Unit Affiliation: Biology and Paleo Environment, Lamont-Doherty Earth Observatory (LDEO)
The climate of the North Atlantic profoundly impacts human populations and ecosystems in adjacent North America and Europe. It is anticipated that this project will help improve understanding of the nature and causes of decadal- and multi-decadal scale climate variability and its spatiotemporal patterns for the North Atlantic sector for modeling and predictive purposes. An enhanced understanding of internal climate system variability at this time scale is critical for decadal-scale prediction, as well as robust detection and attribution of the anthropogenic component of regional and global temperature trends.
This award will support early research experiences for students through an ongoing student internship program at Lamont Doherty Earth Observatory and co-operative and Guest student programs at Woods Hole Oceanographic Institution (WHOI).
The researchers will utilize the newest version of the Old World Drought Atlas (OWDA, representing Europe, North Africa, and the Middle East) and an updated and fully compatible version of the North Atlantic Drought Atlas (NADA) in analyses designed to identify coupled modes of summer hydro-climate variability between continents on opposite sides of the North Atlantic Basin.
This will be accomplished using multivariate tools including singular value decomposition (SVD) to identify simple time domain coupled modes. The existence of band-limited phase-coherent modes will also be investigated using the Multiple Taper Method with Singular Value Decomposition (MTM-SVD), a frequency domain technique.
The research team seeks to identify the likely causes of the identified coupled modes in the drought atlases by comparing the projection coefficients of those modes against fields of climate data covering the North Atlantic Basin and for more extensive global regions (e.g., sea-level pressure or SLP, sea surface temperature or SST). The research team will project the identified forcings back to medieval times using the extended records of summer hydro-climate provided by the OWDA and NADA to produce first-order estimates of how the identified climate forcings have varied and changed over the past millennium; and
Furthermore, the researchers will compare the millennium-length climate forcing projections of the OWDA/NADA coupled modes against relevant climate fields and their characteristic modes of variability from the suite of CMIP3/CMIP5 coupled climate model runs to determine the degree to which data and models agree.
OUTCOMES: Anchukaitis, K., Wilson, R., Briffa, K. Buentgen, U., Cook, E., D?Arrigo, R., Davi, N., Esper, J., Frank, D., Gunnarson, B., Hegerl, G., Helema, S., Klesse, S., Krusic, P., Linderholm, H.W., Myglan, V., Osborn, T., Rydval, M., Schneider, L., Schurer, A.,. "Last millennium Northern Hemisphere summer temperatures from tree rings: Part II, spatially resolved reconstructions.," Quaternary Science Reviews, v.163, 2017, p. 1.
Rao, M.P., Cook, B.I., Cook, E.R., D?Arrigo, R.D., Krusic, P.J., Anchukaitis, K., LeGrande, A., Buckley, B.M., Davi, N.K., C. Leland, C. and Griffin, K.L.. "European and Mediterranean hydroclimate responses to tropical volcanic forcing over the past millennium.," Geophysical Research Letters, 2017. doi:10.1002/2017GL073057