Related Experiment Videos
Orographic enhancement of snowfall
A J Dore1, T W Choularton, D Fowler
1Department of Pure and Applied Physics, UMIST, PO Box 88, Manchester M60 1QD, UK.
Environmental Pollution (Barking, Essex : 1987)
|January 1, 1992
Summary
Snowfall pollutant deposition increases significantly with altitude in Scotland due to seeder-feeder effects. Wind drift and evaporation impact deposition patterns, making direct precipitation measurement challenging.
Area of Science:
- Atmospheric Science
- Environmental Science
- Geosciences
Background:
- Wet deposition by snowfall is crucial for pollutant transport.
- Understanding altitude-driven variations in deposition is key for environmental monitoring.
- Previous studies often focus on rainfall, with less data on snowfall deposition patterns.
Purpose of the Study:
- To investigate the altitudinal variation of wet deposition by snowfall.
- To quantify ion concentrations in snowpack at different altitudes.
- To model orographic enhancement of snowfall and pollutant deposition.
Main Methods:
- Field studies conducted at a Scottish hill site.
- Snow collectors used to measure snowfall deposition.
- Analysis of principal ion concentrations in snow water.
- Modeling of the seeder-feeder effect on snowfall.
Main Results:
- Snow collectors showed inefficient capture due to wind drift, preventing direct precipitation measurement increase with altitude.
- Average concentrations of principal ions increased by factors of 1.4–1.9 over a 400 m altitude rise.
- Modeled orographic enhancement of precipitation and pollutant deposition was significantly greater for snowfall than rainfall.
Conclusions:
- Altitude significantly enhances pollutant deposition via snowfall, particularly through the seeder-feeder mechanism.
- Wind drift of snow crystals and evaporative losses are critical factors influencing deposition patterns.
- Accurate measurement of snowfall deposition requires accounting for complex physical processes beyond simple collection.