Comparison of Microwave Radiometer Profiler (MWRP) and Radiosonde in Taihu and Shouxian Sites

Hsiang-He Lee University of Maryland
Zhanqing Li University of Maryland

Category: Instruments

Working Group: Cloud-Aerosol-Precipitation Interaction

One aim of the ARM Mobile Facility (AMF) deployment in China in 2008 is to study the aerosol indirect effects. Shouxian and Taihu are located along the Meiyu front and convergence zone of the eastern monsoon system. They separated by about 500 km and are generally influenced by similar weather systems but with different types of dominant aerosols. This discrepancy provides a good opportunity to understand the cloud-aerosol interaction and the results of the indirect effects with various aerosol species. The microwave radiometer profiler (MWRP), one of the ground observation instruments of the AMF, provides vertical profiles of temperature, humidity, and cloud liquid-water content as a function of height or pressure. The radiosonde provides in situ measurements (vertical profiles) of both the thermodynamic state of the atmosphere and the wind speed and direction. These parameters lead to understanding the cloud formation in dynamic and microphysical processes. In order to obtain useful meteorological parameters from ground-based observation instruments, evaluation of the accuracy of the AMF instruments is essential. The comparison of MWRP and radiosonde can help eliminate the bias of MWRP-retrieved data from different algorithm retrieval methods. At the Taihu site, MWRP temperature and relative humidity (RH) retrievals in the lower atmosphere are consistent with the sounding profiles from neighboring Nanjing, Hangzhou, and Shanghai sounding stations. MWRP-retrieved temperature is generally lower than sounding temperature in the lower atmosphere (except surface temperature), but higher in the upper troposphere. The temperature differences are within ±2°C. Relative humidity shows opposite bias compared to temperature. Negative bias happens at 2000~5000 m height. Temperature and RH retrievals from the MWRP deployed at Shouxian have less bias compared to the Taihu site, because there is no spatial distinction for MWRP and sounding profile. Retrieved temperature is about 1°C higher, and RH is ~10% lower in the low atmosphere.

This poster will be displayed at ASR Science Team Meeting.