Project Details
Projekt
CORals as archives for EXtreme weather and climate variability (CorEX)
Applicant
Dr. Norel Rimbu
Subject Area
Atmospheric Science
Oceanography
Oceanography
Term
since 2026
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 569200775
Rising global average temperature is associated with widespread changes in weather and climate patterns. A significant increase in the frequency and intensity of extreme weather events such as heat waves, droughts, floods and storm surges, among others, partly related to human-induced climate change, is recorded during the last decades. To better assess the recent changes in climate and weather extremes we need to put them into a long-term perspective using proxy data and climate model simulations. Coral reefs provide an important record of environmental conditions in the tropical and subtropical regions. The chemical composition of the individual coral skeleton reflects changes in local environmental factors, such as seawater, temperature, salinity, and acidity over time scales of months to centuries. Since the low frequency variability of environmental parameters at coral sites is controlled mainly by the large scale atmospheric and oceanic circulation patterns, corals are commonly used to reconstruct large-scale modes of interannual to multidecadal climate variability, such as El Niño-Southern Oscillation, the Indian Ocean Dipole or the Pacific Decadal Oscillation. Tropical and subtropical corals are commonly used to reconstruct seasonal, annual or decadal climate anomalies in the extratropical region via teleconnection patterns of these modes of climate variability. Recent studies showed a strong link between tropical climate anomalies and synoptic scale atmospheric circulation patterns associated with weather extremes in the extratropical region, like atmospheric blocking. The existence of such links provides the possibility to use tropical and subtropical corals to reconstruct part of the interannual to multidecadal variability of weather and climate extremes in the extratropical region. The overall objective of this project is to evaluate the potential of corals to record mid-latitude extreme weather variability as well as to understand how changes in mid-latitude extremes in future climate could impact the coral growth environment. Through complex statistical analysis we aim to investigate the links between coral parameters, i.e. Sr/Ca and δ18O ratios, extreme indices (e.g. cold spells, heat waves, droughts) as well as statistics of specific synoptic scale circulations. e.g. atmospheric blocking, in the extratropical region during the instrumental period. Based on long-term coral records, anomaly patterns of climate extreme indices will be reconstructed for the last centuries. Such reconstructions are used to assess further the significance of the increase in the weather and climate extremes during present and future climatic scenarios. This extended knowledge of paleo-extreme weather events can be transferred to the present-day climate analysis and might eventually help to gauge the risks associated with extreme climate events in a warmer climate and their impact on coral growth environment.
DFG Programme
Priority Programmes
Co-Investigators
Dr. Monica Ionita-Scholz; Professor Dr. Gerrit Lohmann
