Amir Erfanian

Tropical and sub-tropical South America are highly susceptible to extreme droughts. In the past decade (2005 to 2016) alone, the region has experienced several extreme drought events including the two droughts of 2005 and 2010 which exceeded the 100-year return value in the Amazon with profound eco-hydrological and socioeconomic impacts. In 2015–2016, the region was hit by another drought. Here, we show that the severity of the 2016 drought is unprecedented based on multiple precipitation products (since 1900), satellite-derived data on terrestrial water storage (since 2002) and two vegetation indices (since 2004). The ecohydrological consequences from the 2016 drought are more severe and extensive than the 2005 and 2010 droughts. Empirical relationships between rainfall and sea surface temperatures (SSTs) over the tropical Pacific and Atlantic are used to assess the role of tropical oceanic variability in the observed precipitation anomalies. Our results indicate that warmer-than-usual SSTs in the Tropical Pacific (including El Niño events) and Atlantic were the main drivers of extreme droughts in South America, but are unable to explain the severity of the 2016 observed rainfall deficits for a substantial portion of the Amazonia and Nordeste regions.
Here are some of the tools and techniques I used in this project:
- Hypothesis testing, regression, outlier analysis, probability, standardization
- Exploratory data analysis, predictive analytics, time series, correlation, extreme values/events
- Droughts, precipitation, vegetation index, terrestrial water storage

You can find more information about this project at:
Erfanian, Amir, Guiling Wang, and Lori Fomenko. "Unprecedented drought over tropical South America in 2016: significantly under-predicted by tropical SST." Scientific reports 7, no. 1 (2017): 5811.