Airborne observations

The Airborne Campaign extends the observational coverage of the data collected by CarbonARA and provides invaluable context to the satellite and ground-based data. These data will help to assess how representative the fixed ground sites are of the wider landscapes within the study area and support carbon flux estimation in top-down approaches and help improve and validate terrestrial ecosystem models.

Airborne operations are scheduled for 26 September to 20 October 2025 with flights and measurements taken over both primary and secondary instrumented forest sites.

Measurements will be made using the Twin Otter aircraft from the British Antarctic Survey which will be equipped with a variety of remote sensing and in-situ atmospheric sampling apparatus.

All airborne activity will take place within a predefined Area of Operation (AOO), with the permission to carry out the science flights for the CarbonARA project kindly given by the Brazilian Airforce.

The Twin Otter aircraft from the British Antarctic Survey will be fitted with a variety of sensors to provide its scientific measurement capability, these sensors can be sub-divided into those performing remote sensing and those providing in situ atmosphe — The Twin Otter aircraft from the British Antarctic Survey extend the observational coverage of the data collected by CarbonARA and provides scientific remote sensing and in-situ atmospheric sampling.

Airborne observations

The Twin Otter aircraft is fitted with a variety of sensors to provide its scientific measurement capability. These sensors can be sub-divided into those performing remote sensing and those providing in-situ atmospheric sampling surveys:

Remote Sensing Survey

Airborne remote sensing instrumentation will provide information on biophysical processes related to GHG fluxes such as Solar Induced Fluorescence, Fire Radiative Power, concentrations of certain atmospheric gases, including CH₄, N₂O, NO₂, HCHO, HONO, CHOCHO will be made.

Airborne instruments will also make fire-related measurements, relating to column amounts in smoke plumes from fire as well as identifying wildfire location and intensity. These will be compared with ground-based observations to ensure robust estimates of and emissions factors close to the source.

Typically, these surveys would be conducted at a single altitude between 1000 – 10,000’ Above ground level, although some lower overpasses may be required to, for example, achieve measurement of Fire Radiative Power.

In-situ sampling

In-situ sampling instruments will collect samples of air and measure constituent gases and particulates. These measurements are taken in parallel with other variables such as wind speed and direction to support quantification of GHGs and other trace gases, such as carbon monoxide.

Flights will be made at 1000’ – 2000’ Above Ground Level, to sample, for example, smoke plumes.

The box will be orientated such that the upwind and downwind flight lines are perpendicular to the wind direction and so the flight lines will be adjusted just before the flight when accurate wind direction is known. In addition, a spiral ascent must be made in proximity to the target site; this is to determine the height of the boundary layer by detection the temperature inversion on ascent.

The British Antarctic Survey Twin Otter research aircraft

BAS Twin otter plane in hangar, Santarém

Test flight over the Amazon — September test flight over the Amazon

View of secondary forest from the BAS Twin Otter

Core instrumentation used as part of the airborne campaign:

Remote Sensing:	In-Situ:
Telops HyperCam Methane	MIRO MGA-10
InfraTec IR8300	DusTrak DRX/II
Optris PI400 / PIR uc 605 or HD Head	AlphaSense OPC
Specim AisaIBIS	Pressure transducer
SWING	PAH Sampling
	Atmospheric Profiler