The following agenda guided the meeting. The agenda will be presented and
a short summary of relevant agenda items will follow each:
Summary: These descriptions are standard and available from Glenn Gordon at Univ. Wyoming (Gordon@grizzly.uwyo.edu). Grossman will review King Air intercomparisons with the NCAR Electra and NAE Twin Otter in BOREAS to ascertain the adequacy of the gust pr obe system for CASES-97 research objectives. He requested some collaboration on this effort from Dr. Robert Kelly (PI of the King Air for BOREAS) and Dr. Don Lenschow (PI of the Electra during BOREAS). Grossman was advised by Gordon to contact Kelly inform ally. A copy of a draft paper on the intercomparisons has been given to Grossman for evaluation (Grossman Action Item). Post-Flight data reduction and quality control is available and needs to be coordinated with the PIs (Grossman Action Item). A slow (1/e time constant = 10 sec) Ozone instrument (J. Snider, Univ. Wyoming) was proposed as a piggyback. A summary of the research was requested which has since been supplied by Dr. Snider. It appears the instrument may help studies of boundary layer entrainment and will not impact primary objectives. Efforts are being made to include this piggyback in CASES-97 (Grossman Action Item).
Summary: These descriptions are standard and available from Dennis Wellman at NOAA Air Resources Lab (Boulder Office; dWellman@srrb.noaa.gov). Grossman noted that the gust probe system for the NOAA/Twin Otter is relatively new. Intercomparison with tested gust probe systems did not seem available. NOAA Air Resources Lab has developed this gust probe system to be used with several moving platforms (Twin Otter, Long Easy, ships). Grossman felt that installation and testing on the Twin Otter platform needs to be done well before the field phase so any problems that may arise particular to the Twin Otter platform can be taken care of (McMillen Action Item). Post-Flight data reduction and quality control is available and needs to be coordinated with King Air operations (Grossman Action Item). Grossman noted that the facility quality control often emphasizes engineering aspects of the data streams and that CASES-97 aircraft PIs should compliment that by emphasizing quality control aimed more at the CASES-97 objectives; he will draw up a putative scientific quality control package for review and input by Air Resources Lab (Grossman,Lemone,McMillen Action Item).
Summary: The needs of the Aircraft Facilities were presented. Both felt that hangers were necessary. Also described were needs for jet fuel, power carts, runway length, an instrument landing system (ILS), ability to make coordinated takeoffs within a few minutes of one another, and reasonable living accomodations. With these needs in mind, since the meeting, both facilities have reviewed aircraft bases in the CASES area and have agreed that facilities at Ponca City, OK meet all their combined needs. It is likely that Ponca City will be the Aircraft Operations Base for all future CASES expeditions. The choice of Ponca City insured that the Surface (profiler, surface flux station, radar) Operations Base would not be co-located with the Aircraft Operations B ase; this probability was discussed at the general meeting and reviewed at the Aircraft Coordination meeting. This separation of operations bases has occurred before (i.e., FIFE). Based on past experience, coordination between the two Operations Bases wil l be accomplished by a daily conference call (high quality speaker phones need to be available in both Operation Bases) using common materials obtained from an internet weather visualizer (i.e. Univ. Illinois, Purdue, etc) and the CASES Home Page (systems status, aircraft mission modules, CASES surface data displays). Grossman and Lemone will work up the agenda for the daily conference call as part of the CASES-97 Operations Plan (Grossman-Lemone Action Item). Grossman was asked to check out the chosen fac ilities during a January fact-finding mission to Kansas and Oklahoma (Grossman Action Item).
Summary: Grossman presented several modules that could be used singly or by both aircraft in combined operations. He showed how the various modules can be combined to obtain estimates of boundary layer budgets of momentum, sensible heat, and moisture. The se flight mission modules will become part of the CASES-97 Operations Plan (Grossman Action Item). Grossman pointed out that combined aircraft operations can cover two possibilities: extend spatial coverage and extend temporal coverage compared to single a ircraft operations. He requested that the facilities look into a "turn around" base closer to the Walnut River Watershed than Ponca City for the temporally coordinated missions as this will reduce commute time and expense. Since that request, Grossman has inspected Jabara Airport which is at the northeastern border of the Walnut River Watershed. During VFR conditions (CASES-97 primary objective is to study the fair-weather diurnal cycle), Jabara Airport is an excellent candidate. It's only draw back is the lack of an ILS so cannot be used during IFR conditions; it is unlikely aircraft will be launched if IFR conditions are possible within a proposed diurnal cycle study. Radio contact between aircraft, the aircraft and the surface observations operations ba se, and the various surface sites (CLASS launch sites, radar site, ASTER) was discussed. Needs included safety (coordination with balloon launches), surface-mixed layer flux comparisons (ASTER), surface data availability (PAM, ASTER, profiles, radar), and requests for information (boundary layer height, surface wind velocity, surface temperatures, etc). It was determined, following FIFE, that the facilities coordinate aircraft-to-aircraft communications and that aircraft-to-ground communication be limited to the Aircraft and Surface Operations bases. It appears that NOAA/AOC has assigned frequencies for aircraft-to-aircraft communication and will coordinate their use with the NSF Facility (Nokutis or Wellman and Gordon Action Item). Canidiates for Aircraft-to-Ground communication were FM radio (Univ. Wyoming or NCAR/ATD may have units) and cellular phone. Cellular phone was attractive since individual surface sites could also be called, if necessary. The primary need for low-level flux runs was described by Grossman who was aware of the FAA restrictions and waivers to FAA restrictions necessary to carry them out; this will be discussed further in 6c. below. He pointed out that low-level flight lines would be determined during CASES-97 and that these flight lines would be used by future CASES operations as described in the CASES White Paper. Of course, if surface conditions changed (house, tower construction) during the course of CASES, then some low-level flight lines would have to be changed. The pilots ( gasaway, nokutis, finn) commented on their impressions of flight conditions over the Walnut River Watershed. In general, they felt that all proposed flight operations were possible, if the FAA would grant low-level flight restriction waivers to the Facilities for CASES-97. Flight operations were more flexible in the central and eastern parts of the watershed compared to the western part of the watershed which is close to an urban area (Wichita, KS) and a Military Operations Area (MOA).
Summary: We all agreed that all scientific objectives of CASES-97 which involve flight operations must first be subject to safety review. While the Scientific Flight Director may suggest certain flight operations and changes to these operations while in flight, these suggestions are subject to a final go/no-go decision by the Flight Commander. This Safety Principal will never be compromised. As a separate safety issue the crew rest requirements for the NSF and NOAA Facilities were reviewed and found to be compatible with CASES-97 operations; there was no need for more pilots than initially requested (due to crew rest requirements). These will be published as part of the CASES-97 Operations Plan (Grossman Action Item). The need for FAA waiver to current restrictions on low-level flight operations to accomodate 100 ft low-level runs was discussed. NOAA's current restriction on low-level flights is 200 ft (Wellman/Nokutis/Finn please confirm) so in addition to the FAA waiver, NOAA needs to request a further in-house waiver to fly 100 ft runs. The Univ. of Wyoming has a 100 ft low-level limit which is compatible with the CASES-97 objectives. Grossman will conduct a aerial survey in January to determine low-level flight lines. These may or may not be confirmed by the NOAA/AOC pilots; the Univ. of Wyoming will rely on Grossman's assessment. Each Facility will make its own request for a FAA low-level waiver (Nokutis/Gordon Action Item). Grossman and Lemone will provide any scientific justification necessary in the a pplication (Grossman-Lemone Action Item). Grossman has provided each Facility with way points for up to 7 candidate flight lines distributed south through north across the watershed as part of a recent site survey to the area; many of these flight lines are close to proposed surface flux sites. These are presently being reviewed by the Facilities. Scientist-to-pilot communication was briefly discussed. In the King Air the scientist is in the right (co-pilot) seat and there are no communication problems (nominally headphone-microphone). In the Twin Otter, the scientist uses headphone-microphone communication from a station in the center of the aircraft. All agreed that this was more than adequate. Scientist-to-scientist communication (between King Air and Twin Otter Flight Directors) is to be accomplished by the use of radio using a NOAA dedicated frequency (Nokutis/Wellman/Gordon Action Item).
Summary: Flight mission planning will be part of the daily conference call. Flight mission choices will reflect the accomplishment of the operational objectives associated with the scientific objectives (budget missions, mapping missions, temporal variati on missions) and the operational status of the surface flux stations, profilers, CLASS, and (to a lesser extent) radar. Crew rest and aircraft availability must also be taken into account in the misson choice decision. Grossman, Lemone, and McMillen will make the final flight mission decision the night before takeoff. There will always be two choices of missions (a plan A and plan B) even if plan B is to cancel. The flight planning time line will be as follows:
For the analysis of many coordinated aircraft operations, knowledge of biases between similar instruments on the NOAA and NSF aircraft is essential (especially for the coordinated budget missions). Therefore intercomparison legs between the aircraft need to be part of every day operations. One way to do this is to use the ferry flight from Ponca City to Winfield (southern limit of the Walnut River Watershed) as a science leg. Unless decided differently at the daily briefing, all flight missions will fly this leg at 500 ft above the highest object in that flight line (FAA regulations). Coordinated missions will require that the two aircraft fly wing-to-wing formation along this line for intercomparison purposes; the flight directors will log the times of the intercomparison. A running total of intercomparison legs will be part of the operational data compiled for the daily briefing.
Summary: Each flight mission will include a debriefing after the mission is complete. All persons on board are required to attend. Aircraft PIs are also required to attend if they did not fly. Below is a candidate agenda for the debriefing:
As stated earlier, the Facilities normally check engineering aspects of the individual data streams such as noisy signals, calibrations, biases, unrealistic values, differences between similar instruments. Scientists will be responsible for the more sophi sticated quality control such as reasonablness of the data in light of the scientific objectives, adequacy of averaging lengths, spectral-cospectral composition of individual data and flux data streams, intercomparison between aircraft and surface systems , and preliminary budget computations. A general principle that will apply to CASES-97 is that scientists will be responsible for their own hardware and software to carry out their quality control procedures. If invited, they can use Facility computers and software. It would be nice if the NOAA and NSF PIs can agree to use a common software package to estimate airborne fluxes; Grossman is in the final stages of upgrading a candidate flux computation package used in several previous field expeditions (GALE, FIFE, STORMFEST, COARE, CEPEX) and publications (JGR, Mon Wea Rev, J. Climate). Facilities need to coordinate with the PIs to insure the post-flight data media and format are compatible with their hardware and software (Grossman/McMillen/Wellman/Gordon Action Item). NOAA should have the ability to look at NSF data and vice-versa. Thus a common in-the-field data format would be highly advantageous.
Summary: A common output data format for both NOAA and NSF is strongly encouraged as this will greatly speed post-flight analysis. NETCDF format is suggested. We expect three data sets to emerge:
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