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Abstract September–November (e.g., autumn) 2023 produced the fewest western North Pacific (WNP) tropical cyclones (TCs) since 1951, likely as a joint response to El Niño and a warm phase of the North Pacific Mode (NPM). Decreases in both TC genesis frequency and two genesis potential indices (GPIs) over the western WNP were likely the result of El Niño-induced and warm NPM-induced negative low-level relative vorticity anomalies. Over the eastern WNP, TC genesis and GPI reductions were also associated with vorticity decreases over the eastern WNP, where the TC-suppressing effect of the warm NPM surpassed the TC-favoring effect of El Niño. The changes in vorticity were further linked to anomalous anticyclones centered over the South China Sea and the midlatitude central North Pacific. A linear combination of the responses to El Niño and a warm NPM can explain the changes in TC genesis and low-level circulation over most of the WNP in 2023, except east of 160°E where other climate modes may have played more of a role.

Abstract This study investigates the influence of the Northeast China cold vortex (NCCV) on the northward‐moving typhoons (NTCs) over the western North Pacific (WNP). There is a significant inverse relationship between the NCCV during June–September and simultaneous NTCs during 1981–2021. Fewer (more) NTCs are observed during NCCV active (inactive) year a combination of less (more) NTC genesis, particularly over the central Pacific region of 10°–30° N and 130°–150° E, and fewer (more) NTCs moving northwestward and making landfall in coastal regions of the Yellow Sea and Bohai Sea. These regions are characterized by significantly decreased low‐level vorticity and mid‐level humidity, which impedes NTC genesis and notably enhances the deep‐layer subtropical straight westerly steering flow, thus blocking the northward movement of NTCs. These remarkable environmental changes during different NCCV years are clearly linked with the changes of an anomalous anticyclone in the subtropics (20°–30° N, 120°–160° E). In short, more (less) NCCV activity strengthens (weakens) the anomalous anticyclone, resulting in fewer (more) NTCs.

Abstract This study investigates long‐term trends related to the mature stage duration of tropical cyclones (TCs) over the western North Pacific (WNP) during June–November between 1982 and 2021. There is a significant shortening in the mean duration of the WNP mature TC stage, which is defined as the period when a TC is within 5 kt of its lifetime maximum intensity. This shortening is induced by a significant (weak) poleward migration in the starting (ending) location of the WNP mature TC stage, which can be further explained by changes in environmental conditions. From 1982 to 2021, there have been significant increases in maximum potential intensity and 700–500‐hPa relative humidity over most of the WNP, which has broadly expanded the TC‐favorable area poleward. Consequently, WNP TCs can start their mature stages and reach their lifetime maximum intensities at higher latitudes. By contrast, there are only weak changes in 850‐hPa relative vorticity and 850–200‐hPa vertical wind shear (VWS). Given the dominant role of VWS in modulating the TC weakening rate, the TC‐suppressive area over the subtropical WNP has shown lesser changes, thus leading to insignificant changes in the ending location of the mature TC stage.

ObjectiveJianPiHuaTan Formula (JPHTF), a traditional Chinese medicine (TCM), has been utilized as an adjunctive therapy for colorectal cancer (CRC). The study aims to evaluate the potential clinical benefits of JPHTF and its effectiveness in inhibiting tumor growth.Methods300 stage II/III CRC patients and 412 advanced CRC patients were enrolled to verify the clinical value of JPHTF in CRC treatment. Furthermore, CRC patient-derived xenograft (PDX) mice were utilized to investigate the regulatory mechanisms of JPHTF.ResultsJPHTF significantly improved abdominal distension, shortness of breath, drowsiness, loss of appetite, sleep, and tiredness in stage II/III CRC patients, thereby improving their quality of life. Simultaneously, JPHTF served as a supportive therapy in extending the overall survival (OS) of stage IV CRC patients with RAS/RAF mutations undergoing chemotherapy. Additionally, JPHTF effectively impeded tumor progression in CRC PDX models with RAS mutation, accompanied by a reduction in tumor cell content in the JPHTF group. Transcriptomic analysis revealed the involvement of the Hippo and Hedgehog signaling pathways in JPHTF-mediated CRC inhibition. Furthermore, mice in the JPHTF group exhibited increased immune cell infiltration.ConclusionThese findings suggested that JPHTF may inhibits tumor growth in CRC with RAS mutation by modulating RAS/RAF downstream signaling pathways, specifically the Hippo and Hedgehog signaling, leading to increased immune cell infiltration.

BackgroundThe association between natural products and dietary interventions on liver enzymes is unclear; therefore, this study aimed to examine their effects on liver enzymes in adults.MethodsPubMed, Embase, and Cochrane Library of Systematic Reviews databases were searched from inception until March 2023. The Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) systems were used to assess the methodological and evidence quality, and the therapeutic effects were summarized in a narrative form.ResultsA total of 40 meta-analyses on natural products (n = 25), dietary supplements (n = 10), and dietary patterns (n = 5) were evaluated, and results were presented in a narrative form. The overall methodological quality of the included studies was relatively poor. The results indicated that positive effects were observed for nigella sativa, garlic, artichoke, curcumin, silymarin, vitamin E, vitamin D, L-carnitine, propolis, and polyunsaturated fatty acids on certain liver enzymes. The dietary patterns, including high-protein, Mediterranean, and calorie-restriction diets and evening snacks, may reduce liver enzymes; however, other supplements and herbs did not reduce liver enzyme levels or have minimal effects. The evidence quality was generally weak given the risk of bias, heterogeneity, and imprecision.ConclusionThis umbrella review suggests that natural products and dietary interventions have beneficial therapeutic effects on liver enzymes levels. Further clinical trials are necessary to establish the effectiveness of supplements that reduce liver enzymes.

Abstract This study investigates the interannual variability of rapid intensification (RI) magnitude of western North Pacific (WNP) tropical cyclones. There is a significant correlation between basin‐averaged RI magnitude during July–November and the simultaneous Western Pacific (WP) teleconnection index from 1982 to 2021. RI magnitude is, on average, larger (smaller) in positive (negative) WP phases. During a positive WP, RI magnitude changes exhibit a southwest‐northeast dipolar pattern, with significant increases over the southwestern quadrant of the WNP and weak decreases over the northern part of the WNP. The WP teleconnection relates to RI magnitude primarily through modulation of 850–200‐hPa vertical wind shear, with less influence from 850‐hPa relative vorticity. The changes in these two dynamic conditions can be linked to WP‐induced circulation anomalies at lower and upper levels. Our results highlight that different contributors may be responsible for changes in WNP RI occurrence and RI magnitude.

Global processes and their teleconnections, such as the El Niño-Southern Oscillation (ENSO), have been shown to be a large driver of interannual changes in accumulated cyclone energy (ACE) of western North Pacific (WNP) tropical cyclones (TCs), with higher ACE during El Niño and lower ACE during La Niña. However, it remains uncertain whether interannual changes in WNP TC ACE are modulated by sea surface temperature anomalies (SSTAs) in other oceans. This study finds a significant negative correlation between WNP TC ACE during the early season (April–June) and simultaneous SSTAs over the tropical south Atlantic (TSA) in 1970–2021. On average, in warm TSA years, basinwide April–June ACE is significantly lower, with significant ACE decreases mainly occurring over the region spanning 5°–30°N, 115°–150°E. This is a result of reduced TC frequency, intensity and duration, due to a remote modulation of WNP environmental conditions by TSA SSTAs. In warm TSA years, there are significant decreases in 700–500-hPa relative humidity, 850-hPa relative vorticity and 200-hPa divergence and significant increases in 850–200-hPa vertical wind shear over the portion of the WNP with significant ACE reductions. These environmental changes can be linked to an anomalous Walker circulation induced by TSA SSTAs.

The impact of the Northeast China Cold Vortex (NCCV) on tropical cyclone (TC) intensity change was studied based on statistics, revealing a significant decrease in the rate of TC weakening and a lower probability of rapid weakening (RW) in the environments of NCCVs. This is mainly attributable to the external dynamic forcing induced by the NCCV as the eddy angular momentum import at upper levels increases significantly, which offsets the unfavorable decrease in sea surface temperature and increase in vertical wind shear. The upper-level positive potential vorticity anomaly band from the NCCV involves into the TC circulation from the southwestern quadrant, helping the development of convections triggered in the downshear right side of the TC. These results elucidate a fundamental relationship between TCs and NCCVs, and the findings contribute to a deeper comprehension of TC behavior under the influence of NCCVs, thereby providing guidance for forecasting intensity changes of TCs entering mid-latitude regions.

This study investigates the relationship between El Niño-Southern Oscillation (ENSO) and overland accumulated cyclone energy (ACE) of tropical cyclones (TCs) over the western North Pacific (WNP). We find that there is only a weak correlation between ENSO and overland ACE during 1979–2019, compared to the significant relationship between ENSO and basinwide ACE over the WNP as reported in previous publications. Overland ACE is generally smaller in El Niño and La Niña years than that in neutral years, which mainly results from lower landfall frequency and shorter duration after landfall. Relative to neutral years, overland ACE is lower over almost the entire China mainland in both El Niño and La Niña years, which can be related to the changes in the formation and movement of landfalling TCs. During El Niño and La Niña years, fewer landfalling TCs form over the western WNP, mainly resulting from reduced 850-hPa humidity, which leads to a less chance of TCs making landfall over China mainland. In addition, the eastward (westward) shift of the western Pacific subtropical high in El Niño (La Niña) years steers more TCs to make landfall over the southern (northern) China.

Abstract The tendency in tropical cyclone (TC) rainfall is of great concern due to its remarkable contribution to global precipitation and extreme rainfall events. This study finds a decreasing trend in TC inner‐core rain rate over the western North Pacific (WNP) from 1998 to 2019. This basinwide trend is mainly induced by the decreasing TC inner‐core rain rates over the region west of 150°E, while it is seldom linked to the changes in the distribution of TC occurrence. The maximum decreases in TC inner‐core rain rate are observed over the offshore areas along the coastlines of East Asia. Further analysis reveals that the change in atmospheric stability, referred to as a dominant environmental contributor to basinwide TC inner‐core rain rate decreases shown in previous studies, only has a primary impact over the northern South China Sea. By comparison, there is a positive correlation between the variations of the aerosol optical depth and TC inner‐core rain rate over the mid‐latitude regions extending from the East China Sea to Japan. Our result highlights the linkage of the recent decreasing trends in aerosol optical depth and TC inner‐core rain rate over the WNP.

Abstract This study investigates the long‐term tendency in the ratio of rapid intensification (RI) cases to the total number of tropical cyclone cases over the western North Pacific (WNP) during June between 1982 and 2021. There is a significant decreasing trend in RI ratio during June, which is opposite to the increasing trend in RI ratio during July–November. From 1982–2005 to 2006–2021, the June RI ratio significantly decreases over the region of 5°–20°N and 120°–150°N, while showing weak changes over other parts of the WNP. Over the region with a significant RI ratio reduction, significantly reduced 850‐hPa relative vorticity and 200‐hPa divergence and significantly enhanced 850 to 200‐hPa vertical wind shear are the likely primary drivers. The RI‐suppressing effect of the above changes in dynamical variables exceeds the RI‐favoring effect of the warming ocean, for example, significantly increased sea surface temperature and tropical cyclone heat potential, over this same region. Moreover, the changes in dynamic conditions can be related to an anomalous low‐level anticyclonic circulation, anomalous upper‐level convergent flow and a greater enhancement of upper‐level easterlies than lower‐level easterlies. Our study highlights the importance of changes in dynamic variables (e.g., vertical wind shear) in modulating WNP RI activity.

It has been demonstrated that the tornado-scale vortex (TSV) is one of the fine-scale structures associated with extreme updrafts in the tropical cyclone boundary layer (TCBL), but the relationship between surface wind gusts and TSVs is still unclear. In this study, the one-second model output simulated in the Weather Research and Forecast (WRF) model with the large eddy simulation (WRF-LES) is used to investigate the relationships between TSVs and surface wind gusts. Results show that surface wind gust factors in the regions where TSVs are prevalent are significantly larger than those in other regions. 88% of the maximum gust factors associated with TSVs (vertical velocity larger than 20 m s−1) are larger than 1.25 (gust factors larger than 1.25 account for only 1% of the 1-min gust factors in the TC inner core), and the mean maximum 1-min gust factor associated with a TSV is larger than 1.3, while the mean 1-min gust factor in the TC inner core is only 1.1. The surface gust factors associated with TSVs in tropical cyclone eyewall can reach about 1.8, which can cause severe surface wind hazards. This study suggests that potential risk will increase in the regions where TSVs are prevalent because of the large wind gusts and gust factors. Finer real-time observations are needed to monitor the evolution of TSVs for improving the operational TC-related surface gust warnings.

Abstract This study investigates the modulation of tropical cyclone (TC) formation over the western North Pacific (WNP) by coastal El Niño–Southern Oscillation (ENSO). There is a significant inverse relationship between WNP TC frequency during July–October from 1961 to 2019 and simultaneous Niño 1+2 sea surface temperature anomalies. TC formation is significantly suppressed and enhanced over the subtropical and equatorial WNP during coastal El Niño, respectively, while TC formation exhibits opposite‐signed anomalies during La Niña. This north–south dipolar pattern during coastal ENSO is distinct from the pattern observed in basin‐wide ENSO events. Additional analyses show that coastal ENSO influences WNP TC formation through modulation of the large‐scale environment. Changes in mid‐level moisture and low‐level vorticity appear to be the primary large‐scale influences on TC formation during both coastal ENSO phases. These changes can be further linked to the anomalous large‐scale circulation over the WNP during coastal ENSO.

This study investigates the long-term trend in the average 24-h intensity change (ΔV24) of western North Pacific (WNP) tropical cyclones (TCs) before landfall during June-November for the period from 1970–2019. We find a significant increasing trend in basin-averaged ΔV24 during 1970–2019. The increase in ΔV24 is significant over the northern South China Sea (17.5°-25°N, 107.5°-120°E) and to the east of the Philippines (7.5°-15°N, 122.5°-132.5°E), implying a slower weakening rate before landfall for the South China Sea and an increased intensification rate before landfall for the region east of the Philippines. We find a significant linkage between changes in ΔV24 and several large-scale environmental conditions. The increased ΔV24 before landfall in the above two regions is induced by a warmer ocean (e.g., higher sea surface temperatures, maximum potential intensity and TC heat potential) and greater upper-level divergence, with a moister mid-level atmosphere also aiding the ΔV24 increase east of the Philippines. Our study highlights an increasing tendency of ΔV24 before landfall, consistent with trends in ΔV24 over water and over land as found in previous publications.

Previous publications have highlighted the relationship between several climate modes such as El Niño–Southern Oscillation and tropical cyclones (TCs) experiencing rapid intensification (RI) over the western North Pacific (WNP), particularly on a 3–7-yr timescale. This study investigates the modulation of TCs experiencing RI by the WNP monsoon on biennial timescales. There is a significant positive relationship between rapidly intensifying TC (RITC) frequency over the WNP during July–November from 1980 to 2021 and the simultaneous WNP monsoon index. After classifying different WNP monsoon years on biennial timescales, we find significantly more TCs forming over the key region from 5°–25°N, 140°–160°E during strong WNP monsoon years. Some of these TCs then move westward into the portion of the WNP that climatologically has the most RI-favorable environmental conditions. Alternatively, other TCs forming in the key region move northward and undergo RI quickly after genesis, subsequently leading to an increase in rapidly intensifying WNP TC frequency. The WNP monsoon influences rapidly intensifying TC activity predominantly through modulation of large-scale atmospheric conditions. During strong WNP monsoon years, increased low-to-mid-level humidity, low-level vorticity and upper-level divergence and decreased vertical wind shear all favor TC genesis and RI development over the key region. A strong WNP monsoon is also associated with an anomalous 850-hPa cyclone, an anomalous 200-hPa anticyclone, increased 600-hPa moisture convergence and a decrease in the magnitude of 200-hPa winds over the key region. Our study highlights that the WNP monsoon significantly modulates TC and RITC activity at distinct timescales.

This study investigates the modulation of western North Pacific (WNP) tropical cyclone rapid intensification (RI) by the North Pacific Gyre Oscillation (NPGO) on decadal timescales. There is a significant inverse relationship between basinwide RI numbers during July–November and the simultaneous NPGO index from 1970 to 2021. During the positive NPGO phase, suppressed RI occurs over almost the entire WNP, with a distinctly different spatial distribution compared to the Pacific Decadal Oscillation-driven pattern of RI modulation. RI occurrence is significantly reduced over the eastern Philippine Sea (10°–25°N, 140°–155°E). This is primarily caused by enhanced negative low-level vorticity, which can be linked to the horizontal extent of the anomalous low-level anticyclone. By comparison, over the western Philippine Sea (10°–25°N, 125°–140°E), there are only weak RI occurrence changes due to offsetting influences of increased mid-level humidity and decreased low-level vorticity.

This study finds an increasing trend in the decay timescale (τ) of western North Pacific (WNP) tropical cyclone (TCs) making landfall on the Asian continent from 1966–2018. Statistical analysis of individual landfalling TCs shows that τ is significantly positively linked to soil wetness, 850-hPa relative vorticity and 200-hPa divergence, whereas it is weakly correlated with 700–500-hPa relative humidity and 850–200-hPa vertical wind shear. For TCs hitting southeastern China, the observed increasing τ is likely caused by enhanced 850-hPa vorticity and 200-hPa divergence. For TCs hitting southern China, increasing τ is likely driven by increased 850-hPa vorticity. By comparison, there are no significant trends in environmental variables over the eastern Indo-China Peninsula, and τ has not significantly changed in this region. Our results imply that the increasing τ of WNP landfalling TCs on the Asian continent are more likely caused by changes in dynamic variables than changes in thermodynamic variables.

The North Pacific Gyre Oscillation (NPGO) is an important mode of decadal variability in North Pacific sea surface temperature (SST) and sea surface height. This study investigated the potential influence of the NPGO on spatial characteristics of peak season (July to October) tropical cyclone genesis (TCG) number over the western North Pacific (WNP) from 1965 to 2020. We show that the NPGO was the first leading empirical orthogonal function mode of North Pacific SST during the peak tropical cyclone season in that time. On a decadal time scale, the NPGO has opposite impacts on TCG in the west and east WNP. The relatively weak positive correlation west of 140° E and the strong negative correlation east of 140° E result in an overall significant negative correlation between the NPGO and WNP total TCG number ( r = −0.49), which is much more robust than the relationship between the Pacific Decadal Oscillation and TCG. The critical factors of the NPGO that affect TCG are vertical motion in the west WNP and vertical wind shear (VWS) in the east WNP. The positive NPGO pattern could induce an anomalous off-equatorial vertical circulation, resulting in an upward motion and increased convective precipitation in the west WNP, favoring local TCG. The anomalous convective precipitation enhances the zonal gradient of the atmospheric heat source in the east WNP, increasing VWS. The North Pacific low-level anticyclonic and upper-level cyclonic associated with the NPGO further enhance the VWS in the east WNP and lead to the negative low-level relative vorticity, inhibiting local TCG. This study emphasizes the importance of the climate impact of the NPGO in recent decades. The findings here have significant implications for the decadal prediction of change in WNP TCG.

This study investigates the modulation of tropical cyclone (TCs) rapid intensification (RI) over the western North Pacific by the Antarctic Oscillation. There is a significant inverse relationship between basinwide RI number during July–November from 1982 to 2020 and the simultaneous Antarctic Oscillation index. During positive Antarctic Oscillation years, RI occurrence is significantly suppressed over the main RI region (10°–20° N and 125°–150° E) and slightly enhanced over the South China Sea. By contrast, during negative Antarctic Oscillation years, RI is significantly enhanced over the main RI region and slightly suppressed over the South China Sea. The Antarctic Oscillation influences western North Pacific RI occurrence mainly through modulation of the large-scale dynamic environment. During positive Antarctic Oscillation years, increases in 850–200 hPa vertical wind shear and decreases in both low-level vorticity and upper-level divergence all suppress RI occurrence over the main RI region, while thermodynamic variables (e.g. TC heat potential, maximum potential intensity and low-to-middle level relative humidity) show mostly weak changes. These changes in dynamic factors can be linked to a low-level anomalous western North Pacific anticyclone triggered by the positive phase of the Antarctic Oscillation and a low-level anomalous western North Pacific cyclone generated by a negative phase of the Antarctic Oscillation.

Weak tropical cyclone (TC) center positioning is difficult work in operational forecasting. In the present study, a TC-red-green-blue (TC-RGB) composite was designed by using satellite multichannel observations (reflectance, brightness temperature, and brightness temperature differences). Compared with single channel images, TC-RGB composites can clearly show the exposed low-level circulation (LLC) of weak TCs under large vertical wind shear. Based on the guidelines of TC-RGB composites for TC center positioning, we repositioned 83 western North Pacific (WNP) TC cases during 2017–2019. Then, the comparisons of TC center positions were made between the TC-RGB composite and the Regional Specialized Meteorological Centre-Tokyo (RSMC-Tokyo), the Joint Typhoon Warning Center (JTWC) and the China Meteorological Administration-Shanghai Typhoon Institute (CMA-STI). Via case analysis of TC Kalmaegi (2019), it was found that the best-track data from the RSMC-Tokyo, JTWC and CMA-STI would have over 100 km biases at the early stage of TC life history. Taking all the 83 TC cases into account, the results show that the average center position biases and standard deviations for weak TCs under small vertical wind shear in the daytime are 5 km larger than those under large vertical wind shear at nighttime. When considering the 83 TC cases with clear LLC centers, the difference of these two biases is 10 km. The average biases are mostly above 20 km in the areas south of 18° N and north of 36° N over the WNP. Conversely, in the areas between 18° N and 36° N over the WNP, they are mostly below 20 km.

The long-term trend in the annual mean lifetime maximum intensity (LMI) of rapidly intensifying tropical cyclones (RI-TCs) over the western North Pacific (WNP) is investigated in this study. During 1970–2019, a notable upward trend is observed in the average RI-TC LMI, which is primarily linked to a significant increase in the mean intensification rate prior to LMI. This intensification rate increase is caused by an increase in the mean magnitude of RI cases. By contrast there is no significant change in the RI ratio, which is calculated as the proportion of 24 h RI records to all 24 h records before a RI-TC reaches its LMI. Furthermore, there is a significantly greater RI magnitude west of 155° E, where the vast majority of RI cases occur on average. Over this region, there are significant increases in sea surface temperatures, TC heat potential, 700–500 hPa relative humidity and 200 hPa divergence during 1970–2019. Only a small region of significantly reduced 850–200 hPa vertical wind shear is observed to the northeast of the Philippines from 1970–2019. These results imply that both thermodynamic and dynamic variables play an important role in modulating RI magnitude over the WNP.

Rapid intensification (RI) refers to a significant increase in tropical cyclone (TC) intensity over a short period of time. A TC can also undergo multiple RI events during its lifetime, and these RI events pose a significant challenge for operational forecasting. The long-term tendency in RI magnitude of TCs over the western North Pacific is investigated in this study. During 1979–2018, a significant increasing trend is found in RI magnitude, which primarily results from the significant increasing number of strong RI events, defined as 24 h intensity increases of at least 50 kt. Furthermore, there are significantly more (slightly fewer) strong RI occurrences west (east) of 155°E in 1999–2018 than in 1979–1998. Significant increases in strong RI occurrences are located over the region bounded by 10°∼20°N, 120°∼150°E. These changes are likely induced by the warming ocean but appear uncorrelated with changes in the atmospheric environment. By contrast, there are slight decreases in strong RI occurrences over the region bounded by 12.5°∼22.5°N, 155°∼170°E, likely due to the offset between RI-favorable influences of the warming ocean and RI-unfavorable influences of increasing vertical wind shear (VWS).