Changes in extratropical storm track cloudiness 1983-2008: observational support for a poleward shift

Bender, Frida; Ramanathan, V.; Tselioudis, George
May 2012
Climate Dynamics;May2012, Vol. 38 Issue 9/10, p2037
Academic Journal
Climate model simulations suggest that the extratropical storm tracks will shift poleward as a consequence of global warming. In this study the northern and southern hemisphere storm tracks over the Pacific and Atlantic ocean basins are studied using observational data, primarily from the International Satellite Cloud Climatology Project, ISCCP. Potential shifts in the storm tracks are examined using the observed cloud structures as proxies for cyclone activity. Different data analysis methods are employed, with the objective to address difficulties and uncertainties in using ISCCP data for regional trend analysis. In particular, three data filtering techniques are explored; excluding specific problematic regions from the analysis, regressing out a spurious viewing geometry effect, and excluding specific cloud types from the analysis. These adjustments all, to varying degree, moderate the cloud trends in the original data but leave the qualitative aspects of those trends largely unaffected. Therefore, our analysis suggests that ISCCP data can be used to interpret regional trends in cloudiness, provided that data and instrumental artefacts are recognized and accounted for. The variation in magnitude between trends emerging from application of different data correction methods, allows us to estimate possible ranges for the observational changes. It is found that the storm tracks, here represented by the extent of the midlatitude-centered band of maximum cloud cover over the studied ocean basins, experience a poleward shift as well as a narrowing over the 25 year period covered by ISCCP. The observed magnitudes of these effects are larger than in current generation climate models (CMIP3). The magnitude of the shift is particularly large in the northern hemisphere Atlantic. This is also the one of the four regions in which imperfect data primarily prevents us from drawing firm conclusions. The shifted path and reduced extent of the storm track cloudiness is accompanied by a regional reduction in total cloud cover. This decrease in cloudiness can primarily be ascribed to low level clouds, whereas the upper level cloud fraction actually increases, according to ISCCP. Independent satellite observations of radiative fluxes at the top of the atmosphere are consistent with the changes in total cloud cover. The shift in cloudiness is also supported by a shift in central position of the mid-troposphere meridional temperature gradient. We do not find support for aerosols playing a significant role in the satellite observed changes in cloudiness. The observed changes in storm track cloudiness can be related to local cloud-induced changes in radiative forcing, using ERBE and CERES radiative fluxes. The shortwave and the longwave components are found to act together, leading to a positive (warming) net radiative effect in response to the cloud changes in the storm track regions, indicative of positive cloud feedback. Among the CMIP3 models that simulate poleward shifts in all four storm track areas, all but one show decreasing cloud amount on a global mean scale in response to increased CO forcing, further consistent with positive cloud feedback. Models with low equilibrium climate sensitivity to a lesser extent than higher-sensitivity models simulate a poleward shift of the storm tracks.


Related Articles

  • An improved simple snow-atmosphere-soil transfer model. Liu, HuiZhi; Zhai, XiaoDong; Sun, ShuFen; Feng, JianWu; Wang, Lei // SCIENCE CHINA Earth Sciences;Jul2012, Vol. 55 Issue 7, p1206 

    On the basis of a simple snow-atmosphere-soil transfer (SAST) model previously developed, this paper presents an improved snow-atmosphere-soil transfer (ISAST) model that has a new numerical scheme and an improved method of layering the snowpack. The new model takes the snow cover temperature...

  • Future Projection of Extreme Heavy Snowfall Events With a 5‐km Large Ensemble Regional Climate Simulation. Sasai, T.; Kawase, H.; Kanno, Y.; Yamaguchi, J.; Sugimoto, S.; Yamazaki, T.; Sasaki, H.; Fujita, M.; Iwasaki, T. // Journal of Geophysical Research. Atmospheres;12/27/2019, Vol. 124 Issue 24, p13975 

    We have recently experienced several heavy snowfall events, but still do not sufficiently understand how global warming will impact changes in local extreme snowfall events. The analysis relevant to the extreme events requires ensemble experiments with high‐resolution regional climate...

  • Projected change in East Asian summer monsoon precipitation under RCP scenario. Chen, Huopo; Sun, Jianqi // Meteorology & Atmospheric Physics;Jul2013, Vol. 121 Issue 1/2, p55 

    Future changes in East Asian summer monsoon precipitation climatology, frequency, and intensity are analyzed using historical climate simulations and future climate simulations under the RCP4.5 scenario using the World Climate Research Programme's (WCRP) Coupled Model Intercomparison Project 5...

  • Estimating the Ice Crystal Enhancement Factor in the Tropics. Zeng, Xiping; Tao, Wei-Kuo; Matsui, Toshihisa; Xie, Shaocheng; Lang, Stephen; Zhang, Minghua; O''C Starr, David; Li, Xiaowen // Journal of the Atmospheric Sciences;Jul2011, Vol. 68 Issue 7, p1424 

    The ice crystal enhancement (IE) factor, defined as the ratio of the ice crystal to ice nuclei (IN) number concentrations for any particular cloud condition, is needed to quantify the contribution of changes in IN to global warming. However, the ensemble characteristics of IE are still unclear....

  • Sensitivity to deliberate sea salt seeding of marine clouds -- observations and model simulations. Alterskjær, K.; Kristjánsson, J. E.; Seland, Ø. // Atmospheric Chemistry & Physics Discussions;2011, Vol. 11 Issue 10, p29527 

    Sea salt seeding of marine clouds to increase their albedo is a proposed technique to counteract or slow global warming. In this study, we first investigate the susceptibility of marine clouds to sea salt injections, using observational data of cloud droplet number concentration, cloud optical...

  • Simulating river discharge in a snowy region of Japan using output from a regional climate model. Ma, X.; Kawase, H.; Adachi, S.; Fujita, M.; Takahashi, H. G.; Hara, M.; Ishizaki, N.; Yoshikane, T.; Hatsushika, H.; Wakazuki, Y.; Kimura, F. // Advances in Geosciences;2013, Vol. 35, p55 

    Snowfall amounts have fallen sharply along the eastern coast of the Sea of Japan since the mid-1980s. Toyama Prefecture, located approximately in the center of the Japan Sea region, includes high mountains of the northern Japanese Alps on three of its sides. The scarcity of meteorological...

  • Evaluation of ACCMIP outgoing longwave radiation from tropospheric ozone using TES satellite observations. Bowman, K. W.; Shindell, D. T.; Worden, H. M.; Lamarque, J. F.; Young, P. J.; Stevenson, D. S.; Qu, Z.; de la Torre, M.; Bergmann, D.; Cameron-Smith, P. J.; Collins, W. J.; Doherty, R.; Dalsøren, S. B.; Faluvegi, G.; Folberth, G.; Horowitz, L. W.; Josse, B. M.; Lee, Y. H.; MacKenzie, I. A.; Myhre, G. // Atmospheric Chemistry & Physics;2013, Vol. 13 Issue 8, p4057 

    We use simultaneous observations of tropospheric ozone and outgoing longwave radiation (OLR) sensitivity to tropospheric ozone from the Tropospheric Emission Spectrometer (TES) to evaluate model tropospheric ozone and its effect on OLR simulated by a suite of chemistry-climate models that...

  • On the dependence of the OH* Meinel emission altitude on vibrational level: SCIAMACHY observations and model simulations. von Savigny, C.; McDade, I. C.; Eichmann, K.-U.; Burrows, J. P. // Atmospheric Chemistry & Physics Discussions;2012, Vol. 12 Issue 2, p5817 

    Measurements of the OH Meinel emissions in the terrestrial nightglow are one of the standard ground-based techniques to retrieve upper mesospheric temperatures. It is often assumed that the emission peak altitudes are not strongly dependent on the vibrational level, although this assumption is...

  • Can a global model reproduce observed trends in summertime surface ozone levels? Koumoutsaris, S.; Bey, I. // Atmospheric Chemistry & Physics;2012, Vol. 12 Issue 15, p6983 

    Quantifying trends in surface ozone concentrations is critical for assessing pollution control strategies. Here we use observations and results from a global chemical transport model to examine the trends (1991-2005) in daily maximum 8-h average concentrations in summertime surface ozone at...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics