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Modelling co-variability of Holocene rainfall and temperature in Asia

Paper Reviewed
Rehfeld, K. and Laepple, T. 2016. Warmer and wetter or warmer and dryer? Observed versus simulated covariability of Holocene temperature and rainfall in Asia. Earth and Planetary Science Letters 436: 1-9.

In seeking to learn more about the potential for co-variability of rainfall and temperature in Asia, Rehfeld and Laepple (2016) investigated the degree to which there may have been demonstrable linkages between temperature and precipitation throughout much of Asia on inter-annual to multi-centennial timescales, which they did with the help of instrumental data, late Holocene paleoclimate proxy data, and CMIP5/PMIP3 climate model simulations. And what did this diverse set of approaches reveal?

The two German researchers report that in the case of instrumental and proxy data, "negative correlations dominate," so that "cool summers tend to be rainy summers," while "on longer timescales precipitation and temperature are positively correlated," such that "cool centuries tend to be dryer centuries in monsoonal Asia." And in still further contrast, they report that CMIP5 and PMIP3 climate model simulations show a negative correlation between precipitation and temperature on all timescales.

In light of these findings, Rehfeld and Laepple conclude that "climate model simulations might be considerably biased, overestimating the short-term negative associations between regional rainfall and temperature and lacking long-term positive relationships between them." And they thus state that their results "call for a reconciliation of model-data mismatch in the precipitation-temperature relationship which needs attention from both the data and the modeling side."

Posted 6 June 2016