This study analyzed the impact of the 2018 drought in northwestern Europe on carbon uptake by ecosystems. Remote sensing data and ecosystem modeling were used to examine changes in gross primary production (GPP) at regional and ecosystem levels. The key findings were: 1) GPP was significantly reduced during the drought, especially in summer, but spring GPP was slightly enhanced. 2) The annual carbon flux anomaly for the drought-affected region was estimated to be a gain of 20-49 teragrams of carbon, as enhanced spring uptake largely offset reduced summer uptake. 3) Different ecosystem types, such as deciduous and evergreen forests, were impacted differently by drought stress factors like soil moisture.

1. Spring enhancement and summer reduction in
carbon uptake during the 2018 drought in
northwestern Europe
Naomi Smith, Gerbrand Koren, Linda Kooijmans, Auke van der Woude, Erik van Schaik, Niko Wanders, Michel Ramonet,
Irène Xueref-Remy, Lukas Siebicke, Giovanni Manca, Christian Brümmer, Katherine Haynes, Ian Baker, Ingrid Luijkx,
Wouter Peters

2. Drought evolution
2

3. Regional drought effects
7

4. How did Europe’s biospheric carbon
fluxes respond to the drought of
2018?
- Regionally?
- At the ecosystem level?
Aims
8

5. Remote sensing of Gross Primary Production
10
Remote sensing analysis: Gerbrand Koren

6. Vegetative Near-Infrared Reflectance (NIRv)
12
Remote sensing analysis: Gerbrand Koren
Correlations: Linda Kooijmans

7. Regional GPP anomaly
14
SiB4 modelling: Linda Kooijmans
Remote sensing analysis: Gerbrand Koren

8. Ecosystem-level GPP anomaly
16
SiB4 modelling: Linda Kooijmans

9. Ecosystem stress factors
17
Deciduous broadleaf
forest
Evergreen needleleaf
forest
SiB4 modelling: Linda Kooijmans

10. ▪ CarbonTracker Europe
▪ TM5 transport model: 1x1 (3x2)
▪ ICOS drought data +
GLOBALVIEWplus v5.0
▪ 2013 – 2018
▪ Prior 1: SiB4 NEE
▪ Prior 2: Climatology of SiB4 NEE
Inverse modelling
18
Map, ICOS obs. Collection: Michel Ramonet

11. Integrated monthly flux anomalies
19

12. Integrated monthly flux anomalies
20
Drought-affected region
Spring: -46 - -55 TgC
Summer: 52 - 83 TgC
Annual: 20 – 49 TgC

13. Conclusions
21
▪ Significant drop in GPP,
respiration, and NEE
▪ Response even at some
resilient ecosystems
▪ Largely offset by enhanced
spring uptake
▪ Global inverse model in
good agreement with range
of products on regional scale