Joshua Stevens
Portfolio
Selected work
Maps, satellite imagery, and data visualizations from more than a decade in the field.
2026
Canadian Smoke Blankets US Skies
Animating smoke forecasts during the summer of 2026.
Produce Parasite Sickens in Michigan
Interactive map tracking tens of thousands sickened by contaminated produce.
How Storms Shape Words
Whether you say 'fireflies' or 'lightning bugs' might come down to the weather.
Earth in Action
Automated, animated maps of Earth's dynamic processes generated daily.
2025
Hurricane Melissa Breaks Records
Hot seas led to record-breaking intensification and destruction.
Mapping Climate Anxiety in the US
Do people in areas more prone to climate-related disasters have more 'climate anxiety?'
Mapping Meteors
Visualizing meteors entering our atmosphere, as tracked by government sensors.
Mapping the Middles of the United States
Every state has a middle. And there's more than one way to measure that.
2024
The Mass We Made
A high-resolution map of the built environment of the contiguous United States.
Mapping Pinball Machines
There are over 31,000 pinball machines in the U.S. And we can map them.
Counting Up Eclipses
Mapping 5,000 years of solar eclipses.
A Climate Message from the 1980s
What did climate models of the 1980s say about now?
2023
2022
The Shrinking Salt Lake
Water levels in the Great Salt Lake dropped to new record lows.
Measuring War’s Effect on a Global Breadbasket
Using satellites to track the impact of the Russia-Ukraine conflict.
Catastrophic Flooding in Yellowstone
Snowmelt and heavy rain caused historic flooding around the national park.
Tracking the Demise of a Giant Iceberg
Scientists chronicled the death throes of one of the world’s largest icebergs.
Enduring Antarctic Sea Ice
An expedition has located the lost ship of Antarctic explorer Ernest Shackleton.
No Breathing Easy for City Dwellers
Linking air pollution with health outcomes in cities around the world.
Dramatic Changes at Hunga Tonga
NASA scientists have been closely watching the evolution of the volcanic island.
Bathed in a Sea of Artificial Light
A new global atlas extends measurements of nighttime lights to the sea.
2021
Seeing Suomi
Reindeer, indigenous people, and modern meteorology converge.
An Extra Air Pollution Burden
Air quality in D.C. has improved. But the gains have not been realized evenly.
Fires Fueled Unprecedented Blooms
Iron-rich aerosols fertilized huge phytoplankton populations.
Scientific Questions Arrive in Ports
Shipping activity following COVID backlogs may be affecting air quality.
Superbolts Carry Super Power
Scientists reveal details of a rare type of lightning that stretches into space.
California’s Surge of Large Fires
Climate change, a century of fire suppression, and population growth are a recipe for fire.
Fossil Fjords in Namibia
Ice that carved a network of valleys 300 million years ago is gone, but the valleys remain.
Climate Change Pushes Fires to Higher Ground
Wildfires in the western U.S. have been spreading to higher elevations.
Devastating Rain in Tennessee
A burst of severe and extremely localized rainfall led to catastrophic flash floods in Tennessee.
Meteors Great and Small
Abundant streaks of light raced across the night sky during the Perseid meteor shower.
Unusually Smoky Fire Season in Sakha
Wildfires are approaching records for estimated carbon emissions.
Anticipating Future Sea Levels
Scientific understanding of the factors that control sea level has improved dramatically.
Sizing Up a Tabular Iceberg
The topography of Antarctic Iceberg A-76 provides insight into the strange properties of ice.
Discovering the Charlotte Whale
The bones of a beluga whale were excavated from a landlocked central part of Vermont.
Smoke in the Stratosphere
In the stratosphere, aerosols from fires or volcanic eruptions can function like shade.
Rock and Glass Shards Blanket Soufriére
Volcanic ash poses myriad hazards in the air and on the ground.
Surigae Stirs Up the Pacific
The super typhoon reached extreme intensity earlier than any storm in the satellite era.
Tracking La Soufrière’s Plume
Explosive eruptions have flung ash and sulfate particles to the stratosphere.
A Deadly Debris Flow in India
A torrent of debris from a mountain in the Himalaya devastated remote valleys in Uttarakhand.
Shrinking Margins of Greenland
At least 200 of the island’s coastal glaciers have retreated over the past 20 years.
2020
Nitrogen Dioxide Levels Rebound in China
As coronavirus lockdowns lift, signs of renewed industrial activity emerge in the atmosphere.
Flooding of the Red River
The geography and river direction play a role in frequent flooding of the Red River.
Aerosols Plummet During Lockdowns
In the wake of coronavirus quarantines, the air over India became significantly clearer.
Record Low Ozone in the Arctic
Unusual weather led to ozone declines in the northern hemisphere.
Observing Tornado Tracks by Satellite
Storm scars are visible in both natural color and heat signatures on the landscape.
Parched Conditions in Germany
With little spring rain, the country could face a drought for the third summer in a row.
Sea Ice Remains Below Normal
Seasonal bumps in sea ice at both poles were not enough to bring levels back to normal.
Nighttime Lights show Change in China
The impact of coronavirus lockdowns is evident in nighttime lights seen from space.
Satellites Aid Bison Management
The growing season is getting longer for the vegetation fed on by Yellowstone's bison.
Relentless Floods on the James River
Satellites and river gages show year-long flooding has lasted well into winter.
Airborne NO2 Drops over China
Coronavirus lockdowns cause industrial activity and airborne pollutants to plummet.
Phenomenal Faults and Foldse
A story of continental collisions that played out almost two billion years ago.
Remnants of an Ancient Lake
Evidence of Lake Mega Chad remains etched in the sand.
More Rain, More Landslides
Warming temperatures and intense rainfall may lead to increased landslide activity.
Polar Bears Struggle as Sea Ice Declines
Bears are spending less time on sea ice where they hunt and feed the most.
The Second Warmest Year on Record
The past five years have been the warmest of the past 140 years.
2019
A Hidden Threat
An earthquake made the land flow like mud in a place where science previously said it shouldn't.
Fierce Diablo Winds
The notoriously hot, dry winds fanned California's largest wildfire of the 2019 season.
Too Bright at Night
Artificial lighting may disrupt nocturnal wildlife in Chicago's green spaces.
Climate Change brings Landscape Change
A warming world will tansform Alaska's boreal forests.
Darkness after Dorian
South Carolina's coasts were hit with power outages in the wake of the powerful hurricane.
New Maps of Sunburn Risk
NASA and the CDC help the public understand risks behind America's most common cancer.
The Pacific Crest Trail
See the historic and majestic trail from the vantage point of space.
A Second Heatwave Scorches Europe
July temperatures soared 15°C higher than the previous heatwave in June.
Crater Lake Transect
ICESat-2's overflight of Mount Mazama offers a unique look at an iconic lake.
Measuring Earth's Movement
Scientists are getting better at measuring how much earthquakes move the ground.
Green Spaces are Good for Health
The risk of psychiatric disorders is lower for those growing up in greener spaces.
Record-setting Seaweed
A belt of brown algae stretches from West Africa to the Gulf of Mexico.
A Longer Dry Season
The summer dry season has lengthened by 10 days in the Congolese rainforest.
Slow and Severe
Dangerous increases in rain follow tropical cyclones that are stalling over coastal cities.
The Carbon Footprint of Cities
Fewer in number, the largest and most affluent cities account for the greatest emissions.
Facebook and Fires
Observing population movements during disasters through activity on social media.
A Future at Risk
Unstable rainfall patterns bring uncertainty to the food security of vulnerable populations.
The Polar Vortex
Descending Arctic air brought record low temperatures to North America.
The Rincon
Myriad canyons reach out from the serpentine courses of the Colorado and Escalante Rivers.
2018
A Glacial Pace
In response to a warming climate, Asian glaciers are becoming thinner. And slower.
A Laser in Space Pointed at Earth
Photons fired at 10,000 pulses per second reveal the planet's ups and downs.
Ozone Hole Tempered by CFC Reductions
A decline in ozone-depleting chemicals is good news for the stratosphere.
Rainy October Soaks Texas
Storm after storm dumped record rainfall in parts of Texas.
After the Flood
Following torrential rains, North Carolina's rivers carried organic material out to sea.
Florence Inundates the Carolinas
Soils were primed for flooding well before the storm arrived.
The Winds of Hurricane Florence
Wind speeds waxed and waned in the two weeks before Florence made landfall.
One Day of Global Aerosols
Tropical cyclones, dust storms, and fires spread tiny particles throughout the atmosphere.
The Atmospheric Cost of Wildfires
As fires rage on the ground, harmful particulates reach the sky.
Rare Fair Skies
Mapping the likelihood of clouds in the UK and Ireland.
Monument Valley
A quintessential picture of the American West, seen by satellites.
Probing Kilauea's Plume
As fissures split the ground, sulfates billowed into the Hawaiian skies. Satellites reveal their path.
A Smog Over Solar Gains in China
Sun-blocking smog has hamstrung China's solar revolution.
The Channeled Scablands
When a glacial dam broke during the last Ice Age, it changed the Columbian Plateau forever.
Forecasting Landslides
A new model enables scientists to forecast landslide hazards in near real-time.
Earlier Springs in National Parks
Climate change is bringing early springs to America's National Parks.
Cyclone Marcus
The first category-5 cyclone of 2018 got a hot start, then fizzled out over cooler water.
Mangrove Regrowth in Senegal
Mangrove forests are retaking lost ground after decades of drought.
Fire Season in Southeast Asia
Free from the humidity of the monsoon season, human-induced fires are at their peak.
Violent Blast from Sinabung
An explosive eruption in Indonesia sent ash and sulfur dioxide into the atmosphere.
Gita Batters the South Pacific
The worst storm in 60 years battered the islands of Tonga at Category-4 strength.
A Cold Greeting in Pyeongchang
The Winter Olympics kicked off with complaints of broken skis and hypothermia.
Tropical Glaciers in Retreat
There are glaciers in the tropics. For now.
The Cotahuasi Canyon
More than twice as deep as the Grand Canyon, this chasm in Peru is a sight to behold.
Volcán de Fuego Erupts
Multiple sensors get a look at a recent eruption from this active stratovolcano.
Cape Town is Drying Up
The South African city is on a perilous path toward running out of water.
Satellites and Food Safety
Models reveal when—and where—to harvest shellfish and avoid a dangerous neurotoxin.
2017
Pinpointing Where the Lights Went Out in Puerto Rico
NASA assists in recovery after Maria.
The Global Spread of Bare Ground
Human activity is changing the surface of Earth.
Signature of a Storm
Modeling the structure of hurricane Maria's stormy clouds.
Rainy Fingerprints of Irma
Rainfall shows how hurricane paths can both reveal and mislead.
Hot Water Ahead for Hurricane Irma
A direct path into abundant hurricane fuel.
Soil Moisture Satellite Observes Harvey’s Wrath
Record rain fell in a region primed for flooding.
Record-Breaking Smoke Over Canada
Thick plumes could turn day into night.
Mapping Cloudiness During the Eclipse
Analyzing seventeen years of cloud probability.
Finding a Lost City
Could images from space locate a city only known on ancient maps?
Landsat Spots Birth of Iceberg A-68
Thermal imaging sees through the darkness of polar winter.
Winds of Change
Ponds grow, shrink, and merge in the Mississippi River Delta.
Penguin Droppings are Fertile Ground for Science
New colonies discovered from space.
Sources of Ignition
Humans, not lightning, cause most US wildfires.
NASA's Black Marble
Visualizing the human footprint on planet Earth.
2016
Arctic Sea Ice at Record Lows
Polar sea ice is in indisputable decline.
Drought Continues to Grip Southern California
20% of the state under exceptional drought.
Antarctic Sea Ice at Record Lows
Even during growth, Antarctic gains do not offset Arctic losses.
Sulfur Dioxide Spreads Over Iraq
After conflict, sulfur and carbon cloud the skies of Mosul.
Power Outages Plague Southeast
Satellites and power companies reveal Matthew's impact.
Sea Ice Fact Sheet
Floating ice has a profound influence on the polar environment.
A Tale of Fire and Water
A NASA scientist's quest to understand the rain in Africa.
How Cities and Suburbs Affect the Chesapeake Bay
Measuring three decades of growth in Baltimore.
Climate Change and National Parks
Climate records—and ecyosystems—are on the move.
New Seafloor Map Helps Scientists Find New Features
A map based on gravity proves to be useful.
2015
Historic Rainfall in India
Chennai received more rainfall in 24 hours than it had seen on any day since 1901.
Post-quake Mapping of Earth's Motion
Satellites show how a magnitude 8.3 earthquake shifted the Chilean landscape.
A New Identity for Denali
On August 30, 2015 Mount McKinley formally became Denali.
Mapping Forest Loss with Landsat
Calculating carbon loss with cloud computing.