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Tropical cyclone rainfall area controlled by relative sea surface temperature.

Lin Y, Zhao M, Zhang M - Nat Commun (2015)

Bottom Line: Here, using satellite data and global atmospheric model simulations, we show that tropical cyclone rainfall area is controlled primarily by its environmental sea surface temperature (SST) relative to the tropical mean SST (that is, the relative SST), while rainfall rate increases with increasing absolute SST.Our result is consistent with previous numerical simulations that indicated tight relationships between tropical cyclone size and mid-tropospheric relative humidity.Global statistics of tropical cyclone rainfall area are not expected to change markedly under a warmer climate provided that SST change is relatively uniform, implying that increases in total rainfall will be confined to similar size domains with higher rainfall rates.

View Article: PubMed Central - PubMed

Affiliation: Ministry of Education Key Laboratory for Earth System Modeling, Center for Earth System Science, Tsinghua University, Beijing 100084, China.

ABSTRACT
Tropical cyclone rainfall rates have been projected to increase in a warmer climate. The area coverage of tropical cyclones influences their impact on human lives, yet little is known about how tropical cyclone rainfall area will change in the future. Here, using satellite data and global atmospheric model simulations, we show that tropical cyclone rainfall area is controlled primarily by its environmental sea surface temperature (SST) relative to the tropical mean SST (that is, the relative SST), while rainfall rate increases with increasing absolute SST. Our result is consistent with previous numerical simulations that indicated tight relationships between tropical cyclone size and mid-tropospheric relative humidity. Global statistics of tropical cyclone rainfall area are not expected to change markedly under a warmer climate provided that SST change is relatively uniform, implying that increases in total rainfall will be confined to similar size domains with higher rainfall rates.

No MeSH data available.


Potential intensity from HIRAM simulations.Geographical distribution of mean PI (m s−1) for the (a) control, (b) AMIP, (c) P2K and (d) P4K simulations, along with relative changes in PI (% K−1) between (e) the P2K and control simulations, and (f) the P4K and AMIP simulations.
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f6: Potential intensity from HIRAM simulations.Geographical distribution of mean PI (m s−1) for the (a) control, (b) AMIP, (c) P2K and (d) P4K simulations, along with relative changes in PI (% K−1) between (e) the P2K and control simulations, and (f) the P4K and AMIP simulations.

Mentions: Theoretical studies and idealized simulations suggest that PI can affect TC size14151617. PI is closely related to relative SST25.The strong dependence of TC rainfall area on relative SST might therefore indicate a dependence on PI. We attempt to distinguish the effects of relative SST from the effects of PI using the HIRAM simulations. In these simulations only the absolute SST is increasing while the relative SST is fixed, and thus they can be used to isolate the effects of absolute SST alone. As expected, PI increases in the warmer climate simulations (Fig. 6), with the global PI weighted by TC track frequency increasing by roughly 1.2 m s−1 K−1 in the P2K simulation (relative to the control simulation) and 1.0 m s−1 K−1 in the P4K simulation (relative to the AMIP simulation; Supplementary Fig. 3). This amounts to an increase of roughly 2.3–2.7% K−1 (global PI weighted by TC track frequency is 43 m s−1), four times larger than the simulated increase in rainfall area (~0.4–0.6% K−1) (Fig. 4). This result suggests that TC rainfall area may increase at a much slower rate than PI as the climate warms.


Tropical cyclone rainfall area controlled by relative sea surface temperature.

Lin Y, Zhao M, Zhang M - Nat Commun (2015)

Potential intensity from HIRAM simulations.Geographical distribution of mean PI (m s−1) for the (a) control, (b) AMIP, (c) P2K and (d) P4K simulations, along with relative changes in PI (% K−1) between (e) the P2K and control simulations, and (f) the P4K and AMIP simulations.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4382685&req=5

f6: Potential intensity from HIRAM simulations.Geographical distribution of mean PI (m s−1) for the (a) control, (b) AMIP, (c) P2K and (d) P4K simulations, along with relative changes in PI (% K−1) between (e) the P2K and control simulations, and (f) the P4K and AMIP simulations.
Mentions: Theoretical studies and idealized simulations suggest that PI can affect TC size14151617. PI is closely related to relative SST25.The strong dependence of TC rainfall area on relative SST might therefore indicate a dependence on PI. We attempt to distinguish the effects of relative SST from the effects of PI using the HIRAM simulations. In these simulations only the absolute SST is increasing while the relative SST is fixed, and thus they can be used to isolate the effects of absolute SST alone. As expected, PI increases in the warmer climate simulations (Fig. 6), with the global PI weighted by TC track frequency increasing by roughly 1.2 m s−1 K−1 in the P2K simulation (relative to the control simulation) and 1.0 m s−1 K−1 in the P4K simulation (relative to the AMIP simulation; Supplementary Fig. 3). This amounts to an increase of roughly 2.3–2.7% K−1 (global PI weighted by TC track frequency is 43 m s−1), four times larger than the simulated increase in rainfall area (~0.4–0.6% K−1) (Fig. 4). This result suggests that TC rainfall area may increase at a much slower rate than PI as the climate warms.

Bottom Line: Here, using satellite data and global atmospheric model simulations, we show that tropical cyclone rainfall area is controlled primarily by its environmental sea surface temperature (SST) relative to the tropical mean SST (that is, the relative SST), while rainfall rate increases with increasing absolute SST.Our result is consistent with previous numerical simulations that indicated tight relationships between tropical cyclone size and mid-tropospheric relative humidity.Global statistics of tropical cyclone rainfall area are not expected to change markedly under a warmer climate provided that SST change is relatively uniform, implying that increases in total rainfall will be confined to similar size domains with higher rainfall rates.

View Article: PubMed Central - PubMed

Affiliation: Ministry of Education Key Laboratory for Earth System Modeling, Center for Earth System Science, Tsinghua University, Beijing 100084, China.

ABSTRACT
Tropical cyclone rainfall rates have been projected to increase in a warmer climate. The area coverage of tropical cyclones influences their impact on human lives, yet little is known about how tropical cyclone rainfall area will change in the future. Here, using satellite data and global atmospheric model simulations, we show that tropical cyclone rainfall area is controlled primarily by its environmental sea surface temperature (SST) relative to the tropical mean SST (that is, the relative SST), while rainfall rate increases with increasing absolute SST. Our result is consistent with previous numerical simulations that indicated tight relationships between tropical cyclone size and mid-tropospheric relative humidity. Global statistics of tropical cyclone rainfall area are not expected to change markedly under a warmer climate provided that SST change is relatively uniform, implying that increases in total rainfall will be confined to similar size domains with higher rainfall rates.

No MeSH data available.