Limits...
Hydroclimatic contrasts over Asian monsoon areas and linkages to tropical Pacific SSTs

View Article: PubMed Central - PubMed

ABSTRACT

Knowledge of spatial and temporal hydroclimatic differences is critical in understanding climatic mechanisms. Here we show striking hydroclimatic contrasts between northern and southern parts of the eastern margin of the Tibetan Plateau (ETP), and those between East Asian summer monsoon (EASM) and Indian summer monsoon (ISM) areas during the past ~2,000 years. During the Medieval Period, and the last 100 to 200 years, the southern ETP (S-ETP) area was generally dry (on average), while the northern ETP (N-ETP) area was wet. During the Little Ice Age (LIA), hydroclimate over S-ETP areas was wet, while that over N-ETP area was dry (on average). Such hydroclimatic contrasts can be broadly extended to ISM and EASM areas. We contend that changes in sea surface temperatures (SSTs) of the tropical Pacific Ocean could have played important roles in producing these hydroclimatic contrasts, by forcing the north-south movement of the Intertropical Convergence Zone (ITCZ) and intensification/slowdown of Walker circulation. The results of sensitivity experiments also support such a proposition.

No MeSH data available.


Related in: MedlinePlus

Comparison of hydroclimatic changes in N-ETP and EASM areas.(a) (red) is composited precipitation in N-ETP areas (see Supplementary 1 for details). (b) (orange) is precipitation reconstructed from tree ring width at Qilian Mt.8 (c) (blue) is the Dulan tree ring width data9. (d) (purple) and (e) (green) denote the grain size and organic matter C/N ratio values in Lake Qinghai sediments7. (f) (magenta) is the drought/flood index at Longxi inferred from historical literature11. (g) (purple) is the lamina thickness of a stalagmite in Shihua Cave22. (i) (orange) is the drought index at Seoul, South Korea27. See the comparison sites in Fig. 1 and Table S3. The yellow shaded columns indicate the Medieval Period and the last ~200 years, and the blue shaded column indicates the LIA.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5016894&req=5

f2: Comparison of hydroclimatic changes in N-ETP and EASM areas.(a) (red) is composited precipitation in N-ETP areas (see Supplementary 1 for details). (b) (orange) is precipitation reconstructed from tree ring width at Qilian Mt.8 (c) (blue) is the Dulan tree ring width data9. (d) (purple) and (e) (green) denote the grain size and organic matter C/N ratio values in Lake Qinghai sediments7. (f) (magenta) is the drought/flood index at Longxi inferred from historical literature11. (g) (purple) is the lamina thickness of a stalagmite in Shihua Cave22. (i) (orange) is the drought index at Seoul, South Korea27. See the comparison sites in Fig. 1 and Table S3. The yellow shaded columns indicate the Medieval Period and the last ~200 years, and the blue shaded column indicates the LIA.

Mentions: Climatic changes over N-ETP areas are well-synchronized on centennial/multi-decadal time scales (Fig. 2). For example, the long term trends in precipitation at Lake Qinghai inferred from sedimentary C/N ratios and grain size7 (see details in Supplementary 1) are similar to those reconstructed from tree ring widths at Qilian Mt.8, Dulan9 (Fig. 2), and Delingha10 (Fig. S3), and similar to the trend of drought/flood index derived from historical literature11.


Hydroclimatic contrasts over Asian monsoon areas and linkages to tropical Pacific SSTs
Comparison of hydroclimatic changes in N-ETP and EASM areas.(a) (red) is composited precipitation in N-ETP areas (see Supplementary 1 for details). (b) (orange) is precipitation reconstructed from tree ring width at Qilian Mt.8 (c) (blue) is the Dulan tree ring width data9. (d) (purple) and (e) (green) denote the grain size and organic matter C/N ratio values in Lake Qinghai sediments7. (f) (magenta) is the drought/flood index at Longxi inferred from historical literature11. (g) (purple) is the lamina thickness of a stalagmite in Shihua Cave22. (i) (orange) is the drought index at Seoul, South Korea27. See the comparison sites in Fig. 1 and Table S3. The yellow shaded columns indicate the Medieval Period and the last ~200 years, and the blue shaded column indicates the LIA.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5016894&req=5

f2: Comparison of hydroclimatic changes in N-ETP and EASM areas.(a) (red) is composited precipitation in N-ETP areas (see Supplementary 1 for details). (b) (orange) is precipitation reconstructed from tree ring width at Qilian Mt.8 (c) (blue) is the Dulan tree ring width data9. (d) (purple) and (e) (green) denote the grain size and organic matter C/N ratio values in Lake Qinghai sediments7. (f) (magenta) is the drought/flood index at Longxi inferred from historical literature11. (g) (purple) is the lamina thickness of a stalagmite in Shihua Cave22. (i) (orange) is the drought index at Seoul, South Korea27. See the comparison sites in Fig. 1 and Table S3. The yellow shaded columns indicate the Medieval Period and the last ~200 years, and the blue shaded column indicates the LIA.
Mentions: Climatic changes over N-ETP areas are well-synchronized on centennial/multi-decadal time scales (Fig. 2). For example, the long term trends in precipitation at Lake Qinghai inferred from sedimentary C/N ratios and grain size7 (see details in Supplementary 1) are similar to those reconstructed from tree ring widths at Qilian Mt.8, Dulan9 (Fig. 2), and Delingha10 (Fig. S3), and similar to the trend of drought/flood index derived from historical literature11.

View Article: PubMed Central - PubMed

ABSTRACT

Knowledge of spatial and temporal hydroclimatic differences is critical in understanding climatic mechanisms. Here we show striking hydroclimatic contrasts between northern and southern parts of the eastern margin of the Tibetan Plateau (ETP), and those between East Asian summer monsoon (EASM) and Indian summer monsoon (ISM) areas during the past ~2,000 years. During the Medieval Period, and the last 100 to 200 years, the southern ETP (S-ETP) area was generally dry (on average), while the northern ETP (N-ETP) area was wet. During the Little Ice Age (LIA), hydroclimate over S-ETP areas was wet, while that over N-ETP area was dry (on average). Such hydroclimatic contrasts can be broadly extended to ISM and EASM areas. We contend that changes in sea surface temperatures (SSTs) of the tropical Pacific Ocean could have played important roles in producing these hydroclimatic contrasts, by forcing the north-south movement of the Intertropical Convergence Zone (ITCZ) and intensification/slowdown of Walker circulation. The results of sensitivity experiments also support such a proposition.

No MeSH data available.


Related in: MedlinePlus