All you can measure at the Planetary Emissivity Laboratory (PEL) at DLR, in Berlin

The Institute for Planetary Research has an expertise in spectroscopy of minerals, rocks, meteorites, and organic matter, build up in more than two decades. The available equipment allows spectroscopy from the visible to TIR range using bi-conical reflection, transmission and emission spectroscopy. The institute has an outstanding heritage in designing and building infrared remote-sensing instruments for planetary missions. The PEL has been operating in various configurations for the last 10 years. The laboratory experimental facilities consist of the main emissivity spectrometer laboratory, a supporting spectrometer laboratory for reflectance and transmission measurements, sample preparation facilities and an extensive collection of rocks and minerals

The observed recent surface air temperature development across Svalbard and concurring footprints in local sea ice cover

The Svalbard archipelago in the Arctic North Atlantic is experiencing rapid changes in the surface climate and sea ice distribution, with impacts for the coupled climate system and the local society. Using observational data of surface air temperature (SAT) from 1980–2016 across the whole Svalbard archipelago, and sea ice extent (SIE) from operational sea ice charts, a systematic assessment of climatologies, long-term changes and regional differences is conducted. The proximity to the warm water mass of the West Spitsbergen Current (WSC) drives a markedly warmer climate in the western coastal regions compared to northern and eastern Svalbard. This imprints on the SIE climatology in southern and western Svalbard, where the annual maxima of 50–60% area ice coverage are substantially less than 80–90% in the northern and eastern fjords. Owing to winter-amplified warming, the local climate is shifting towards more maritime conditions, and SIE reductions of between 5% to 20% per decade in particular regions are found, such that a number of fjords in the west have been virtually ice-free in recent winters. The strongest decline comes along with SAT forcing and occurs over the most recent 1–2 decades in all regions. In the 1980s and 1990s, enhanced northerly winds and sea ice drift can explain 30–50% of SIE variability around northern Svalbard, where they had correspondingly lead to a SIE increase. At the same time, interannual temperature fluctuations within the WSC waters can explain 20-37% of SIE variability in a number of fjords on the west coast. With an ongoing warming it is suggested that both the meteorological and cryospheric conditions in eastern Svalbard will become increasingly similar to what is already observed in the western fjords, namely suppressed typical Arctic climate conditions

Laboratory studies of thermal space weathering on airless bodies

Deriving the surface composition of Mercury from remote sensing hyper spectral data is a challenging task. Mercury’s surface has a low iron abundance, which complicates the application of “traditional” space weathering approach. In addition the high temperatures on Mercury lead to previously unseen changes in the spectral characteristics, which we call “thermal space weathering”. The Planetary Emissivity Laboratory (PEL) at DLR in Berlin was setup specifically to study the effects of high temperatures on the spectral characteristics of planetary analog materials. It allows characterizing “thermal space weathering” and adds temperature as another important factor for the creation of spectral libraries. Thermal space weathering can produce reversible as well as irreversible changes in the spectral characteristics of materials. In comparison to “traditional space weathering” it acts on much shorter timescales. We are going to present a number of examples for thermal space weathering effects in the visible as well as infrared spectral range

Cold Air Outbreaks in Fram Strait: Climatology, Trends, and Observations During an Extreme Season in 2020

Fram Strait in the northern North Atlantic is a key region for marine cold air outbreaks (MCAOs), southward discharges of polar air under northerly air flow, which have a strong impact on air-sea heat fluxes, boundary layer processes and severe weather. This study investigates climatologies and decadal trends of Fram Strait MCAOs of different intensity classes based on the ERA5 reanalysis product for 1979–2020. Among striking interannual variability, it is shown that the main MCAO season is December through March, when MCAOs occur around 2/3 of the time. We report on significant decadal MCAO decreases in December and January, and a significant increase in March. While the mid-winter decrease is mainly related to the different paces of warming between the surface and the lower atmosphere, the increase in March can be related to changes in synoptic circulation patterns. As an explanation for the latter, a possible feedback between retreating Barents Sea sea ice, enhanced cyclonic activity and Fram Strait MCAOs is postulated. Exemplifying the trend toward stronger MCAOs during March, the study details the recordbreaking MCAO season in early 2020, and an observational case study of an extreme MCAO event in March 2020 is conducted. Thereby, radiosonde observations are combined with kinematic air back-trajectories to provide rare observational evidence for the diabatic cooling and drying during the MCAO preconditioning phase

Radiation balance diversity on NW Spitsbergen in 2010–2014

This article presents the results of observations of selected fluxes of the radiation balance in north-western Spitsbergen in the years from 2010 to 2014. Measurements were taken in Ny-Ålesund and in the area of Kaffiøyra, on different surface types occurring in the Polar zone: moraine, tundra, snow and ice. Substantial differences in the radiation balance among the various types of surface were observed. The observations carried out in the summer seasons of 2010–2014 in the area of Kaffiøyra demonstrated that the considerable reflection of solar radiation on the Waldemar Glacier (albedo 55%) resulted in a smaller solar energy net income. During the polar day, a diurnal course of the components of the radiation balance was apparently related to the solar elevation angle. When the sun was low over the horizon, the radiation balance became negative, especially on the glacier. Diurnal, annual and multi-annual variations in the radiation balance have a significant influence on the functioning of the environment in polar conditions

On the Effect of Emerging Angle on Emissivity Spectra: Application to Small Bodies

We studied the influence of emerging angle on emissivity spectra measured in air and in vacuum, with particular attention to asteroids-like conditions

Correlation of wind and solar power in high-latitude arctic areas in Northern Norway and Svalbard

This paper assesses the possibilities for combining wind and solar power in a household-scale hybrid renewable energy system in arctic high-latitude areas in the North of Norway. By combining two complementary renewable energy sources, the efficiency and reliability of the power output can be improved compared to a system utilizing wind or solar power independently. This paper assesses the correlation between wind and solar power on different timescales in four different locations in Northern Norway and Svalbard. For all locations complementary characteristics of wind and solar power are found, however, the strength of the correlation is highly variable for each location and for the different timescales. The best correlation for all places is found on a monthly timescale. HOMER is used to run simulations on hybrid renewable energy systems (HRES) for each location. For three of the four locations the HRES produces more power than what is consumed in the household