Webbläsaren som du använder stöds inte av denna webbplats. Alla versioner av Internet Explorer stöds inte längre, av oss eller Microsoft (läs mer här: * https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Var god och använd en modern webbläsare för att ta del av denna webbplats, som t.ex. nyaste versioner av Edge, Chrome, Firefox eller Safari osv.

profile

Anders Ahlström

Universitetslektor

profile

Carbon cycle uncertainty in the Alaskan Arctic

Författare

  • J. B. Fisher
  • M. Sikka
  • W. C. Oechel
  • D. N. Huntzinger
  • J. R. Melton
  • C. D. Koven
  • Anders Ahlström
  • M. A. Arain
  • I. Baker
  • J. M. Chen
  • P. Ciais
  • C. Davidson
  • M. Dietze
  • B. El-Masri
  • D. Hayes
  • C. Huntingford
  • A. K. Jain
  • P. E. Levy
  • M. R. Lomas
  • B. Poulter
  • D. Price
  • A. K. Sahoo
  • K. Schaefer
  • H. Tian
  • E. Tomelleri
  • H. Verbeeck
  • N. Viovy
  • R. Wania
  • N. Zeng
  • C. E. Miller

Summary, in English

Climate change is leading to a disproportionately large warming in the high northern latitudes, but the magnitude and sign of the future carbon balance of the Arctic are highly uncertain. Using 40 terrestrial biosphere models for the Alaskan Arctic from four recent model intercomparison projects - NACP (North American Carbon Program) site and regional syntheses, TRENDY (Trends in net land atmosphere carbon exchanges), and WETCHIMP (Wetland and Wetland CH4 Inter-comparison of Models Project) - we provide a baseline of terrestrial carbon cycle uncertainty, defined as the multi-model standard deviation (sigma) for each quantity that follows. Mean annual absolute uncertainty was largest for soil carbon (14.0+/-9.2 kgCm(-2)), then gross primary production (GPP) (0.22+/-0.50 kgCm(-2) yr(-1)), ecosystem respiration (Re) (0.23+/-0.38 kgCm(-2) yr(-1)), net primary production (NPP) (0.14+/-0.33 kgCm(-2) yr(-1)), autotrophic respiration (Ra) (0.09+/-0.20 kgCm(-2) yr(-1)), heterotrophic respiration (Rh) (0.14+/-0.20 kgCm(-2) yr(-1)), net ecosystem exchange (NEE) (-0.01+/-0.19 kgCm(-2) yr(-1)), and CH4 flux (2.52+/-4.02 g CH4 m(-2) yr(-1)). There were no consistent spatial patterns in the larger Alaskan Arctic and boreal regional carbon stocks and fluxes, with some models showing NEE for Alaska as a strong carbon sink, others as a strong carbon source, while still others as carbon neutral. Finally, AmeriFlux data are used at two sites in the Alaskan Arctic to evaluate the regional patterns; observed seasonal NEE was captured within multi-model uncertainty. This assessment of carbon cycle uncertainties may be used as a baseline for the improvement of experimental and modeling activities, as well as a reference for future trajectories in carbon cycling with climate change in the Alaskan Arctic and larger boreal region.

Avdelning/ar

  • Institutionen för naturgeografi och ekosystemvetenskap
  • MERGE: ModElling the Regional and Global Earth system
  • BECC: Biodiversity and Ecosystem services in a Changing Climate

Publiceringsår

2014

Språk

Engelska

Sidor

4271-4288

Publikation/Tidskrift/Serie

Biogeosciences

Volym

11

Issue

15

Dokumenttyp

Artikel i tidskrift

Förlag

Copernicus GmbH

Ämne

  • Physical Geography

Status

Published

ISBN/ISSN/Övrigt

  • ISSN: 1726-4189