NASA TRACE-P 2001

Florida State University

All products on the following pages were calculated from analysis data assembled by The European Centre for Medium - Range Weather Forecasts. The data set has a 1.0 degree by 1.0 degree horizontal resolution, 61 sigma levels in the vertical, and was supplied at 6 hourly intervals throughout the TRACE-P period. The data sets closest to the time of the actual flights were used for product generation. All products are grouped according to flight number, selected at the bottom of this narrative. Streamlines at 5 constant pressure levels (200, 300, 500, 700 and 850 hPa) as well as mean sea level pressure are shown for each flight. All steamlines and mean sea level pressure plots are shown for both a broad hemispheric region and a more localized flight region. Five day backward trajectories were calculated using a kinematic model, i.e., employing the u, v, and w wind components from the ECMWF analyses. A cubic spline procedure was used to vertically interpolate the gridded data from the 61 initial sigma levels to 191 constant pressure levels at 5-hPa intervals between 1000 and 50 hPa. Linear interpolation provided values within these 5-hPa intervals and at the parcel's precise horizontal locations. Linear interpolation also was used to temporally interpolate at 5-min time steps. Additional details about the trajectory model, along with a comparison between kinematic and isentropic trajectories, are given in Fuelberg et al., [J. Geophys. Res., 101, 23927-23939 1996]. Trajectories were calculated for DC-8 and P-3B flights. Available products include trajectories calculated from exact flight postions as well as trajectories arriving at constant pressure levels (300, 500, 700 and 850 hPa) along the flight path. The trajectories were calculated at 5 minute intervals, and to obtain additional trajectories during ascents and descents, additional trajectories were added in 25 hPa intervals. Arrows indicate daily trajectory postions. Red asterisks mark final trajectory positions at the end of 5 days, while red crosses denote trajectories which arrive at the domain boundary prior to the end of the 5 day period. To facilitate easy viewing of a specific flight segment, 4 vertical layers for each aircraft: DC-8 (300, 700 and 850 hPa) and P3-B (500, 700 and 850 hPa). A new flight leg was defined each time the aircraft passed into a different layer. Thus, each flight consists of approximately 25 flight legs. Trajectories and steamlines arriving along each leg of the flight can be viewed by selecting a flight below. All digital trajectory data including clusters and constant pressure levels can be accessed through FSU's anonymous FTP site given below. Check the README file for a complete description of the data.

The materials below constitute Florida State University's data product. Therefore, if you use the materials in your publications, we hope that you will follow the GTE data protocol.