TY  - GEN
A1  - Acevedo, Walter
A1  - Fallah, Bijan
A1  - Reich, Sebastian
A1  - Cubasch, Ulrich
T1  - Assimilation of pseudo-tree-ring-width observations into an atmospheric general circulation model
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - Paleoclimate data assimilation (DA) is a promising technique to systematically combine the information from climate model simulations and proxy records. Here, we investigate the assimilation of tree-ring-width (TRW) chronologies into an atmospheric global climate model using ensemble Kalman filter (EnKF) techniques and a process-based tree-growth forward model as an observation operator. Our results, within a perfect-model experiment setting, indicate that the "online DA" approach did not outperform the "off-line" one, despite its considerable additional implementation complexity. On the other hand, it was observed that the nonlinear response of tree growth to surface temperature and soil moisture does deteriorate the operation of the time-averaged EnKF methodology. Moreover, for the first time we show that this skill loss appears significantly sensitive to the structure of the growth rate function, used to represent the principle of limiting factors (PLF) within the forward model. In general, our experiments showed that the error reduction achieved by assimilating pseudo-TRW chronologies is modulated by the magnitude of the yearly internal variability in themodel. This result might help the dendrochronology community to optimize their sampling efforts.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 627 
KW  - high resolution paleoclimatology
KW  - sparse proxy data
KW  - climate reconstructions
KW  - limiting factors
KW  - Kalman filter
KW  - co-limitation
KW  - ensemble
KW  - variability
KW  - reanalysis
KW  - framework
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-418743
SN  - 1866-8372
IS  - 627
SP  - 545
EP  - 557
ER  - 
TY  - JOUR
A1  - Acevedo, Walter
A1  - Fallah, Bijan
A1  - Reich, Sebastian
A1  - Cubasch, Ulrich
T1  - Assimilation of pseudo-tree-ring-width observations into an atmospheric general circulation model
JF  - Climate of the past : an interactive open access journal of the European Geosciences Union
N2  - Paleoclimate data assimilation (DA) is a promising technique to systematically combine the information from climate model simulations and proxy records. Here, we investigate the assimilation of tree-ring-width (TRW) chronologies into an atmospheric global climate model using ensemble Kalman filter (EnKF) techniques and a process-based tree-growth forward model as an observation operator. Our results, within a perfect-model experiment setting, indicate that the "online DA" approach did not outperform the "off-line" one, despite its considerable additional implementation complexity. On the other hand, it was observed that the nonlinear response of tree growth to surface temperature and soil moisture does deteriorate the operation of the time-averaged EnKF methodology. Moreover, for the first time we show that this skill loss appears significantly sensitive to the structure of the growth rate function, used to represent the principle of limiting factors (PLF) within the forward model. In general, our experiments showed that the error reduction achieved by assimilating pseudo-TRW chronologies is modulated by the magnitude of the yearly internal variability in themodel. This result might help the dendrochronology community to optimize their sampling efforts.
Y1  - 2017
U6  - https://doi.org/10.5194/cp-13-545-2017
SN  - 1814-9324
SN  - 1814-9332
VL  - 13
SP  - 545
EP  - 557
PB  - Copernicus
CY  - Göttingen
ER  -