predicting the response of tropical oceans to future changes in the frequency and intensity of dust deposition events. The objective of this project is to examine the specific effects of aeolian dust on heterotrophic microbes in a tropical marine system under controlled conditions. The central hypothesis is that in oligotrophic tropical systems numerically minor opportunistic bacteria are the first responders to influx of dust constituents and respond primarily by rapidly accessing soluble trace metals and limiting nutrients that are deposited with Saharan dust. The project will focus on two specific aims: 1) Quantify changes in community structure, composition and transcriptional activity among marine microbial populations upon exposure to dust, and 2) Identify key components in Saharan dust aerosols that stimulate or repress growth and/or activity in Vibrio, a model opportunistic marine heterotrophic group. The study will use a series of controlled experiments designed to identify and quantify heterotrophic microbial response to dust deposition events using both natural communities and model bacteria (Vibrio) through metagenomics, transcriptomics and atmospheric and marine biogeochemical techniques. This innovative approach will identify the most critical (reactive) components leached from dust aerosols on the microbial community as well as elucidate potential mechanisms of response.

There is great interest in the biological response to dust aerosols given its potentially large influence on biogeochemical cycling, but there has been relatively little work that has addressed the mechanisms of response (especially among the heterotrophic microbial fraction) or identified the relative importance of specific constituents of dust aerosols. A detailed framework for microbial response (focusing on opportunistic heterotrophs) will facilitate efforts to link autotrophic and heterotrophic processing. This contribution is significant because it will provide one of the first end-to-end (chemistry to physiology to ecology) mechanistic pathways for marine biological response to desert dust aerosols.