DLR Falcon instrumentation

The DLR Falcon aircraft will conduct local research flights from the base at Kiruna. Its instrumentation will be similar to the one used for DEEPWAVE in New Zealand.

As a remote sensing instrument the 2 um Doppler wind lidar from IPA samples the disturbed wind field and gravity waves. The wind profiles are retrieved from line-of-sight measurements of the Doppler lidar by the velocity-azimuth display (VAD) technique. The instrument performs a conical step-and-stare scan around the vertical axis with a nadir angle of 20 deg°. Combined with the movement of the aircraft, this results in acycloid scan pattern. The horizontal resolution of the wind profiles (5-10 km) is determined by the time needed for one scanner revolution (24 times 1 or 2 s as accumulation time per scan position, plus 6 s for the scanner motion) and the aircraft velocity (160-240 m/s). The vertical resolution of 100 m is determined by the pulse length of the laser [full width at half maximum (FWHM) = 400 ns (~120 m)] and the nadir angle of 20 deg. Nadir pointing measurements only without scanningmode will provide vertical winds in a horizontal resolution of ~ 200 m.

Falcon is equipped with an airglow imager by DFD, DLR (Carsten Schmidt, Michael Bittner and Sabine Wüst). This allows to image gravity waves and breaking during flight, i.e. also in cloud conditions when Falcon flies above clouds.

HALO instrumentation

The instrumentation of the HALO research aircraft is described on the POLSTRACC Wiki.

Middle atmosphere lidars

The CORAL lidar by IPA is a ground-based system installed at Sodankylä, Finnland. The system is housed in an 8-foot container and consists of a laser emitter, trigger electronics, receiving telescopes, detectors and controlling software. It will provide night-time measurements of density and temperature (20-90 km). The lidar system emits at 532 nm and employs a 63 cm aperture telescope for reception. The field of view is 200 microrad. The resolution is 500 m to 2 km and 5-60 min depending on altitude. Additional Rayleigh lidars are installed further west at ALOMAR, Norway (IAP) and Esrange, Sweden (MISU). The IAP Fe lidar is also stationed at ALOMAR.

Airglow

All three sites (ALOMAR, Kiruna, Sodankylä) are equipped with Advanced mesospheric temperature mappers (AMTMs).

Radiosondes from Kiruna

One system which is used is the GRAW DFM-09. The DFM-09 has a ceramic temperature sensor and a capacitive polymer humidity sensor. Pressure as well as wind are determined via GPS (global positioning system) data. The accuracy of the measurements is < 0.2 K for temperature, < 5 % for relative humidity, < 0.3 hPa for pressure and < 0.2 m/s for wind speed.

The second system is a Vaisala Digicora MW41 sounding system with RS-41 radiosondes. The RS-41 has a platinum resistor temperature sensor with a total accuracy < 0.15 K for 1080-100 hPa and < 0.3 K for < 100 hPa. The capacitive humidity sensor has an accuracy of 2 %. The GPS determined pressure has an accuracy of 0.5~hPa for 1080-100~hPa and 0.2 hPa for 100-10hPa. The GPS wind finding has an accuracy of 0.15 m/s in wind speed and 2 degrees in wind direction. Data are stored in 1~s interval. The mean balloon ascent rate of 5~ms$^{-1}$ leads to a vertical resolution of about 5 meters.

Radiosondes are also launched at ALOMAR and Sodankylä.

Wind radars at Andenes

The MAARSY radar at ALOMAR can be operated in troposphere mode to measure zonal and meridional wind around the Falcon flight altitude.

The meteo radar provides zonal and meridional winds in the upper mesosphere.