The Utility of Lidars

Research Topics

Over the past decade, the application of lidar to atmospheric monitoring and research has increased in popularity. Based on its ability to capture information of the atmosphere in high resolution, it is easy to see why lidars can facilitate a broad spectrum of research topics focused on both the characteristics of biogenic and anthropogenic aerosols.

Lidars are often implemented with other sensors (satellite imagery, Doppler radar, etc) to provide ancillary data for rapidly changing phenomena. And, when LiDAR output is continuous, we can observe the evolution of atmospheric structures at a range of different temporal and spatial scales.

*Field tip: What types of scales and their associated influences are observable on lidar imagery? It may be worthwhile noting these if you are looking at LiDAR output. Some representative scale structures are discussed in our Interpretation section. Consider the following:

Spatial	Near-field (local) scale
	Regional
	Continental or trans-continental (hemispheric/global)

Temporal	Diurnal – patterns in local source strength
	Hebdomadal – source strength variations from weekend to weekday
	Seasonal – affecting source strength, type, and dispersion

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The key to understanding atmospheric observation with lidar is to know that, besides obvious aerosol (smoke, dust) plumes and clouds, aerosols can act as tracers to reveal atmospheric structures.

Examples of transient features and phenomena discernible by upward-pointing lidar include, but are not limited to:

• Cloud microphysics
• Cloud-base height
• Boundary Layer (BL) or Mixed Layer (ML) height
• Thermals
• Frontal passages
• Gravity waves
• Plumes
• Industrial pollutant advection
• Forest fire (smoke)
• Volcanic aerosols
• Dust
• Fireworks

Purpose of CORALNet

CORALNet (Canadian Observational Research Aerosol Lidar Network), as it’s name suggests, is a lidar network across Canada, currently composed of 5 sites stationed from as far west as Vancouver (UBC), BC, to Wolfville (Acadia), NS. With a network of lidars, we are able to observe the large-scale transport of aerosol plumes (possibly from station to station). Understanding how pollutants travel allows us to understand trans-boundary air quality issues, and the effects of aerosols on climate change.

Notably, the UBC lidar station in Vancouver was the first established by CORALNet in April of 2008 in order to study long range (trans-Pacific) transport of pollutants from Asia (and even the Sahara desert) to North America. This is of particular importance as there are few measurements of aerosols along the west coast.

Using continuous measurements, lidar products such as those provided by CORALNet have the potential to be used for weather forecasting and air quality management in providing timely forecasts and publicly accessible information. And, by using the various output channels of the lidar data, it is now possible to provide more definitive explanations of aerosol sources and air quality issues even on a daily basis.

You can read more about CORALNet’s mission statement here.

Summary

• Lidars are extremely useful in observing rapidly changing phenomena due to their nearly-continuous, high-resolution measurements
• Lidar imagery is able to capture data on various temporal (diurnal, seasonal, annual) and spatial (near-field, regional, trans-continental) scales
• We can observe different atmospheric phenomena by using aerosols act as tracers for atmospheric structures
• The purpose of the CORALNet-UBC lidar was to primarily study long-range transport across the Pacific Ocean.

Continue to the Interpretation of Lidar Output >>