| This paper reports on an investigation into the chronology of El Niño/Southern
Oscillation (ENSO) events, during the period from the arrival of
conquistadores in Ecuador in 1532 until the year 1900. A number of probable
El Niño events and drought years can be dated from anecdotal reports of
significant rainfall and drought in the equatorial region.
The evidence of ENSO has been documented from early reports in the South
America archives. A large number of books and articles have been reviewing
from the Ecuadorian archives to obtain information on El Niño events
that have occurred over the past centuries. This information is based on
evidence obtained from the equatorial region, where strong and very strong
El Niño events clearly separate the northern part of the Ecuadorian
coast from the southern region, the normally rainy season specially from
west-central to the south coast of Ecuador, as well as the drought years,
reported in this region which is climatologically and oceanographically
different from the moist Northern coast of Ecuador. Given the normal
occurrence of rains in the southern coast of Ecuador, it is reasonable to
expect that at least some of the major rainy seasons would be recorded in
local chronicles and publications. This information has been compared with
reports obtained from Peru.
Relative strengths of events are based on such considerations as wind and
current effects on travel times of ancient sailing ships, degree of physical
damage and destruction, amounts of rainfall and flooding, human disease
epidemic, mass mortality of endemic marine organism, rises in sea
temperatures and sea levels, effects on coastal fisheries.
This paper is the first survey of the historical sources concerned the
rainfall and drought in Ecuador. In the course of this investigation we also
noted some extended periods of time, near decadal or longer over the past
records, when the amount and/or strength of El Niño and its resulting
effects appeared to represent significant long-term climate changes. |