SOLVE Journal

Pre-SOLVE activities

Dr. Paul A. Newman
Code 916
Atmospheric Chemistry and Dynamics Branch
Laboratory for Atmospheres
NASA's Goddard Space Flight Center
Greenbelt, MD 20771

Building 33, Room E320
(301) 614-5985 fax: x-5903

SOLVE

Intro

The SOLVE mission is a measurement campaign designed to examine the processes controlling ozone levels at mid- to high latitudes. The development of SOLVE began more than 2 years ago as an effort to provide validation information for the launch of the SAGE III instrument aboard a Russian Meteor-3 satellite. In 1998, NASA issued a Research Announcement of SOLVE. A large number of groups from NASA, NOAA, Universities, and international communities responded to this announcement with proposals for participating in SOLVE. In the Fall of 1998, these proposals were evaluated, and instruments and teams were selected for participation in SOLVE. In January 1999, the SOLVE science team met in Lancaster, California to discuss the objectives and plans for SOLVE.

SOLVE and SAGE III

An initial delay into 1999 led us to add both the NASA ER-2 and some heavy lift balloons into the SOLVE campaign. Unfortunately, further slips have moved the SAGE launch into the spring of 2000, after SOLVE. However, data collected during SOLVE will help perform ozone retrieval simulations for SAGE. In addition, measurements by currently flying satellite instruments such as TOMS, SAGE II, HALOE, POAM, GOME, and MSX will eventually overlap with SAGE III. Additional validation of current instruments will assist the calibration of SAGE III when it is finally orbited.

November 1999

DC-8 integration

Integration of all of the DC-8 instruments began at NASA/Dryden during November. Integration requires a tremendous amount of work to insure that instruments and inlets are properly attached to the plane, and that the instruments can be safely operated. Since many of the instruments use hazardous substances, they must be thoroughly looked over, checked for flaws, and every possible failure contingency is examined. Such care is necessary to insure the safety of the aircraft and crew. In addition, the scientists carefully examine and test their instruments to make sure they're working properly. After a set of check flights to test the handling of the DC-8, an 8-hour test flight was flown on the Monday evening of 22 November, 1999. We're very sorry that they had to miss Monday Night Football. However, they were able to see DC United beat the LA Galaxy on Sunday for the MLS soccer cup.

Mark Schoeberl reports that the test flight of 22 November was fairly successful. The plane took off from NASA/Dryden at 2:36 PM local time, and headed south and then turned back north at 25 N to do a sun run. The DC-8 then turned back south to 12.5 S along 118 W, and then passing over JPL's Table Mountain site on the way back to NASA/Dryden. The forecast called for clear skies over the area, with a possibility of sub visible cirrus toward the south end of the flight track, but no sub visible cirrus was actually seen.

As with any integration, there are always problems. Many of the investigators will be working through the holidays to make minor repairs and changes in instrumentation.

OMS balloon operations

The balloon campaign began with the airlift of the balloon gondola and instruments to Kiruna, Sweden from Wright-Patterson AFB aboard a C-141 cargo aircraft. Balloon operations are being conducted at Esrange by NSBF. After much preparation, the in-situ payload was ready for flight on 12 November. The balloon team went though a dry-run launch on Saturday (13 November). Bill Brune and the rest of the science team then patiently waited for the polar vortex to drift overhead before launching on 19 November. In Bill's words:

Everything went really well -- the dry run that we had done the previous Saturday really helped get the bugs out. We launched at 5:36 AM. A beautiful launch.
Despite some early launch scares, all the instruments worked quite well on the OMS in situ gondola. We got to float at 104 thousand feet in about 2 hours and then began a slow descent over Finland. When we descended to 60 thousand ft, it became clear that the gondola would come down near a town if we let it descend further on the balloon to 30 kft. Because the helicopter pilot couldn't get out of fog, we had no one in sight of the gondola to terminate either the science or the parachute and balloon. So it had to be done from here when the balloon was at 55 kft. Thus the parachute was not separated from the gondola after impact. But we knew that the winds were light and that the area had lots of pine trees.
Because the pilot ran into some low clouds and couldn't figure out how to get around them, despite instructions from Esrange, we were unable to recover the payload on Friday. But on Saturday, the helicopter located it, picked it up, and put it on the truck. The gondola had landed standing up with no damage, the 5th time out of 8 launches that it has landed standing up. All the instruments are in excellent shape. After we had it back in the lab on Saturday evening (20 November), everyone was busy recovering hard disks and cleaning things up. Danny Ball just stood there shaking his head at how lucky we are. Now, everyone has checked out their instruments and left, except for me, NSBF, and the remote sensing guys and their JPL colleagues.
The preliminary data are quite interesting. We got well into the vortex over the whole altitude range and saw lots of descent. The air appears to have strong mesospheric signatures, but the details await further investigation and better data reduction with calibrations fully applied. I should say that we saw some very low temperatures -- I believe below PSC temperatures, although I have not do the calculations using all the available data. I expect that we have had some processing for our flight, although HCl seems to indicate that it is not very much, and Geoff Toon may observe some processing for his flight.

This launch took quite a bit of work. Congratulations to the OMS In-situ balloon team and to the NSBF personnel. Good luck to Geoff Toon and the OMS remote payload that will probably be launched on Friday (11/26).

September 1999

The Tracer Inter comparison Experiment for SOLVE (TIES)

The Tracer Inter comparison Experiment for SOLVE (TIES) was originally developed as a test of the N2O observations on the NASA ER-2 aircraft. Because N2O is such a key observation for characterizing air-masses, and because it is critical for comparing vortex data to results from other missions, the accuracy and precision of these observations must be carefully scrutinized. We typically use N2O to characterize polar stratospheric air. We know from past experience that polar vortex air has very low N2O. Therefore, we need very good observations of N2O to determine the origin of air coming northward from the tropics, or southward from the North Pole. The TIES flights were the first SOLVE flights. These flights took place from NASA/Dryden in September 1999 as part of an inter comparison of N2O and CH4 measurements aboard the NASA ER-2. This TIES experiment included a 2 hour flight on 23 September, and 8-hour flights on 25 September and 28 September 1999.

Five instruments were flown as part of TIES: the Airborne Tunable Laser Absorption Spectrometer (ATLAS), the Aircraft Laser Infrared Absorption Spectrometer (ALIAS), the Four-Channel Airborne Chromatograph for Atmospheric Trace Species (ACATS IV), the Whole Air Sampler (WAS), and the Argus Tunable Diode Laser Instrument. Integration began on September 13 and moved quite slowly, with a successful test flight was on 990923. This flight was immediately followed by an 8-hour northern survey flight on 990925. Failures of ATLAS and ACATS on the 990925 flight forced us to fly a second 8-hour northern survey flight on September 28.

The TIES results are still being analyzed. However, they revealed a number of problems that are currently being corrected by the various instrument groups. Such preliminary flights oftentimes reveal problems that are not easily identified in the benign conditions of the laboratory. In addition to the N2O instruments, the Harvard ClONO2 and HOx instruments and the NASA/Ames MMS instruments were flown on the ER-2.

SOLVE Links

General

Forecasting

Stratospheric meteorology

Last Updated: 1999-11-23
Author: Dr. Paul A. Newman (NASA/GSFC, Code 916) (newman@notus.gsfc.nasa.gov)

Web Curator: Dr. Leslie R. Lait (Raytheon ITSS) (lrlait@ertel.gsfc.nasa.gov)
Responsible NASA organization/official: Dr. Paul A. Newman, Atmospheric Chemistry and Dynamics Branch