Work Item
ASTM WK70254
New Guide for Mixing Layer Height from Ceilometer
1. Scope
This guide presents a procedure for the determination of mixing layer height in the atmosphere as measured by a Ceilometer. The guide employs a lidar ceilometer which transmits laser light pulses into the atmosphere and measures backwards scattered signal by a receiver. The measured signal is converted into vertical profiles of attenuated backscatter coefficient which describes scattering and extinction by aerosols aloft. The attenuated backscatter profile is then analyzed by an algorithm to calculate the mixing layer height and other elevated layers that describe the vertical structure of aerosol distributions. The guide for the mixing layer height will result in real-time height estimates and time-averaged mean layer height estimates. Using this guide will enable the real-time monitoring of the mixing layer height, which may be used for forecasting, monitoring and understanding local mixing layer height conditions. The guide will provide information for use in other applications, such as verification of numerical modeling of air pollution, and therefore will help improve air quality monitoring and forecasting.
Keywords
Ceilometer, LIDAR, mixing layer height, convection, planetary boundary layer, air quality, numerical modeling
Rationale
This standard will provide guidance for the real-time monitoring of mixing layer height by using lidar Ceilometer. The guide will be used by air pollution monitoring agencies, contractors and other stakeholders interested in ambient air pollution monitoring, dispersion and fates.
The title and scope are in draft form and are under development within this ASTM Committee.
Work Item Status
Date Initiated: 10-18-2019
Technical Contact: Raisa Lehtinen
Item: 009
Ballot: D22 (22-03)
Status: Will Reballot Item