|
|
CAMEX-4 NOAA WP-3D Radar (KAMP) Table of Contents
The Convection And Moisture EXperiments (CAMEX) are a series of field research investigations sponsored by the Earth Science Enterprise of the National Aeronautics and Space Administration (NASA). CAMEX-4 focused on the study of tropical cyclone (hurricane) development, tracking, intensification, and landfalling impacts using NASA-funded aircraft and surface remote sensing instrumentation. The fourth field campaign in the CAMEX series (CAMEX-4) ran from 16 August to 25 September, 2001 and was based out of Jacksonville Naval Air Station, Florida. An important addition to CAMEX-4 was the participation of the NOAA weather reconnaissance WP-3D that collected radar, video and microphysical data. Each WP-3D aircraft has three radars: nose, lower fuselage and tail. The nose radar (a solid-state C-band radar with a 5° circular beam) is used strictly for flight safety and is not recorded for research purposes. The lower fuselage and tail radars are used for research purposes and the data are recorded on Digital Audio Tape since 1993. Radar CharacteristicsThe lower fuselage and tail radar characteristics are:
The major drawback of the Lower Fuselage radar is the large vertical beamwidth (4.1°) which causes inadequate illumination of the targets in the beam. Inadequate beam filling is a severe problem in the estimation of the reflectivity of a storm at ranges >60-90 km (see the Appendix of Marks, 1985). The critical parameters that determine the beam illumination of the target storm are the beam's vertical dimension and orientation, and the aircraft altitude. At close range there is little loss because the radar beam is narrow enough to be totally within the strong reflectivity region at lower altitudes in the storm. As range increases, the height of the center of the beam increases and more of the beam is unfilled, or filled with the less reflective portion of the storm. This problem can be solved by compositing a number of radar sweeps in time over a fixed domain. (storm- or earth-relative) The major drawback of the Tail radar is the 3.22 cm wavelength (X-band) and high PRF. X-Band radars suffer from intervening rain attenuation which limit the maximum range at which Doppler estimates are obtained. This problem is remedied by flying close to the area of interest, reducing the distance the beam has to travel through the intervening rainfall. The high PRF, coupled with the short wavelength result in a low velocity Nyquist interval and unambiguous range. The low Nyquist velocity is the hardest of the two to compensate for as intervening attenuation minimizes problems with second trip echoes. The low Nyquist velocity can be overcome through unfolding utilizing the measured component of the air velocity along the radar beam at the aircraft as a first guess. HRD has successfully unfolded velocities as high as 90 m/s using this approach in hurricanes. http://www.aoml.noaa.gov/hrd/HRD-P3_radar.html Tape FormatsThe RADAR data tapes were created on Hewlett Packard 16 bit machines. These tapes contain raw binary data records with variable record lengths. The binary format of the data is outlined in section II of the MARS ROS: Prog. Des. Manual, as supplied by NOAA/AOML/Hurricane Research Division. http://www.aoml.noaa.gov/contact.html A local copy of this document in PDF form is included with the documentation, and can be seen here. Data DistributionData are archived and distributed on 8mm tapes. Distributed tapes are byte for byte copies of our master tape, via a 8mm tape duplicator. Flight Identification and Times for these data: These tapes were supplied by:
Any Question about the data, or the data format should be directed to the data supplier. ReferencesKollias, P., B.A. Albrecht, and F.D. Marks. 2003 "Cloud radar observations of vertical drafts and microphysics in convective rain." Journal of Geophysical Research, 108(D2) pp.4053 Black, M.L., J.F. Gamache, F.D. Marks, C.E. Samsury, and H.E. Willoughby. 2002 "Eastern Pacific Hurricanes Jimena of 1991 and Olivia of 1994 pp. The effect of vertical shear on structure and intensity." Monthly Weather Review, 130(9) pp.2291-2312 Kollias, P., B.A. Albrecht, and F.D. Marks. 2002 "Why Mie?" Bulletin of the American Meteorological Society, 83(10) pp.1471-1483 Walsh, E.J., C.W. Wright, D. Vandemark, W.B. Krabill, A.W. Garcia, S.H. Houston, S.T. Murillo, M.D. Powell, P.G. Black, and F.D. Marks. 2002 "Hurricane directional wave spectrum spatial variation at landfall." Journal of Physical Oceanography, 32(6) pp.1667-1684 Atlas, D., C.W. Ulbrich, F.D. Marks, R.A. Black, E. Amitai, P.T. Willis, and C.E. Samsury. 2000 "Partitioning tropical oceanic convective and stratiform rains by draft strength." Journal of Geophysical Research, 105(D2) pp.2259-2267 Lee, W.-C., and F.D. Marks. 2000 "Tropical cyclone kinematic structure retrieved from single Doppler radar observations, Part II: The GBVTD-simplex center finding algorithm." Monthly Weather Review, 128(6) pp.1925-1936 Lee, W.-C., B. J.-D. Jou, P.-L. Chang, and F.D. Marks. 2000 "Tropical cyclone kinematic structure retrieved from single-Doppler radar observations. Part III: Evolution and structures of Typhoon Alex (1987)." Monthly Weather Review, 128(12) pp.3982-4001 Reasor, P.D., M.T. Montgomery, F.D. Marks, and J.F. Gamache. 2000 "Low-wavenumber structure and evolution of the hurricane inner core observed by airborne dual-Doppler radar." Monthly Weather Review, 128(6) pp.1653-1680 Rogers, R.F., J.M. Fritsch, and W.C. Lambert. 2000 "A simple technique for using radar data in the dynamic initialization of a mesoscale model." Monthly Weather Review, 128(7) pp.2560-2574 Dodge, P.P., R.W. Burpee, and F.D. Marks. 1999 "The kinematic structure of a hurricane with sea-level pressure less than 900 mb." Monthly Weather Review, 127(6) pp.987-1004 Black, M.L., R.W. Burpee, and F.D. Marks. 1996 "Vertical motion characteristics of tropical cyclones determined with airborne Doppler radial velocities." Journal of the Atmospheric Sciences, 53(13) pp.1887-1909 Marks, F.D., 1985 "Evolution and structure of precipitation in Hurricane Allen (1980)." Mon. Wea. Rev., 113, 909-930. Contact InformationTo order these data or for further information, please contact:
|