Heat Transport

Number of papers: 7

Heat Transport Compensation in Atmosphere and Ocean over the Past 22,000 Years — Nature Scientific Reports, 2015; Yang et al

The authors use a sophisticated model to show that the North and South hemispheres practically offset each other during the past 20k years and that the total energy balance stays within a fairly narrow range.

Reduction in Meridional Heat Export Contributes to Recent Indian Ocean Warming — Journal of Physical Oceanography, 2022; McGonigal et al.

“Over 2005–15, Indian Ocean heat content has increased by 1.97 × 1022 J or 0.06 PW. This balances, within error bars, the heat convergence, implying that net air–sea fluxes over the Indian Ocean were near zero over the 2010s. In contrast, previous studies all found divergences of Indian Ocean heat of order 0.5 PW (Table 1), implying warming of the Indian Ocean through the air–sea interface and net buoyancy gain during the 2000s (Bryden and Beal 2001). If the net air–sea heat flux has reduced since the 2000s, even while the Indian Ocean has rapidly warmed, this is further evidence that the warming has been driven by significant changes in oceanic fluxes and not by surface forcing.”

Pacific Ocean Heat Content During the Past 10,000 Years — Science, 2013; Rosenthal et al.

The authors “present a temperature record of western equatorial Pacific subsurface and intermediate water masses over the past 10,000 years that shows that heat content varied in step with both northern and southern high-latitude oceans. The findings support the view that the Holocene Thermal Maximum, the Medieval Warm Period, and the Little Ice Age were global events, and they provide a long-term perspective for evaluating the role of ocean heat content in various warming scenarios for the future.”

The Partitioning of Poleward Heat Transport between the Atmosphere and Ocean — American Meteorological Society Journal, 2006; Czaja and Marshall

This very technical paper says that 1) water stores heat, 2) water moves heat from the tropics to the temperate zones (outside the tropic of Cancer/Capricorn), and 3) poleward from the tropics, air (wind) is responsible for the majority of heat transfer. In the north Atlantic, these are the “Westerlies.” Their patterns define the climate on the downwind side of the ocean basin. The point is that since ocean heat transport is the main driver of our climate, variability is far less than most people think. (See the paper above as well.)

Role for Eurasian Arctic shelf sea ice in a secularly varying hemispheric climate signal during the 20th 2 century — Climate Dynamics, 2013; Wyatt and Curry

Also known as “the stadium-wave paper,” the abstract states: “A hypothesized low-frequency climate signal propagating across the Northern Hemisphere through a network of synchronized climate indices was identified in previous analyses of instrumental and proxy data. The tempo of signal propagation is rationalized in termsof the multidecadal component of Atlantic Ocean variability — the Atlantic Multidecadal Oscillation. Through multivariate statistical analysis of an expanded database, we further investigate this hypothesized signal to elucidate propagation dynamics. The Eurasian Arctic Shelf-Sea Region, where sea ice is uniquely exposed to open ocean in the Northern Hemisphere, emerges as a strong contender for generating and sustaining propagation of the hemispheric signal. Ocean-ice-atmosphere coupling spawns a sequence of positive and negative feedbacks that convey persistence and quasi-oscillatory features to the signal. Further stabilizing the system are anomalies of co-varying Pacific-centered atmospheric circulations. Indirectly related to dynamics in the Eurasian Arctic, these anomalies appear to negatively feed back onto the Atlantic‘s freshwater balance. Earth’s rotational rate and other proxies encode traces of this signal as it makes its way across the Northern Hemisphere.”

Coupled stratosphere-troposphere-Atlantic multidecadal oscillation and its importance for near-future climate projection — NPJ Climate and Atmospheric Science, 2022; Omrani et al.

This is a complex model of the way heat moves north from the Equator. It’s important because they are starting to build models that more accurately match the earth’s actual climate. The authors conclude: “This coupled variability improves the performance of statistical models, which project further weakening of North Atlantic Oscillation, North Atlantic cooling and hiatus in wintertime North Atlantic-Arctic sea-ice and global surface temperature just like the 1950s–1970s.” In other words, the North Atlantic is cycling back into a cooling phase. The NAO and the AMO are the true drivers of climate in Europe.

They also conclude that the effects on ozone concentration may indicate ozone depletion might not be entirely anthropogenic. In my view, the ozone “hole” is entirely unaffected by humans, but I’m still looking for good evidence either way.

The North Atlantic Oscillation as a driver of rapid climate change in the Northern Hemisphere — Nature Geoscience, 2016; Delworth et al.

This paper shows important correlations between the NAO and heat transport to the Arctic. They assume there have been more hurricanes in the past decades, which has since been shown not to be the case. I like this paper for the graphs — the AMO is a roughly 60-year cycle that is now turning colder. That should lead to cooler temperatures in Europe.