Whilst browsing the journal pages, as one does, some unexpected papers appear which seem to receive little or no publicity. There’s probably good reason, in many cases, why this is so, but a couple of publications caught my eye, so I thought we could share them.

How could one resist:

Suggestive correlations between the brightness of Neptune, solar variability, and Earth’s temperature

H. B. Hammel

Space Science Institute, Boulder, Colorado, USA

G. W. Lockwood

Lowell Observatory, Flagstaff, Arizona, USA

Abstract

Long-term photometric measurements of Neptune show variations of brightness over half a century. Seasonal change in Neptune’s atmosphere may partially explain a general rise in the long-term light curve, but cannot explain its detailed variations. This leads us to consider the possibility of solar-driven changes, i.e., changes incurred by innate solar variability perhaps coupled with changing seasonal insolation. Although correlations between Neptune’s brightness and Earth’s temperature anomaly—and between Neptune and two models of solar variability—are visually compelling, at this time they are not statistically significant due to the limited degrees of freedom of the various time series. Nevertheless, the striking similarity of the temporal patterns of variation should not be ignored simply because of low formal statistical significance. If changing brightnesses and temperatures of two different planets are correlated, then some planetary climate changes may be due to variations in the solar system environment.

http://www.agu.org/pubs/crossref/2007/2006GL028764.shtml

Well, we already know that some climate change is due to variations in the solar system environment, but it’s kinda fun thinking that we may be able to more accurately assess the solar impact on earth by comparing it to measures of brightness of other planets.

On a slightly more serious note:

GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L05701, doi:10.1029/2006GL028275, 2007

Effect of air-sea coupling in the assessment of CO2-induced intensification of tropical cyclone activity

Akira Hasegawa

Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Japan

Seita Emori

Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Japan
Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan
Center for Climate System Research, University of Tokyo, Kashiwa, Japan

Abstract

We compared the CCSR/NIES/FRCGC coupled general circulation model (GCM) with the atmospheric GCM under control and future warmed conditions to investigate the effects of air-sea coupling on tropical cyclone properties, such as intensity and precipitation. Air-sea coupling suppresses tropical cyclone activity, because water vapor supply is reduced by sea surface temperature (SST) decrease due to the cold wakes under the tropical cyclones. Air-sea coupling tends to suppress tropical cyclone activity to a greater extent in a warmer world, because of the higher base SST and a larger decrease in SST due to the enhanced thermal stratification of the upper ocean. The overestimation of tropical cyclone activity in atmospheric models is more significant for extreme variables such as maximum precipitation than for averaged variables. Therefore, changes in tropical cyclone activity due to global warming based on atmosphere-only models may be overestimated, especially for extreme events.

There has been plenty of discussion on the difficult problem of understanding the relationship between climate change and tropical cyclones, but I hadn’t noticed this particular paper come up (yet). Perhaps a reader can point us to some comment elsewhere. The last sentence is, of course, the critical one: changes in activity derived from AGCMs (rather than AOGCMs) may be overestimated, especially for extreme events.

I have no idea how this might effect some of the other findings which have recently been published. I suspect that most work has been done on the AOGCMs, and that this phenomenon is known and considered in the production and analysis of model runs, but, just in case it isn’t, I thought it was worth bringing to the attention of a (slightly) larger audience.

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