Separating the effects of albedo from eco‐physiological changes on surface temperature along a successional chronosequence in the southeastern United States

Juang, Jehn‐Yih; Katul, Gabriel G.; Siqueira, Mario; Stoy, Paul C.; Novick, Kimberly A.

doi:10.1029/2007gl031296

Cited by 211 publications

(242 citation statements)

References 21 publications

Supporting

Mentioning

226

Contrasting

Unclassified

Order By: Relevance

“…During the growing season, these two forests are not very different. During the non-growing season, transpiration from evergreen forests may be higher than that from deciduous forests [11]. This means that the cooling effect caused by ET in evergreen forests is greater than that in deciduous forests.…”

Section: Discussionmentioning

confidence: 93%

Local Effects of Forests on Temperatures across Europe

Tang

Zhao

2018

Remote Sensing

View full text Add to dashboard Cite

Forests affect local climate through biophysical processes in terrestrial ecosystems. Due to the spatial and temporal heterogeneity of ecosystems in Europe, climate responses to forests vary considerably with diverse geographic and seasonal patterns. Few studies have used an empirical analysis to examine the effect of forests on temperature and the role of the background climate in Europe. In this study, we aimed to quantitatively determine the effects of forest on temperature in different seasons with MODIS (MODerate-resolution Imaging Spectroradiometer) land surface temperature (LST) data and in situ air temperature measurements. First, we compared the differences in LSTs between forests and nearby open land. Then, we paired 48 flux sites with nearby weather stations to quantify the effects of forests on surface air temperature. Finally, we explored the role of background temperatures on the above forests effects. The results showed that (1) forest in Europe generally increased LST and air temperature in northeastern Europe and decreased LST and air temperature in other areas; (2) the daytime cooling effect was dominate and produced a net cooling effect from forests in the warm season. In the cold season, daytime and nighttime warming effects drove the net effect of forests; (3) the effects of forests on temperatures were mainly negatively correlated with the background temperatures in Europe. Under extreme climate conditions, the cooling effect of forests will be stronger during heatwaves or weaker during cold spring seasons; (4) the background temperature affects the spatiotemporal distribution of differences in albedo and evapotranspiration (forest minus open land), which determines the spatial, seasonal and interannual effects of forests on temperature. The extrapolation of the results could contribute not only to model validation and development but also to appropriate land use policies for future decades under the background of global warming.

show abstract

Section: Discussionmentioning

confidence: 93%

Local Effects of Forests on Temperatures across Europe

Tang

Zhao

2018

Remote Sensing

View full text Add to dashboard Cite

show abstract

“…The marginal distribution sampling (MDS) filling method is based on Reichstein et al (2005), and the ERA-Interim filling method can be found in Vuichard and Papale (2015 ration (ET), and land surface temperature changes due to historical LULCC (Boisier et al, , 2014 and the climatic effects of forest (Li et al, 2015). Meanwhile, the development of FLUXNET (Baldocchi et al, 2001) enables the study of land surface responses to different land-cover types based on paired field observations from neighboring flux towers over forest and open land (Juang et al, 2007;Lee et al, 2011;Luyssaert et al, 2014;Teuling et al, 2010;Williams et al, 2012). In terms of LSM evaluation, the paired site observations have been mainly used to simulated impacts of LULCC on land surface temperature (Chen and Dirmeyer 2016;Lejeune et al, 2016;Vanden Broucke et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Pairing FLUXNET sites to validate model representations of land-use/land-cover change

Chen

Dirmeyer

Guo

et al. 2018

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. Land surface energy and water fluxes play an important role in land-atmosphere interactions, especially for the climatic feedback effects driven by land-use/landcover change (LULCC). These have long been documented in model-based studies, but the performance of land surface models in representing LULCC-induced responses has not been investigated well. In this study, measurements from proximate paired (open versus forest) flux tower sites are used to represent observed deforestation-induced changes in surface fluxes, which are compared with simulations from the Community Land Model (CLM) and the Noah MultiParameterization (Noah-MP) land model. Point-scale simulations suggest the CLM can represent the observed diurnal and seasonal changes in net radiation (R net ) and ground heat flux (G), but difficulties remain in the energy partitioning between latent (LE) and sensible (H ) heat flux. The CLM does not capture the observed decreased daytime LE, and overestimates the increased H during summer. These deficiencies are mainly associated with models' greater biases over forest land-cover types and the parameterization of soil evaporation. Global gridded simulations with the CLM show uncertainties in the estimation of LE and H at the grid level for regional and global simulations. Noah-MP exhibits a similar ability to simulate the surface flux changes, but with larger biases in H , G, and R net change during late winter and early spring, which are related to a deficiency in estimating albedo. Differences in meteorological conditions between paired sites is not a factor in these results. Attention needs to be devoted to improving the representation of surface heat flux processes in land models to increase confidence in LULCC simulations.

show abstract

“…This feedback is crucial in the model predictions; without it other biophysical processes may overwhelm the albedo effect to generate warming instead 5 . Ongoing land-use activities, such as land management for climate mitigation, are occurring at local scales (hectares) presumably too small to generate the feedback, and it is not known whether the intrinsic biophysical mechanism on its own can change the surface temperature in a consistent manner 6,7 . Nor has the effect of deforestation on climate been demonstrated over large areas from direct observations.…”

mentioning

confidence: 99%

“…Forests have lower surface albedo than shrubs, grasses and pastures 6,7,14 . Deforestation decreases the net shortwave absorption by an amount DS that depends in part on climate regimes.…”

mentioning

confidence: 99%

Observed increase in local cooling effect of deforestation at higher latitudes

Lee

Goulden

Hollinger

et al. 2011

Nature

Self Cite

599

715

View full text Add to dashboard Cite

Deforestation in mid-to high latitudes is hypothesized to have the potential to cool the Earth's surface by altering biophysical processes [1][2][3] . In climate models of continental-scale land clearing, the cooling is triggered by increases in surface albedo and is reinforced by a land albedo-sea ice feedback 4,5 . This feedback is crucial in the model predictions; without it other biophysical processes may overwhelm the albedo effect to generate warming instead 5 . Ongoing land-use activities, such as land management for climate mitigation, are occurring at local scales (hectares) presumably too small to generate the feedback, and it is not known whether the intrinsic biophysical mechanism on its own can change the surface temperature in a consistent manner 6,7 . Nor has the effect of deforestation on climate been demonstrated over large areas from direct observations. Here we show that surface air temperature is lower in open land than in nearby forested land. The effect is 0.85 6 0.44 K (mean 6 one standard deviation) northwards of 456 N and 0.21 6 0.53 K southwards. Below 356 N there is weak evidence that deforestation leads to warming. Results are based on comparisons of temperature at forested eddy covariance towers in the USA and Canada and, as a proxy for small areas of cleared land, nearby surface weather stations. Night-time temperature changes unrelated to changes in surface albedo are an important contributor to the overall cooling effect. The observed latitudinal dependence is consistent with theoretical expectation of changes in energy loss from convection and radiation across latitudes in both the daytime and night-time phase of the diurnal cycle, the latter of which remains uncertain in climate models 8 .The latitudinal gradient of land-use impact is evident in the comparison of the surface air temperature recorded at FLUXNET (www.fluxnet.ornl.gov) forest towers 9 (Supplementary Table 1 and Supplementary Fig. 1) and surface weather stations in North America (Fig. 1a). Here we use the surface stations as proxies for cleared land. In accordance with the requirement of the World Meteorological Organization, these stations are located in open grassy fields that have biophysical characteristics similar to those of open land, such as being covered by snow in northern latitudes in the winter 10 . Latitude accounts for 31% of the variations in the temperature difference DT between the forest sites and the adjacent open lands (number of site pairs n 5 37). The rate of change in DT with latitude is 20.070 6 0.010 K per degree (mean 6 one standard error, s.e., P , 0.005). At these sites, the annual net all-wave radiation R n

show abstract

Separating the effects of albedo from eco‐physiological changes on surface temperature along a successional chronosequence in the southeastern United States

Cited by 211 publications

References 21 publications

Local Effects of Forests on Temperatures across Europe

Local Effects of Forests on Temperatures across Europe

Pairing FLUXNET sites to validate model representations of land-use/land-cover change

Observed increase in local cooling effect of deforestation at higher latitudes

Contact Info

Product

Resources

About