Projected Response of Tropical Cyclone Intensity and Intensification in a Global Climate Model

Abstract

As one of the first global coupled climate models to simulate and predict category 4 and 5 (Saffir–Simpson scale) tropical cyclones (TCs) and their interannual variations, the High-Resolution Forecast-Oriented Low Ocean Resolution (HiFLOR) model at the Geophysical Fluid Dynamics Laboratory (GFDL) represents a novel source of insight on how the entire TC intensification distribution could be transformed because of climate change. In this study, three 70-yr HiFLOR experiments are performed to identify the effects of climate change on TC intensity and intensification. For each of the experiments, sea surface temperature (SST) is nudged to different climatological targets and atmospheric radiative forcing is specified, allowing us to explore the sensitivity of TCs to these conditions. First, a control experiment, which uses prescribed climatological ocean and radiative forcing based on observations during the years 1986–2005, is compared to two observational records and evaluated for its ability to capture the mean TC behavior during these years. The simulated intensification distributions as well as the percentage of TCs that become major hurricanes show similarities with observations. The control experiment is then compared to two twenty-first-century experiments, in which the climatological SSTs from the control experiment are perturbed by multimodel projected SST anomalies and atmospheric radiative forcing from either 2016–35 or 2081–2100 (RCP4.5 scenario). The frequency, intensity, and intensification distribution of TCs all shift to higher values as the twenty-first century progresses. HiFLOR’s unique response to climate change and fidelity in simulating the present climate lays the groundwork for future studies involving models of this type.

Potential Increase in Hazard From Mediterranean Hurricane Activity With Global Warming

“…These experiments are described in further detail in previous studies (Bhatia et al, 2018;van der Wiel et al, 2017). It is therefore important to note that here we run idealized simulations that are representative of each 20-year periods where interannual variability is not considered.…”

“…FLOR was derived from the Geophysical Fluid Dynamics Laboratory Climate Model, version 2.5 (GFDL CM2.5 [Delworth et al, 2012]). Both CM2.5 and FLOR have been used in several studies on regional climate change (Bhatia et al, 2018;Delworth et al, 2016;Delworth & Zeng, 2014;Kapnick et al, 2014;Pascale et al, 2017). FLOR is identical to CM2.5 but features a coarser ocean horizontal resolution (1 × 1°), which increases toward the equator.…”

“…Under the RCP4.5 scenario, global temperature change is likely to be within 2 and 4°C by the end of the 21st century, and it is compatible with measures to reduce CO 2 emissions and land use to stabilize radiative forcing at 4.5 W/m 2 by 2100 (Collins et al, 2013). This experimental setup (Bhatia et al, 2018;van der Wiel et al, 2017) prevents the development of substantial biases in SSTs arising in the freely running coupled model (Li & Xie, 2012), while still retaining the effects of air-sea interaction for timescale shorter than 5 days. This experimental setup (Bhatia et al, 2018;van der Wiel et al, 2017) prevents the development of substantial biases in SSTs arising in the freely running coupled model (Li & Xie, 2012), while still retaining the effects of air-sea interaction for timescale shorter than 5 days.…”

Changing geo‐ecological functions of coral reefs in the Anthropocene

“…A major consequence of these changes in accretion rates is that many reefs may increasingly lose the ability to maintain their functional roles in terms of buffering coasts from wave energy exposure, and the ability to track rising sea levels. This will be an especially critical issue if projections of increasing Tropical Cyclone intensity are realised (Bhatia, Vecchi, Murakami, Underwood, & Kossin, ). Several recent studies have modelled SLR impacts on wave energy regimes across reefs (e.g., Beetham, Kench, & Popinet, ; Storlazzi, Elias, Field, & Presto, ) and three key controls related to reef structure and accretion rates emerge: (a) reef width and profile; (b) surface structural complexity; and (c) reef growth relative to the rate of water depth increase.…”

Science Directions in a Post COP21 World of Transient Climate Change: Enabling Regional to Local Predictions in Support of Reliable Climate Information

“…This will be due to prolonged changes of the Earth's global heat content and available fresh water, and it will severely impact the cryosphere (further mass loss) and sea level (further increases) for decades to centuries. Climate change has already increased the likelihood of some types of extreme event (e.g., Stott et al, 2004), but their prediction, especially in the case of extreme tropical or extratropical cyclones, is still limited by our lack of fundamental understanding of the mechanisms and processes driving them (Bhatia et al, 2018). There is also concern that the ongoing warming would affect the characteristics of internal modes of variability (e.g., Cai et al, 2015) or the frequency and intensity of extreme events (Diffenbaugh et al, 2017).…”