Spring Onset

Understanding the climatic controls on the “start of spring” (S.O.S.)
In 2012, warmer temperatures in March brought a large number of plants and crops out of dormancy prematurely, rendering them vulnerable to a climatologically average freeze event in April. The cost to agriculture in Michigan alone was half a billion dollars (Knudson, 2012). How likely are such events in the future? Answering this question requires us to deepen our understanding of the climatic controls on spring weather, their predictability on sub-seasonal to decadal timescales, and their representation in the current generation of climate models.

Publications from this work include:
Monahan, W. B., Rosemartin, A., Gerst, K. L., Fisichelli, N. A., Ault, T., Schwartz, M. D., Gross, J. E., and Weltzin, J. F. (2016): Climate change is advancing spring onset across the us national park system. Ecosphere, 7(10) (http://onlinelibrary.wiley.com/doi/10.1002/ecs2.1465/full).

Labe, Z., Ault, T., and Zurita-Milla, R. (2016): Identifying anomalously early spring onsets in the CESM large ensemble project. Climate Dynamics, pages 1–18 (https://link.springer.com/article/10.1007/s00382-016-3313-2).

Ault, T. R., M. D. Schwartz, R. Zurita-Milla, J. F. Weltzin, and J. L. Betancourt (2015): Trends and natural variability of North American spring onset as evaluated by a new gridded dataset of spring indices, Journal of Climate, doi: http://dx.doi.org/10.1175/JCLI-D-14-00736.1.

Ault, T. R. R. Zurita-Milla, M. D. Schwartz (2015): A Matlab© toolbox for calculating spring indices from daily meteorological data, Computers & Geosciences, 83, 46-53, http://dx.doi.org/10.1016/j.cageo.2015.06.015.

Ault, T. R., G. M. Henebry, K. M. de Beurs, M. D. Schwartz, J. L. Betancourt, David Moore (2013): The False Spring of 2012, Earliest in the North American Record. EOS, 94, 181-183 (http://onlinelibrary.wiley.com/doi/10.1002/2013EO200001/abstract).

Cook, B.I., E.M. Wolkovich, J.T. Davies, T.R. Ault, J.L. Betancourt, J.M. Allen, K. Bolmgren, E.E. Cleland, T.M. Crimmins, N.J.B. Kraft, L.T. Lancaster, S.J. Mazer, G.J. McCabe, B.J. McGill, C.P., S. Pau, J. Regetz, N. Salamin, M.D. Schwartz, S.E. Travers. Sensitivity of spring phenology to warming across temporal and spatial climate gradients in two independent databases. Ecosystems, 15, 1283-1294, doi:10.1007/s10021-012-9584-5 (http://link.springer.com/article/10.1007%2Fs10021-012-9584-5).

Ault, T.R., J.E. Cole, and S. St. George, (2012): The amplitude of decadal to multidecadal variability in precipitation simulated by state-of-the-art climate models. Geophysical Research Letters, 39 (21), L21 705, doi:10.1029/2012GL053424 (http://onlinelibrary.wiley.com/doi/10.1029/2012GL053424/suppinfo).

Schwartz, M.D., T.R. Ault, and J.L. Betancourt (2012): Spring Onset Variations and Trends in the Continental USA: Past and Regional Assessment Using Temperature-Based Indices, International Journal of Climatology, doi: 10.1002/joc.3625 (http://onlinelibrary.wiley.com/doi/10.1002/joc.3625/abstract).

Ault, T.R., A. Macalady, G.T. Pederson, J. Betancourt, M. Schwartz (2011): Northern Hemisphere modes of variability and the timing of spring in western North America. Journal of Climate, 24 (15): 4003-4014, doi: 10.1175/2011JCLI4069.1 (http://journals.ametsoc.org/doi/abs/10.1175/2011JCLI4069.1).

McCabe, G., T.R. Ault, B. Cook, J. Betancourt, and M.D Schwartz (2011): Influences of ENSO and the PDO on the Timing of North American Spring. International Journal of Climatology, doi: 10.1002/joc.3400 (http://onlinelibrary.wiley.com/doi/10.1002/joc.3400/abstract).