Data: INTEX-B 2006

10 March 2006 (Flight #1909)

CAR QuickLook Imagery

Overview

Preflight goals focused on getting AOD & water vapor profiles and transects, SSFR fluxes, CAR circles, and RSP legs over the Gulf in or near the overlap between MISR local mode and MODIS-Terra glint-free swaths in the King Air lidar curtain. This included a J31 spiral coordinated with a C-130 spiral. See planned and actual flight tracks in Figures 1 and 2.

Engine on: 1456 UT
Engine off: 1804 UT

Takeoff: 1515 UT
Land: 1800 UT

1652 UT Terra overpass

Pilot Summary

Everything good. Coord w 2 airplanes perfect.  Got to point within 5 min of each other.

Discussion of Flight

Flight Scientist: Very good flight. Headed to 1st waypoint—worse clouds there. Headed back to better location. Outside local mode box. Spiral under King Air, top of aerosol layer at 3 km.  Spiraled all way down in clear spot. Lots of wind & whitecaps. Headed to WP 4 for coord. Only 1 or 2 short blips of cirrus in direct beam, but could see cirrus off right wing & far off left wing. OD=0.17 to 0.20. Very even & solid.  Variations very gradual, 1608 to 1639 at 200’ & 200 kt. Straight & level for RSP in principal plane toward WP 4. Spiral ascent at WP 4—see data in Figures 4-5.

Communication from cockpit very good. Good warnings to power down instruments, etc.

Cirrus holes 10-20 nmi wide. Transit had cirrus AODs <=0.01.

Instrument Performance & Status

AATS: Operated fine. Data file was difficult to find because of wrong month on laptop date. Data file was found evening of flight. Raw AATS data look fine. However, late in the flight J31 static pressure developed problems (see NavMet below). GPS altitude and sonde pressure profiles will be used to correct this in post-processing.

CAR:  OK. No problems start to end. Lots of cirrus. Expect interesting comparisons to RSP. Principal vs perp plane. No BRDFs on this flight. No very clear slot.

RSP: Worked fine. Chillin out. SWIR channels very quiet.

SSFR: Fine.

POS: Turned on & off. Worked fine.

NavMet: NavMet delivered data (see Figure 3).  NASA logo covers some numbers on display. Postflight analysis of pressure data showed a problem that developed late in the flight: drifting differences between J31 pressure and sonde pressure, echoed by differences between GPS altitude and J31 pressure altitude. The suspected cause is a leak or restriction in the tubing between the pressure port and the rack-mounted pressure transducer.

Flight Path, Timing, and Measurements (all times UT [VER local +6])

1517: Ascend to 15,500’ en route to 1st waypoint.

1534: Some Ci in AATS data

1552: Adjusted point 2 because of clouds.

1608: Spiral descent to 200’, some wispy Ci clouds, not visible in AATS data.
Aerosol top in spiral is ~3 km.
End of spiral. Strong winds, whitecaps.

1619: 200’ completely clear over solar disk.

1622: 200’ Ci over right wing

1627: 200’ possible Ci

1633: King Air over WP 4

1635: C-130 over WP 4

1639: 200’ straight for RSP leg

1640: 200’ turn around for WP 4

1646: short Ci blip in AATS data

1659: 15,000’ top of spiral, heading 133 deg in principal plane.

1700: start RSP leg in principal plane

1711: right turn across principal plane.

1714: 16,500’ ascend for RTB

1750: Ramp descent into VER, continuous AATS trace. See Figure 6 for postflight comparison of J31 water vapor in this decent to 18 Z VER radiosonde.

Figure 1. Planned flight track, J31 Flight VER05, 10 Mar 2006.

Figure 2. Actual flight track, J31 Flight VER05, 10 March 2006.

Figure 3. NavMet data, J31 Flight VER05, 10 March 2006. Pressure and static temperature data shown are before postflight correction. - larger image

Figure 4. AATS aerosol optical depth (AOD) and column water vapor data, J31 Flight VER05, 10 March 2006. Pressure altitudes in bottom frame are after postflight correction of static pressure. - larger image

Figure 5. Left frame: Vertical profiles of AOD at wavelengths 0.3535 to 2.1393 microns, measured in the spiral ascent flown 16.72-16.98 UT, 10 March 2006.  Right frame: Vertical profiles of aerosol extinction derived by vertically differentiating spline fits to the AOD profiles in the left frame. Terra overpass was at 1652 UT (16.87 UT in decimal hours), about midway through the spiral ascent. - larger image

CAR - (quicklook)
Imagery from CAR Instrument

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