The research teams of the National Land Survey of Finland and the Finnish Meteorological Institute have studied the future of Antarctic snow and ice in the LAS3R project. The project is special in the way that it investigates new methods for determining snow surface roughness using satellite observations, remote sensing and physical measurements. Photo: Antero Kukko/FINNARP
ANTERO KUKKO
Research professor,
FGI- National Land Survey of Finland
Translated with small modifications based on the original story published in POSITIO magazine on 10.5.2023. Read the story in Finnish: https://positio-lehti.fi/2023/05/las3r-projekti-lumen-ja-jaan-tutkimista-etelamantereella/
The research teams of the Finnish Geospatial Research Institute of the National Land Survey of Finland and the Finnish Meteorological Institute worked together at Antarctica to carry out snow and sea ice measurements in the LAS3R project. The researchers spent three months at the Finnish research station Aboa, from November 2022 to the beginning of February 2023. The expedition team included Antero Kukko (FGI-NLS), Aleksi Rimali (FMI) and Leena Leppänen (FMI, Arctic Centre). In addition, there were geologists and FINNARP staff who participated in the expedition. The project is funded by the Academy of Finland and the field research to Antarctica was carried out with the support of FINNARP.
Snow researchers of the LAS3R project and geologists from the Central Museum of Natural Sciences loading cargo at Troll Station in Antarctica that is maintained by the Norwegian Polar Institute. From the left, Arto Luttinen, Jussi Heinonen, Aleksi Rimali, Leena Leppänen and Antero Kukko. Photo: Antero Kukko/ FINNARP.
LAS3R project – aiming to make better estimates on the future of Antarctic snow and ice
The LAS3R project develops methods for determining the surface roughness of snow in large areas, which has not been possible before. The snow roughness data is compared to simultaneous satellite observations and in-situ measurements of physical properties in snow pits. Laser scanning and hyperspectral imaging with drones were carried out in the area and the incoming and reflected solar radiation from the snow surface was measured directly below the orbits of certain satellites. The satellites were for example Sentinel-2 optical remote sensing satellite, CryoSat with SAR interferometric radar altimeter and ICESat-2 probing the glaciers of the earth with a green laser. The work also contributes snow and ice models to be applied on the future ESA CRISTAL mission data, satellite planned to be launched in 2027.
The goal is to improve the models of Antarctic snow and ice refraction and the reliability of the interpretation of satellite data covering large areas. These data have an impact on global weather and climate models. With a sufficiently large drone, such surface models can be produced for relatively large areas. Accurate crystal measurements reveal the finest structure of the snow and with a slightly larger scale we can see the surface patterns formed by the wind drift of snow, such as small ridges, larger snowpacks and sastruga, and zooming out even further, the wavy surface of the glacier. There are very few previous observations on the surface roughness of Antarctic snow and sea ice, and no similar research with such set-up has been carried out before.
The reflectance of the snow surface measured by the laser scanner (scale of image -15 – -12 dB) already gives a good picture of the variation in the microtopography of the snow surface. The darker areas are loose snow piled up by the wind, yellow and red are hard snow surfaces with stronger reflectance, where the ice crystals carried by the strong winds have blasted patterns on the snow surface. At a wavelength of 1550 nm, dry snow reflects about 10% of the laser light, the reflection of wet snow and ice is even weaker. Image: Antero Kukko/ FINNARP.
Life in Aboa research station
The Finnish research station Aboa is in an area called Queen Maud’s Land, just south of the 73rd latitude. Home is a good 15,000 kilometers away. Continental ice thickness in Antarctica is on average 2300 meters and can measure up to almost five kilometers. The glacier covers 98 percent of the surface of Antarctica, an area 41 times the size of Finland.
Accommodation at the station is either in separate containers or rooms in the main building. The main building has a mess and a kitchen. There is also a sauna, washroom, and a washing machine. For the first weeks, the expedition melted their water from the snow and by Antarctic midsummer water could also be obtained from the glacial lake below Basen.
Antarctic petrels nest on the rocky cliffs of Basen, skuas can also be seen from time to time. Other life forms are a few Antarctic algae, mosses and lichens. The rest of the landscape is volcanic rock, ice and snow, the wind whistles constantly in the ears and the sun does not set in the summer.