Intensification Rate Research Articles

P916 Off-label dose escalation of Ustekinumab in Inflammatory Bowel Disease patients. Incidence rate, timing, dosing patterns and outcomes

Abstract Background In patients with inflammatory bowel disease (IBD), after intravenous induction,Ustekinumab (UST) is administered as maintenance 90 mg every 8 (Q8) or 12 weeks (Q12) subcutaneously. As with other biological drugs, dose intensification may be effective after inadequate response or loss of response. However, different dosing regimens have been used and the best strategy is unknown. Our aim was to evaluate the incidence and efficacy of UST off-label dose escalation in IBD. Methods We performed an observational cohort study in 2 hospitals in Vigo,Spain. All patients who started UST between 1 June 2017 and 31 December 2022 to control their active IBD were enrolled. The primary endpoints were incidence rate and outcomes of UST off-label dose intensification. Secondary endpoints were the timing of dose escalation and the patterns indicated. Results 1 173 IBD patients received UST: females 53.8% (93), mean age 49.7(15.5) years, Crohn´s disease 82% (142), previous anti-TNF 93.6% (162) and vedolizumab 22.5% (39) (Table 1). Subcutaneous UST was maintained Q8 in 63.6% (110) and Q12 in 34.7% (60). Baseline activity data were higher in Q8 patients (p=0.001). At 16 week 23 patients (13.3%) had no response, but 9 (39.1%) became late responders at 6 months. Of the 173 IBD patients included, 38.2% and 30.6 % achieved clinical response and clinical remission at 1 year. Dose escalation was performed in 32.4% (56) with different patterns: 54.5% Q4 (30), 21.8% reinduction plus Q4 (12), 12.7% Q6 (7) and 10.9% only intravenous reinduction (6). The timing of dose escalation was: before 6 months in 19.6% (11), at 12 months 42.8% (24) and at 2 years 73.2% (41). Response and remission were achieved in 28.6% (16) and 41.1% (23) after dose escalation respectively. In 6.4% of the patients (11) a second dose escalation was indicated. Neither previous anti-TNF or vedolizumab nor concomitant use of steroids at starting UST were associated to dose escalation. IBD patients that were initially scheduled to receive subcutaneous UST Q12 needed less dosing escalation (p<0.001). Conclusion Off-label UST dose escalation was frequent and effective in achieving response in IBD patients. The schemes of dose-escalation were heterogeneous between the participants. Patients initially scheduled Q12 due to lower inflammatory activity required less dose escalation.

Influence of the Atlantic Multidecadal Oscillation on the Rapid Intensification Magnitude of Tropical Cyclones over the Western North Pacific

Abstract Rapid intensification (RI) of tropical cyclones (TCs), which refers to an explosive increase of TC intensity exceeding a certain threshold [e.g., 30 kt (1 kt ≈ 0.51 m s−1) in 24 h] within a short time period, poses a great challenge to both forecasting and disaster prevention efforts. Recent studies have documented a significant increase in the magnitude of TC RI (RIM; measured as the mean intensification rate of all TC RI records in a TC season) over the western North Pacific (WNP) since 1979, and have attributed it to the impacts of global warming. In this study, results from statistical analyses show that the TC RIM over the WNP during 1951–2021 exhibits significant interdecadal variability, which is found to be closely related to the Atlantic multidecadal oscillation (AMO). Further analyses indicate that the response of the local thermodynamic conditions to the AMO plays a dominant role in shaping this relationship. The positive AMO phase fosters a high TC RIM over the WNP by producing significant warm sea surface temperature (SST) anomalies, which in turn enhances TC heat potential and the midtropospheric relative humidity in the main region of TC RI occurrence. Results from both data analyses and numerical model experiments demonstrate that the AMO modulates thermodynamic conditions over the WNP, such as SST and ocean heat content, by affecting local heat fluxes and the Ekman heat transport in the WNP via the modulation of Walker circulation from the Atlantic to the Pacific.

СТРАТЕГІЧНЕ ЗНАЧЕННЯ РІДКІСНОЗЕМЕЛЬНИХ ЕЛЕМЕНТІВ ДЛЯ СУЧАСНИХ ТЕХНОЛОГІЙ ТА ПЕРСПЕКТИВИ ВІТЧИЗНЯНИХ РОДОВИЩ

In the context of sustainable development, the reorientation of a wide range of technological industries is an inevitable phenomenon that predetermines the perturbations of the established list of raw materials of strategic importance. Changes in priorities are primarily derived from the transition need to innovative approaches in order to solve old problems and ensure all the needs of modern society. So far, integrating into numerous global economic chains, rare earth elements open up a whole range of new opportunities. Within the study information on the main areas of REE use, its market conditions, existing and projected price dynamics were analyzed and summarized; a systematization of stimulating and restraining factors of REE mineral resource base development according to economic, ecological, geological, resource and technological indicators was also made; the connection of the modern "Green Energy Transition" global strategy with the work intensification rate at potential REE mining objects is traced, arguments regarding the primary need to concentrate efforts on replenishing the market for elements of the cerium group, which includes neodymium and praseodymium are given as well. Based on the results of the study, a conclusion regarding the main factors in the development of the REE market was made, and the most promising areas for geological prospecting and mining implementation on the territory of Ukraine were identified.

The Pairing of Rapid Intensification Events and Eyewall Replacement Cycles in Tropical Cyclones in the Atlantic Basin from 2015 to 2020

Rapid intensification (RI) and eyewall replacement cycles (ERCs) frequently occur in intense tropical cyclones (TCs), often causing rapid, significant changes in intensity and structure. In some TCs, RI and ERCs can occur concurrently or within a short period of one another. This study investigates whether there is a link between RI and ERCs by conducting a statistical analysis of TCs that occurred in the North Atlantic basin from 2015 to 2020. The HURDAT2 dataset was used to detect RI events, while the Morphed Integrated Microwave Imagery archive by the Cooperative Institute for Meteorological Satellite Studies was used to detect ERC events. Three sets of data were constructed from this analysis: TCs with paired RI/ERC events that occurred within 24 h of each other, TCs with RI only, and TCs with ERCs only. Statistics selected for analysis within the constructed datasets were mean duration of phenomena, mean rate of intensification, and mean peak intensity. We performed t-tests to determine the statistical significance of results. The results of this study show that TCs with these paired RI/ERC events often intensified at a faster rate, intensified for longer, and ended up stronger than TCs that only experienced RI or ERCs in isolation.

Intense Tropical Cyclones in the Western North Pacific Under Global Warming: A Dynamical Downscaling Approach

AbstractThis study aims to assess the global warming's impact on intense tropical cyclones (TCs) over the western North Pacific (WNP) through dynamical downscaling. 379 and 179 TCs reaching Category 1 in the High‐Resolution Atmospheric Model (HiRAM) are downscaled for use in the Weather Research and Forecasting (WRF) model at 5‐km horizontal resolution in the current climate (1979–2015) and for use in the Representative Concentration Pathways 8.5 (RCP8.5) in the future climate (2074–2100) scenarios, respectively. Inclusion of the downscaling simulations by WRF helps better reproduce the probability distribution of the TC's lifetime maximum intensity (LMI). In the warmer climate, the LMI of very intense TCs in WNP are projected to be stronger. Such an increase in intensity is statistically significant, and can be primarily explained by enhanced intensification rate. Meanwhile, TCs among the top 5% in LMI can reach higher intensities which cannot be attained in the current climate. After downscaling, the probability of WNP TCs reaching Category 4–5 increases by 6.5 percentage points in the late 21st century. This increase is 1.7 percentage points higher than the increase projected exclusively by HiRAM. Moreover, for TCs among the top 5% in LMI, a 233‐km and 300‐km westward shift of LMI locations is identified in the late 21st century for simulations with and without the downscaling approach, respectively. Both results suggest that very intense TCs would pose a higher threat to the WNP lands under global warming, as they become substantially stronger, and as their LMI locations migrate toward the coast.

Quantifying the Environmental Effects on Tropical Cyclone Intensity Change Using a Simple Dynamically Based Dynamical System Model

Abstract Accurate prediction of tropical cyclone (TC) intensity is quite challenging due to multiple competing processes among the TC internal dynamics and the environment. Most previous studies have evaluated the environmental effects on TC intensity change from both internal dynamics and external influence. This study quantifies the environmental effects on TC intensity change using a simple dynamically based dynamical system (DBDS) model recently developed. In this simple model, the environmental effects are uniquely represented by a ventilation parameter B, which can be expressed as multiplicative of individual ventilation parameters of the corresponding environmental effects. Their individual ventilation parameters imply their relative importance to the bulk environmental ventilation effect and thus to the TC intensity change. Six environmental factors known to affect TC intensity change are evaluated in the DBDS model using machine learning approaches with the best track data for TCs over the North Atlantic, central, eastern, and western North Pacific and the Statistical Hurricane Intensity Prediction Scheme (SHIPS) dataset during 1982–2021. Results show that the deep-layer vertical wind shear (VWS) is the dominant ventilation factor to reduce the intrinsic TC intensification rate or to drive the TC weakening, with its ventilation parameter ranging between 0.5 and 0.8 when environmental VWS between 200 and 850 hPa is larger than 8 m s−1. Other environmental factors are generally secondary, with their respective ventilation parameters over 0.8. An interesting result is the strong dependence of the environmental effects on the stage of TC development.

Features and prognosis of patients with lupus nephritis receiving glucocorticoid treatment: a descriptive study using a Japanese claims database

Objective To evaluate the status of lupus nephritis treatment particularly regarding the need for intensification of treatment in Japan from 2010 to 2019 using a large-scale claims database. Methods This descriptive study included adult lupus nephritis patients who were administered glucocorticoid equivalent to ≥15 mg prednisolone as the initial dose. After summarizing patient characteristics, we assessed the rate of treatment intensification using the Kaplan–Meier method among six groups based on initial dose of glucocorticoid. Results We identified 403 patients (mean age, 42.7 years; 68.5% women) with the median initial glucocorticoid dose of 30 mg/day prednisolone equivalent. We observed 56 treatment intensifications; the incidence rate was 71.3 per 1,000 person-years (95% confidence interval: 52.6–90.0). The rate in higher glucocorticoid dose groups was higher than that in lower glucocorticoid dose groups. Conclusions We found that the rate of treatment intensification was higher in the high-dose glucocorticoid groups than in the low-dose glucocorticoid groups. Further studies are needed to clarify the relationship between the initial dose of glucocorticoids and the prognosis of lupus nephritis patients.

Diabetes mellitus type 2: National Russian guidelines vs real clinical practice

According to the "Federal Law on the Fundamentals of Protection of the Public Health", medical care for patients should be provided in accordance with National Russian guidelines for the relevant nosology, which are based on the principles of evidence-based medicine. The article presents an analysis of the compliance with the completeness of implementation of National Russian guidelines in the treatment of patients with type 2 diabetes mellitus (DM 2) in real clinical practice. The analysis of the actual state of management of DM 2 patients was carried out from the Federal Register of diabetes as of 01.01.2023. Incomplete compliance with the guidelines on the frequency of measuring glycated hemoglobin, the rate of intensification of hypoglycemic therapy, and the appointment of new classes of hypoglycemic drugs was established. Possible reasons for the identified discrepancies between real practice and guidelines requirements are discussed, as well as possible measures to overcome these discrepancies.

Testing interventions to reduce clinical inertia in the treatment of hypertension: rationale and design of a pragmatic randomized controlled trial

Clinical inertia, or failure to intensify treatment when indicated, leads to suboptimal blood pressure control. Interventions to overcome inertia and increase antihypertensive prescribing have been modestly successful in part because their effectiveness varies based on characteristics of the provider, the patient, or the provider-patient interaction. Understanding for whom each intervention is most effective could help target interventions and thus increase their impact. This three-arm, randomized trial tests the effectiveness of 2 interventions to reduce clinical inertia in hypertension prescribing compared to usual care. Forty five primary care providers (PCPs) caring for patients with hypertension in need of treatment intensification completed baseline surveys that assessed behavioral traits and were randomized to one of three arms: 1) Pharmacist e-consult, in which a clinical pharmacist provided patient-specific recommendations for hypertension medication management to PCPs in advance of upcoming visits, 2) Social norming dashboards that displayed PCP's hypertension control rates compared to those of their peers, or 3) Usual care (no intervention). The primary outcome was the rate of intensification of hypertension treatment. We will compare this outcome between study arms and then evaluate the association between characteristics of providers, patients, their clinical interactions, and intervention responsiveness. Forty-five primary care providers were enrolled and randomized: 16 providers and 173 patients in the social norming dashboards arm, 15 providers and 143 patients in the pharmacist e-consult arm, and 14 providers and 150 patients in the usual care arm. On average, the mean patient age was 64 years, 47% were female, and 73% were white. Baseline demographic and clinical characteristics of patients were similar across arms, with the exception of more Hispanic patients in the usual care arm and fewest in the pharmacist e-consult arm. This study can help identify interventions to reduce inertia in hypertension care and potentially identify the characteristics of patients, providers, or patient-provider interactions to understand for whom each intervention would be most beneficial. Clinicaltrials.gov (NCT, Registered: NCT04603560).

Using interpretable gradient‐boosted decision‐tree ensembles to uncover novel dynamical relationships governing monsoon low‐pressure systems

AbstractLow‐pressure systems (LPSs) are the primary rainbringers of the South Asian monsoon. Yet, their interactions with the large‐scale monsoon circulation, as well as the highly variable land and sea surfaces they pass over, are complex and generally not well understood. In this article, we present a novel, top‐down approach to investigate these relationships and quantify their importance in describing LPS behaviour. We also show that, if the approach is sufficiently well posed, it is productive at hypothesis generation. For each of five predictands (i.e., LPS intensification rate, propagation speed/direction, post‐landfall survival, peak intensity, and precipitation rate) we train an additive decision‐tree ensemble model using the XGBoost algorithm. Shapley value analysis is then applied to the models to determine which variables are important predictors and to establish their relationship with the predictand, with additional analysis following cases of interest. Novel relationships established using this technique include that LPS vorticity intensifies preferentially in the early morning at the same time as the peak in the diurnal cycle of their convection occurs, that vertical wind shear suppresses continued growth of strong LPSs, that large‐scale barotropic instability plays an important role in both the inland penetration and peak intensity of LPSs, and that LPS propagation depends on the depth of its vortex with shallower LPSs advected by low‐level winds and taller LPSs advected by mid‐level winds. We also use this framework to identify and discuss potential new avenues of research for monsoon LPSs.

An Open‐Source, Physics‐Based, Tropical Cyclone Downscaling Model With Intensity‐Dependent Steering

AbstractAn open‐source, physics‐based tropical cyclone (TC) downscaling model is developed, in order to generate a large climatology of TCs. The model is composed of three primary components: (a) a random seeding process that determines genesis, (b) an intensity‐dependent beta‐advection model that determines the track, and (c) a non‐linear differential equation set that determines the intensification rate. The model is entirely forced by the large‐scale environment. Downscaling ERA5 reanalysis data shows that the model is generally able to reproduce observed TC climatology, such as the global seasonal cycle, genesis locations, track density, and lifetime maximum intensity distributions. Inter‐annual variability in TC count and power‐dissipation is also well captured, on both basin‐wide and global scales. Regional TC hazard estimated by this model is also analyzed using return period maps and curves. In particular, the model is able to reasonably capture the observed return period curves of landfall intensity in various sub‐basins around the globe. The incorporation of an intensity‐dependent steering flow is shown to lead to regionally dependent changes in power dissipation and return periods. Advantages and disadvantages of this model, compared to other downscaling models, are also discussed.

Oil and fat industry of the East Kazakhstan region: growth reserves

The goal is to monitor the current state and prospects of the oil and fat subcomplex of the East Kazakhstan region, to determine the reasons that impede its development. Methods – balance sheet, abstract-logical, statistical-economic, monographic. Results – using the example of the Eastern region, oilseed production and the fat and oil industry have been analyzed over the past five years. Sectoral, regional, socio-economic aspects of the functioning of the oil and fat industry are considered. The sown areas, yields, gross harvest of the main oilseeds (soybeans, sunflower, safflower, rapeseed, flax), volumes of fat and oil products, use of the average annual production capacity of enterprises for the production of vegetable oils are shown. Based on the study, factors reducing the rate of intensification of the oil and fat subcomplex were identified. The main ones are the reduction in crop area, gross output, lack of raw materials and, as a result, the low level of processing. Conclusions – it is necessary to take a set of measures to stabilize the market for oilseeds and processed products in the Eastern region of the country, providing agricultural sector with government assistance in the form of subsidies and loans without collateral at low interest rates; establishing a duty on the export of sunflower seeds for a longer period; formation of integrated structures; creation of advanced training centers for agricultural producers on the basis of research institutes and universities in the East Kazakhstan region. Solving the issues related to expanding the activities of oil and fat enterprises and supplying the population of the region with oil and fat products in the required quantities is one of the main tasks of the state. It is necessary to use innovative approaches to the technological process, the implementation of which will make it possible to produce a high-quality environmentally friendly food product that is in demand in the domestic and foreign markets.

Recent global increase in multiple rapid intensification of tropical cyclones

The rapid intensification (RI ≥ 30 knots/24-h) of tropical cyclones (TCs) makes TC forecasting difficult, resulting in severe damage to property and life. Forecasting can get even worse if TCs have experienced RI more than once (referred to as "multiple-RI TCs") in their lifetime. On a global scale, the relation between long-term trends of multiple-RI TC frequency and maximum potential intensity (MPI) changes is investigated in this study. During 1981–2020, the frequency of multiple-RI TCs significantly increased at a rate of 1.2 TCs/decade, which was primarily due to the upper phases of TC becoming conducive to RI as MPI increased. Our analysis shows that the frequency of multiple-RI TCs has increased by 82.43% in 2000–2020 compared to that in 1981–2000, whereas the frequency of single RI TCs has increased by only 1.63%. The rise in MPI elevates the initial intensity at which a TC undergoes maximum intensification rate, making post-Tropical Storm stages of TCs conducive to RI. As a result, TCs can undergo RI multiple times even following a weakening before the intensity approaches MPI.

Subtropical Mode Water south of Japan impacts typhoon intensity.

Subtropical Mode Water (STMW), characterized by vertically uniform temperature of ~17°C, is distributed horizontally over 5000 kilometers at the 100- to 500-meter depths in the subtropical North Pacific Ocean. Its formation and spreading fluctuate in relation to the Pacific Decadal Oscillation and the Kuroshio path variation, but the feedback from STMW on the sea surface temperature (SST) and the overlying atmosphere remains unclear. Using Argo profiling float data, we show that STMW south of Japan, whose thickness varies decadally, modulates the overlying thermal structure throughout the year by increasing isotherm uplift with increasing thickness. The STMW-induced decadal temperature change has a magnitude of up to ~1°C and is large in the warm season in the presence of the seasonal thermocline. Furthermore, 50-year observations, together with numerical simulation, show that SST, upper ocean heat content, and typhoon intensification rate have been significantly lower in years with thicker STMW and higher in years with thinner STMW.

Abstract P350: Longitudinal And Summary Blood Pressure Measures And Clinical Decision-making Around Antihypertensive Therapeutic Intensification

Background: The rate of treatment intensification (TI) emerges as the most important factor impacting BP control. BP has been consistently reported as the most potent clinical factor in deciding to intensify pharmacotherapy for hypertension. This study aims to quantify the relationship between measured BP and variance in therapeutic intensification (TI). Methods: Data for defining and modeling antihypertensive TI comes from ambulatory primary care clinics at five distinct health care organizations. Mixed-effects logistic regression was used to model longitudinal BP related information and antihypertensive TI at visits with uncontrolled BP (≥140/≥90 mmHg). Results: TI increased as a function of progressively higher SBP (Table 1) and DBP for both current and previous visit BP values. Yet, current and prior visit BP accounted for only 2.8% and 0.8%, respectively, of the variance in TI. Conclusion: Current and historical BP values impact TI. While BP is the most important factor influencing TI, its impact is limited. Highly efficient point-of-care access to previous BP might improve the rate of TI. Yet, there are potent factors limiting TI which require attention.

Diurnal Variations on the Initiation Time and Intensification Rate of Rapidly Intensifying Tropical Cyclones

AbstractThis study investigates whether the initiation time and intensification rate (INTRATE) of intensifying tropical cyclones (TCs) vary diurnally and how they are related to deep convection. TC intensifying events are identified and classified into slowly intensifying (SI) and rapidly intensifying (RI) events. RI events last ∼42 hr on average, much longer than SI events. More importantly, the onset of the TC intensification, especially RI, markedly peaks at 00–06 local time. However, the INTRATEs of both RI and SI events show very weak diurnal variability. The INTRATE continues to increase after RI initiation and slightly peaks in the late afternoon (at 90% significance level). Inner‐core convection of all intensifying events maximizes in the early morning, in phase with the peak initiation time. In short, our results suggest that the nocturnally enhanced inner‐core convection may play a role in triggering TC intensification (e.g., RI), but not maximizing the INTRATE.

Testing heavy rainfall change in Jeju Island, Korea and its linkage to typhoon activity over East Asia during the Holocene

Understanding the spatiotemporal variability of extreme hydrologic events, especially those driven by typhoons over Asia, and their controlling factors is essential to testing and predicting their future changes under global warming. Here, we present a series of direct heavy-rainfall records over the past ca. 10,000 years based on lake sediments from a volcanic cone (Sara Oreum) on Jeju Island, Korea, where orographic amplification of precipitation is dominant and sensitive to present typhoon activity. The reconstructed heavy rainfall index based on the high-resolution elemental ratios (e.g., Ti/Al and Sr/Si) shows clear variability at centennial timescales and is similar to records of coastal flooding events along the southern coast of Korea, typhoon-driven overwash events along the south-western coast of Japan, indicating strong typhoon influence on the heavy rainfall events in Jeju Island during the Holocene. Furthermore, this heavy rainfall-typhoon linkage has been influenced by past El Niño–Southern Oscillation (ENSO) activity and sea surface temperature (SST) in the western Tropical Pacific, showing time-varying influences. This study suggests that on decadal to multi-centennial timescales, stronger ENSO activity is responsible for eastward shift in the location of typhoon genesis, resulting in more frequent recurving tracks of typhoon and increased landfalls in Korea and Japan, whereas SST affects the intensification rate of typhoon. The heavy rainfall index reconstructed from the volcanic cones of Jeju Island may be used as an indicator of past frequency and track changes of typhoon over highly populated East Asia.

Intensification Rates of Tropical Cyclone–Like Vortices in a Model with Downtilt Diabatic Forcing and Oceanic Surface Drag

Abstract Tropical cyclones are commonly observed to have appreciable vertical misalignments prior to becoming full-strength hurricanes. The vertical misalignment (tilt) of a tropical cyclone is generally coupled to a pronounced asymmetry of inner-core convection, with the strongest convection tending to concentrate downtilt of the surface vortex center. Neither the mechanisms by which tilted tropical cyclones intensify nor the time scales over which such mechanisms operate are fully understood. The present study offers some insight into the asymmetric intensification process by examining the responses of tilted tropical cyclone–like vortices to downtilt diabatic forcing (heating) in a 3D nonhydrostatic numerical model. The magnitude of the heating is adjusted so as to vary the strength of the downtilt convection that it generates. A fairly consistent picture of intensification is found in various simulation groups that differ in their initial vortex configurations, environmental shear flows, and specific positionings of downtilt heating. The intensification mechanism generally depends on whether the low-level convergence σb produced in the vicinity of the downtilt heat source exceeds a critical value dependent on the local velocity of the low-level nondivergent background flow in a reference frame that drifts with the heat source. Supercritical σb causes fast spinup initiated by downtilt core replacement. Subcritical σb causes a slower intensification process. As measured herein, the supercritical intensification rate is approximately proportional to σb. The subcritical intensification rate has a more subtle scaling, and expectedly becomes negative when σb drops below a threshold for frictional spindown to dominate. The relevance of the foregoing results to real-world tropical cyclones is discussed.

Evaluating the Impacts of COSMIC-2 GNSS RO Bending Angle Assimilation on Atlantic Hurricane Forecasts Using the HWRF Model

Abstract This study evaluates the impact of assimilating Global Navigation Satellite System (GNSS) radio occultation (RO) bending angles from Formosa Satellite Mission-7/Constellation Observing System for Meteorology, Ionosphere, and Climate-2 (COSMIC-2) receiver satellites on Hurricane Weather Research and Forecasting (HWRF) Model tropical cyclone (TC) forecasts. Launched in June 2019, the COSMIC-2 mission provides significantly higher tropics data coverage compared to its predecessor COSMIC constellation. GNSS RO measurements yield information about atmospheric pressure, temperature, and water vapor profiles. HWRF is cycled with and without COSMIC-2 bending angle data assimilation for six 2020 Atlantic hurricane cases. COSMIC-2 assimilation has little impact on HWRF track forecasts, consistent with HWRF’s design limiting cycled data assimilation impacts on surrounding large-scale flows; however, COSMIC-2 assimilation results in a statistically significant ∼8%–12% mean absolute forecast error reduction in minimum central sea level pressure for t = 36-, 54-, 60-, and 108–120-h lead times. Forecasts initialized from analyses assimilating COSMIC-2 observations also have a 1%–4% smaller 600–700-hPa specific humidity (SPFH) root-mean-squared deviation compared to radiosondes and dropwindsondes for most lead times. While not all HWRF intensity forecasts benefit from COSMIC-2 assimilation, a few show notable improvement. For example, assimilating two COSMIC-2 profiles within the inner core of developing Hurricane Hanna (2020) increases 800-hPa SPFH by up to 1 g kg−1 locally, helping to correct a dry bias. The forecast initialized from this analysis better captures Hanna’s observed intensification rate, likely because its moister inner core facilitates development of persistent deep convection near the TC center, where diabatic heating is more efficiently converted to cyclonic wind kinetic energy. Significance Statement Tropical cyclone (TC) intensification can be strongly sensitive to the lower-to-midtropospheric water vapor distribution near the storm. The COSMIC-2 GNSS radio occultation (RO) receiver satellite mission provides denser spatial coverage of atmospheric water vapor and temperature profiles over the tropics compared to other GNSS RO observation platforms. Herein, using six 2020 Atlantic TC cases, we evaluate the impacts of assimilating COSMIC-2 RO bending angles into a regional forecast model that already assimilates clear-sky satellite radiances. It is shown that COSMIC-2 assimilation yields a modest ∼10% intensity forecast skill improvement for several lead times, although more substantial intensity forecast improvement is found for a few forecasts where the COSMIC-2 observation assimilation helps correct a lower-to-midtropospheric water vapor bias.

The effects of flash drought on the terrestrial ecosystem in Korea

Typified by rapid intensification in a short time, flash droughts (FDs) have attracted increasing attention because of their effects on water resources and ecosystems. Water use efficiency (WUE) is a key indicator for understanding the interaction between the carbon dynamic and water cycle. However, the effects of FDs on terrestrial ecosystems in Korea remain mostly unknown. Therefore, we identified FD events in Korea using the soil moisture (SM)-based rate of intensification (RI) and the evapotranspiration (ET)-based Standardized Evaporative Stress Ratio (SESR) with flux tower data. Continuous satellite data from the Moderate Resolution Imaging Spectroradiometer (MODIS) were used to examine spatiotemporal patterns and trends in FD-related factors, Potential ET (PET), Actual ET (AET), Gross Primary Productivity (GPP), Evaporative Stress Ratio (ESR), and WUE from 2001 to 2020. The frequency, duration, and intensity of FDs in Korea were investigated and responses in WUE to FDs in different landcover types were examined. The SESR and RI had a similar performance in capturing FD events in flux tower site data. At the regional scale, a lower ESR was mainly observed in the western and southern parts of the study area, indicating progressively drier climate conditions. The mean frequency percentage and number of Korean FD events in the past 20 years were 61.3% and 16, respectively. In addition, more FD events occurred in the northern and eastern regions of the study area, where the main landcover type is forest, and northeastern Korea suffered from long FD events (over 30 days). FDs caused a positive response of WUE in most of the study area. However, the change in WUE after FD events varied by FD severity and landcover type. The changes in WUE after moderate FD events were largely driven by the change in GPP, and the highest sensitivity of WUE to FD intensity was found in croplands. These findings highlight the characteristics and effects of FDs on WUE across landcover types, which will be helpful in managing potential environmental risks in Korea.