From 19 to 21 July 2021, Henan province of China experienced an extreme precipitation event that caused massive flooding and great loss of lives. This event is thus far the second heaviest precipitation event observed by rain gauges in this region. Based on the ERA5 reanalysis data, the ECMWF operational global ensemble forecasts and numerical simulations using the ARW-WRF model, impacts of an upper tropospheric cold low (UTCL) on the extreme precipitation are examined. It is found that due to the influence of the persistent intrusion of stratospheric high potential vorticity (PV) air, a long-lived UTCL was detached from the upper level flow a week prior to the extreme precipitation event. The UTCL then moved westward, reaching the Yellow Sea and the East China Sea and maintaining there until the precipitation event ended. During this event, a broad northeast-southwest oriented area of ascending motion associated with the UTCL could be observed in front of the UTCL and strong ascending motions developed in the upper troposphere above Henan province. Analysis of the ECMWF operational global ensemble forecasts reveals that the amount of precipitation over Henan is positively correlated with the UTCL intensity. The UTCL impact on the extreme precipitation and the underlying mechanisms are further investigated based on results of numerical experiments. The control experiment reasonably reproduces the UTCL location as well as the distribution and evolution of the extreme precipitation. When the UTCL intensity is reduced in the initial condition using the piecewise PV inversion for sensitivity experiment, the upper tropospheric divergence reduces correspondingly and the dynamical ascending motion weakens in the second precipitation stage. As a result, the amount and intensity of precipitation both decrease. When the UTCL is completely removed from the initial condition, the sensitivity experiment indicates that the upper tropospheric divergence and dynamical ascending motion further weaken, resulting in a large decrease in precipitation intensity during the whole precipitation period. These findings highlight that the occurrence of the long-lived UTCL is a crucial factor that affects the intensity of the extreme precipitation event.
Abstract Using the ERA5 reanalysis data, we analyzed the impacts of the Arctic stratospheric polar vortex weakening on Ural Blocking (UB). The results indicate that UB activities are suppressed following the weakening of the polar vortex. Specifically, the probability of UB is significantly reduced, with a maximum decrease of 30% observed around day 24 following the polar vortex weakening. The average life cycle of UB shortens by approximately one day. The amplitude of UB, as measured by the negative potential vorticity (PV) anomalies over the Urals, experiences a significant decrease, particularly with the presence of positive PV anomalies on the western side of Urals. Further analysis indicates that the suppression of UB following the weakened polar vortex is closely linked to both the equatorward horizontal transport of high‐PV air over the Arctic across the dynamic tropopause, and the anomalous increase in static stability over the Urals resulting from a descent of the isentropic surface near the tropopause. Finally, we evaluate the relative roles of the polar vortex weakening and the negative phase of the Arctic Oscillation (AO) in suppressing the development of UB. Our analysis reveals that the impacts of the weak polar vortex on the suppression of UB are stronger and more long‐lasting compared to the negative AO, suggesting that the impacts of the weakened polar vortex on UB cannot be simply explained by the AO response.
Background: According to the Fudan University Shanghai Cancer Center (FUSCC) system, triple-negative breast cancer (TNBC) is divided into four stable subtypes: (I) luminal androgen receptor, (II) immunomodulatory, (III) basal-like immune-suppressed (BLIS), and (IV) mesenchymal-like. However, the treatment outcomes of the corresponding targeted therapies are unsatisfactory, especially for the BLIS subtype. Therefore, we aimed to identify the key long noncoding RNAs (lncRNAs) to construct a prognostic model for BLIS subtype and discover potential targets to explore potential therapeutic strategies in this study. Methods: The FUSCC cohort was used to establish a prognostic risk model via least absolute shrinkage and selection operator (LASSO) and Cox regression analysis. The Cancer Genome Atlas (TCGA) cohort was then used to evaluate and verify the model. To understand the functional aspects of the model, functional, immune landscape, mutation, and drug sensitivity analyses were performed between high- and low-risk groups. Results: Ten prognostic-related lncRNAs identified, including C5ORF66-AS2, DIO3OS, FZD10-DT, LINC00393, LNC-ERI1-32, LNC-FOXO1-2, LNC-SPARCL1-1, HCG23, LNC-MMD-4 and LNC-TMEM106C-6, were selected for risk score system construction. The results showed that the model constructed could divide the patients with BLIS subtype into two groups of high and low risk, and patients with higher risk scores had shorter recurrence-free survival. In addition, drug sensitivity analysis identified 3 compounds, including BMS-754807, cytochalasin b, and linifanib, that could have a potential therapeutic effect on patients with the BLIS subtype. Conclusions: The risk prognosis model showed good prognostic value for the BLIS subtype patients, and the ten lncRNAs may be potential therapeutic targets.
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