Abstract
The authors describe the characteristics of tropical cyclone (TC) activity in the GISS general circulation ModelE2 with a horizontal resolution 1°×1°. Four model simulations are analysed. In the first, the model is forced with sea surface temperature (SST) from the recent historical climatology. The other three have different idealised climate change simulations, namely (1) a uniform increase of SST by 2 degrees, (2) doubling of the CO2 concentration and (3) a combination of the two. These simulations were performed as part of the US Climate Variability and Predictability Program Hurricane Working Group. Diagnostics of standard measures of TC activity are computed from the recent historical climatological SST simulation and compared with the same measures computed from observations. The changes in TC activity in the three idealised climate change simulations, by comparison with that in the historical climatological SST simulation, are also described. Similar to previous results in the literature, the changes in TC frequency in the simulation with a doubling CO2 and an increase in SST are approximately the linear sum of the TC frequency in the other two simulations. However, in contrast with previous results, in these simulations the effects of CO2 and SST on TC frequency oppose each other. Large-scale environmental variables associated with TC activity are then analysed for the present and future simulations. Model biases in the large-scale fields are identified through a comparison with ERA-Interim reanalysis. Changes in the environmental fields in the future climate simulations are shown and their association with changes in TC activity discussed.
Highlights
As the spatial resolutions of climate models have increased in recent years, some climate models have been shown to simulate some characteristics of tropical cyclone (TC) activity well (e.g. Zhao et al, 2009; Camargo and Wing 2016)
A full description of this model is given in Schmidt et al (2014), using the horizontal resolution that was used in the CMIP5 archive (28 )2.58), while a description of the CMIP5 historical simulations of this model is given in Miller et al (2014)
While the CMIP5 model description given in Schmidt et al (2014) uses the typical horizontal resolution of 28)2.58 on a Cartesian grid, in our simulations we used a version of the model with finer resolution, namely C9018) on a cubed sphere grid, which has not been described previously by the GISS modelling group
Summary
As the spatial resolutions of climate models have increased in recent years, some climate models have been shown to simulate some characteristics of tropical cyclone (TC) activity well (e.g. Zhao et al, 2009; Camargo and Wing 2016). Kim et al (2012) examined the sensitivity of both the simulated MaddenÁ Julian oscillation and TC activity to changes in the convection scheme in the GISS model at the same 28 )2.58 resolution, including the TC activity in that analysis. Shaevitz et al (2014) present an overview of the performance of the entire ensemble for the simulations of recent historical climate and include the present climate simulation examined here in the GISS model as part of that. We include the idealised climate change simulations and complement the analysis of TC activity with an analysis of large-scale environmental variables relevant to TC activity, neither of which was included in Shaevitz et al (2014).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
