Publications
-
-
Narayanappa, Devaraju; Nilsen, Irene Brox & Falk, Stefanie
(2021).
Avskoging og den indiske monsunen ("Deforestation and the indian monsoon").
blogg.forskning.no- søkelys på skogplantning.
Full text in Research Archive
-
Narayanappa, Devaraju; Berntsen, Terje Koren & Stordal, Frode
(2021).
Simulated runoff and river discharge in CTSM version 5.1:
Evaluation over Scandinavia.
Full text in Research Archive
Show summary
Reliable representation of terrestrial water and energy balance in global climate models is crucial to better understand the response of the hydrological cycle to climate change. Though the current generation of global climate models have improved substantially, they still fail to represent all terrestrial processes adequately. Specifically simulating runoff and river discharge are important for many applications such as water resources management and future water availability projections. In this study, we use the land surface model component of the Norwegian Earth System Model which is Community Land Model version 5 (CLM5) to evaluate against observation-based estimates of runoff and river discharge data of selected catchments data. For the latest three decades (1985-2015), we compare the CLM5 simulated grid-scale runoff with observation-based gridded runoff estimates (E-RUN version 1.1) and with data from the Global Runoff Data Centre (GRDC). CLM5 is also capable of simulating river discharge to the oceans through the Model for Scale Adaptive River Transport (MOSART) and is applicable across local, regional, and global scales. The 3-hourly 0.5o meteorological forcing for CLM5 was provided by the Global Soil Wetness Project version 3v1, an international land surface modeling project. We also compare the simulated river discharge data with selected station discharge data in Norway and Sweden. I will present the detailed evaluation results at the conference. Briefly, the evaluation analysis suggests the further calibration to hydrologic parameters is needed to improve simulations of runoff and river discharge, especially subsurface runoff.
-
Narayanappa, Devaraju
(2020).
Vegetation atmosphere interactions in earth system models.
Full text in Research Archive
Show summary
I have presented results from the idealized large-scale deforestation simulations performed using coupled global climate models. The focus was mainly on global temperature change and monsoonal rainfall changes.
Increasing human activities altering the land surface at large-scale for agriculture, urbanization, firewood, and timber purposes. Today about 50% of the ice-free land surface is covered by crops or pastures and, in many parts of the world, we continue to expand these areas for food because the world’s population is growing (IPCC-SRCCL 2019). This continued land cover change (LCC) is one of the major drivers of regional and global climate change through altered biophysical (BPH; changes in physical characteristics such as albedo, evapotranspiration, and roughness) and biogeochemical (BGC; changes in atmospheric composition) processes and is increasingly recognized in today's assessments of anthropogenic impacts. In this presentation, I mostly discuss about biophysical effects of deforestation to understand the impact of large perturbations to global land cover. Specifically, if deforested areas are abandoned and forests are allowed to re-grow, will the climate system go back to its natural state? How long will it take for the climate system to reach a new equilibrium in such a case? What determines the time scale? Are there interactions between forests and the atmosphere that gets severely altered for large scale land cover change? Does the monsoon rainfall across the world alters due to large-scale deforestation? I have addressed these questions in this talk using simulations from Earth system models.
View all works in NVA
Published
Aug. 11, 2020 1:14 PM
- Last modified
Aug. 11, 2020 1:14 PM