2011 - Cooperative Institute for Research in Environmental Sciences ...

GEODYNAMICS
GEO-07 Geophysical Data Systems
n NGDC-05 Improved Integration and Modeling
of Geomagnetic Data
NGDC-05 Improved Integration and Modeling
of Geomagnetic Data
FEDERAL LEAD: SUSAN McLEAN
CIRES LEAD: HEINRICH MAUS
NOAA Goal 4: Transportation.
Project Goal: Produce reference
models of the geomagnetic field
for land, sea, air and spaceborne
magnetic navigation and attitude/
heading systems. Develop realtime
models of the magnetic field
for advanced magnetic accuracy
requirements and space weather
applications. Derive ionospheric
parameters from magnetic field observations
to monitor and predict
ionospheric disturbances affecting
global positioning systems and
radio communication.
Milestone 1: Satellite-derived
crustal magnetic field model:
Using the latest measurements
from the CHAMP satellite
(CHAllenging Minisatellite
Payload), develop a global
crustal magnetic field model to
spherical harmonic degree and
order 150 and integrate it into
NGDC/CIRES magnetic reference
products for navigation and
heading.
Satellites in low-Earth orbit
(LEO) provide an effective
means of mapping the long
wavelengths of the magnetic
field caused by the magnetization
of the Earth’s crust. The
MF7 model was produced using
CHAllenging Microsatellite Payload
(CHAMP) measurements
from May 2007 to April 2010.
It resolves the crustal magnetic
Figure 1
field to spherical harmonic degree 133, corresponding to a
half-wavelength resolution of 150 km.
Figure 1 shows the vertical component of the crustal
magnetic field at an altitude of 100 km above the Earth’s
surface. Magnetic anomalies are generally stronger over
continents than over the oceans. They also increase with
age and thickness of the crust. Linear features in the
oceans are due to sea floor spreading, while strong anomalies
over subduction zones are thought to be caused by
metamorphic processes in and above the down-going slab.
PLANETARYMETABOLISM
PM-02 Biosphere-Atmosphere
Interactions
n CSD-07 Biosphere-Atmosphere Exchange
n CSD-14 Tropical Ocean Productivity
n NGDC-07 Anthropogenic Remote Sensing
CSD-07Biosphere-AtmosphereExchange
FEDERAL LEADS: JIM BURKHOLDER AND JIM ROBERTS
CIRES LEAD: CHRISTINE ENNIS
NOAA Goal 3: Weather and Water
Project Goal: Improved understanding of how the exchange
of gases between the surface and the atmosphere shapes
regional climate and air quality.
Milestone 1: Continue studies to measure reaction rate
coefficients and evaluate the atmospheric degradation
mechanisms of key biogenic species. Impact: This research
will provide information needed to quantitatively evaluate
the role of biogenic compounds in regional ozone
production and secondary organic aerosol formation. This
research has implications for regional air quality.
Laboratory kinetic studies were performed to investigate the
gas-phase reactivity of two classes of biogenic species. Rate
coefficients, k, for the gas-phase reaction of the OH radical
with (Z) 3 hexen 1 ol (Z) CH3CH2CH=CHCH2CH2OH) (k1),
1 penten 3 ol (CH3CH2CH(OH)CH=CH2) (k2), (E) 2 penten 1
ol ((E) CH3CH2CH=CHCH2OH) (k3) and (E) 2 hexen 1 ol ((E)
CH3CH2CH2CH=CHCH2OH) (k4)—unsaturated alcohols
that are emitted into the atmosphere following vegetation
wounding and, thus, impact regional air quality—were
measured. Rate coefficients were measured using pulsed laser
photolysis (PLP) to produce OH radicals and laser induced
fluorescence (LIF) to monitor the OH temporal profile. The
obtained rate coefficients were
independent of pressure with
negative temperature dependences.
The results of this study
provide information that is
necessary to evaluate the impact
of these naturally emitted
compounds on the oxidation
capacity of the troposphere and
regional air quality.
In the second study, rate coefficients
for the gas-phase reaction
of CH3COCHO (methylglyoxal)
with the OH and NO3
radicals and (CHO)2 (glyoxal)
with the NO3 radical were
measured. Methylglyoxal and
glyoxal are abundant oxygen-
Figure1: Measured rate
coefficients for the OH
radical reaction with several
unsaturated “green
leaf” alcohols.
ated species that are primarily formed in the atmosphere
in the degradation of natural and manmade compounds
that are emitted into the atmosphere. The results from this
study reduce the uncertainty in the rate coefficient for the
OH + methylglyoxal reaction, which is a critical step in the
CIRES Annual Report 2011 123