All work
Remote Sensing & GIS

Global Warming and Cyclonic Activity

An ArcGIS StoryMap on how ocean warming reshaped hurricane intensity and reach

2024 · ESS205 · ArcGIS StoryMaps · University of Toronto

ArcGIS web map of North America and the Atlantic with hundreds of overlapping blue and pink hurricane tracks fanning from the tropics toward the U.S. East Coast over a state choropleth.
Key result

Mapping 150 years of hurricane tracks against sea-surface temperature showed storm counts staying roughly flat while high-intensity storms grew steadily more common, with the strongest storms clustering over the warmest water (80°F and above).

Result

Across roughly 150 years of hurricane data, the number of storms stayed about the same while the share of high-intensity storms climbed. Plotting tracks against sea-surface temperature made the link plain: the strongest hurricanes cluster over the warmest water (80°F and up), and storms in cooler water rarely reach top strength.

Objective

The goal was to test, with maps rather than text alone, how global warming has changed the intensity, count, and location of cyclones. I built the argument as an Esri ArcGIS StoryMap so each claim sits next to the map that supports it.

Approach

The StoryMap pulls from several sources and layers them. NOAA’s IBTrACS archive supplied historical hurricane tracks, which I split into 17-year phases from 1851 to 2020 to watch intensity change over time. A sea-surface-temperature basemap let me compare where storms form and strengthen against ocean heat. To carry the analysis into human impact, I overlaid FEMA national expected-loss data and U.S. Census American Community Survey low-income block groups against the track network. Every quantitative claim in the narrative is tied to a peer-reviewed source, including Chand et al. (2022) on declining overall frequency and work by Emanuel and others on warming-driven rainfall and wind.

Findings

The time series is the heart of it. The 1851-1868 phase shows tracks across the basin but very few high-intensity segments. The 2003-2020 phase shows a similar count of storms with far more red and pink (Category 4-5) track segments, which matches the literature: total frequency is roughly flat or regionally mixed, but the storms that do form trend stronger. The temperature comparison reinforces the mechanism, and the FEMA overlay shows the highest expected-loss areas are the same coasts hurricanes hit most.

Why it matters

The low-income overlay turns a climate trend into an equity problem. Poorer coastal communities sit directly under frequent storm paths and have the least capacity to rebuild, so the map doubles as a targeting tool for where hurricane-resistant infrastructure and aid would do the most good.

Figures

Historical hurricane paths against sea-surface temperature. Storms form in both hemispheres, but the strongest tracks sit over the warmest water and largely avoid the cooler mid-latitudes.
Global map with hurricane tracks in blue and pink concentrated in bands north and south of the equator across the Atlantic, Pacific, and Indian Oceans, over a dark sea-surface-temperature basemap.

Historical hurricane paths against sea-surface temperature. Storms form in both hemispheres, but the strongest tracks sit over the warmest water and largely avoid the cooler mid-latitudes.
Earliest 17-year phase (1851-1868). Tracks cross the basin, but very few reach the highest-intensity category.
Map of the Gulf of Mexico and western Atlantic showing 1851 to 1868 hurricane tracks mostly in dark blue with only a few light pink high-intensity segments.

Earliest 17-year phase (1851-1868). Tracks cross the basin, but very few reach the highest-intensity category.
Most recent phase (2003-2020). Track counts resemble the 1800s, but high-intensity red and pink segments are far more common, the core finding of the time series.
Map of the same Gulf and western Atlantic region showing 2003 to 2020 hurricane tracks with many thick red and pink high-intensity segments mixed among the blue tracks.

Most recent phase (2003-2020). Track counts resemble the 1800s, but high-intensity red and pink segments are far more common, the core finding of the time series.
Low-income block groups (green) intersected with hurricane paths. The overlap flags where storm exposure and limited resources compound, sharpening where aid and resilient infrastructure should go.
Map of the southeastern United States overlaying green Census low-income block groups with a dense web of blue and red hurricane tracks crossing the same coastal areas.

Low-income block groups (green) intersected with hurricane paths. The overlap flags where storm exposure and limited resources compound, sharpening where aid and resilient infrastructure should go.