{"content":[{"text":"The tropical Pacific, home of ENSO, may well be “control central” of global change4. Not only does \n the tropical Pacific maintain thermal stability of its low-latitude home-base through highly \n changeable atmospheric/oceanic dynamics5-9, but those changes that convey stability to the tropics \n send signals to high latitudes and upper levels of the atmosphere, forcing changes in those \n regions, some of which are ultimately communicated back to “control central” (Slide 5).","bbox":{"left":0.147058,"top":0.090522,"width":0.706058,"height":0.086932}},{"text":"This paper will examine the dominant and ancillary modes of climate variability. Discussion begins \n with “control central”, the tropical Pacific - a little history and an overview of ENSO basics, rounded \n out with a glance at the paleo-history and more recent history of ENSO behavior. Following is a \n relatively in-depth examination of the communication - zonally, meridionally, and vertically - of \n signals from the tropical Pacific to remote regions, revealing links to the numerous ancillary \n oscillatory patterns. Annular modes are considered next. Signals transmitted to, or deflected by, \n these modes reveal a relationship between high latitude variability and tropical dynamics. \n Fluctuations of the thermohaline circulation (THC), as orchestrated by ENSO and annular-mode \n dynamics, round out discussion of climate variability. Numerous questions evolve from the \n complexities described, suggesting directions for future research.","bbox":{"left":0.14706,"top":0.194765,"width":0.706009,"height":0.173901}},{"text":"THE TROPICAL PACIFIC: SO & ENSO: \n A Little History: \n It was only a little more than a century ago, that atmospheric pressure fluctuations in Sydney, \n Australia were recognized to be out-of-phase with those in Buenos Aires, Argentina10. Within a few \n years came the realization that these fluctuations oscillated fairly regularly – about every 3.8 \n years11. Furthermore, it was noted that this as-yet unnamed oscillation was almost global in \n extent11-12.","bbox":{"left":0.147057,"top":0.386128,"width":0.7060820000000001,"height":0.12162899999999999}},{"text":"“When the pressure is high in the Pacific Ocean, it tends to be low in the Indian Ocean from Africa \n to Australia,” observed the Director-General of Observatories in India, Sir Gilbert Walker. He \n based his observations on pressure readings in Jakarta, Darwin, and Cairo compared to those in \n Santiago, Honolulu, and Manila. He identified one such pressure fluctuation - the pressure \n fluctuation between the Indian Ocean and the eastern tropical Pacific - as the Southern Oscillation \n (SO). Gilbert also took note of temperatures in Madras, rainfall patterns in India and Chile, and the \n fluctuations in the Nile floods. He was motivated to understand the occasional, but disastrous \n failures of the Indian monsoons. In 1923 and 1937 he published work that showed the SO to be \n correlated strongly with precipitation and wind patterns over the tropical Pacific and Indian Oceans, \n as well as with temperature fluctuations in southeastern Africa, southwestern Canada, and \n southeastern U.S.13-14. Despite these observations, short and incomplete records handicapped \n further evaluation. Skepticism by Gilbert’s peers dampened general interest in the topic. At the \n time, only the atmospheric component was recognized; no one realized that the ocean may play a \n part. It was not until near the end of Gilbert’s life that the ocean was identified as playing a role \n linked to the fluctuations of the SO, or more accurately, the SOI – the Southern Oscillation Index, \n the difference between the pressure centers. When that difference is higher-than-normal, the SOI \n is positive; when it is lower-than-normal, the SOI is negative.","bbox":{"left":0.147058,"top":0.525219,"width":0.7061729999999999,"height":0.29556800000000005}},{"text":"Despite the hiatus of collective interest in the phenomenon, focus was not diverted for long. Using \n observations of Walker and others, Dutch meteorologist Berlage, in the 1950s, generated a map \n that illuminated the SO as a barometric record of the exchange of atmospheric mass along the \n entire global tropical circumference. An impressive degree of organization within the SO is","bbox":{"left":0.147058,"top":0.838098,"width":0.706141,"height":0.06950699999999999}},{"text":"2","bbox":{"left":0.843136,"top":0.935922,"width":0.009785000000000044,"height":0.015136999999999956}}],"images_bbox":[],"images_bbox_not_text_overlap":[]}