Title: A differential emissivity imaging technique for measuring hydrometeor mass and type

Abstract

Abstract. The Differential Emissivity Imaging Disdrometer (DEID) is a new evaporation-based optical and thermal instrument designed to measure the mass, size, density and type of individual hydrometeors as well as their bulk properties. Hydrometeor spatial dimensions are measured on a heated metal plate using an infrared camera by exploiting the much higher thermal emissivity of water compared with metal. As a melted hydrometeor evaporates, its mass can be directly related to the loss of heat from the hotplate assuming energy conservation across the hydrometeor. The heat loss required to evaporate a hydrometeor is found to be independent of environmental conditions including ambient wind velocity, moisture level and temperature. The difference in heat loss for snow vs. rain for a given mass offers a method for discriminating precipitation phase. The DEID measures hydrometeors at sampling frequencies of up to 1 Hz with masses and effective diameters greater than 1 µg and 200 µm, respectively, determined by the size of the hotplate and the thermal camera specifications. Measurable snow water equivalent (SWE) precipitation rates range from 0.001 to 200 mm h−1, as validated against a standard weighing bucket. Preliminary field experiment measurements of snow and rain from the winters of 2019 and 2020 provided continuous automated measurementsmore » of precipitation rate, snow density and visibility. Measured hydrometeor size distributions agree well with canonical results described in the literature.« less

Authors:

Singh, Dhiraj K.; Donovan, Spencer; Pardyjak, Eric R. ;

• Search DOE PAGES for author "Pardyjak, Eric R."
• Search DOE PAGES for ORCID "0000-0002-0180-0857"

Garrett, Timothy J.

• Search DOE PAGES for author "Garrett, Timothy J."
• Search DOE PAGES for ORCID "0000-0001-9277-8773"

Publication Date:

Thu Nov 04 00:00:00 EDT 2021

Research Org.:

Particle Flux Analytics Inc., Salt Lake City, UT (United States)

Sponsoring Org.:

USDOE Office of Science (SC); National Science Foundation (NSF); Colorado Department of Transportation

OSTI Identifier:

1829174

Alternate Identifier(s):

OSTI ID: 1830816

Grant/Contract Number:  

SC-0017168; SC0017168

Resource Type:

Published Article

Journal Name:

Atmospheric Measurement Techniques (Online)

Additional Journal Information:

Journal Name: Atmospheric Measurement Techniques (Online) Journal Volume: 14 Journal Issue: 11; Journal ID: ISSN 1867-8548

Publisher:

Copernicus GmbH

Country of Publication:

Germany

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; 47 OTHER INSTRUMENTATION