Drivers of shortwave radiation fluxes in Arctic tundra across scales

Juszak, Inge; Iturrate-García, Maitane; Gastellu-Etchegorry, Jean-Philippe; Schaepman, Michael E.; Maximov, Trofim C.; Schaepman‐Strub, Gabriela

doi:10.1016/j.rse.2017.02.017

Cited by 33 publications

(33 citation statements)

References 101 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mean growing season albedo of 0.15 for dwarf shrubs and 0.17 for sedges observed in our study agree well with literature values (Chapin et al, 2000a;Eugster et al, 2000;Ahrends et al, 2012). The measured albedo values are within the range provided by modelling results of the two vegetation types at the same study site (Juszak et al, 2016). While the difference between dwarf shrub albedo and wet sedge albedo is relatively small, the modelling results indicate that the albedo of other vegetation types present at the field site varies more strongly.…”

Section: Above-canopy Radiation Budgetsupporting

confidence: 90%

“…In the shortwave range, we found an average growing season transmittance of 0.36 below dwarf shrubs and 0.28 below sedges (Table 2). These values are in the same range as modelling results of dwarf shrubs and wet sedges by Juszak et al (2016). In comparison with other vegetation types present at the site, the transmittance of both types is small.…”

Section: Soil Shadingsupporting

confidence: 82%

“…While the difference between dwarf shrub albedo and wet sedge albedo is relatively small, the modelling results indicate that the albedo of other vegetation types present at the field site varies more strongly. Juszak et al (2016) found albedo variation between 0.18 for dry sedge wetland and 0.09 for waterlogged sedges. Therefore, the above canopy radiation budget is more variable if multiple vegetation types are taken into account and may influence the permafrost more strongly.…”

Section: Above-canopy Radiation Budgetmentioning

confidence: 90%

“…However, the above and below canopy radiation budget of dwarf shrubs and wet sedges is relatively similar which implies that other factors contribute more strongly to the differences in soil heat flux. Other vegetation types present at the site vary more strongly in albedo and reveal much higher transmittance (Juszak et al, 2016). Therefore, the radiation budget may explain more of the spatial variability in active layer thickness if more vegetation types are considered.…”

Section: Soil Heat Flux and Permafrost Active Layermentioning

confidence: 99%

See 3 more Smart Citations

Contrasting radiation and soil heat fluxes in Arctic shrub and wet sedge tundra

et al. 2016

Self Cite

View full text Add to dashboard Cite

Abstract. Vegetation changes, such as shrub encroachment and wetland expansion, have been observed in many Arctic tundra regions. These changes feed back to permafrost and climate. Permafrost can be protected by soil shading through vegetation as it reduces the amount of solar energy available for thawing. Regional climate can be affected by a reduction in surface albedo as more energy is available for atmospheric and soil heating. Here, we compared the shortwave radiation budget of two common Arctic tundra vegetation types dominated by dwarf shrubs (Betula nana) and wet sedges (Eriophorum angustifolium) in North-East Siberia. We measured time series of the shortwave and longwave radiation budget above the canopy and transmitted radiation below the canopy. Additionally, we quantified soil temperature and heat flux as well as active layer thickness. The mean growing season albedo of dwarf shrubs was 0.15 ± 0.01, for sedges it was higher (0.17±0.02). Dwarf shrub transmittance was 0.36 ± 0.07 on average, and sedge transmittance was 0.28 ± 0.08. The standing dead leaves contributed strongly to the soil shading of wet sedges. Despite a lower albedo and less soil shading, the soil below dwarf shrubs conducted less heat resulting in a 17 cm shallower active layer as compared to sedges. This result was supported by additional, spatially distributed measurements of both vegetation types. Clouds were a major influencing factor for albedo and transmittance, particularly in sedge vegetation. Cloud cover reduced the albedo by 0.01 in dwarf shrubs and by 0.03 in sedges, while transmittance was increased by 0.08 and 0.10 in dwarf shrubs and sedges, respectively. Our results suggest that the observed deeper active layer below wet sedges is not primarily a result of the summer canopy radiation budget. Soil properties, such as soil albedo, moisture, and thermal conductivity, may be more influential, at least in our comparison between dwarf shrub vegetation on relatively dry patches and sedge vegetation with higher soil moisture.

show abstract

Section: Above-canopy Radiation Budgetsupporting

confidence: 90%

Section: Soil Shadingsupporting

confidence: 82%

Section: Above-canopy Radiation Budgetmentioning

confidence: 90%

Section: Soil Heat Flux and Permafrost Active Layermentioning

confidence: 99%

See 2 more Smart Citations

Contrasting radiation and soil heat fluxes in Arctic shrub and wet sedge tundra

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…Such VIs can be highly useful for estimating biological parameters such as vegetation productivity and the leaf-area index (LAI; e.g. see Aasen et al 2015, Wehrhan et al 2016), and for the purpose of vegetation classification (Juszak et al 2017, Ahmed et al 2017, Müllerová et al 2017, Samiappan et al 2017, Dash et al 2017). Particularly in remote high-latitude ecosystems, where satellite records suggest a ‘greening’ based on NDVI time series (Fraser et al 2011, Guay et al 2014, Ju and Masek 2016), multispectral drone monitoring could play an important role in validating satellite remotely-sensed productivity trends (see Laliberte et al 2011, Matese et al 2015).…”

Section: Introductionmentioning

confidence: 99%

Vegetation monitoring using multispectral sensors – best practices and lessons learned from high latitudes

Assmann

Kerby

Cunliffe

et al. 2018

Preprint

View full text Add to dashboard Cite

17Emerging drone technologies have the potential to revolutionise ecological monitoring. The 18 rapid technological advances in recent years have dramatically increased affordability and 19 ease of use of Unmanned Aerial Vehicles (UAVs) and associated sensors. Compact 20 multispectral sensors, such as the Parrot Sequoia (Paris, France) and MicaSense RedEdge 21 (Seattle WA, USA) capture spectrally accurate high-resolution (fine grain) imagery in visible 22 and near-infrared parts of the electromagnetic spectrum, providing supplement to satellite 23 and aircraft-based imagery. Observations of surface reflectance can be used to calculate 24 vegetation indices such as the Normalised Difference Vegetation Index (NDVI) for 25 productivity estimates and vegetation classification. Despite the advances in technology, 26 challenges remain in capturing consistently high-quality data, particularly when operating in 27 extreme environments such as the high latitudes. Here, we summarize three years of 28 ecological monitoring with drone-based multispectral sensors in the remote Canadian Arctic. 2We discuss challenges, technical aspects and practical considerations, and highlight best 30 practices that emerged from our experience, including: flight planning, factoring in weather 31 conditions, and geolocation and radiometric calibration. We propose a standardised 32 methodology based on established principles from remote sensing and our collective field 33 experiences, using the Parrot Sequoia sensor as an example. With these good practises, 34 multispectral sensors can provide meaningful spatial data that is reproducible and 35 comparable across space and time. 36 37

show abstract

The Energy Balance of Permafrost Soils and Ecosystems

Huissteden

2020

Thawing Permafrost

View full text Add to dashboard Cite

Drivers of shortwave radiation fluxes in Arctic tundra across scales

Cited by 33 publications

References 101 publications

Contrasting radiation and soil heat fluxes in Arctic shrub and wet sedge tundra

Contrasting radiation and soil heat fluxes in Arctic shrub and wet sedge tundra

Vegetation monitoring using multispectral sensors – best practices and lessons learned from high latitudes

The Energy Balance of Permafrost Soils and Ecosystems

Contact Info

Product

Resources

About