Through stable oxygen and carbon analyses of rapidly accumulating sediment
cores from the eastern Arabian Sea, we show that the excess of evaporation
over precipitation (E-P) steadily appears to have decreased during the last
similar to 10 000 to similar to 2000 years, most probably due to an increa
sing trend in the summer monsoon rainfall, contrary to the land-based paleo
climatic data from this region, which indicate onset of aridity around 4000
years ago. Our results are consistent with the hypothesis that significant
spatial variability in the monsoon rainfall observed today was persistent
during most of the Holocene. Alternatively, the trend can be seen as an adj
ustment between two phases, one between similar to 10 000 and similar to 60
00 years ago of increasing precipitation and another between 3500 and 2000
years ago after the arid episode. We also report a significant similar to 7
00 year periodicity, similar to that reported recently from the South China
Sea, indicating that the centennial/millennial scale response of the India
n and Chinese monsoons to high latitude forcing may be alike. (C) 2000 Publ
ished by Elsevier Science B.V. All rights reserved.