The spatiotemporal pattern of the Bond 4 event (5.2 ka) : a global data-based review

• Main Authors: Jalali, Bassem, Sicre, Marie-Alexandrine
• Other Authors: Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2021
• Subjects: [SDU]Sciences of the Universe [physics]; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; Greenland; Pacific; East Greenland; east greenland current; Iceland; North Atlantic Deep Water; North Atlantic
• Online Access: https://hal.archives-ouvertes.fr/hal-03503452; https://doi.org/10.5194/egusphere-egu21-15576

International audience The Bond 4 event starting at 7000 yr BP and culminating around 5200 yr BP corresponds to the largest (in magnitude and duration) invasion of drifting ice across the subpolar North Atlantic during the Holocene (Bond et al., 2001). While several studies have focused on other events of the Holocene, such as the 8.2 ka, the 4.2 ka and the Little Ice Age, little is known about the mid-Holocene 5.2 ka event. Here we present a global compilation of carefully selected high-resolution time series of sea surface temperature (SST; N=58) and humidity/precipitation (N=35) to characterize in space and time the 5.2 ka event pattern.The SST records show the occurrence of cold conditions in the North Atlantic, western Mediterranean as well as in the western Pacific Ocean. However, they indicate warming in the high latitude North Atlantic, the southeastern Atlantic, the eastern Mediterranean and the Arabian and Red seas. Humidity/precipitation data (mainly based on oxygen isotope records in speleothems) indicate dry conditions in the northern hemisphere subtropical and mid latitude regions of all continents. Based on these data and others from marine and lacustrine records in tropical regions, we suggest a possible weakening of monsoon systems, i.e. in Africa, North America, southwest Asia as well as East Asia. Precipitation reduced as well in most regions of the Mediterranean (i.e. except Iberian Peninsula). All together these data indicate severe climate conditions during the 5.2 ka event.Based on the recent compilation of sortable silt from the high latitude North Atlantic of McCave and Andrews (2019), the 5.2 ka event coincides with a decrease of the main Shallow and bottom ocean flows (i.e. North Iceland Irminger Current, East Greenland Current, Iceland-Scotland over flow) probably reflecting a weakening of the North Atlantic Deep Water formation. This event also corresponds to the occurrence of several solar minima as well as several tropical volcanic mega-eruptions that could have triggered a ...