Rufus “Ty” White
PhD Candidate
Howard University
&
NOAA Student fellow
NOAA Center for Atmospheric
Science
Interest
1. Instrumentation, Measurements, and
Data Analysis
2. Investigations of the cycles of chemical
elements such as carbon, oxygen,
nitrogen, and sulfur,as well as their stable
ions and isotopes in the atmosphere.
Research Experience
– University of Guam, Marine Laboratory.
This research investigated environmental
pollutions, and flux of nutrients, energy,
and microorganisms among fresh, brackish
and marine waters.
We measured the pollution by recording
and observing phosphate, silicate, and
nitrate levels.
Also measured bacterial organism growth.
Research Experience
– EPA CASNET Site
Energy Research Center of the Netherlands (ECN)
developed the MARGA, instrument for Measuring
AeRosol and GAses, for the determination of the
following air-polluting species.
Ammonia, nitric acid nitrous acid, sulphur dioxide,
hydrochloric acid in the gas phase and ammonium,
nitrate, sulphate, chloride, sodium, potassium,
magnesium and calcium in aerosols.
– MARGA
– MARGA measures the hourly averaged
concentrations of these compounds. MARGA is
an extension of the SJAC (Steam Jet Aerosol
Collector) for on-line collection and analysis of
aerosol components with IC.
MARGA
The novelty of MARGA that it contains a wet-
denuder. Compared with the classical denuder
filter pack method, this instrument offers high
time resolution, no contamination by off-line
handling and no artifacts introduced by semi-
volatile ammonium salts. New is also the
capability of long-term stand-alone
measurements (over a week). Gas
denuder
Steam Jet Aerosol Collector
Current Research Topic
MARGA and the factors that limit the formation of Fine
Secondary Inorganic Aerosols at an agricultural site in
Beltsville, MD.
• (MARGA 1 &2 intra-comparison) Principle component
factor analysis (PCA), These factors are used to explain
the pattern of relationships among the data points. Close
factor variability percentage equated to a common source.
(refer to next slide)
• These factors also were used to illuminate major
processes that contribute to the production of particles in
this environment.
• NOAA’s Hysplit Back Trajectory. Back trajectories were
produced to determine the direction the polluted air mass
was traveling and the source region. (see poster)
Component
1 2 3 4 5 6 7
M2 SO4 0.519 0.674
M1 SO4 0.513 0.679
M2 NO3 0.508
M1 NO3 0.708
M2 HNO3 0.777
M1 HNO3 0.804
M2 NH3 0.799
M1 NH3 0.741
M2 NH4 0.732
M1 NH4 0.748
M1 HNO2 0.606
M2 HNO2 0.670
M2 SO2 0.824
M1 SO2 0.819
TE SO2 0.829
TE NO 0.890
TE NOY -0.574 0.600
TE CO 0.713
RH 0.581
TE ozone 0.875
WD
temp 0.830
radiation 0.505
MDE Nox -0.775
MDE NO -0.655
MDE NO2 -0.718
Extraction Method: Principal Component Analysis.
left to do:
Once the correlation between the ratios
and local versus long-range emissions is
determined the data will be summarized,
the temp/RH and diurnal variability
investigated
Pollution events, local versus long-range
pollution sources will be quantified, local
variability assessed and cause of local
particle formation will be determined.
Professional and Academic Goals
•Complete PhD program
•Work for an environmental think-tank
•Start a consultant firm
THANK YOU
ANY QUESTIONS