Exercise 10.1: The relationship between ENSO and the Indian Monsoon system was subject to a paper by Torrence and Webster (1999), Inter-decadal Changes in the ENSO Monsoon System, Journal of Climate, 12, 2679-2690. The authors analysed changes in the Pacific Ocean sea surface temperature indices NiÃ±o 3 and NiÃ±o 4, the Southern Oscillation Index (SOI), and the all-Indian rainfall since 1871. The data and paper are also contained in the relevant course directories (see /data/ and /Further Reading/). Request: Produce a time series of the NiÃ±o3.4 sea surface temperature anomaly and the Southern Oscillation Index for the period 1970 to end of data record. Describe your graphic in about 100 â€“ 150 words. (Note: after importing the data into a spreadsheet, remove all data not required, and convert the â€˜monthâ€™ into fraction of year).