A study of macrophysical and microphysical properties of warm clouds over the Northern Hemisphere using CloudSat/CALIPSO data

Abstract

This study investigates the general macrophysical and microphysical properties of single-layer warm clouds over the Northern Hemisphere using standard CloudSat products during 2008. The yearly averaged occurrence frequency of single-layer warm clouds is 20.9% over oceans and 9.5% over land, respectively. The cloud top heights over land in different latitude zones exhibit a broader spectral width and more frequent occurrence of strong cloud systems in tropics than that over higher latitudes. The maximum values of liquid water content over land are approximately 10-30% smaller but the occurring altitudes are about 0.5 km higher than those over oceans with the same liquid water path (LWP). The reflectivity profiles clearly demonstrate the growth processes of cloud particles and how these processes vary with increasing LWP. The evolutions of reflectivity over land show a frequency shift toward weaker dBZ values relative to that over oceans with the same LWP, suggesting that high aerosol concentrations may induce suppressed drizzle and delayed precipitation in warm clouds. Additionally, there exists a significant difference between warm clouds formation at the initial stage over ocean and land areas. When LWP is 0.1-0.2 kg m À2 and optical depth exceeds 25, the dBZ values over oceans increase rapidly downward with increasing optical depth (decreasing height). The faster growth may be caused by the evaporation-condensation mechanism. Over land, however, large droplets are unlikely to appear in the early stage possibly because continental aerosols prevent the evaporation-condensation mechanism to occur, resulting in partially delayed drizzle formation.

Multi-sensor quantification of aerosol-induced variability in warm clouds over eastern China

“…Namely, cloudy samples account for 56.69% of the total vertical profiles. The percentage of cloudy samples found here is in good agreement with that found over the land of the northern hemisphere (Gao et al, 2014). The SASC scenario accounts for 9.51% of the total samples, with almost one half (4.71%) belonging to the mixed case versus 3.06% belonging to the separated case.…”

Trumpet‐Shaped Topography Modulation of the Frequency, Vertical Structures, and Water Path of Cloud Systems in the Summertime Over the Southeastern Tibetan Plateau: A Perspective of Daytime–Nighttime Differences

“…The 2B‐CLDCLASS‐LIDAR products provide cloud classification data, including the cloud‐type information, CTH and cloud‐base heights, and the cloud layers (Gao et al, ; Yu et al, ). The clouds are divided into eight types: cirrus (Ci), altostratus (As), altocumulus (Ac), stratus (St), stratocumulus (Sc), cumulus (Cu), nimbostratus (Ns), and deep convective (DC).…”

Cloud-Precipitation Parameters and Radiative Forcing of Warm Precipitating Cloud over the Tropical Pacific Ocean Based on TRMM Datasets and Radiative Transfer Model

“…Due to the limited ability of PR and VIRS in cloud-base detection, the height of the cloud base is set to be a constant value for the averaged WPC. According to the study by Gao et al [67], most of the lowest warm cloud-base cloud is about 0.5 km. The constant value of WPC cloud base is set to 0.5 km in our simulation.…”