Biogenic Aerosol - Effect on Clouds and Climate (BAECC-ERI). Extended Radiosonde Intensive Operational Period Final Campaign Summary

Nicoll, Ken A.¹  O'Connor, E.² 

[1] Univ. of Reading (United Kingdom);Univ. of Helsinki (Finland)

关键词: radiosondes;    cloud properties;    cloud microphysics;   

DOI  :  10.2172/1255447
RP-ID  :  DOE/SC-ARM--15-031
PID  :  OSTI ID: 1255447

学科分类：环境科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

Large-scale properties of clouds such as lifetime, optical thickness, and precipitation are all dependent on small-scale cloud microphysical processes. Such processes determine when droplets will grow or shrink, their size, and the number of cloud droplets. Although our understanding of cloud microphysics has vastly improved over the past several decades with the development of remote sensing methods such as lidar and radar, there remain a number of processes that are not well understood, such as the effect of electrical charge on cloud microphysics. To understand the various processes and feedback mechanisms, high-vertical???resolution observations are required. Radiosondes provide an ideal platform for providing routine vertical profiles of in situ measurements at any location (with a vertical resolution of a few meters). Modified meteorological radiosondes have been extensively developed at the University of Reading for measuring cloud properties, to allow measurements beyond the traditional thermodynamic quantities (pressure, temperature and relative humidity) to be obtained cost-effectively. This project aims to investigate a number of cloud processes in which in situ cloud observations from these modified radiosondes can provide information either complementary to or not obtainable by lidar/radar systems. During two intensive operational periods (IOPs) in May and August 2014 during deployment to Hyyti?��l?��, Finland, the Atmospheric Radiation Measurement (ARM) Climate Research Facility???s Second ARM Mobile Facility (AMF2) launched a total of 24 instrumented radiosondes through a number of different cloud types ranging from low-level stratiform cloud to cumulonimbus. Twelve balloon flights of an accelerometer turbulence sensor were made, which detected significant turbulence on eleven of these flights. Most of the turbulent episodes encountered were due to convective processes, but several were associated with the transition from troposphere to stratosphere at the tropopause. Similarities in the location of turbulent layers were generally found between the balloon turbulence sensor and the Ka-band radar, but with discrepancies between the orders of magnitude of turbulence detected. The reason for these discrepancies is the subject of future work.