Is long-term climate memory important in temperature/precipitation predictions over China?

Abstract

Long-term climate memory is ubiquitous in climate systems, but its contribution to climate prediction has not been assessed systematically. We used an integral fractional statistical model (FISM) to quantify climate memories in different variables over China. Their contributions to climate prediction were estimated using explained variances. We found different climate memory effects for different variables in different regions. The contribution of climate memory to climate variability is stronger in temperature than in precipitation records. For temperatures (including both air temperature and land temperature), the average variance explained by climate memory is around 3∼4%. For precipitation, the average explained variance was 0.6%. The low values for explained variances indicate that, on average, the contributions of climate memory to temperature and precipitation predictions are small. But in specific regions, higher climate memory effects may occur. For precipitation, climate memory can contribute 3% of the variance in southeast China. For temperature, climate memory can explain ≥ 10% of the variance in northeast and southwest China, which is not low and should be considered in prediction. Therefore, for more accurate climate prediction, we suggest first determining the contribution of climate memory. For variables or regions with strong climate memory effects, a scheme considering climate memory effects may help improve future climate predictions.