Differential expansion speeds of Indo-Pacific warm pool and deep convection favoring pool under greenhouse warming

Leung, Jeremy Cheuk‐Hin; Zhang, Banglin; Gan, Qiuying; Wang, Lei; Qian, Weihong; Hu, Zeng‐Zhen

doi:10.1038/s41612-022-00315-w

Cited by 12 publications

(12 citation statements)

References 67 publications

(127 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this study, the IPWP is divided into the Indian and Pacific Ocean sectors (see figure S1), respectively referred to as the IOWP and the WPWP, based on the basin mask information from NOAA's National Oceanographic Data Center (Locarnini et al 2010). The image histogram approach (Chen et al 2002, Cheng and Shi 2004, Xu et al 2010, Wong et al 2016, Leung et al 2022 was applied to display the spatial probability frequency distributions (PFDs) of SST and to estimate the capacity for change in warm pool size under ocean warming. Heat budget analyses were used to diagnose the seasonal variation of climatological SST.…”

Section: Methodsmentioning

confidence: 99%

Weakening seasonality of Indo-Pacific warm pool size in a warming world since 1950

Gan

Leung²,

Wang

et al. 2023

Environ. Res. Lett.

Self Cite

View full text Add to dashboard Cite

The seasonal variation of Indo-Pacific warm pool (IPWP) plays an important role in the oceanographic and climatological processes. While the IPWP expansion under greenhouse warming has been widely discussed, the response of the IPWP seasonality to climate change has received limited attention. In this study, we found an obvious seasonal diversity in the IPWP expansion from 1950–2020, with a maximal (minimal) expansion trend of 0.28×107 km2/decade in winter (0.17×107 km2/decade in spring), which consequently reduces the seasonality amplitude of the IPWP size variation. This is primarily attributed to the seasonal difference in the climatological spatial SST pattern over the Indo-Pacific Ocean, especially that over the tropical Indian Ocean, which determines the capacity for the IPWP expansion. Heat budget analyses show that the seasonal shortwave radiation and latent heat fluxes are the major factors controlling the capacity for IPWP size change across seasons. The presented analyses emphasize the significant weakening of the seasonality of the IPWP size, which may have great impacts on IPWP ecological environment and tropical climate system, and remind that the intrinsic properties of the climate background of Indo-Pacific SST hold important clues on the IPWP expansion under climate change.

show abstract

Section: Methodsmentioning

confidence: 99%

Weakening seasonality of Indo-Pacific warm pool size in a warming world since 1950

Gan

Leung²,

Wang

et al. 2023

Environ. Res. Lett.

Self Cite

View full text Add to dashboard Cite

show abstract

“…These anomalies stand for the impact of climate change (Anom = Future-HIST). To identify changes in the SST-precipitation relationship, we defined the two variables as follows: (1) deep convection threshold SST (CTT) is derived from the minimum SST which precipitation exceeds 10 mm d −1 , the threshold value that is favorable to deep convection based on (Leung et al 2022); and (2) saturation threshold SST (STT) is defined as the SST value at which the monthly mean precipitation peaks based on the joint probability density distribution. A hypothesis proposes that precipitation initially exhibits a continuous increase until reaching its maximum, after which it begins to decrease.…”

Section: Methodsmentioning

confidence: 99%

“…A significant increase in precipitation is shown over the regions where climatological precipitation is greater than 6 mm d −1 (figure 1(b), gray contour). Especially, 8 mm d −1 is considered as the minimum requirement of atmospheric deep convection (Leung et al 2022). When it comes to the areas where precipitation is more than 8 mm d −1 , a significant increasing trend of precipitation is displayed over the western Pacific.…”

Section: The Recent Warming Sst and Intensified Deep Convection Over ...mentioning

confidence: 99%

“…Some studies have shown that the intensity of deep convection is influenced not only by variations in the SST but also by the size of the IPWP (Clement et al 2001, Roxy et al 2019. The convection threshold typically refers to a SST value when deep convection initiates, and it has been studied in many ways including the outgoing longwave radiation, column water vapor, buoyancy, and precipitation (Lau et al 1997, Peters and Neelin 2006, Neelin et al 2009, Johnson and Xie 2010, Ahmed and David Neelin, 2018, Leung et al 2022. According to Graham and Barnett (1987), SST greater than 27.5 • C is necessary for the occurrence of large-scale deep convection.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Changes in the SST-precipitation relationship over the Indo-Pacific warm pool under a warming climate

Kim

Lau

2023

Environ. Res. Lett.

View full text Add to dashboard Cite

The Indo-Pacific warm pool (IPWP) is a region known for its strong atmospheric convection, which plays a key role in global climate. However, in recent decades, the IPWP has experienced human-induced warming, and it has been observed to have a non-linear relationship between Sea Surface Temperature (SST) and precipitation. Despite the rising SSTs, the increase in precipitation is limited until a specific SST, which is defined as saturation threshold SST (STT). The STT indicates a distinct transition before and after the STT, highlighting the non-linear response of precipitation to SST. Nevertheless, the impact of warmer climates on the SST-precipitation relationship and STT remains uncertain. To investigate future changes in this relationship, we analyzed a joint distribution of SST and precipitation using the historical data and three different Shared Socioeconomic Pathway (SSP) scenarios (SSP2-4.5, SSP3-7.0, and SSP5-8.5). We examined the near future (2041-2060), and far future (2081-2100). Our findings reveal that the STT increases with the shift in mean state due to the involvement of atmospheric stratification. This increase is observed across all three scenarios in both future periods, with the SSP5-8.5 scenario exhibiting the most substantial rise during the far future. The warming climate leads to a more pronounced warming in the upper troposphere than the surface, resulting in tropospheric stabilization. This process contributes to the increase in STT through Moist-Adiabatic Lapse Rate (MALR) adjustment. Additionally, the weakening of vertical motion constrains the increase in precipitation, despite the availability of abundant moisture. This study sheds light on the changing SST-precipitation relationship and provides a possible mechanism for the limited increase in precipitation. Therefore, this study offers a background for a better understanding of the non-monotonic response of precipitation to SST in the context of climate change.

show abstract

“…The patterns of the linear trends and differences are similar and exhibit a La Niña‐like structure with strengthened zonal SST and D20 anomaly gradients, strengthened zonal trade winds, and suppressed deep convection in the central equatorial Pacific. The warming trends in the western tropical Pacific are likely due to human ‐induced warming (e.g., Jiang & Zhu, 2020; Leung et al., 2022; Weller et al., 2016). These trends and differences are also consistent with the ENSO regime shift and mean state changes across the equatorial Pacific in 1999/2000 (England et al., 2014; Z.‐Z.…”

Section: Impact Of the Mean State Changes In The Tropical Pacificmentioning

confidence: 99%

Triple‐Dip La Niñas in 1998–2001 and 2020–2023: Impact of Mean State Changes

Li,

Hu,

McPhaden

et al. 2023

JGR Atmospheres

View full text Add to dashboard Cite

This study compares the evolution of atmospheric and oceanic anomalies as well as predictions for the two most recent triple‐dip La Niña events in 1998–2001 and 2020–2023. Subsurface cooling in the equatorial Pacific was stronger and more persistent during 1998–2001. In contrast, surface easterly winds were stronger during 2020–2023 as was the east‐west sea surface temperature (SST) contrast along the equator. We argue that in the absence of appreciable equatorial Pacific heat discharge, persistent and strong surface trade winds and a strengthened mean zonal SST contrast across the tropical Pacific contributed to the development of the 2020–2023 triple‐dip La Niña. In terms of the subsurface layer heat budget, the growth and maintenance of unusually cold SSTs during the triple‐dip La Niña in 1998–2001 were mainly the result of ocean vertical entrainment and diffusion, as well as meridional advection, associated with enhanced equatorial upwelling; while for the triple‐dip La Niña in 2020–2023, zonal advection was the largest contributor. The two events were mostly well predicted by multi‐model averages at 1–8 months lead times. We hypothesize that mean state change with enhanced zonal SST contrast and trade winds over the last several decades altered the physical processes associated with the growth and maintenance of the most recent La Niña, affecting its predictability. Successful prediction in real‐time of the 2020–2023 event more than half a year in advance was surprising because there was little memory in oceanic heat content which is often considered a key predictor.

show abstract

Differential expansion speeds of Indo-Pacific warm pool and deep convection favoring pool under greenhouse warming

Cited by 12 publications

References 67 publications

Weakening seasonality of Indo-Pacific warm pool size in a warming world since 1950

Weakening seasonality of Indo-Pacific warm pool size in a warming world since 1950

Changes in the SST-precipitation relationship over the Indo-Pacific warm pool under a warming climate

Triple‐Dip La Niñas in 1998–2001 and 2020–2023: Impact of Mean State Changes

Contact Info

Product

Resources

About