Quantifying Environmental Control on Tropical Cyclone Intensity Change

Abstract

Composite analysis is used to examine environmental and climatology and persistence characteristics of tropical cyclones (TCs) undergoing different intensity changes in the western North Pacific (WPAC) and North Atlantic (ATL) ocean basins. Using the cumulative distribution functions of 24-h intensity changes from the 2003-08 best-track data, four intensity change bins are defined: rapidly intensifying (RI), intensifying, neutral, and weakening. The Navy Operational Global Atmospheric Prediction System daily 0000 and 1200 UTC global analysis and Tropical Rainfall Measuring Mission Microwave Imager data are then used as proxies for the real atmosphere, and composites of various environmental fields believed relevant to TC intensity change are made in the vicinity of the TCs. These composites give the average characteristics near the TC, prior to undergoing a given intensity change episode.For the environmental variables, statistically significant differences are examined between RI storms and the other groups. While some environmental differences were found between RI and weakening/neutral TCs in both basins, an interesting result from this study is that the environment of RI TCs and intensifying TCs is quite similar. This indicates that the rate of intensification is only weakly dependent on the environmental conditions, on average, provided the environment is favorable. Notable exceptions were that in the WPAC, RI events occurred in environments with significantly larger conditional instability than intensifying events. In the ATL, RI events occurred in environments with weaker deep-layer shear than intensifying events. An important finding of this work is that SSTs are similar between intensifying and rapidly intensifying TCs, indicating that the rate of intensification is not critically dependent on SST.The TCs in both basins were more intense prior to undergoing an RI episode than an intensifying or neutral episode. In the WPAC, the three groups had similar translational speeds and headings, and average initial position. In the ATL, RI storms were located farther south than intensifying and neutral storms, and had a larger translational speed and a more westward component to the heading.

Sensitivity to Horizontal Resolution of the Simulated Intensifying Rate and Inner-Core Structure of Typhoon Ida, an Extremely Intense Typhoon

“…php), occur in both the North Atlantic and the North-have suggested that the intensifying rate of a TC is only weakly dependent on environmental conditions (e.g., Hendricks et al 2010). Furthermore, many observational and numerical studies have shown that RI processes are closely related to the inner-core structure and convective activity of TC (e.g., Kieper and Jiang 2012;Rogers et al 2013;Wang and Wang 2014).…”

Impacts of climatic variables on cyclone in the coastal regions of Bangladesh

“…In Figure 5(a), the mean value of RH for 16 stations have represented from where the comparison of the stations is clearly seen along with their total mean value. The result is important as because temperature and RH relates to each other (Lawrence, 2004;Skilling, 2009) and the RH has a good influence on the formation of cyclone (Kaplan and DeMaria, 2003;Emanuel et al, 2004;Hendricks et al, 2010;Kaplan al., 2010). …”

“…Relative humidity (RH) is another important climatic factor and is also responsible for the formation of any kind of unsteady condition. Study on this parameter is also important because temperature and RH relates t (Lawrence, 2004;Skilling, 2009) and RH has a good influence on the formation of cyclone (Kaplan and DeMaria, 2003;Emanuel et al, 2004;Hendricks 2010;Kaplan et al, 2010). Wu et al (2012) showed that about 82% RH is responsible for the occurrence of North Atlantic Tropical cyclone.…”

On the Sensitivity of Tropical Cyclone Intensification under Upper-Level Trough Forcing

“…It is, therefore, necessary to (i) quantify and communicate forecast uncertainty and (ii) unravel the mechanisms leading to TC spinup, and/or better resolve multiscale processes in prediction models. Indeed, both large-scale (e.g., Molinari and Vollaro 1989;Hanley et al 2001;Davidson et al 2008;Hendricks et al 2010) and vortex-scale (e.g., Willoughby et al 1982;Montgomery and Kallenbach 1997;Schubert et al 1999;Wang 2002;Montgomery et al 2006;Nguyen et al 2011) processes have been demonstrated to control TC intensification.…”