Author Profile: R J Sima

Publications from R. J. Sima

Large outrigger canoe silhouetted against an orange Hawaiian sky

News 13 May 2020

Humans Colonized Polynesia Much Earlier Than Previously Thought

Evidence from mud, charcoal, and feces suggests humans arrived in East Polynesia during the driest period in 2 millennia.

Ocean Sciences

Photo of a low rock jetty separating the ocean from a fish pond

News 28 April 2020

Groundwater Is the “Hidden Connection” Between Land and Sea

The importance of fresh groundwater to coastal ecosystems is revealed using the first computer model at a global scale.

Atmospheric Sciences

Multiple lightning strikes descend from clouds at night

News 13 March 2020

Mapping Lightning Strikes from Space

A new technique spatially tracks lightning in real time and has been adapted by the National Weather Service.

Mathematical Geophysics

News 4 March 2020

Combining AI and Analog Forecasting to Predict Extreme Weather

New deep learning technique brings an obsolete forecasting method “back to life” to predict extreme weather events.

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Climate Change

Man in a wetsuit holds a cross section of a tree while standing in a lake.

News 4 February 2020

How the Cold Climate Shaped Scotland’s Political Climate

Tree rings reveal how severe cold and political isolation brought disaster to Scotland, inspired a colonization effort in Panama, and helped drive union with England.

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Climate Change

Image of orange sun above hazy Tokyo cityscape

News 20 December 2019

Heat Waves Born of Earth and Sky

Researchers use computer simulations to uncover the significant contributions that dry soil and atmospheric wind patterns make to major heat waves.

Hydrology, Cryosphere & Earth Surface

Image of eroded ground under a tilled, yellowing prairie landscape

News 10 December 2019

A Dirty Truth: Humans Began Accelerating Soil Erosion 4,000 Years Ago

Recent research combining analysis of carbon dating, sediment accumulation rates, and pollen records from 632 lake beds worldwide finds deforestation tied to increased soil erosion.

Hydrology, Cryosphere & Earth Surface

Side view of individual trees generated in a lidar image

News 18 October 2019

The Bigger They Are, the Harder They Fall

New research tracking 1.8 million trees found that tall trees died at more than twice the rate of smaller ones toward the end of extreme and persistent drought.

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