Browse Data
Brief summaries of the aircraft and ground based missions involving the PALMS instrument follow. Select a mission, then choose a date. This will display a graph showing altitude and latitude for that flight (or meteorological data for ground-based measurements). Next, click on the region of the graph to begin viewing spectra starting at that portion of the flight.
WB-57 Aerosol Mission (WAM)
The WAM mission took place in the Spring of 1998. All six flights originated in Houston, Texas, and covered a latitude range of 9N to 46N. Most flights were about six hours in duration. The PALMS instrument collected over 28,000 spectra of individual particles during WAM, the first aircraft mission that the instrument participated in. MJ Mahoney supplied the MTP data which is used to show the tropopause height in the graphs. In addition, there are some nice photos of the WB-57F aircraft at Ellington Field in Houston.
| WAM | |||||
|---|---|---|---|---|---|
| Date | Duration | Lat | Lon | Events | Comments |
| 19980408 | 2.25 hr | 29N-31N | 92W-95W | 2187 | Test flight from Houston |
| 19980409 | 6 hr | 17N-30N | 83W-95W | 2923 | Test flight southeast from Houston - cold soak |
| 19980411 | 6 hr | 30N-46N |
95W-109W |
5316 | Science flight northwest from Houston - two dips |
| 19980501 | 5.5 hr | 13N-30N | 94W-95W | 8752 | Science flight south from Houston |
| 19980504 | 6.5 hr |
9N-30N |
94W-95W | 10415 | Science flight south from Houston |
| 19980506 | 5 hr | 29N-45N | 89W-95W | 6216 | Science flight north from Houston |
| 19980507 | 6 hr | 29N-35N | 73W-95W | 7986 | Science flight east from Houston |
Atmospheric Chemistry of Combustion Emissions Near the Tropopause (ACCENT)
The ACCENT mission took place in the Spring and Fall of 1999, though the PALMS instrument participated in the Fall portion only. Most flights originated in Houston Texas. Also, there was a flight south to Costa Rica, with the return flight to Houston occuring the following day. Another flight went west to California to do a "rocket intercept", flying through the exhaust plume of a rocket launch at Vandenburg Air Force Base. The return flight to Houston was about a week later. The main mission objectives were to characterize exhaust emisions from different types of rocket motors, and measure the distribution and characteristics of aerosols in and out of major commercial aviation flight corridors as well as over the Pacific Ocean. NASA's Dr. Paul Newman's Spring ACCENT mission and ACCENT Fall deployment describe the mission with many photos, including some taken from the cockpit of the WB-57F showing the exhaust plumes of various rockets that the airplane has encountered.
Also, refer to RISO (Rocket Impacts on Stratospheric Ozone) for more information and interesting photos of the rocket plume intercept missions.
| ACCENT | |||||
|---|---|---|---|---|---|
| Date | Duration | Lat | Lon | Events | Comments |
| 19990903 | 4 hr | 29N-39N | 92W-97W | ?? | Test flight |
| 19990913 | 5 hr | 29N-33N | 80W-95W | 6387 | East coast survey flight |
| 19990915 | 5.5 hr | 29N-32N | 80W-95W | 5964 | Hurricane Floyd over-flight |
| 19990917 | 5.25 hr | 29N-34N | 95W-97W | 2914 | Air traffic corridors |
| 19990920 | 5.25 hr | 5N-30N | 84W-95W | 12302 | Houston to San Jose, Costa Rica |
| 19990921 | 4.5 hr | 10N-30N | 82W-95W | 9817 | Costa Rica to Houston |
| 19990922 | 3.5 hr | 28N-33N | 95W-100W | 3287 | Test flight |
| 19990924 | 5 hr | 29N-35N | 95W-121W | 9699 | Rocket intercept. Landed at Edwards AFB, CA |
| 19991004 | 3.75 hr | 29N-35N | 95W-118W | 2241 | Edwards AFB to Houston |
Atmospheric Chemistry of Combustion Emissions Near the Tropopause II (ACCENT- II)
The ACCENT II mission took place in September of 2000. Mission objectives were 1) to make detailed measurements of the composition and impact of combustion emissions from a solid rocket motor (SRM) in the lower stratosphere, and 2) to study the mixing and transport in the tropical upper troposphere and lower stratosphere. This mission consisted of seven flights using the WB-57 aircraft. There was a flight to Florida to intercept the exhaust plume from the space shuttle as it blasted off to the international space station. The return flight to Houston was on the following day. Another series of three flights went to Costa Rica one day, south from Costa Rica to reach a latitude of 4S, and back to Costa Rica on the second day. The third flight returned to Houston.
Idaho Hill 1993
The Idaho Hill measurements took place in September 1993 during the Tropospheric OH Photochemistry experiment. Several techniques for measuring the OH radical were compared and the chemistry leading to the hydroxyl radical was studied (Mount and Williams, J. Geophys. Res., 102, 6171, 1997). Idaho Hill is at 3070 m (10070 feet) elevation just east of the continental divide. It is about 25 km west-northwest of Boulder and the Denver metropolitan area. The Idaho Hill measurements were the first field measurements of single particle composition. Mass spectra of over 5000 particles were obtained with an early version of the PALMS instrument. Notably, the mass spectrometer resolution was lower than in later measurements and the excimer laser was operated at 248 nm rather than 193 nm.
Idaho Hill ground site
Cape Grim 1995
The Cape Grim measurements were conducted in November-December 1995 during the ACE-1 Aerosol Characterization Experiment. The experiment studied aerosols in a very clean marine location. Our mass spectra helped show that sea salt aerosols are a significant source of cloud condensation nuclei in marine regions with high wind speeds and low sulfate pollution.
For further information, refer to the Australian Bureau of Meteorology Cape Grim Baseline Air Pollution Station or NOAA PMEL ACE-1 Southern Hemisphere Aerosol Characterization Experiment.
Atlanta 1999
The ground version of the PALMS instrument was operated by Dr. Ann Middlebrook and Dr. Shanhu Lee at the EPA Supersite in Atlanta during late summer 1999. Over 500,000 mass spectra of individual particles were recorded. For more information about this measurement campaign, go to Atlanta Supersite Study.