Biomass heat storage dampens diurnal temperature variations in forests


Date

2019-08

Publication Type

Journal Article

ETH Bibliography

yes

Citations

Altmetric

Data

Abstract

Observational evidence suggests that compared to non-forested areas, forests have a cooling effect on daytime land surface temperature (LST) and a warming effect on nighttime LST in many regions of the world, thus implying that forests dampen the diurnal temperature range. This feature is not captured by current climate models. Using the Community Land Model 5.0 (CLM5.0), we show that this diurnal behavior can be captured when accounting for biomass heat storage (BHS). The nighttime release of energy absorbed by the vegetation biomass during the day increases both nighttime LST and ambient air temperature in forested regions by more than 1 K. The daytime cooling is weaker than the nighttime warming effect, because the energy uptake by the biomass is compensated by a reduction in the turbulent heat fluxes during day. This diurnal asymmetry of the temperature response to BHS leads to a warming of daily mean temperatures, which is amplified during boreal summer warm extremes. Compared to MODIS, CLM5.0 overestimates the diurnal LST range over forested areas. The inclusion of BHS reduces this bias due to its dampening effect on diurnal LST variations. Further, BHS attenuates the negative bias in the nighttime LST difference of forest minus grassland and cropland, when compared to MODIS observations. These results indicate that it is essential to consider BHS when examining the influence of forests on diurnal temperature variations. BHS should thus be included in land surface models used to assess the climatic consequences of land use changes such as deforestation or afforestation.

Publication status

published

Editor

Book title

Volume

14 (8)

Pages / Article No.

84026

Publisher

IOP Publishing

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Biomass heat storage; Land use change; Land surface modeling

Organisational unit

03778 - Seneviratne, Sonia / Seneviratne, Sonia check_circle

Notes

Funding

Related publications and datasets

Is referenced by: