Methodology

How every number on Earthasium is made: what goes in, the steps, and what a number is not. When a method changes, the change is dated at the end of this page.

Principles

• Every number shows its source, its time and its age. Old data is never passed off as fresh.
• Nothing is invented or filled in. What's on the globe was measured, or modeled by a named source and labeled "model".
• Evidence, not verdicts: claims are graded (below) and written as "linked to", never "caused by".
• Companies are named only from public records we may reuse. Individuals are never named.
• Heat and haze are kept apart: fires explain smoke; El Niño, the Indian Ocean Dipole and the dry season drive heat.
• We show exposure (people under unhealthy air), never our own estimates of health harm.

Evidence grades

Every evidence card carries its grade, its source and date, and a corrections link.

How fresh the data is

• Each source has an expected interval (how often it publishes) and a latency (the normal delay from observation to availability). Together they make its window.
• A source's age is the time since its newest good data. It is on time within one window, late beyond it, and unavailable beyond three windows or when we never got any.
• Menu › Status lists every source with its state and last update.
• Late data keeps its age on screen. Fire detections that are late say how old the newest one is, and no count is made over a day they don't cover.

Active fires

• Input: NASA FIRMS near-real-time detections from VIIRS (NOAA-20, NOAA-21, and Suomi NPP until 2 November 2026) and MODIS (Terra, Aqua).
• Window: the 24 hours before each update. FIRMS's daily files reach back about two days, so older detections are left out rather than shown as recent.
• Each dot is one detection, at its pixel's center, colored and sized by its fire radiative power (FRP) on a log scale: 1 MW is faint and small, 1,000 MW and up is the brightest. Where FRP isn't reported, the dot shows at a low fixed level and its card says "not reported". Overlapping dots never add up: a cluster of weak fires doesn't look like one strong fire.
• Kalimantan count: the detections inside the Kalimantan box in the 24 hours before you read it, shown only while the detections are on time.
• Grade: every detection is Seen: a satellite measured heat there. A detection is not proof of a fire's cause, size or whether it was set on purpose.

The 2026 fire season in Kalimantan

• The season: from 1 January 2026 to the newest detection, so the year's early fires and every warning before the dry season are inside it.
• Input: every VIIRS detection from NOAA-20, NOAA-21 and Suomi NPP inside the box from 108.5° to 119.5° E and 4.5° S to 4.5° N: earlier days from NASA's archive of FIRMS detections (through NASA GIBS), the last week also from FIRMS's newest files. A detection found in both counts once. A day we couldn't read is left out and read again, never filled in.
• Cells: each detection is placed on a 375 m grid, the size of a VIIRS pixel straight below the satellite.
• Fire areas: cells within two cells of each other (about 0.75 to 1.06 km) belong to one area, whatever the day. Groups of 10 or more detections count; the 24 largest are listed and analysed. Over a whole season, burning peatland joins into very large areas.
• Names: each area is named for the nearest town to its middle, with the distance and direction from it ("45 km southwest of Pulang Pisau"). Towns come from GeoNames: places of 5,000 people or more and every Indonesian provincial and regency seat. The same towns label the map.
• Active-fire footprint: the number of distinct cells × 0.140625 km². It shows where fire was detected, not the burned area: pixels widen toward the edge of a satellite's view, and ground that burned between passes or under thick smoke goes unseen.
• Outline growth: the day-to-day change in the radius of a circle as large as the outline around every cell detected so far, in km per day: how the outline grew, not the speed of a flame front, which daily passes can't measure.
• Fire radiative power: the daily total adds every detection's FRP that day; the peak is the strongest single detection.
• Key moments: the earliest and latest detections this season, the day with the highest total FRP, and the strongest detection. The fire may have started before the earliest.
• The timeline: one bar a day for the region's detections, from the season's first day. The dots under it are the official warnings, status changes and policies from the event log (Recorded), each with its source. The newest day is marked "so far" until its satellite passes are all in, and the 7-day figures use whole days.
• Provinces and regencies: each detection is counted in the regency or city it falls in (boundaries from Indonesia's statistics office, BPS, with WFP and OCHA, 2020) and that regency's province. Malaysian states and Brunei come from Natural Earth.
• On the map: each 750 m cell where fire was detected by the day shown is drawn on the terrain, colored by how long before that day fire was first detected there: pale yellow on the day itself, then yellow, orange and red, to deep red two months or more before. Over it stand 3D columns, one per hexagon of about 253 km²: their height and color show the detections in the 7 days to the day shown (taller and brighter is more fire). A flame marks each of the 24 largest fire areas, numbered as in Places. The ground comes from a cloud-free satellite mosaic, in even daylight, with ×2.5 vertical exaggeration, stated on the page. The day's satellite images (clouds and smoke) are off unless you turn them on.
• Air and weather: for 20 towns and cities in Kalimantan and the places its haze reaches, day by day: fine particles (PM2.5) from the Copernicus Atmosphere Monitoring Service's global model (CAMS, about 40 km; a model, not a measurement), colored by the US EPA's categories for 24-hour averages; rain, heat, humidity and wind from ERA5, about five days behind; and Singapore's official 24-hour PSI from its National Environment Agency (NEA). These show exposure, never our own estimate of harm to health.
• The event log: every warning, official action, report and figure of the season, each dated, graded (Recorded: from the issuing authority; Reported: news, NGO or research) and linked to its sources. Offices are named, never individuals; a company only from a court decision or an official enforcement release. Health figures appear only as officials or established outlets reported them.
• Grades: detections are Seen; footprints, outlines, growth, names, columns and areas are worked out from them, as above; air and weather are Model; Singapore's PSI is Recorded.

Model maps: air temperature, rain, wind

• Input: NOAA GFS on its 0.5° grid, from the newest run that has published the hour nearest the present. Its hours are 3 apart, so "now" is at most 1.5 hours off, and the map says which hour.
• What each shows: air temperature 2 m above the ground; the precipitation rate at that hour, not an average over time; wind 10 m above the ground.
• Drawing: each place takes the value between the four nearest grid points, colored on a scientific color scale (cmocean thermal for temperature, rain for rain, on a log scale from 0.1 to 50 mm/h). Under 0.05 mm/h the map shows no rain color at all.
• Labels: each map says "model", its source (NOAA GFS), the hour it's valid for and the run it came from. A map we don't have data for isn't offered.

Where the air came from

• Places: about 14,000 places worldwide, one for each area of about 1,770 km² holding a town of 15,000 people or more (GeoNames), named for its largest town. A tap is answered by the nearest of these places within about 70 km, and the card names it and how far away it is.
• Winds: NOAA GFS at 925 hPa (about 750 m up, where most haze travels in Southeast Asia), every 3 hours.
• Tracing: the air is traced backward 72 hours from the newest wind, step by step every 15 minutes, with the wind taken between grid points and between hours.
• Fires crossed: NASA FIRMS detections within 25 km of the air's path, seen within 12 hours before or after it passed.
• What it isn't: a measurement of where the air was (it's a model), or proof that a fire's smoke reached the place (it's a link in space and time). The card says both.
• Updates: with each new GFS hour, about every 3 hours.

Why now

• El Niño: NOAA's Oceanic Niño Index, the 3-month sea surface temperature anomaly in the Niño 3.4 region. The card gives the newest season's value and how many seasons in a row have been at or above +0.5 °C (or at or below −0.5 °C for La Niña). NOAA counts five in a row as an episode; we give the count, not our own verdict.

Place forecasts, air quality, rivers and sea

• Source: Open-Meteo, for a point rounded to 0.1° (about 11 km). Forecasts blend the best models for the place (ECMWF, DWD, NOAA and others): current conditions every 15 minutes, hourly to 48 hours, daily to 16 days. Air quality: CAMS global (about 40 km), with the US and European indices. Rivers: GloFAS discharge for the nearest river, 30 days back and ahead, against its usual level for the date. Sea: wave height, period and direction, and sea surface temperature.
• In the past: the hour nearest the moment, from ERA5 when it's more than six days old, else from the forecast models' recent past.
• Grade: all Model. The air-quality indices show exposure, never an estimate of harm.

Time and the archive

• Live follows the clock: each dated layer shows its newest image that Earthasium holds a whole-world copy of, or else NASA's newest.
• Archive shows a moment in the past: each dated layer shows its newest image at or before that moment, or nothing when it has none. A newer image never stands in for an older moment. The sun and the night side follow the moment.
• Fire detections in the archive: the 24 hours before the moment, when we hold them.
• Live only: the model maps (each is for one hour) and the earthquake and disaster alerts (the past day).
• One moment on screen: the sun, every dated layer and Live or Archive follow one moment. On the Kalimantan Fires page it is the season's timeline, and Time moves the timeline; elsewhere it is the globe's own, which comes back when you leave the page.

The globe screen

• Loading: the loading screen counts real work only: the globe starting, the data the first view needs, and the view's own satellite images, loaded or failed for good. It reaches 100% only once everything has loaded. Later, while new images load, "Loading…" shows beside the logo with its percentage.
• Whole-globe views are drawn from one whole-world image per satellite layer (2048 × 1024 pixels), which Earthasium makes at least hourly from NASA GIBS and EUMETSAT at a stated moment. Closer views load NASA's own tiles of that same moment, so a view never mixes two times.
• Coordinates: WGS84 latitude and longitude under the pointer, or at the middle of the screen on touch screens, with as many decimals as a screen pixel is worth (2 for a continent, 5 for a street).
• Scale bar: ground distance per screen pixel at the middle of the screen; the bar shows the longest round distance that fits.
• Show My Location: your browser's location, rounded to 0.1° (about 11 km) before anything uses it. Only that rounded point leaves your browser, for the forecast and the air's path there. Nothing is stored.

Plain words

Cards give a word beside each main number, so they read at a glance; the number always shows too, with its source and time.

The temperature words are ours: how the air feels, not a health measure.

Place search

• Places: towns and cities of 15,000 people or more worldwide, and of 1,000 or more in Indonesia (GeoNames), each with its province and other spellings; countries from Natural Earth.
• Matching: every word must match a name, a province or a country; accents don't matter, and a close misspelling of a longer word still matches.
• Coordinates: decimal degrees, degrees and minutes, or degrees, minutes and seconds, with N, S, E, W or the Indonesian LU, LS, BT and BB.
• No street addresses: finding them needs an outside service, which would receive what you type.

Units

Values stay in the units their source publishes and convert only on screen. Metric is the default (°C, km, m); Menu › Units switches to imperial, or changes any quantity on its own. Beaufort uses the WMO's thresholds; UTM follows Snyder (1987) on WGS84; MGRS comes from the proj4js library.

Changes

• 24 October 2026: fire events in Kalimantan, time travel, place forecasts and units of your choice.
• 24 October 2026: the Kalimantan page covers the whole 2026 season, from 10 July, with named fire areas and the ground colored by when fire was first detected.
• 24 October 2026: late fire detections show their age, and no count is given for a period they do not cover.
• 25 October 2026: the Kalimantan page covers 2026 from 1 January, with provinces and regencies, 3D columns, air, weather and Singapore's PSI, and the season's event log. The ground's colors are now a fire ramp, pale yellow to deep red.
• 24 October 2026: metric units by default for everyone.
• 24 October 2026: whole-globe views are drawn from whole-world images made at a stated time.