Jouni T. Pulliainen

Comment on egusphere-2025-5778

Karoliina Särkelä, Timo Vesala, Torben R. Christensen, Juval Cohen et autres

Abstract. Although boreal peatlands play a critical role in the global carbon cycle, their year-round carbon dioxide (CO₂) dynamics — and particularly the contribution of the non-growing season (NGS) — remain poorly constrained in annual balance estimates. Using 17 years (2005–2021) of …

fi, dk, gl (code pays fourni par la source)

Comment on egusphere-2025-5778

Karoliina Särkelä, Timo Vesala, Torben R. Christensen, Juval Cohen et autres

Abstract. Although boreal peatlands play a critical role in the global carbon cycle, their year-round carbon dioxide (CO₂) dynamics — and particularly the contribution of the non-growing season (NGS) — remain poorly constrained in annual balance estimates. Using 17 years (2005–2021) of …

fi, dk, gl (code pays fourni par la source)

Ecosystem respiration during snowmelt and soil thaw leads to a rare annual CO₂ net loss in a boreal fen

Karoliina Särkelä, Timo Vesala, Torben R. Christensen, Juval Cohen et autres

Abstract. Although boreal peatlands play a critical role in the global carbon cycle, their year-round carbon dioxide (CO₂) dynamics — and particularly the contribution of the non-growing season (NGS) — remain poorly constrained in annual balance estimates. Using 17 years (2005–2021) of …

fi, dk, gl (code pays fourni par la source)

Updated monthly and new daily bias correction for assimilation-based passive microwave SWE retrieval

Pinja Venäläinen, Colleen Mortimer, Kari Luojus, Lawrence R. Mudryk et autres

Snow water equivalent (SWE) is a valuable characteristic of global snowpack, and it can be estimated using passive spaceborne radiometer measurements. The radiometer-based GlobSnow SWE retrieval methodology, which assimilates weather station snow depth observations with passive microwave brightness temperatures, has improved the …

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Environmental drivers constraining the seasonal variability in satellite-observed and modelled methane at northern high latitudes

Ella Kivimäki, Maria Katariina Tenkanen, Tuula Aalto, Michael Buchwitz et autres

Methane emissions from Northern Hemisphere high-latitude wetlands are associated with large uncertainties, especially in the rapidly warming climate. Satellite observations of column-averaged methane concentrations (XCH 4 ) in the atmosphere exhibit variability due to time-varying sources and sinks as well as atmospheric …

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Tracking improvements in remotely sensed snow water equivalent from GlobSnow to the ESA Snow CCI program

Colleen Mortimer, Pinja Venäläinen, Kari Luojus, Lawrence R. Mudryk et autres

Snow water equivalent (SWE) estimates based on microwave remote sensing require information on snow characteristics, including snow grain size, and so often rely heavily on ancillary information. Two decades ago, Pulliainen (2006) described how information from passive microwave (PMW) brightness temperatures and …

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Updated monthly and new daily bias correction for assimilation-based passive microwave SWE retrieval

Pinja Venäläinen, Colleen Mortimer, Kari Luojus, Lawrence R. Mudryk et autres

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 snow depth observations with passive microwave brightness temperatures, has improved …

fi, ca (code pays fourni par la source)

Environmental drivers constraining the seasonal variability of satellite-observed methane at Northern high latitudes

Ella Kivimäki, Tuula Aalto, Michael Buchwitz, Kari Luojus et autres

Abstract. Methane emissions from Northern high-latitude wetlands are associated with large uncertainties, especially in the rapidly warming climate. Satellite observations of column-averaged methane concentrations (XCH4) in the atmosphere exhibit variability due to time-varying sources and sinks. In this study, we investigate how …

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Preface to the special issue on Monitoring and Modelling of Carbon-Balance-, Water- and Snow-Related Phenomena at Northern Latitudes

Tuula Aalto, Mikko Peltoniemi, Mika Aurela, Kristin Böttcher et autres

Non peer reviewed

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Empirical algorithms for Secchi disk depth using optical and microwave remote sensing data from the Gulf of Finland and the Archipelago Sea

Yuanzhi Zhang, Jouni T. Pulliainen, Sampsa Koponen

In this paper empirical algorithms for determining the Secchi disk depth (SDD) are developed and employed using optical (e.g., Landsat TM) and microwave (e.g., ERS-2 SAR) remote sensing data from the Gulf of Finland and the Archipelago Sea. The SDD is an …

Increase in gross primary production of boreal forests balanced out by increase in ecosystem respiration

Jouni T. Pulliainen, Mika Aurela, Tuula Aalto, Kristin Böttcher et autres

Changes in the net carbon sink of boreal forests constitute a major source of uncertainty in the future global carbon budget and, hence, climate change projections. The annual net ecosystem exchange of carbon dioxide (CO2) controlling the terrestrial carbon stock results from …

Detection of soil and canopy freeze/thaw state in the boreal region with L and C Band Synthetic Aperture Radar

Juval Cohen, Juha Lemmetyinen, Jorge Jorge Ruiz, Kimmo Rautiainen et autres

Satellite instruments operating at microwave frequencies enable the monitoring of soil freeze/thaw (F/T) state of large areas. In this study, seasonal variations in space-borne SAR backscatter at L (1.2 GHz) and C (5.4 GHz) bands are investigated in the context of F/T …

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