Instrumental records were used to assess the interannual variability of precipitation for the greater Asian monsoon region (50°N-15°S, 60°E-150°E). Correlation analysis shows intriguing teleconnections between subtropical and midlatitude precipitation regions. Principal components analyses show that ENSO (EI Niño-Southern Oscillation) is the dominant factor associated with recent interannual variation of precipitation in the region. The strongest relationships between ENSO and boreal summer precipitation were found in subtropical regions, as weIl as North Central China and southeastern Kazakhstan; boreal winter precipitation in the tropics and subtropics also exhibited strong relationships with ENSO. Scenarios for reconstructing spatial and temporal patterns of Asian monsoon precipitation variation were generated by selecting individual records based on 1) correlation with regional time series and 2) length of record. Spatial patterns were highly dependent on the type of record selected; however, temporal patterns were reasonably weIl reproduced regardless of station selection criteria. The implication of the latter result is that the dominant modes of boreal summer and winter precipitation for East Asia might be reconstructed using relatively few sites.
Mean temperature of March and April for the Qinling Mountains has been reconstructed based on Abies chensiensis tree-ring width for the last 250 years, with good chronology replication since 1828 to 1991 A.D. The explained variance of the reconstruction was 50.8%. Eight relative cold and 8 warm periods for early spring have been found. Power spectrum analysis displays 24, 21.82, 20.00, 18.46, 2.76, 2.73, 2.26, 2.11 and 2.09 yrs cycles. The reconstruction was significantly negatively correlated to dryness/wetness indices, which were derived from historical documents, with r = -0.297 (N3 = 229, p < 0.0001) after 10 year moving average. After 1900, r reached -0.718 (N4 = 75, p < 0.0001). This suggests that the lower mean temperature of March-April could be a signal of drought for the year, and vice versa.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.