1 of 12

The Effects of Slash and Burn Agriculture Practices in the Amazon on Antarctic Ice Sheets During 2019

by Gehan Boteju and Sudip Chakraborty

2 of 12

Fires in the Amazon forest in 2019

Man-made forest fire in Amazon.
Driven by forest clearing and burning for agriculture or other anthropogenic activities. (Purdue News, 2020)
The location of the wildfires are closely related to areas that were cleared the year prior. (Purdue News, 2020)
Wildfires generate various aerosols and gases like black carbon, organic carbon, sulfate etc.

(Purdue News ,2020)

Aerosols generated over a region can be transported far from their source region through narrow and elongated channels or aerosol atmospheric rivers (Chakraborty et al 2021, 2022).
Aerosol atmospheric rivers (AAR) are narrow and elongated channels of extreme mass transport. They contribute 40-100% of annual particulate transport.

3 of 12

Fire generated from AAR�22^nd September 2019; 1800 UTC

4 of 12

Background

Aerosols can darken the ice surface or reduce albedo (reflectivity of sunlight).
This leads to more absorption of solar energy.
As a result, snow temperature increases.
That leads to higher melting and loss of snow/ice mass.

5 of 12

Research Question

Did the anthropogenic fire in 2019 darken the snow and accelerate ice-sheet melting in Antarctica?

(NASA GRACE Satellite, 2023)

6 of 12

Domain

This study focuses on the Antarctic region and this plot shows which areas of sea water near Antarctica has gotten warmer, indicated by the red

7 of 12

Category	Parameter	Satellite / data Source	Resolution	Period
Radiative Properties	Surface temperature	AIRS (netcdf)	Horizontal: 1 degree Temporal: daily	2018-2020
Radiative Properties	Reflected Shortwave energy at surface; Emitted Longwave energy at Surface, Top of the Atmosphere (TOA) forcing	CERES (netcdf)	Horizontal: 1 degree Temporal: daily	2018-2020
AAR	AAR data	(https://doi.org/10.25346/S6/CXO9PD, Chakraborty, 2022). MERRA-2. (netcdf and txt)	0.625° × 0.5° Temporal: 6 hourly	2018-2020
Dynamics	Wind speed at 10 m. u10 and v10 u10: East to West wind v10: North to South wind	ERA interim	0.25 degree	2018-2020
Oceanic Properties	Sea Surface Sea Surface Temperature	NOAA/NASA (netcdf)	0.25 degree	2018-2020
Snow and Ice properties	Snow albedo and cover	MODIS (hdf)	500 m (sinusoidal grid) Temporal: daily	2018-2020
Snow and Ice properties	Snow depth, snow cover and Ice images	ICESAT 1 and 2 (hdf)	25 km	2018-2020
Ice melting	MEaSUREs Greenland Surface Melt	SMMR, SSM/I, SSMIS, NIMBUS-7 (hdf)	Horizontal: 25 km Temporal: 1 day, 2 day	2018-2020
Ice melting	Snow thickness altimetry, melt days	ICESAT-1 and 2 (hdf)	25 km	2018-2020

8 of 12

Data Preprocessing

We used Python’s XESMF package to pre-process the data.
We have re-gridded all the data at a resolution of 0.25deg x 0.25 deg.
No information is lost.

Before regriding

After regriding

AIRS Surface Temperature data; 2019

9 of 12

Antarctica Albedo Levels

Nov 1, 2018

Nov 20, 2018

Dec 5, 2018

Dec 5, 2019

Nov 1, 2019

Nov 20, 2019

Feb 1, 2020

Feb 25, 2020

Feb 1, 2019

Feb 25, 2019

Before the fire 2019 season

During the fire 2019 season

After the fire 2019 season

10 of 12

Future plan on causality

Is that snow browning due to the transported aerosols or temperature?

We will analyze the importance of various meteorological parameters using

Random Forest Method to identify which feature is the most important.

Granger causality Analysis to find what causes the melting.

11 of 12

Sources

Chakraborty, S., Guan, B., Waliser, D. E., da Silva, A. M., Uluatam, S., & Hess, P. (2021). Extending the atmospheric river concept to aerosols: Climate and air quality impacts. Geophysical Research Letters, 48, e2020GL091827. https://doi.org/10.1029/2020GL091827
Hall, D. K. and G. A. Riggs. (2021). MODIS/Terra Snow Cover Daily L3 Global 500m SIN Grid, Version 61 [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/MODIS/MOD10A1.061. Date Accessed 05-10-2023.
Purdue News. (2020, December 16). Deforestation drove massive Amazon rainforest fires of 2019. Purdue University News. https://www.purdue.edu/newsroom/releases/2020/Q4/deforestation-drove-massive-amazon-rainforest-fires-of-2019.html
NASA. (2023, March 2). Ice sheets. NASA. https://climate.nasa.gov/vital-signs/ice-sheets/