A5047279751- Cryospheric studies and observations
- Climate change and permafrost
- Arctic and Antarctic ice dynamics
- Soil Moisture and Remote Sensing
- Precipitation Measurement and Analysis
- Meteorological Phenomena and Simulations
- Climate variability and models
- Atmospheric and Environmental Gas Dynamics
- Hydrology and Watershed Management Studies
- Landslides and related hazards
- Aerospace Engineering and Energy Systems
- Geophysics and Gravity Measurements
- Water Resources and Management
- Winter Sports Injuries and Performance
- Fire effects on ecosystems
- Calibration and Measurement Techniques
- Plant Water Relations and Carbon Dynamics
- Computational Physics and Python Applications
- Seismic Waves and Analysis
- Ocean Waves and Remote Sensing
- Geographic Information Systems Studies
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Science and Climate Studies
- Scientific Research and Discoveries
Finnish Meteorological Institute
2015-2025
Arctic Research Centre
2007
Space Systems Finland (Finland)
2004
Abstract We describe the Northern Hemisphere terrestrial snow water equivalent (SWE) time series covering 1979–2018, containing daily, monthly and bias-corrected SWE estimates. The GlobSnow v3.0 dataset combines satellite-based passive microwave radiometer data (Nimbus-7 SMMR, DMSP SSM/I SSMIS) with ground based synoptic depth observations using bayesian assimilation, incorporating HUT Snow Emission model. original retrieval methodology has been further developed is presented in its current...
Significance We quantified a 36-y trend of advanced spring recovery carbon uptake across the northern hemisphere boreal evergreen forest zone. From this trend, we estimated corresponding change in global gross primary production (GPP) and further magnitude spatiotemporal variability GPP, that is, cross-photosynthetic by forest. Our main findings are following: ( i ) developed proxy indicator for from situ flux data on CO 2 exchange recent satellite snowmelt products ii established relation...
Snow cover is highly critical for global water and energy cycles because of its wide areal extent, high reflectivity good thermal insulation. Knowledge snow conditions, e.g., equivalent (SWE) depth, significant to hydrologic climatologic processes. Spaceborne passive microwave (PMW) data, namely, brightness temperature (TB), have been in use depth SWE retrieval at the scale since 1978. However, sensitivity TB these parameters complex due metamorphism (e.g., grain size, GS), which limits...
The European Space Agency (ESA) Snow Climate Change Initiative (CCI+) provides long-term, global time series of daily snow cover fraction and water equivalent (SWE). CCI+ SWE Version 1 (CCIv1) product is built on the GlobSnow algorithm, which combines passive microwave (PMW) data with in situ depth (SD) measurements to estimate SWE. While CCIv1 remains algorithmically similar most recent (GlobSnow 3), 2 (CCIv2) incorporates two notable differences. CCIv2 uses updated PMW from NASA MEaSUREs...
Determining the date of snowmelt clearance is an important issue for hydrological and climate research. Spaceborne radiometers are ideally suited global monitoring. In this paper, four different algorithms used to determine from Scanning Multichannel Microwave Radiometer Special Sensor Microwave/Imager data a nearly 30-year period. Algorithms based on thresholding channel differences, applying neural networks, time series analysis. The results compared with ground-based observations snow...
Abstract. We investigated the potential capability of random forest (RF) machine learning (ML) model to estimate snow depth in this work. Four combinations composed critical predictor variables were used train RF model. Then, we utilized three validation datasets from out-of-bag (OOB) samples, a temporal subset, and spatiotemporal subset verify fitted algorithms. The results indicated following: (1) accuracy is greatly influenced by geographic location, elevation, land cover fractions; (2)...
Abstract. Snow water equivalent (SWE) is an important variable in describing global seasonal snow cover. Traditionally, SWE has been measured manually at transects or using observations from weather stations. However, these measurements have a poor spatial coverage, and good alternative to situ use spaceborne passive microwave observations, which can provide coverage daily timescales. The reliability accuracy of estimates made radiometer data be improved by assimilating with station depth as...
Sentinel-1 (S-1) Synthetic Aperture Radar (SAR) is an important source of information for safe winter navigation in the Baltic Sea. The Finnish Meteorological Institute (FMI) and Swedish Hydrological (SMHI) jointly perform daily ice charting over charts are published during each~ season other SAR data main sources charting. also utilized a portfolio automated sea products provided near-real-time (NRT)~ after reception of~ imagery, mosaics. Both part Copernicus Marine Service (CMEMS) Sea Ice...
Abstract. Snow water equivalent (SWE) is a valuable characteristic of snow cover, and it can be estimated using passive spaceborne radiometer measurements. The radiometer-based GlobSnow SWE retrieval methodology, which assimilates weather station depth observations with microwave brightness temperatures, has improved the reliability accuracy when compared to stand-alone PMW methods. However, even this assimilation-based method fails estimate large (> 150 mm) values as changes from...
Seasonal snow is the largest single component of cryosphere, covering about 50% Northern Hemisphere’s land surface during mid-winter. Snow plays an important Earth’s hydrological and climate systems provides a significant feedback effect in warming owing to its high albedo. also major, if not dominant, freshwater source many regions contribution global water cycle.Within Copernicus Climate Change Service (C3S) Finnish Meteorological Institute will offer consistent...
Snow water equivalent (SWE) estimates based on microwave remote sensing require information snow characteristics, including grain size, and so often rely heavily ancillary information. Two decades ago, Pulliainen (2006) described how from passive (PMW) brightness temperatures in situ depth observations could be combined to better estimate SWE, compared solely PMW data. This innovation led the GlobSnow (GS) line of SWE products. Research development GS algorithm has continued under auspices...
This paper describes the methodology for deriving yearly pixel-wise snow melt-off day maps from optical data-based FSC (Fractional Snow Cover) without conducting any interpolation cloud-obscured pixels or otherwise missing data. The Copernicus CryoLand Pan-European time series 2001–2016 re-gridded to 0.1° serves as input production of 16 years Europe. These are compared with passive microwave radiometer (MWR) melt retrievals, compare performance these two independent datasets, particularly...
Information on snow properties is of critical relevance for a wide range scientific studies and operational applications, mainly hydrological purposes. However, the ground-based monitoring dynamics challenging task, especially over complex topography under harsh environmental conditions. Remote sensing powerful resource providing observations at large scale. This study addresses potential using Sentinel-2 high-resolution imagery to assess moderate-resolution products, namely H10—Snow...
This paper presents the efforts for creating two global scale snow dataset covering 15 and 30 years of satellite-based observations, one describing extent cover (SE) other water equivalent (SWE) characteristics. The main emphasis is validation work carried out SWE product that will non-mountainous regions Northern Hemisphere on a daily basis starting from 1979. has been within ESA Globsnow project.
As spaceborne C-band synthetic aperture radar (SAR) observations are used for monitoring the snow cover during spring melt period, temporal changes in backscatter from forest disturb mapping of cover. This paper presents an analysis backscattering properties eight test areas situated around weather stations. Test represent open and forested landscapes Northern Finland. Analyses carried out using extensive multitemporal ERS-2 SAR data set period. We validate following topics: 1) model...
Abstract. Snow water equivalent (SWE) is a valuable characteristic of snow cover, and it can be estimated using passive spaceborne radiometer measurements. The radiometer-based GlobSnow SWE retrieval methodology, which assimilates weather station depth observations into the retrieval, has improved reliability accuracy when compared to stand-alone retrievals. To further improve we investigate implementing spatially temporally varying densities procedure. Thus far, used constant density...
The presence and amount of snow, given in terms snow water equivalent (SWE), is an essential physical characteristic influencing climate hydrological processes. For the recent decades, remote sensing has proven to be a valuable tool for deriving regional global scale information on SWE. However, determining SWE reliably from data many local-scale applications remains challenge. Microwave radiometers are currently best option determine since they respond depth density. Further, weather...
We examined the use of data from active (QuikScat on SeaWinds) and passive (SSM/I DMSP) space-borne microwave sensors for monitoring key snow parameters in Finland. The feasibility these task was determined both separately using a combined set. results are based satellite ground truth 21 test sites Finland covering winters 1999-2000, 2000-2001, 2001-2002. show that Ku-band scatterometer with fixed incidence angle provides reasonable accuracy retrieval dry water equivalent (SWE). Using...