arXiv subjects

Ka-Kit Tung

Publications and source records attributed to Ka-Kit Tung.

4 recordsLinked to original sources

arXiv2024

Optimal Marital Strategies: How Couples Develop Successful Interaction Styles

The study of marriage dynamics and of strategies to reduce the likelihood of divorce has been an important research area for many years. Gottman's research on successful marriages revealed three matched interaction styles: conflict-avoiding, validating, and volatile. There has, however, been little progress in explaining how couples develop these styles of interaction and why failure to do so leads to failed marriages. In this paper, we show that these interaction styles arise as solutions to an optimal control problem where the couples jointly maximize a common goal. The validating style arises when the benefit from achieving joint happiness is balanced by the emotional cost of adopting a particular style. The ubiquitous conflict-avoider style arises naturally when the couple does not care about the cost. The volatile style is not an optimal solution, but volatile marriages may still be successful for couples with highly positive natural dispositions. The problem of the spouses having different goals in marriage is relevant to marriage repair, and this problem will be studied in the next paper using differential game theory.

math.OC↗

arXiv2023

Solar Cycle as a Distinct Line of Evidence Constraining Earth's Transient Climate Response

Severity of warming predicted by climate models depends on their Transient Climate Response (TCR). Inter-model spread of TCR has persisted at ~100% of its mean for decades. Existing observational constraints of TCR are based on observed historical warming to historical forcing and their uncertainty spread is just as wide, mainly due to forcing uncertainty, and especially that of aerosols. Contrary, no aerosols are involved in solar-cycle forcing, providing an independent, tighter, constraint. Here, we define a climate sensitivity metric: time-dependent response regressed against time-dependent forcing, allowing phenomena with dissimilar time variations, such as the solar cycle with 11-year cyclic forcing, to be used to constrain TCR, which has a linear time-dependent forcing. We find a theoretical linear relationship between the two. The latest coupled atmosphere-ocean climate models obey the same linear relationship statistically. The proposed observational constraint on TCR is about 1/3 as narrow as existing constraints. The central estimate, 2.2$^\circ$C, is at the midpoint of the spread of the latest generation of climate models, which are more sensitive than those of the previous generations.

physics.ao-ph↗

arXiv2023

Evidence lacking for a pending collapse of the Atlantic Meridional Overturning Circulation

A catastrophic collapse of the Atlantic Meridional Overturning Circulation (AMOC) will have serious impacts on global climate. Based on eight AMOC proxies across the Atlantic basin Boers claimed to have found Early Warning Signals (EWS) that point to its imminent collapse. Here we show that common to all eight of Boers' AMOC proxies are artificial rises in variance as observational coverage increased, giving false alarms; we demonstrate how climate models without EWS could be made to yield apparent EWS of a tipping point when sampled according to the increasing historical observational coverage. In addition, Boers' salinity proxy was based on our work; this and another of his sub polar AMOC proxy have their signs reversed erroneously. The narrative that AMOC is declining towards collapse cannot be supported when the sign is corrected.

physics.ao-ph↗

arXiv2006

Recent Developments in Understanding Two-dimensional Turbulence and the Nastrom-Gage Spectrum

Two-dimensional turbulence appears to be a more formidable problem than three-dimensional turbulence despite the numerical advantage of working with one less dimension. In the present paper we review recent numerical investigations of the phenomenology of two-dimensional turbulence as well as recent theoretical breakthroughs by various leading researchers. We also review efforts to reconcile the observed energy spectrum of the atmosphere (the spectrum) with the predictions of two-dimensional turbulence and quasi-geostrophic turbulence.

nlin.CD↗