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Global Tropospheric Experiment Pacific Exploratory Mission-West B (GTE PEM West B) Langley ASDC Data Set Document |
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This document provides information on data products obtained during the GTE Pacific Exploratory Mission-West B atmospheric science expedition conducted over the western Pacific during February and March 1994. The objective of the mission was to investigate the atmospheric chemistry of ozone and its precursors and to examine the natural budgets of these species and the impact of anthropogenic sources. Measurements were made primarily by investigators' instruments located on the NASA Ames Research Center DC-8 airborne laboratory. Also provided are a list of principal investigators, a brief summary of measurement techniques and a list of publications.
This document provides information for the following PEM West B data sets:
| gte_pemwb_dc8_msn_XX.zip: | DC-8 Aircraft Data for flight XX |
| gte_pemwa_jpg_msn_XX.zip: | Time series and altitude plots of in situ measurements on DC-8 flight XX |
| gte_pemwb_ground_ak.zip: | Measurements of Acidic Compounds, Particle concentrations, Total nitrate
PAN, PPN, HCl, HBr, HNO3, SO2, and NH3,
from ground site on Oki Island, Japan; Measurements of SO2, NOx,
O3 from PECAMPOT aircraft; Measurements of vertical profiles of O3 recorded at Mt. HAPPO, Japan, and Okinawa, Japan; Measurements of vertical profiles of O3 and CO recorded from Oki Island; |
| gte_pemwb_ground_la.zip: | Measurements of CO and O3 from ground station located at 22.2 N latitude by 114.3 E longitude |
| gte_pemwb_ground_li.zip: | Measurements of SO2, CO, O3, and meteorological parameters from ground site at Kenting, Taiwan 21.9N, 121.86E); Rawinsonde sounding from Taipei station (25.03N, 121.5E), Hualien station (23.98N, 121.E), Ma-gong station (23.31N, 117.34E), Lyu-Dao station (22.28N, 120.28E), and Dong-Gang station (22.41N, 121.3E) |
| gte_pemwb_ground_pr.zip: | High volume samples of bulk aerosols for analysis of major ions and trace elements collected from ground sites at Cheju Island, Korea, Hong Kong, Okinawa Japan, Lin'An, China, Midway Island, Oahu, Hawaii, Shemya, Alaska, and Ken-Ting, Taiwan, |
| gte_pemwb_ground_ro.zip: | Aerosol nitrate and sulfate, HNO3, NO SO2, NOx, O3, andd HC's from ground site at Lin'An, China |
| gte_pemwb_ground_zh.zip: | Measurements of SO2, NO, NOx, O3, |
| gte_pemwb_satellite_mmdd.zip: | Full disk satellite image for month mm, and day dd |
| gte_pemwb_lightning.zip: | DMSP Monthly Total Lightning Flashes for February and March |
| gte_pemwb_ozone_sonde.zip: | Ozonesonde launches from Hong Kong |
NASA funded the investigators involved in the PEM West B mission. The funded investigators, their organization and their grant, agreement or contract number were:
| Investigator | Organization | Grant |
|---|---|---|
| Aircraft: | ||
| A. Bandy | Drexel U | NAG-1-1224 |
| J. Bradshaw | Georgia Tech | NAG-2-954 |
| E. Browell | NASA Langley | N/A |
| G. Gregory | NASA Langley | N/A |
| B. Heikes | U of Rhode Island | N/A |
| R. Pueschel | NASA Ames | N/A |
| S. Rowland | U of California-Irvine | NAG-1-1553 |
| G. Sachse | NASA Langley | N/A |
| H. Singh | NASA Ames | N/A |
| R. Talbot | U of New Hampshire | N/A |
| Ground: | ||
| R. Arimoto | U of Rhode Island | N/A |
| J. Prospero | U of Miami | N/A |
| Modeling: | ||
| D. Davis | Georgia Tech | N/A |
| S. Liu | NOAA Boulder | N/A |
| J. Merrill | U of Rhode Island | NAG-1-1235 |
| R. Newell | Mass Inst of Tech | N/A |
| J. Rodriguez | AER | N/A |
Aircraft data sets are available for each investigation for each flight. Airborne measurements were typically obtained at constant altitude over the North Pacific during transit flights (i.e. "survey" flights), and over multiple altitudes closer to Asia during flight from the intensive sites. Flight missions were conducted during PEM West B from February 7 through March 14, 1994. Hoell et al., [1997] lists the flight dates as well as the takeoff and landing times and site. Flight tracks and profiles are also shown in Hoell et al., [1997]. The duration, altitude range, ascent and descent rate, and flight path for each mission varied depending on mission objectives and environmental conditions. Further information about the measurement region and time frame may be found in the Journal of Geophysical Research, Vol. 102, No. D23, 28223-28239, December 20, 1997.
This data set contains the DC-8 aircraft data submitted to the GTE data archive by the PEM West B investigators listed in Section 1.d. Included are the atmospheric chemistry, meteorological and navigational data recorded aboard the NASA DC-8 airborne. Additionally ground data, ozonesondes, rawinsondes, and satellite images are also included. Trajectories and merged data sets are not included in this archive. These data products can be found at the GTE data archive at http://www-gte.larc.nasa.gov.
The atmospheric species and other parameters measured are listed in Hoell et al., [1997]. Also listed for each are the name and affiliation of the principal investigator.
PEM West B investigators have individually reported the results of their investigations in the Journal of Geophysical Research, Vol. 102, No. D23, December 20, 1997.
There are data sets available from the Langley ASDC for 13 other GTE missions conducted from 1983 to 2001. See the GTE home page at http://www-gte.larc.nasa.gov and/or the ASDC at http://eosweb.larc.nasa.gov/PRODOCS/gte/table_gte.html for a description of the available data.
Global Tropospheric Experiment Pacific Exploratory Mission West B (PEM West B)
If the person is known to be retired, deceased or no longer at the organization, it is noted and the contact information may be omitted. The contact information provided was current during the mission, but may no longer be current.
John Bradshaw (Principal Investigator, Deceased)
Scott Sandholm (Co-Investigator)The following persons have more specialized knowledge than the investigators listed in Section 1.d, as indicated, about the data in the data sets.
The following persons have either specialized knowledge in their field or general knowledge about the mission, its execution and the data sets.
OR Contact:
Airborne Science Program Coordinator OfficeJoseph W. Drewry (retired)
G. Chen
Dept. of Atmospheric Sciences
National Taiwan University
Taipei, Taiwan
Telephone: 886-2-363-1991
Fax: 886-2-363-3642
R. E. Newell (deceased 12/02)
J. K. Park
J. M. Prospero
P. P. Sham
Director, Royal Observatory
134a Nathan Road
Hong Kong
Telephone: 852-3732-9221
Fax: 852-3721-5034
Hanwant B. Singh
NASA Ames Research Center
Mail Stop 245-5
Moffett Field CA 94035
Telephone: 415-604-6769
Fax: 415-604-3265
E-mail: hb_singh@arc.nasa.gov
Y. Sugimura
Head, Geochemical Laboratory
Meteorological Research Institute
Nagamine 1-1
Yatabe, Tsukuba
Ibaraki305, Japan
Telephone: 81-298-51-7111
Fax: 81-298-51-1449
N. D. Sze
X. Zhou
Potential usage and applications of the described data sets can be seen in the articles that comprise the Journal of Geophysical Research PEM West B Special Section (Vol. 102, No. D23, December 20, 1997).
For convenience of the users, the calculated variables below are provided.
Mach Number, M: |
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M = Mach Number Ps = Static Pressure Qc = Differential Pressure |
Static Air Temperature, Ts: | |
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TS = Static Air Temperature (°K) TT = Total Air Temperature (°K) γ = 1.4, ratio of specific heat of air at constant pressure and volume |
True Air Speed, TAS: | |
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TAS = True Air Speed (knots) TS = Static Air Temperature (°K) M = Mach Number a = Speed of Sound |
Potential Temperature, θ: | |
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θ = Potential Temperature (°K) TS = Static Air Temperature (°K) Ps = Static Pressure (mb) |
Vapor Pressure, e :
ewater (mb) = [1.0007 + (3.46 * 10-6 * PS)] * 6.1121* EXP[17.502 * T/(240.97 + T)]
eice (mb) = [1.0003 + (4.18 * 10-6 * PS)] * 6.1115* EXP[22.452 * T/(272.55 + T)]
e = Partial Pressure of Water Vapor (mb)
PS = Static Pressure (mb)
T = Static Air Temperature (°C) for Saturation Vapor Pressure
or
T = Dew/Frost Point (°C) for Partial Pressure of Water Vapor
Note:
ProjDP of zero or greater should be used to derive the partial pressure of water vapor w.r.t water (ewater) and the ProjDP less than zero should be used to derive the partial pressure of water vapor w.r.t ice (eice).
StatTempDegC and ProjDP parameters recorded in the P-3B data set are substituted to calculate saturation vapor pressure and partial pressure of water vapor, respectively.
TSDEGC and ProjDP parameters recorded in the DC-8 data set are substituted to calculate saturation vapor pressure and partial pressure of water vapor, respectively. Also notice in the DC-8 data set there is a redundant static air temperature measurement, TSCALC, which is calculated by DADS. Although TSDEGC and TSCALC track closely they can diverge by ≈1° at the low and high ends of the measurement range.
Specific Humidity, q: | |
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Mixing Ratio, r: | |
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| Note: ppmv = 1.608 * ppmw ppmw = 0.622 * ppmv | |
Relative Humidity, %: | |
w.r.t. water,![]() |
w.r.t. ice,![]() |
Interested readers should see the Journal of Geophysical Research, Vol.102, No. D23, December 20, 1997, and documents referenced therein, for plots and the results of analysis of data.
See the GTE Data Format Document at http://eosweb.larc.nasa.gov/guide/gte/gte_fmt.html.
A general description of data granularity as it applies to the IMS appears in the EOSDIS Glossary. Aircraft data sets are available for each investigation for each flight.
This data set contains the DC-8 aircraft data submitted to the GTE data archive by the PEM West B investigators listed in Section 1.d. Included are the atmospheric chemistry, meteorological and navigational data recorded aboard the NASA DC-8 airborne laboratory and data obtained from surface level sites. Ground data, ozonesondes, rawinsondes, modeling products, satellite images, trajectories and merged data sets are not included in this archive. These data products can be found at the GTE data archive at http://www-gte.larc.nasa.gov. No additional data products relevant to PEM West B are anticipated.
This data is available online or on a CDROM via the LaRC ASDC at http://eosweb.larc.nasa.gov and from the GTE data archive at http://www-gte.larc.nasa.gov/. Users may also order data by letter, telephone, and electronic mail from the ASDC.
The Atmospheric Science Data Center at NASA's Langley Research Center.
Publication of a portion(s) of the data archive should acknowledge the principal investigator(s) responsible for the data by referencing the appropriate manuscript in the Journal of Geophysical Research, Vol. 102, No. D23, December 20, 1997.
Airborne measurements were made over the western Pacific. A more detailed description of the surface level environmental characteristics for the experiment region is provided in the individual papers for each investigation included in the Journal of Geophysical Research, Vol. 102, No. D23, December 20, 1997. Additional information may be found in other publications authored by the principal investigators or on the GTE homepage at http://www-gte.larc.nasa.gov/.
Airborne measurements were made predominately over the western Pacific Ocean. A more detailed description of the surface level environmental characteristics for the experiment region is provided in the individual papers for each investigation included in the Journal of Geophysical Research Vol. 102, No. D23 December 20, 1997. The duration, altitude range, ascent and descent rate, and flight path of each mission varied depending on mission objective and environmental (weather) conditions. The nominal airspeed ranged from greater than 485 knots (approximately 560 mph) at 13 km altitude to 317 knots (approximately 365 mph) at 0.20 km.
| Measurement Platform | Min Lat | Max Lat | Min Lon | Max Lon |
|---|---|---|---|---|
| DC-8 Aircraft | 9.6S | 60.9N | 164.0E | 173.2W |
Resolution varies for each measurement. See Hoell et al, [1997].
No data gridding or binning of data to a geographic grid occurred during data processing.
Sixteen aircraft missions were conducted from February 7 through March 14, 1994. Hoell et al, [1997] gives dates and times for each flight.
Not all of the parameters are in each data set granule. Also, the ranges vary between data sets and between granules within each data set. Species measured are given in Hoell et al, [1997].
The variables measured are standard atmospheric chemical and meteorological species requiring no further elaboration here.
The units of measure vary widely depending on species and measurement environment and are addressed in the individual papers for each investigation included in the Journal of Geophysical Research, Vol. 102, No. D23, December 20, 1997.
The instruments used in making the measurements are listed in Hoell et al, [1997].
The ranges of data vary widely depending on species and measurement environment and are addressed in the individual papers for each investigation included in the Journal of Geophysical Research, Vol. 102, No. D23, December 20, 1997.
The GTE Data Format Document at http://eosweb.larc.nasa.gov/guide/gte/gte_fmt.html contains examples of each data set type.
The sources of error vary depending on species and measurement environment and are addressed in the papers included in the PEM West B special issue of the Journal of Geophysical Research, Vol. 102, No. D23, December 20, 1997, and/or papers referenced in that publication and readme files and/or header records associated with each data file.
None reported for the current archive version. See the readme files and header records included with each data set for information provided by the responsible investigator.
The data sets submitted to the ASDC are considered final and no further updates are anticipated. However, modifications will be considered if requested by the investigators or otherwise justified.
Details of data acquisition and materials are addressed the papers contained in the Journal of Geophysical Research PEM West B Special Section (Vol. 102, No. D23, December 20, 1997).
GTE Bibliography (http://www-gte.larc.nasa.gov/gte_pubs_update.htm)
PEM West B Special Section, Journal for Geophysical Research, Vol. 102, No. D23, December 20, 1997.
Hoell, J. M., D. D. Davis, S. C. Liu, R. E. Newell, H. Akimoto, R. J. McNeal, and R. J. Bendura, The Pacific Exploratory Mission-West Phase B; February-March 1994, J. Geophys. Res., 102, 28223-28239, 20 December 1997.