Multi-model assessment of trends, variability and drivers of terrestrial carbon uptake in India

Rao, Ananya S. and Bala, Govindasamy and Ravindranath, NH and Nemani, Rama (2019) Multi-model assessment of trends, variability and drivers of terrestrial carbon uptake in India. In: JOURNAL OF EARTH SYSTEM SCIENCE, 128 (4).

PDF Jou_Ear_Sys_Sci_128_04__2019.pdf - Published Version Restricted to Registered users only Download (4MB) | Request a copy

Abstract

A multi- model- based assessment is made to assess the trends and variability in the land carbon uptake in India during the period 1901- 2010. Data from nine models, used in a recent land surface model inter- comparison project called TRENDY, are used for this purpose. Our analysis is focused on the trends and variability in the net primary productivity ( NPP), net ecosystem productivity ( NEP) and net ecosystem exchange ( NEE). The multi- model mean NPP shows a positive trend of 2.03% per decade during this period. The NEP, which is the difference between NPP and heterotrophic respiration, has a mean value of - 0.138 +/- 0.086 PgCyr - 1 over this region. According to our analysis of TRENDY multimodels, the inter- annual variation in NPP and NEP is strongly driven by precipitation, but remote drivers such as El Ni no Southern Oscillation ( ENSO) and Indian Ocean Dipole ( IOD) do not have a strong influence. The water use efficiency ( WUE) shows an increase of about 25% over the 110- yr period. Our multi- model- based estimate of the cumulative NEE is 0.613 +/- 0.1PgC during 1901- 2010, indicating that the Indian terrestrial ecosystem was neither a strong source nor a significant sink during this period. However, we caution that our conclusion is based on a limited set of offline land models, and the results presented here have large uncertainties due to model resolution and parameterisation of various land surface processes, the inadequate validation procedures and the use of limited number of models and land use change data sets. Further investigations using more observational data, rigorous validation using extensive observational data sets and a set of comprehensive coupled models that include several feedbacks between land, atmosphere, ocean and the cryosphere are needed to assess the robustness of our results.

Item Type:	Journal Article
Publication:	JOURNAL OF EARTH SYSTEM SCIENCE
Publisher:	INDIAN ACAD SCIENCES
Additional Information:	Copyright of this article belongs to INDIAN ACAD SCIENCES
Keywords:	TRENDY multi-model; regional carbon cycle; trends in NPP; NEP over India; water use efficiency
Department/Centre:	Division of Mechanical Sciences > Centre for Sustainable Technologies (formerly ASTRA) Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	17 May 2019 13:21
Last Modified:	17 May 2019 13:21
URI:	http://eprints.iisc.ac.in/id/eprint/62313

Actions (login required)

View Item