Is land surface processes representation a possible weak link in current Regional Climate Models?


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Date

2016-07

Publication Type

Journal Article

ETH Bibliography

yes

Citations

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Data

Abstract

The representation of land surface processes and fluxes in climate models critically affects the simulation of near-surface climate over land. Here we present an evaluation of COSMO-CLM2, a model which couples the COSMO-CLM Regional Climate Model to the Community Land Model (CLM4.0). CLM4.0 provides a more detailed representation of land processes compared to the native land surface scheme in COSMO-CLM. We perform historical reanalysis-driven simulations over Europe with COSMO-CLM2 following the EURO-CORDEX intercomparison protocol. We then evaluate simulations performed with COSMO-CLM2, the standard COSMO-CLM and other EURO-CORDEX RCMs against various observational datasets of temperature, precipitation and surface fluxes. Overall, the results indicate that COSMO-CLM2 outperforms both the standard COSMO-CLM and the other EURO-CORDEX models in simulating sensible, latent and surface radiative fluxes as well as 2-meter temperature across different seasons and regions. The performance improvement is particularly strong for turbulent fluxes and for daily maximum temperatures and more modest for daily minimum temperature, suggesting that land surface processes affect daytime even more than nighttime conditions. COSMO-CLM2 also alleviates a long-standing issue of overestimation of interannual summer temperature variability present in most EURO-CORDEX RCMs. Finally, we show that several factors contribute to these improvements, including the representation of evapotranspiration, radiative fluxes and ground heat flux. Overall, these results demonstrate that land processes represent a key area of development to tackle current deficiencies in RCMs.

Publication status

published

Editor

Book title

Volume

11 (7)

Pages / Article No.

74027

Publisher

IOP Publishing

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Regional climate model; Land surface model; EURO-CORDEX; Land processes; COSMO-CLM 2

Organisational unit

03778 - Seneviratne, Sonia / Seneviratne, Sonia check_circle

Notes

Funding

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