Journal cover Journal topic
Ocean Science An interactive open-access journal of the European Geosciences Union
Ocean Sci., 11, 719-741, 2015
https://doi.org/10.5194/os-11-719-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
18 Sep 2015
Global representation of tropical cyclone-induced short-term ocean thermal changes using Argo data
L. Cheng1, J. Zhu1, and R. L. Sriver2 1International Center for Climate and Environment Sciences, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
2Department of Atmospheric Sciences, University of Illinois, Urbana-Champaign, IL, USA
Abstract. Argo floats are used to examine tropical cyclone (TC) induced ocean thermal changes on the global scale by comparing temperature profiles before and after TC passage. We present a footprint method that analyzes cross-track thermal responses along all storm tracks during the period 2004–2012. We combine the results into composite representations of the vertical structure of the average thermal response for two different categories: tropical storms/tropical depressions (TS/TD) and hurricanes. The two footprint composites are functions of three variables: cross-track distance, water depth and time relative to TC passage. We find that this footprint strategy captures the major features of the upper-ocean thermal response to TCs on timescales up to 20 days when compared against previous case study results using in situ measurements. On the global scale, TCs are responsible for 1.87 PW (11.05 W m−2) of heat transfer annually from the global ocean to the atmosphere during storm passage (0–3 days). Of this total, 1.05 ± 0.20 PW (4.80 ± 0.85 W m−2) is caused by TS/TD and 0.82 ± 0.21 PW (6.25 ± 1.5 W m−2) is caused by hurricanes. Our findings indicate that ocean heat loss by TCs may be a substantial missing piece of the global ocean heat budget. Changes in ocean heat content (OHC) after storm passage are estimated by analyzing the temperature anomalies during wake recovery following storm events (4–20 days after storm passage) relative to pre-storm conditions. Results indicate the global ocean experiences a 0.75 ± 0.25 PW (5.98 ± 2.1 W m−2) heat gain annually for hurricanes. In contrast, under TS/TD conditions, the ocean experiences 0.41 ± 0.21 PW (1.90 ± 0.96 W m−2) ocean heat loss, suggesting the overall oceanic thermal response is particularly sensitive to the intensity of the event. The ocean heat uptake caused by all storms during the restorative stage is 0.34 PW.

Citation: Cheng, L., Zhu, J., and Sriver, R. L.: Global representation of tropical cyclone-induced short-term ocean thermal changes using Argo data, Ocean Sci., 11, 719-741, https://doi.org/10.5194/os-11-719-2015, 2015.
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Short summary
1. Argo floats were used to examine tropical cyclone (TC) induced ocean thermal changes on the global scale by comparing temperature profiles before and after TC passage. 2. Global average of the vertical structure of the average ocean thermal response for two different categories: tropical storms/depressions (TS/TD) and hurricanes were presented. 3. Significant differences between weak storm (TS/TD) and strong storm (hurricane) were found.
1. Argo floats were used to examine tropical cyclone (TC) induced ocean thermal changes on the...
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