{"content":[{"text":"Patterns of Global Climate Variability: Are the Tropics “Control Central”? \n Marcia Glaze Wyatt (2007) \n ABSTRACT: \n Fluctuations in mean global climate from interannual to decadal and possibly millennial timescales \n largely can be attributed to two dominant modes of variability – ENSO and the annular modes. \n Signals sent between the two modes, directly and through intermediary patterns, convey a network \n of opposing feedbacks that may contribute to stability of the global climate system, absent extreme \n cases of external perturbation.","bbox":{"left":0.147059,"top":0.090522,"width":0.706188,"height":0.13905299999999998}},{"text":"This paper endeavors to illuminate the roles played by these dominant modes of variability and to \n highlight contributions made by ancillary patterns that serve to enhance the global network of \n communication. The tropical Pacific is home not only to one of the dominant modes of variability – \n ENSO – but home also to patterns that initiate and facilitate communications among disparate \n regions, including latitudes at which annular modes govern. The ability to teleconnect to remote \n regions and thereby engage a sequence of feedbacks that have the potential to stabilize global \n climate suggests that the dynamics of the tropical Pacific might suitably be framed in the context of \n “control central” (PPT Slide 1).","bbox":{"left":0.147059,"top":0.247037,"width":0.706121,"height":0.13905299999999998}},{"text":"INTRODUCTION: \n Distinct regional patterns of winds, ocean currents, sea-level pressure, precipitation distributions, \n and temperature fluctuations emerge from a background of global climate noise. The list of \n patterns is long: TAV, Atlantic-Nino, SAIM, PDO, IPO, NPO, SO, AO, AAO, NAM, SAM, PNA, PSA, \n GEW, ACW, NAO, IOD, QBO, MJO, and ENSO (See glossary, p 30). Likely I have missed a few. \n All appear to be quasi-cyclic with that quasi-cyclic periodicity, itself, changing on quasi-cyclic time \n frames. Variability on scales of days to multiple decades can be identified from this collection of \n oscillatory behavior. In addition, some variability is internal – something inherent in any random \n system. Some variability is extraterrestrial – with incoming solar variability on a variety of \n timescales being the most relevant. There are the added complications of geomagnetic variability, \n the slowly fluctuating variability of orbital parameters, and the slower-yet variability of Earth’s \n tectonic rearrangements and cycles. All work together on a mind-dizzying level to generate \n patterns of coupled interactions among the various Earth systems – the lithosphere, cryosphere, \n hydrosphere, biosphere, and atmosphere – to ultimately create what we know as “climate”. \n Teasing out the dominant players of this scenario that operate on timescales relevant to human \n perception is the challenge lying before climate researchers today. (Slide 4)","bbox":{"left":0.147059,"top":0.403401,"width":0.7061679999999999,"height":0.27829499999999996}},{"text":"Most climate variability appears traceable to two dominant modes – ENSO and the annular \n modes1-3. Each mode is of regional origin yet of global influence. ENSO - interannually oscillating \n phases manifested most markedly as changes in SSTs in the eastern equatorial Pacific - reigns in \n the tropical Pacific. Through atmospheric and oceanic media, it transmits its influence both zonally \n and meridionally, touching every corner of the globe to some degree. Annular modes, responsive \n to perturbations of tropical origin, as well as to solar fluctuations, volcanics, aerosols, greenhouse \n gases, sea-ice extent, and SSTs, are pronounced seasonal tropospheric expressions of the \n stratospheric polar vortex in the high latitudes, yet extend their fingerprints to the tropics and \n beyond. The remaining above-mentioned oscillatory patterns, born of tectonics, ocean/atmosphere \n dynamics, and thermal gradients, play critical to ancillary roles as linkages and amplifiers to these \n two dominant modes.","bbox":{"left":0.147059,"top":0.699007,"width":0.706135,"height":0.19132499999999997}},{"text":"1","bbox":{"left":0.843136,"top":0.935922,"width":0.009785000000000044,"height":0.015136999999999956}}],"images_bbox":[],"images_bbox_not_text_overlap":[]}