Tuesday, February 18, 2014

New paper finds global cloudiness has increased over past 5 years, corroborates Svensmark theory of climate

A paper published today in the Journal of Geophysical Research Atmospheres finds that upper and lower tropospheric clouds have increased globally over the past 5 years. 

The paper would appear to corroborate the Svensmark cosmic ray theory of climate, which predicts increased cloud formation associated with decreased solar activity. 

A global survey of the instantaneous linkages between cloud vertical structure and large-scale climate

Journal of Geophysical Research, Atmospheres by Ying Li, David W. J. Thompson, Graeme L. Stephens, Sandrine Bony

The instantaneous linkages between cloud vertical structure and various large-scale meteorological parameters are investigated using five years of data from the CloudSat/CALIPSO instrument and ECMWF analyses products. The linkages are systemically explored and quantified at all vertical levels and throughout the global ocean in both the long-term mean and on month-to-month timescales. A number of novel large-scale meteorological parameters are used in the analysis, including tropopause temperatures, uppertropospheric stability and storm track activity. The results provide a baseline for evaluating physical parameterizations of clouds in GCMs, and a reference for interpreting the signature of large-scale atmospheric phenomena in cloud vertical structure. In general, the linkages observed in the long-term mean are similar to those found on month-to-month timescales. In the long-term mean, upper tropospheric cloud incidence throughout the globe increases with: 1) decreasing tropopause temperature (at a rateof ~2–4% K− 1); 2) decreasing upper tropospheric stability (~5–10% per K km − 1); and 3) increasing large-scale vertical motion (~1–4% per 10 hPa day − 1). In contrast, lower tropospheric cloud incidence increases with: 1) increasing lower tropospheric stability (10% per K km − 1) and descending motion (1% per 10 hPa day − 1) in regions of subtropical regime; but 2) decreasing lower tropospheric stability (4% per K km − 1) and ascending motion (2% per 10 hPa day − 1) over the Arctic region. Variations in static stability and vertical motion account for ~20–35% of the month-to-month variance in upper tropospheric cloudiness but less than 10% of the variance in lower tropospheric clouds. Upper tropospheric cloud incidence in the storm track regions is strongly linked to the variance of large-scale vertical motion and thus the amplitude of baroclinic waves.


  1. http://wattsupwiththat.com/2014/02/18/how-much-sunlight-actually-enters-the-system/

  2. I think you are too hasty connecting this paper with Svensmark. The paper talks about cloud incidence increases in function of various parameters (tropopause temperature, tropospheric stability, large scale vertical motion, etc), but not with time over the past 5 years.