scholarly journals Statistical Structure of Intrinsic Climate Variability under Global Warming

2016 ◽  
Vol 29 (16) ◽  
pp. 5935-5947 ◽  
Author(s):  
Xiuhua Zhu ◽  
John Bye ◽  
Klaus Fraedrich ◽  
Isabella Bordi

Abstract Climate variability is often studied in terms of fluctuations with respect to the mean state, whereas the dependence between the mean and variability is rarely discussed. Here, a new climate metric is proposed to measure the relationship between means and standard deviations of annual surface temperature computed over nonoverlapping 100-yr segments. This metric is analyzed based on equilibrium simulations of the Max Planck Institute Earth System Model (MPI-ESM): the last-millennium climate (800–1799), the future climate projection following the A1B scenario (2100–99), and the 3100-yr unforced control simulation. A linear relationship is globally observed in the control simulation and is thus termed intrinsic climate variability, which is most pronounced in the tropical region with negative regression slopes over the Pacific warm pool and positive slopes in the eastern tropical Pacific. It relates to asymmetric changes in temperature extremes and associates fluctuating climate means with increase or decrease in intensity and occurrence of both El Niño and La Niña events. In the future scenario period, the linear regression slopes largely retain their spatial structure with appreciable changes in intensity and geographical locations. Since intrinsic climate variability describes the internal rhythm of the climate system, it may serve as guidance for interpreting climate variability and climate change signals in the past and the future.

2018 ◽  
Vol 51 (1) ◽  
pp. 104-125 ◽  
Author(s):  
THEEPAKORN JITHITIKULCHAI ◽  
BRUCE A. MCCARL ◽  
XIMING WU

AbstractThis article examines the effects of ocean-related decadal climate variability (DCV) phenomena on climate and the effects of both climate shifts and independent DCV events on crop yields. We address three DCV phenomena: the Pacific Decadal Oscillation (PDO), the Tropical Atlantic Sea-Surface Temperature Gradient (TAG), and the Western Pacific Warm Pool (WPWP). We estimate the joint effect of these DCV phenomena on the mean, variance, and skewness of crop yield distributions. We found regionally differentiated impacts of DCV phenomena on growing degree days, precipitation, and extreme weather events, which in turn alter distributions of U.S. regional crop yields.


Thesis Eleven ◽  
2018 ◽  
Vol 145 (1) ◽  
pp. 77-98 ◽  
Author(s):  
Jose Jowel Canuday

In popular imagery, the littorals of Sulu and Zamboanga conjure visions of pirates, terrorists, and bandits marauding its rough seas, open shores, and rugged mountains. These bleak accounts render the region nothing but a violent and peripheral southern Philippine backdoor inconspicuous to the sophisticated constituencies of the world’s metropolitan centres. Obscured from these imageries are the lasting cosmopolitan traits of openness, flexibility, and reception of local folk to trans-local cultural streams that marked Sulu and Zamboanga as a globalised space across the ages and oceans. The distinctive features of these cosmopolitan sensibilities are strikingly discernible in inter-generationally shared narratives, artefacts, and performances that were continually renewed from the days when Sulu and Zamboanga served as a borderless trading and cultural enclave nestled at the crossroads of the Pacific and the Indian Oceans. These enduring cosmopolitan sensibilities are embodied in the blending, among others, of the time-honoured dance of pangalay and the pop-musical dance genre celebrated on actual, analogue, and digitally-mediated spaces of the contemporary world. Furthermore, these embodied sensibilities are evident in song compositions that proclaim the humanistic themes of hope, peace, and prosperity to their place and the world in ways that exemplify the local people’s broader sense of connections beyond the narrow association of family, community, ethnicity, religion, and identity. This mixed bag of age-old and recent imaginaries and cultural traffic evoke a sociality that link the social spaces of the troubled but once and current globalised region to continuing acts of transcendence in history, memory, and visions of the future. In these marginalized places, we can see an unyielding tradition of cultural re-adaptation and creativity made up of myriad everyday acts that are down-to-earth, pragmatic, interstitial, and practical cosmopolitanism.


2021 ◽  
Vol 9 (3) ◽  
pp. 299 ◽  
Author(s):  
Naomasa Oshiro ◽  
Takumi Tomikawa ◽  
Kyoko Kuniyoshi ◽  
Akira Ishikawa ◽  
Hajime Toyofuku ◽  
...  

Ciguatera fish poisoning (CFP) is one of the most frequently reported seafood poisoning diseases. It is endemic to the tropical region and occurs most commonly in the regions around the Pacific Ocean, Indian Ocean, and Caribbean Sea. The principal toxins causing CFP are ciguatoxins (CTXs). In the Pacific region, more than 20 analogs of CTXs have been identified to date. Based on their skeletal structures, they are classified into CTX1B-type and CTX3C-type toxins. We have previously reported species-specific and regional-specific toxin profiles. In this study, the levels and profiles of CTXs in fish present in the tropical western Pacific regions were analyzed using the liquid chromatography–tandem mass spectrometry (LC–MS/MS) technique. Forty-two fish specimens, belonging to the categories of snappers, groupers, Spanish mackerel, and moray eel, were purchased from various places such as Fiji, the Philippines, Thailand, and Taiwan. Only the fish captured from Fijian coastal waters contained detectable amounts of CTXs. The toxin levels in the fish species found along the coastal regions of the Viti Levu Island, the main island in Fiji, and the toxin profiles were significantly different from those of the fish species present in other coastal regions. The toxin levels and profiles varied among the different fish samples collected from different coastal areas. Based on the toxin levels and toxin profiles, the coast was demarcated into three zones. In Zone-1, which covers the northern coast of the main island and the regions of the Malake Island and Korovau, CTXs in fish were below the detection level. In Zone-2, CTX3C-type toxins were present in low levels in the fish. CTX1B-type and CTX3C-type toxins co-occurred in the fish present in Zone-3. The toxin profiles may have reflected the variation in Gambierdiscus spp.


2012 ◽  
Vol 25 (6) ◽  
pp. 1963-1995 ◽  
Author(s):  
Zhengyu Liu

Abstract The emerging interest in decadal climate prediction highlights the importance of understanding the mechanisms of decadal to interdecadal climate variability. The purpose of this paper is to provide a review of our understanding of interdecadal climate variability in the Pacific and Atlantic Oceans. In particular, the dynamics of interdecadal variability in both oceans will be discussed in a unified framework and in light of historical development. General mechanisms responsible for interdecadal variability, including the role of ocean dynamics, are reviewed first. A hierarchy of increasingly complex paradigms is used to explain variability. This hierarchy ranges from a simple red noise model to a complex stochastically driven coupled ocean–atmosphere mode. The review suggests that stochastic forcing is the major driving mechanism for almost all interdecadal variability, while ocean–atmosphere feedback plays a relatively minor role. Interdecadal variability can be generated independently in the tropics or extratropics, and in the Pacific or Atlantic. In the Pacific, decadal–interdecadal variability is associated with changes in the wind-driven upper-ocean circulation. In the North Atlantic, some of the multidecadal variability is associated with changes in the Atlantic meridional overturning circulation (AMOC). In both the Pacific and Atlantic, the time scale of interdecadal variability seems to be determined mainly by Rossby wave propagation in the extratropics; in the Atlantic, the time scale could also be determined by the advection of the returning branch of AMOC in the Atlantic. One significant advancement of the last two decades is the recognition of the stochastic forcing as the dominant generation mechanism for almost all interdecadal variability. Finally, outstanding issues regarding the cause of interdecadal climate variability are discussed. The mechanism that determines the time scale of each interdecadal mode remains one of the key issues not understood. It is suggested that much further understanding can be gained in the future by performing specifically designed sensitivity experiments in coupled ocean–atmosphere general circulation models, by further analysis of observations and cross-model comparisons, and by combining mechanistic studies with decadal prediction studies.


Author(s):  
Vagner de Alencar Arnaut de Toledo ◽  
Regina Helena Nogueira-Couto

This experiment was carried out to study the internal temperature regulation of a colony of Africanized honey bees (AFR), compared with hybrid Caucasian (CAU), Italian (ITA), and Carniolan (CAR) bees, during the period of one year and different size hives located in a sub-tropical region. The instant internal temperature, 33.7 ± 1.5° C for the AFR, 33.5 ± 1.4° C for the CAU, 33.7 ± 1.5° C for the ITA and 33.8 ± 1.4° C for the CAR, did not show any significant difference (P>0.05). The maximum temperature (36.1 ± 2.3° C) was statistically different (P<0.05) from the minimum (27.6 ± 5.3° C). There was no difference (P>0.05) in the mean internal temperature, between the nucleus (31.7 ± 6.3° C) and the brood nest (32.1 ± 5.3° C) measured between two and four o'clock in the afternoon.


Author(s):  
Steve Kite ◽  
James Pitchforth ◽  
Sammy Yip ◽  
Paz Artejo ◽  
Gerardo Ramon Galang

<p>The sizing of the main span dimensions for new marine bridge crossings needs to consider the current shipping vessels using the waterways and the future growth in marine traffic. Internationally accepted guidelines are used for initial sizing of the navigation clearances, but confirmation of the safe passage of vessels requires simulations to be undertaken. For two major marine bridges planned in the Philippines the marine navigation clearance assessments have been carried out, and the results verified via realistic simulations carried out at the facilities available in the Maritime Academy of Asia and the Pacific (MAAP). This paper outlines methodology of the theoretical calculations and the simulations performed, which confirmed the clearances and informed the design of the required navigation aids.</p>


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