Ground-based remote sensor observations during the PROBE experiment in the tropical western Pacific

From January 6, 1993, to February 28, 1993, the second phase of the Prototype Radiation Observation Experiment (PROBE) was conducted in Kavieng, Papua New Guinea. Data taken during PROBE included radiosondes, 915-MHz wind profiler/Radio Acoustic Sounding System (RASS) observations of winds and temperatures, and lidar measurements of cloud-base heights. In addition, a dual-channel Microwave Water Substance Radiometer (MWSR) at 23.87 and 31.65 GHz and a Fourier Transform Infrared Radiometer (FTIR) were operated. The FTIR operated between 500 and 2000 cm/sup -1/ and measured some of the first high-spectral resolution radiation data taken in the tropics. The microwave radiometer provided continuous measurements with 30-s resolution of precipitable water vapor (PWV) and integrated cloud liquid (ICL), RASS measured virtual temperature profiles every 30 min, and the cloud lidar provided episodic measurements of clouds every minute. The remote-sensing data, the radiosonde data, and conventional in situ meteorological and radiation data provide information that will be extremely valuable to climate models. The RASS, MWSR, and FTIR data taken during PROBE are compared with radiosonde data. Broadband longwave and shortwave irradiance data and lidar data are used to identify the presence of cirrus clouds and clear conditions. Comparisons are presented between measured and calculated radiance during clear conditions, using radiosonde data as input to a Line-By-Line Radiative Transfer Model (LBLRTM). Comparisons of RASS-measured virtual temperature with radiosondes revealed a significant cold bias below 500 m.