Observing the Amazon: the Role of Time and Place in Cloud Measurements

Burleyson, C. D., Pacific Northwest National Laboratory

Cloud Distributions/Characterizations

Cloud Life Cycle

Burleyson CD, Z Feng, SM Hagos, J Fast, LA Machado, and ST Martin. 2016. "Spatial Variability of the Background Diurnal Cycle of Deep Convection around the GoAmazon2014/5 Field Campaign Sites." Journal of Applied Meteorology and Climatology, 55(7), 10.1175/jamc-d-15-0229.1.

Science

Research led by Department of Energy scientists at Pacific Northwest National Laboratory laid the groundwork for future explorations of the Green Ocean Amazon, GOAmazon, 2014/15 field campaign data sets by documenting the variability in space and time of deep convection around the field campaign surface sites distributed upwind and downwind of Manaus, Brazil. Understanding the naturally occurring background variability is an important step for quantifying the human-caused impact of the city of Manaus emissions on clouds and precipitation forming in an otherwise pristine environment.

Impact

The analysis allows other researchers to understand how the field campaign measurements may have changed if different sites were chosen or if the campaign took place in a different year. The research found some spatial patterns of convection that were unique to the Manaus region and would need to be accounted for before isolating manmade impacts. The research also showed that 2014 was a fairly representative year to study deep convection (storm clouds) in the Amazon.

Summary

The GoAmazon2014/15 field campaign was designed to measure and understand the influence of the city of Manaus on clouds and precipitation forming in an otherwise pristine environment. The team examined the aircraft data as well as comparing data from a handful of ground sites strategically placed upwind and downwind of Manaus. A key challenge was to understand how much of the difference between the ground sites is due to the city and how much is due to naturally occurring spatial variability between the sites. This research used 15 years of satellite data to quantify the naturally occurring spatial variability. The researchers showed that the wet season convection around Manaus has some unique characteristics that need to be accounted for when looking for anthropogenic signals. They found that the position of the sites with respect to the river plays a large role in determining the frequency and timing of deep convection over each of the ground sites. The sites east of the Negro River have up to 20% more frequent deep convection than the sites west of the river due to the convergence of the river breezes and trade winds.