A5048438229- Cryospheric studies and observations
- Climate change and permafrost
- Arctic and Antarctic ice dynamics
- Winter Sports Injuries and Performance
- Soil Moisture and Remote Sensing
- Remote Sensing and LiDAR Applications
- Remote Sensing in Agriculture
- Landslides and related hazards
- Atmospheric aerosols and clouds
- Arctic and Russian Policy Studies
- Species Distribution and Climate Change
- Meteorological Phenomena and Simulations
- Atmospheric Ozone and Climate
- Indigenous Studies and Ecology
- Advanced Optical Sensing Technologies
- Methane Hydrates and Related Phenomena
- Land Use and Ecosystem Services
- Climate variability and models
- Urban Heat Island Mitigation
- Icing and De-icing Technologies
- Precipitation Measurement and Analysis
- Atmospheric chemistry and aerosols
Finnish Meteorological Institute
2016-2025
University of Lapland
2022-2024
University of Helsinki
2019
In-situ snow measurements conducted by European institutions for operational, research, and energy business applications were surveyed in the framework of Cooperation Science Technology (COST) Action ES1404, called “A network a harmonised monitoring benefit climate change scenarios, hydrology, numerical weather prediction”. Here we present results this survey, which was answered 125 participants from 99 operational research institutions, belonging to 38 countries. The typologies environments...
Abstract Manually collected snow data are often considered as ground truth for many applications such climatological or hydrological studies. However, there sources of uncertainty that not quantified in detail. For the determination water equivalent cover (SWE), different core samplers and scales used, but they all based on same measurement principle. We conducted two field campaigns with 9 commonly used observational measurements research Europe northern America to better quantify...
Current methods for retrieving SWE (snow water equivalent) from space rely on passive microwave sensors. Observations are limited by poor spatial resolution, ambiguities related to separation of snow microstructural properties the total mass, and signal saturation when is deep (~>80 cm). The use SAR (Synthetic Aperture Radar) at suitable frequencies has been suggested as a potential observation method overcome coarse resolution Nevertheless, sensors operating are, up now, unavailable....
Abstract. The manual snow survey program of the Arctic Research Centre Finnish Meteorological Institute (FMI-ARC) consists numerous observations natural seasonal taiga snowpack in Sodankylä, northern Finland. easily accessible measurement areas represent typical forest and soil types boreal zone. Systematic measurements began 1909 with depth (HS) water equivalent (SWE). In 2006 expanded to cover macro- microstructure from regular pits at several sites using both traditional novel techniques....
Abstract Knowledge of snow microstructure is relevant for modelling the physical properties cover and simulating propagation electromagnetic waves in remote-sensing applications. Characterization field conditions is, however, a challenging task due to complex, sintered variable nature natural cover. A traditional measure applied as proxy microstructure, which can also be determined conditions, visually estimated grain size. Developing techniques allow measurement, example, specific surface...
Land surface temperature (LST) is a crucial geophysical parameter for understanding cryospheric processes such as snow accumulation, freeze-thaw cycles, and the energy budget. However, most existing passive microwave LST retrieval algorithms are not optimized Snow Surface Temperature (LSST) estimation, presenting significant limitation remote sensing observation of cryosphere. To address this, this study developed robust, all-weather, near real-time, standalone microwave-based LSST algorithm...
Svalbard is one of the hot spots Arctic Amplification, i.e., fastest warming places on Earth. Most often dust and black carbon (BC, soot) investigations in have been carried out clean remote areas close to settlement coal mines are rare. Therefore, our investigation focused vicinity Mine 5 7 (coal mining) Longyearbyen surroundings, as well samples collected from a nearby glacier. Dust storms observed (e.g., 11 September 2024).During 22-28 April 2024, Faculty Environmental Sciences - Czech...
Abstract. This is the first study to encompass a wide range of coupled snow evolution and microwave emission models in common modelling framework order generalise link between snowpack microstructure predicted by required reproduce observations brightness temperature as simulated models. Brightness temperatures at 18.7 36.5 GHz were 1323 ensemble members, formed from 63 Jules Investigation Model simulations, three functions, seven model configurations. Two years meteorological data Sodankylä...
While many microwave studies related to tree emission have been undertaken, a few considered the effect of phenological change on from coniferous trees. The permittivity vegetation tissue is known be influenced by water content, while content and phase sensitive temperature in particular at temperatures below freezing. In addition temperature, canopy-intercepted snow might also modify transmissivity range. this paper, season-long experiment was designed quantify accumulation observed tree. A...
Abstract. Information about forest background reflectance is needed for accurate biophysical parameter retrieval from canopies (overstory) with remote sensing. Separating under- and overstory signals would enable more modeling of carbon energy fluxes. We retrieved values the normalized difference vegetation index (NDVI) understory multi-angular Moderate Resolution Imaging Spectroradiometer (MODIS) bidirectional distribution function (BRDF)/albedo data (gridded 500 m daily Collection 6...
Volume scattering (VS) estimation plays a critical role in microwave emission modeling of the snowpack. However, it is challenging to obtain VS accurately for different frequencies by using model layered snowpacks (MEMLS), which one representative models. This article develops new method consider frequency and exponential correlation length based on snowfield campaign from November 2015 April 2016 Altay, China. Compared with commonly used empirical improved Born approximation (IBA)...
Abstract. Rain-on-snow (ROS) events occur across many regions of the terrestrial Arctic in mid-winter. Snowpack properties are changing, and extreme cases ice layers form which affect wildlife, vegetation soils beyond duration event. Specifically, satellite microwave observations have been shown to provide insight into known events. Only Ku-band radar (scatterometer) has applied so far entire Arctic. Data availability at this frequency is limited, however. The utility other frequencies from...
Snow sampling, either by inserting a tube through the entire snowpack or taking samples from vertical profile, is widely applied to measure snow depth, density, and water equivalent (SWE). A comparative study of snow-sampling methods was carried out on 24 March 2022 in Sodankylä, Finland. Six groups five countries (Estonia, Finland, Greenland, Iceland, Sweden) participated, using 12 different samplers, including 9 bulk samplers 3 density cutters. The cross-sectional area SWE varied 11 100...
Abstract. The Arctic Snow Microstructure Experiment (ASMEx) took place in Sodankylä, Finland the winters of 2013–2014 and 2014–2015. Radiometric, macro-, microstructure measurements were made under different experimental conditions homogenous snow slabs, extracted from natural seasonal taiga snowpack. Traditional modern measurement techniques used for macro- observations. Radiometric microwave emission on reflector absorber bases at frequencies 18.7, 21.0, 36.5, 89.0, 150.0 GHz, both...
Measuring winter precipitation in cold and windy regions is recognized as a difficult task. Nonetheless, the accurate measurement of solid provides important input data for predicting snowmelt floods avalanche danger monitoring climate change. The difficulties measuring are associated with environmental factors technological issues. Environmental that contribute to errors include wind, freezing rain, rime, large range particle shapes sizes. Technological issues gauge configuration, need...
Snow microstructure is an important factor for microwave and optical remote sensing of snow. One parameter used to describe it the specific surface area (SSA), which defined as surface-area-to-mass ratio snow grains. Reflectance at near infrared (NIR) short-wave (SWIR) wavelengths sensitive grain size therefore also SSA through theoretical relationship between equivalent size. To observe SSA, IceCube measures hemispherical reflectance a 1310 nm laser diode from sample surface. The recently...
Abstract. This is the first study to encompass a wide range of coupled snow evolution and microwave emission models in common modelling framework order generalise link between snowpack microstructure predicted by required reproduce observations brightness temperature as simulated models. Brightness temperatures at 18.7 36.5 GHz were 1323 ensemble members, formed from 63 Jules Investigation Model simulations, three functions seven model configurations. Two years meteorological data Sodankylä...
The absorption of shortwave irradiance in snow depends on the physical properties (e.g., grain size and shape, liquid water content, etc.) light-absorbing particles (LAP). Originating from natural anthropogenic sources, LAP has been reported to accelerate snowmelt significantly different regions globally. Yet, our process-level understanding after deposition onto remains rather limited. Here we investigate impacts artificial surfaces an outdoor environment northern Finland. Following dry...
In this study, snow slab data collected from the Arctic Snow Microstructure Experiment were used in conjunction with a six-directional flux coefficient model to calculate individual absorption and scattering coefficients. These coefficients formed basis for new semiempirical extinction model, using both frequency optical diameter as input parameters, along complex dielectric constant of snow. Radiometric observations, at 18.7, 21.0, 36.5 GHz horizontal polarization (H-Pol) vertical (V-Pol),...
The specific surface area (SSA) is a measure of the snow microstructure and can be determined using an instrument called IceCube. IceCube measures reflectance from sample with 1310 nm infrared laser. In this study, uncertainties associated measurements SSA were analyzed in two locations: Sodankylä, Finland Queen Maud Land, Antarctica. study tests repeatability by measuring several samples same height homogenous snowpack. Additionally, rotated to find minimum maximum values test uncertainty...
Abstract. Rain-on-Snow (ROS) events occur across many regions of the terrestrial Arctic in mid-winter. Snow pack properties are changing and extreme cases ice layers form which affect wildlife, vegetation soils beyond duration event. Specifically, satellite microwave observations have been shown to provide insight into known events. Only Ku-band radar (scatterometer) has applied so far entire Arctic. Data availability at this frequency is limited, however. The utility other frequencies from...
The Finnish Meteorological Institute (FMI) operates a suite of ground-based active and passive microwave instruments at test site representative the Northern boreal forest zone. provide hourly to daily multifrequency observations signatures from natural landscape throughout year. Supported by comprehensive in situ soil, vegetation, snow atmospheric conditions, data enable testing formulation new methods retrieve geophysical parameters remote sensing data. Complementing observations, airborne...