4.0 MISSION DESIGN
The objectives of the TRACE-P study are discussed
in Section 2.0.
To accomplish these objectives, the mission design includes a pre-deployment
phase involving ozonesonde launches from six sites in Hong Kong,
Japan, and Taiwan, the field deployment phase utilizing the instrumented
NASA DC-8 and P-3B aircraft from two operational sites in the western
Pacific, and the post deployment analyses and reporting phase.
The pre-deployment phase was initiated in March 2000, and continues
through March 2002; the field deployment phase is scheduled for
early spring 2001; and the analyses and reporting phase is scheduled
for completion with submittal of manuscripts by the investigators
for publication TBD.
4.1 Measurement Requirements
The instrument detection limits and time resolutions
for species/parameter measurements are listed in Table
4.1-1. A description of the priority ratings and footnotes
for Table 4.1-1 are
listed in Table
4.1-2.
Table 4.1-1 Measurement
Requirements for the DC-8 and P-3B Instrumentation
Species/Parameter |
Detection Limit(a) |
Time Resolution |
DC-8
Priority |
P-3B
Priority |
O3 (in situ)
|
3 ppbv
1 ppbv(b) |
1 sec
|
1 |
1 |
NO |
3 pptv
1 pptv(b) |
1 min
10 sec(b) |
1 |
1 |
H2O(c) |
3 ppmv
|
1 min
10 hz(b) |
1 |
1 |
CO |
5 ppbv |
1 sec |
1 |
1 |
Atmospheric
State Parameters (d) |
Aircraft standard |
1 sec |
1 |
1 |
Vertical Winds(d) |
10 cm/sec |
10 hz |
NA |
2 |
Remote ozone
(nadir and zenith) |
5 ppbv |
Z<500 m
X<60 km |
1 |
NA |
Remote aerosol
(nadir and zenith) |
Scattering ratio .02
@ 600 nm |
Z<60 m
X<500 m |
2 |
3
(nadir) |
Range-resolved remote water vapor |
0.01g/kg |
Z< 500m
X<70km |
2 |
NA |
PAN |
5 pptv |
5 min |
2 |
2 |
HNO3 |
5 pptv |
5 min |
2 |
2 |
H2O2 |
10 pptv |
5 min
1 min(b) |
2 |
2 |
CH3OOH |
10 pptv |
5 min |
2 |
2 |
Speciated Hydrocarbons (C2-C8) |
20 pptv |
5 min |
2 |
2 |
Halocarbons |
2 pptv |
5 min |
2 |
2 |
OH |
1x 105 molec/cm3 |
5 min |
2 |
2 |
HO2 |
1x107 molec/cm3 |
5 min |
2 |
2 |
NO2 |
5 pptv |
1 min |
2 |
2 |
CO2 |
0.5 ppmv (e) |
1 min |
2 |
2 |
N2O |
0.5 ppbv (e) |
1 min |
2 |
2 |
CH4 |
20 ppbv (e) |
1 min |
2 |
2 |
Acetone |
50 pptv |
5 min |
2 |
3 |
Spectrally resolved nadir & zenith actinic flux for
J-value determination |
0.1 µw/nm/cm-2
280 nm - 420 nm
@ 1nm resolution |
30 sec |
2 |
2 |
J {O(1D)} |
2 X 10 -4 /s |
30 sec |
2 |
2 |
J {NO2} (d)
(nadir & zenith) |
1 X 10-4/s |
30 sec |
2 |
2 |
SO2 |
5 pptv |
5 min
1 min(b) |
2 |
2 |
Lightning events (d) |
Range 400 km |
<3 min hold time |
2 |
2 |
CH2O |
50 pptv |
5 min
1 min(b) |
2 |
2 |
Aerosols size/
number distribution |
10 nm - 20 µm |
5 min per scan |
2 |
2 |
Aerosol composition
(ionic analysis) |
5 pptv |
10 min<> 5 min(b) |
2 |
2 |
Range-resolved remote temperature sounding |
2 K |
1 km |
2 |
NA |
Black Carbon |
0.1 µg/m3 |
5 min |
3 |
2 |
In situ aerosol light
scattering coefficient |
10-7/m |
10 sec |
3 |
3 |
Organic nitrates
(Alkyl nitrates) |
6 pptv |
5 min |
3 |
3 |
Condensation Nuclei |
10/cm3 |
10 sec |
4 |
2 |
Ultra fine aerosols |
Size range 3-15 nm |
5 min |
3 |
2 |
DMS |
1 pptv |
5 min |
3 |
3 |
H2SO4 (g) |
2 x 105 molec/m3 |
5 min |
3 |
2 |
Alcohols |
20 pptv |
5 min |
3 |
3 |
Organic acids |
10 pptv |
5 min |
3 |
3 |
222Rn |
0.05 Bq/SCM |
5 min |
3 |
NA |
210Pb |
0.1 Bq/SCM |
10 min
5 min(b) |
3 |
NA |
7Be |
1.0 Bq/SCM |
10 min
5 min(b) |
3 |
NA |
NH3 |
10 pptv |
5 min |
3 |
3 |
Column content of trace gases (e.g., CO) |
Species –dependent
|
10 min
5 min(b) |
3 |
3 |
Isotopic content of water vapor |
Isotope-dependent
|
10 min
5 min(b) |
3 |
3 |
MSA(g) |
2 x 105 molec/cm-3 |
1 min |
4 |
4 |
DMSO(g) |
2 x 106 molec/cm-3 |
1 min |
4 |
4 |
HNO4 |
5 pptv |
5 min |
5 |
5 |
RO2 |
0.1 pptv |
5 min |
5 |
5 |
>C1 - Aldehydes |
20 pptv |
5 min |
5 |
5 |
C3 - ketones |
20 pptv |
5 min |
5 |
5 |
Ethene/Propene |
2 pptv |
1 min with real time output |
5 |
5 |
Size Resolved Single Particle Chemical Composition |
Species-dependent
|
<1 min |
5 |
5 |
Range-resolved measurement of other chemical species |
Species-dependent
|
5 min |
5 |
5 |
Table 4.1-2 Description
of Priority Ratings and Footnotes for Table 4.1-1
Rating |
Description |
Meaning |
1 |
Mission Critical |
The measurement is essential to the interpretation of data
related to the objectives of mission. |
2 |
Very Important |
The measurement is important to several scientific issues
being addressed by the mission. |
3 |
Important |
The measurement is important to some scientific aspects
of the mission. Space requirements of instrument will be
a prime consideration for inclusion in the payload. |
4 |
Less Important |
Measurements would be useful but information not considered
critical to interpretation of mission results. A measurement
at this level will be considered only if it utilizes an instrument
used also to make another measurement at the priority 1 or
2 level. |
5 |
New Technology/
Very Important Measurement |
Measurements involving instruments that represent the application
of new technologies/approaches to measuring species of very
high scientific interest. Measurement involves technical
risk, but consideration will be given to including at least
one such measurement in the payload. |
(a) Detection limit at S/N=2
(b) Preferred characteristics
(c) Water vapor at 1mm resolution will be provided by the GTE Project
Office
(d) Provided by GTE Project Office
(e) Precision of measurement
|
4.2 Aircraft Investigations
Tables 4.2-1 and 4.2-2 list
the Principal Investigators and measurements aboard the DC-8 and
P-3B aircraft respectively. A brief description of each investigation,
including measurement technique and characteristics of the parameters
measured may be found at the GTE homepage on the internet (http://www-gte.larc.nasa.gov/).
Layout of the instruments aboard each aircraft is shown at the
same internet site and in Figures 4.2-1 and 4.2-2,
which follow. Aircraft characteristics are listed in Appendix
C of this document.
Table 4.2-1 DC-8 Investigators/Parameters
PI |
Organization |
Parameter |
Bruce E. Anderson |
NASA Langley |
Ultra fine aerosols, aerosol size/number distribution, black
carbon, in-situ aerosol light scattering coefficient, condensation
nuclei |
Eric C. Apel and
Daniel D. Riemer |
NCAR
University of Miami |
Alcohols, > C1-aldehydes |
Elliot L. Atlas |
NCAR |
Organic nitrates, halocarbons |
Melody A. Avery and Stephanie Vay |
NASA Langley |
O3, CO2 |
Donald R. Blake |
University of California – Irvine |
CO, CH4, speciated HC (C2-C8),
DMS, halocarbons, organic nitrates |
Edward V. Browell |
NASA Langley |
Remote O3 (N & Z), remote aerosol profiles
(N & Z) |
William H. Brune |
Pennsylvania State University |
OH, HO2 |
Alan Fried |
NCAR |
CH2O |
Brian G. Heikes |
University of Rhode Island |
CH3OOH, H2O2, CH2O |
Project Office
(John Barrick) |
NASA Langley |
See
Table 4.3-1 |
Glen W. Sachse |
NASA Langley |
CO, CH4, N2O, H2O |
Scott T. Sandholm |
Georgia Institute of Technology |
NO, NO2 |
Richard E. Shetter |
NCAR |
Spectrally-resolved N & Z actinic flux for J-value determination,
J{O(1D)}, J{NO2} (N & Z) |
Hanwant B. Singh |
NASA Ames |
PAN, acetone, alcohols, organic nitrates |
Robert W. Talbot |
University of New Hampshire |
HNO3, SO2, aerosol composition, 210Pb, 7Be |
Table 4.2-2 P-3B Investigators/Parameters
PI |
Organization |
Parameter |
Elliot L. Atlas |
NCAR |
Organic nitrates, halocarbons |
Melody A. Avery and Stephanie A. Vay |
NASA Langley |
O3, CO2 |
Alan R. Bandy |
Drexel University |
SO2, DMS |
Donald R. Blake |
University of California – Irvine |
CO, CH4, speciated HC (C2-C8),
DMS, halocarbons, organic nitrates |
Christopher A. Cantrell |
NCAR |
HO2, RO2 |
Antony D. Clarke |
University of Hawaii |
Aerosol size/number distribution, black carbon, in-situ
aerosol light scattering coefficient, condensation nuclei |
Fred L. Eisele |
Georgia Institute of Technology |
OH, H2SO4, MSA, HNO3 |
Frank Flocke |
NCAR |
PAN, PPN, MPPN |
Yutaka Kondo |
Tokyo University |
NO, NO2 |
Project Office
(John Barrick) |
NASA Langley |
See
Table 4.3-1 |
Project Office
(John Barrick) |
NASA Langley |
TAMMS (Latitude,
Longitude, Pressure altitude, Static pressure, Impact pressure,
Static temperature, Pitch, Roll, True heading, U, V, W,
Specific humidity (q1011), Specific
Humidity (LymanAlpha), Virtual
potential temperature) |
Glen W. Sachse |
NASA Langley |
CO, CH4 |
Richard E. Shetter |
NCAR |
Spectrally-resolved N & Z actinic flux for J-value determination,
J{O(1D)}, J{NO2} (N & Z) |
Rodney J. Weber |
Georgia Institute of Technology |
Ultra fine aerosols, aerosol composition |
Figure
4.2-1 DC-8 Instrument Layout
Figure
4.2-2 P-3B Instrument Layout
4.3 Project Measurements
Table
4.3-1 presents the parameters describing meteorological,
navigational, and other aircraft parameters or "housekeeping
measurements" to be measured aboard the two aircraft. These
measurements will be obtained by the DC-8 Data Acquisition and
Distribution System (DADS) and the P-3B Project Data System (PDS)
and are to be provided to all investigators by the GTE Project
Office.
Table 4.3-1 TRACE-P Project
Measurements
Parameter
|
Aircraft
|
Origin
|
Day
|
Both
|
1
|
Time
|
Both
|
1
|
Latitude
|
Both
|
1
|
Longitude
|
Both
|
1
|
Pitch
|
Both
|
1
|
Roll
|
Both
|
1
|
Wind
speed
|
Both
|
1
|
Wind
direction
|
Both
|
1
|
True
air speed
|
Both
|
1,
3
|
Ground
speed
|
Both
|
1
|
True
heading
|
Both
|
1
|
Drift
angle
|
DC-8
|
1
|
Pressure
altitude
|
Both
|
1
|
Radar
altitude
|
Both
|
1
|
Indicated
air speed
|
DC-8
|
1
|
Vertical
speed
|
DC-8
|
1
|
Distance
to go
|
DC-8
|
1
|
Time
to go
|
DC-8
|
1
|
Alignment
status
|
DC-8
|
1
|
Align/from/to
|
DC-8
|
1
|
Mach
Number
|
Both
|
1,
3
|
Cross
track distance
|
DC-8
|
1
|
Desired
Track
|
DC-8
|
1
|
Track
angle error
|
DC-8
|
1
|
Track
angle
|
Both
|
1
|
D/F
point temp.
|
Both
|
2
|
D/F
point temp. (2 & 3-stage)
|
DC-8
|
1
|
Static
air temp.
|
Both
|
1,3
|
Total
air temp.
|
Both
|
1,2
|
Potential
temp.
|
Both
|
3
|
Cabin
altitude
|
Both
|
2
|
Static
Pressure
|
Both
|
1,
2
|
Differential
pressure
|
P-3B
|
2
|
Partial
pressure H2O wrt ice
|
Both
|
3
|
Partial
pressure H2O wrt water
|
Both
|
3
|
Rel.
humid. wrt ice
|
Both
|
3
|
Rel.
humid. wrt water
|
Both
|
3
|
Sat.
vapor press. of H2O wrt ice
|
Both
|
3
|
Sat.
vapor press. of H2O wrt water
|
Both
|
3
|
IR
surface temp.
|
Both
|
2
|
Sun
elev. grd. ref.
|
DC-8
|
3
|
Sun
azim. grd. ref.
|
DC-8
|
3
|
Sun
elev. A/C ref.
|
DC-8
|
3
|
Sun
azim. A/C ref.
|
DC-8
|
3
|
Forward
nadir cloud video
|
Both
|
2
|
Storm scope
|
Both
|
2
|
Weather radar
|
DC-8
|
1
|
Polar Sat. images
|
DC-8
|
1
|
J (NO2) zenith & nadir
|
Both
|
2
|
Origin
notes: 1--
aircraft sensor
2--
Project sensor
3--
calculated
(DC-8
listed first and P-3B second)
4.4 Ozonesonde Network
The pre-deployment phase of TRACE-P, consisting
of a 12 ozonesonde network, was initiated to provide a time history
of tropospheric ozone in the TRACE-P study region and to augment
the data obtained aboard the aircraft during deployment. Ozonesonde balloons are released from Trinidad Head, California;
Hilo, Hawaii; Sapporo, Tsukuba, Naha, and Kagoshima Japan; Java,
Indonesia; Fiji; American Samoa; Hong Kong; Taiwan; and Cheju Island,
Korea. More details
of the network are given in Section
5.3.
4.5 Ground Measurements
4.5.1 Trace Gases
Continuous measurements of key species by a ground-based
instrument will be conducted as part of the TRACE-P mission. PI
Makoto Koike (Tokyo University) will measure tropospheric
column amounts of carbon monoxide (CO), ethane (C2H6),
and hydrogen cyanide (HCN) using Fourier-transform infrared spectrometers
(FTIR). These instruments have been placed at the Moshiri (44.4°N,
142.3°E) and Rikubetsu (43.5°N, 143.8°E) Observatories and Tsukuba(36.0°N,
140.1°E), Japan.
FTIR measurements of CO, C2H6, and HCN will
be made before, during, and after the TRACE-P deployment. Comparing
results obtained by the DC-8 and P-3B aircraft with the FTIR results
obtained during the TRACE-P deployment will provide important information
on the spatial and temporal changes in these species. FTIR results
obtained over a longer time period will provide useful information
on the seasonal changes of these key species.
4.5.2 Ozonesondes
As part of the TRACE-P mission, PI Samuel J. Oltmans
(NOAA) will operate two ozonesondes located at Trinidad Head, California
(41.1°N, 124.8°W) and Hilo, Hawaii (19.4°N, 155.1°W). During TRACE-P
deployment the soundings at Hilo, Hawaii and Trinidad Head, California
will increase to three per week in order to better capture the
frequency of events that may reach the mid-Pacific or west coast
of the United States. Eighteen soundings will be performed during
a six-week period at each site. In addition, weekly ozonesonde
data beginning in early 2000 through spring 2002 will be provided
to the TRACE-P data archive.
The enhanced number of ozone vertical profiles
to be carried out at the two downwind sites during TRACE-P deployment
will provide an opportunity to investigate the extent to which
Asian emissions may be affecting ozone in the troposphere over
the Pacific and the west coast of North America. Analysis of the
ozone profile data will include the use of back trajectory calculations
to characterize the flow patterns that bring air parcels to these
sites and climatological trajectory analyses.
4.6 Meteorological Support
Overall meteorological support will be provided
by investigator teams from the Massachusetts
Institute of Technology and Florida
State University. The Principal Investigators from these teams
also serve as the Co-mission Meteorologists (see Table
3.0) providing forecasting for flight planning during the deployment
phase of TRACE-P. Members of these teams will conduct post-mission
research and analyses focused on understanding the meteorological
setting of TRACE-P, and the meteorological impact on long-range
transport of the chemical constituents measured during the expedition.
The Hong Kong Observatory, Yokota
Air Force Base Meteorology Office, and GTE Project Office will
also provide additional meteorological support.
4.7 Model Investigations
In addition to the analyses and modeling studies
that will be conducted as part of the experimental investigations
listed in Tables 4.2-1 and 4.2-2,
more focused modeling investigations (Table
4.7-1) will also be conducted by those Science Team members
whose role is listed as "Theoretical Investigation" in Table
3.0-1.
The modeling activities are planned as a part
of the "real-time" field activities as well as post-mission
analyses. These analyses will incorporate various chemical models
focusing on specific science issues as well as meteorological models
for real time air mass trajectories. Table
4.7-1 lists the modeling products for each investigation, along
with a brief description of the models.
Table 4.7-1 Modeling and
Meteorological Analyses
PI |
Organization |
Parameter |
Gregory R. Carmichael |
University of Iowa |
3D CTM and emission inventory |
James H. Crawford |
NASA Langley |
Box model and meteorology support |
Douglas D. Davis |
Georgia Institute of Technology |
Box model |
Johann Feichter |
Max-Plank-Institut fur Meteorologie |
3D CTM and meteorology support |
Henry E. Fuelberg |
Florida State University |
Meteorology support |
Daniel J. Jacob |
Harvard University |
Box model and 3D CTM |
Reginald E. Newell |
MIT |
Meteorology support |
Michael J. Prather |
University of California – Irvine |
3D CTM |
Anne M. Thompson |
NASA Goddard |
Meteorology support |
4.8 Satellite Data Products
The use of satellite data products will play an
integral part in the TRACE-P mission. In addition to the use of
satellite data by Science Team members listed in Table
4.7-1 for modeling and meteorological analysis, some Science
Team members will focus their analyses on satellite data products
for mission planning and post mission analysis. These Science Team
members are listed in Table
4.8-1 and in Table
3.0-1 with the role of "Satellite Data Analysis." This
data will be available on the individual instrument web pages.
Table 4.8-1 Satellite Data
Products
PI |
Organization |
Products |
Anne M. Thompson |
NASA Goddard |
SeaWIFS (smoke, dust, ocean color, clouds, lightning)
TOMS (total absorbing aerosol (smoke and dust), tropospheric
ozone) |
Charles R. Trepte |
NASA Langley |
SAGE II (tropospheric ozone and aerosol) |
4.9 Aircraft Measurement
Methodology
The combined instrumentation payload aboard the
DC-8 and P-3B (see Tables 4.2-1 and 4.2-2)
was selected to meet the objectives and tasks (addressed in Section
2.4) of the TRACE-P investigations. Differences in aircraft
characteristics and payloads aboard each aircraft suggest differences
in the methodology to be employed by the respective P-3B and DC-8
investigator teams in designing flight plans. For TRACE-P both
planes will be focused on the single set of objectives and tasks
given in Section 2.4.
The DC-8 payload, for example, includes the DIAL
system, which provides an important capability for characterization
of the ozone and aerosol structure above and below the DC-8 flight
altitude. A significant addition to the capabilities of the DC-8
payload, over that during PEM-Tropics A and B is the measurement
of aerosols. The DC-8 aircraft has the capability for longer range
and higher altitude coverage than the P-3B aircraft. Because of
these important characteristics of the aircraft capability and
payload, it is anticipated that the DC-8 flights will tend to emphasize
characterization of ozone photochemical precursors concentrations
on a very large scale, together with a more detailed air mass characterization
based on measurements of both photochemical as well as non-photochemical
species.
The P-3B's characteristics and payload differ
from the DC-8's in several important ways. For example, it operates
more efficiently at low altitudes. It will also have instrumentation
for making hydroxyl radical measurements as well as systems for
measuring several important sulfur compounds and aerosol composition.
In addition, the P-3B will be instrumented for turbulent air motion
measurements (e.g., TAMMS). The hydroxyl and sulfur instrumentation
should make possible a more in-depth examination of both the photochemical
oxidizing characteristics of the tropical troposphere, and sources
and critical transformation processes controlling atmospheric sulfur.
The TAMMS system, on the other hand, will offer the capability
for boundary layer flux measurements of selected species. Because
of these payload and operational characteristics, it is anticipated
that the P-3B flights will tend to emphasize process-oriented studies
associated with sulfur and ozone/hydroxyl photochemistry and include
some boundary layer flux investigations.
The locations of the experiments aboard each aircraft
are given in Figures 4.2-1 and 4.2-2 and
the GTE homepage (http://www-gte.larc.nasa.gov/).
Aircraft characteristics are listed in Appendix
C.
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