Instruments at the edge of the cryosphere

01Data story

Faster than the globe.

The Arctic Monitoring and Assessment Programme found Arctic surface air temperature rose three times as fast as the global mean between 1971 and 2019¹. A later study using several datasets found close to four times as fast since 1979². The ratio depends on the period; the direction does not.

Figure as text: Arctic warming relative to the global mean

A bar chart: the global rate as one, the 1971 to 2019 Arctic rate as three times, and the 1979 to 2021 Arctic rate as nearly four times.

02Map story

Where the long records come from.

A handful of baseline observatories carry the longest Arctic records of greenhouse gases and aerosols, among them Alert in Nunavut and Utqiaġvik in Alaska, listed in the Global Atmosphere Watch station register³. Cambridge Bay hosts Canada’s High Arctic research campus⁴. Polar-orbiting radar satellites see the sea ice through the polar night⁵.

Figure as text: Selected Arctic observing sites and a polar orbit

A wireframe globe viewed over the Arctic with four labelled observing sites and a polar orbit with its ground track.

• Alert (82.5° N, 62.5° W): Global Atmosphere Watch station
• Utqiaġvik (71.3° N, 156.6° W): Global Atmosphere Watch station
• Cambridge Bay (69.1° N, 105.1° W): High Arctic research campus
• Ny-Ålesund (78.9° N, 11.9° E): Global Atmosphere Watch station

03Simulator

Seeing the pole from orbit.

A satellite in a near-polar orbit passes over high latitudes on every revolution, so Arctic sites are revisited more often than equatorial ones. Its footprint above a given elevation mask follows from geometry alone⁶. Lower the orbit and the delay shrinks, but so does the circle it can serve.

Figure as text: Footprint and delay of a low polar orbit

A section through the Earth with a satellite above it and its footprint arc in red.

04Field scene

What it takes to keep one running.

A station on the tundra is a microgrid, a satellite terminal, a weather mast and a geodetic receiver, each specified for −40 °C and months of darkness. The design is mundane and decisive: the record is only as long as the station’s worst winter.

Figure as text: An Arctic station and its links

A wireframe Arctic station with a microgrid, satellite terminal, weather station, GNSS monument and edge node.

• Satellite terminal
• Weather
• Microgrid