The Critical Role of Cloud–Infrared Radiation Feedback in Tropical Cyclone Development

2021 ◽  
Author(s):  
James Ruppert ◽  
Allison Wing ◽  
Xiaodong Tang ◽  
Erika Duran
Keyword(s):  
Greenhouse Effect ◽  
Lead Time ◽  
Critical Role ◽  
Longwave Radiation ◽  
Lead Times ◽  
Convective Clouds ◽  
Numerical Model Experiments ◽  
Local Cloud ◽  
Radiation Feedback

<p>The deep convective clouds of developing tropical cyclones (TCs) are highly effective at trapping the infrared (or longwave) radiation welling up from the surface. This “cloud greenhouse effect” locally warms the lower–mid-troposphere relative to the TC’s surroundings – an effect that manifests in all stages of the TC lifecycle. While idealized studies suggest the importance of this feedback for TC formation, this issue has remained unexplored for TCs in nature, where non-zero background flow, wind shear, and synoptic-scale variability are known to greatly constrain TC development.</p><p>To address this gap, we examine the potential role of this cloud–infrared (or longwave) radiation feedback in the context of two archetypal storms: Super Typhoon Haiyan (2013) and Hurricane Maria (2017). We conduct a set of numerical model experiments for both storms with a convection-resolving model (WRF-ARW) from the very early stages of TC development. We examine sensitivity experiments wherein this cloud–radiation feedback is removed at various lead-times prior to TC genesis and the onset of rapid intensification (RI). In both storms, removing this cloud–radiation feedback at a lead-time of ~1 day or less leads to delayed and/or weaker intensification than in the control case. When this feedback is removed with a lead-time of two days or longer, however, the storms altogether fail to development and intensify. This local cloud greenhouse effect strengthens the thermally direct transverse circulation of the incipient storm, in turn both promoting saturation within its core and accelerating the spin-up of its surface tangential circulation via angular momentum convergence. These findings indicate that the cloud greenhouse effect plays a critical role in accelerating and promoting TC development in nature. Progress in the prediction of TC formation and intensification has been very limited in recent decades. Cloud–radiation feedback represents a large source of uncertainty in models, which hence manifests as uncertainty in the prediction of TC development. Our findings highlight the pressing need to better constrain this feedback in models. Doing so holds promise for advancing our ability to forecast TCs.</p>

Creativity Just in Time? The Role of Delivery Precision in Product Development

2015 ◽  
Vol 12 (05) ◽  
pp. 1550026
Author(s):  
Katarina Lund Stetler
Keyword(s):  
Product Development ◽  
Automotive Industry ◽  
Lead Time ◽  
Project Planning ◽  
Survey Study ◽  
Just In Time ◽  
Lead Times ◽  
The Creation ◽  
The Relationship

This paper presents the results from a quantitative survey study in the research and development (R&D) department of company in the automotive industry. The focus of the study has been on exploring the relationship between delivery precision and creativity. Given today's increasingly competitive market, companies must be able to both cut lead times and maintain high creativity and innovativeness in the organization. This study is an attempt to increase our understanding of how one means of cutting lead time, the imposition of high demands on delivery precision, is related to the creation of novel ideas in the industrialization phase of product development. The results point to an interesting relationship in which the imposition of high demands on delivery precision actually increases the perception of the creation of novel ideas. The results have implications for project planning and the role of time dedicated to exploratory tasks in product development.

scholarly journals Lead Time and Prognostic Role of Serum CEA, CA19-9, IL-6, CRP, and YKL-40 after Adjuvant Chemotherapy in Colorectal Cancer

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3892
Author(s):  
Kaisa Lehtomäki ◽  
Harri Mustonen ◽  
Pirkko-Liisa Kellokumpu-Lehtinen ◽  
Heikki Joensuu ◽  
Kethe Hermunen ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Adjuvant Therapy ◽  
Lead Time ◽  
Disease Free Survival ◽  
Phase Iii ◽  
Lead Times ◽  
Curative Intent ◽  
Serum Cea ◽  
Resected Stage

In colorectal cancer (CRC), 20–50% of patients relapse after curative-intent surgery with or without adjuvant therapy. We investigated the lead times and prognostic value of post-adjuvant (8 months from randomisation to adjuvant treatment) serum CEA, CA19-9, IL-6, CRP, and YKL-40. We included 147 radically resected stage II–IV CRC treated with 24 weeks of adjuvant 5-fluorouracil-based chemotherapy in the phase III LIPSYT-study (ISRCTN98405441). All 147 were included in lead time analysis, but 12 relapsing during adjuvant therapy were excluded from post-adjuvant analysis. Elevated post-adjuvant CEA, IL-6, and CRP were associated with impaired disease-free survival (DFS) with hazard ratio (HR) 5.21 (95% confidence interval 2.32–11.69); 3.72 (1.99–6.95); 2.58 (1.18–5.61), respectively, and elevated IL-6 and CRP with impaired overall survival (OS) HR 3.06 (1.64–5.73); 3.41 (1.55–7.49), respectively. Elevated post-adjuvant IL-6 in CEA-normal patients identified a subgroup with impaired DFS. HR 3.12 (1.38–7.04) and OS, HR 3.20 (1.39–7.37). The lead times between the elevated biomarker and radiological relapse were 7.8 months for CEA and 10.0–53.1 months for CA19-9, IL-6, CRP, and YKL-40, and the lead time for the five combined was 27.3 months. Elevated post-adjuvant CEA, IL-6, and CRP were associated with impaired DFS. The lead time was shortest for CEA.

scholarly journals The role of convective overshooting clouds in tropical stratosphere–troposphere dynamical coupling

2014 ◽  
Vol 14 (16) ◽  
pp. 23745-23761 ◽  
Author(s):  
K. Kodera ◽  
B. M. Funatsu ◽  
C. Claud ◽  
N. Eguchi
Keyword(s):  
Deep Convection ◽  
Correlation Coefficients ◽  
Longwave Radiation ◽  
Convective Activity ◽  
Convective Clouds ◽  
Circulation Change ◽  
Tropospheric Circulation ◽  
Dynamical Coupling ◽  
The Tropics

Abstract. This paper investigates the role of deep convection and overshooting convective clouds in stratosphere–troposphere dynamical coupling in the tropics during two large major stratospheric sudden warming events in January 2009 and January 2010. During both events, convective activity and precipitation increased in the equatorial Southern Hemisphere as a result of a strengthening of the Brewer–Dobson circulation induced by enhanced stratospheric planetary wave activity. Correlation coefficients between variables related to the convective activity and the vertical velocity were calculated to identify the processes connecting stratospheric variability to the troposphere. Convective overshooting clouds showed a direct relationship to lower stratospheric upwelling at around 70–50 hPa. As the tropospheric circulation change lags behind that of the stratosphere, outgoing longwave radiation shows almost no simultaneous correlation with the stratospheric upwelling. This result suggests that the stratospheric circulation change first penetrates into the troposphere through the modulation of deep convective activity.

scholarly journals Scientific Verification of Deterministic River Stage Forecasts

2009 ◽  
Vol 10 (2) ◽  
pp. 507-520 ◽  
Author(s):  
Edwin Welles ◽  
Soroosh Sorooshian
Keyword(s):  
Model Calibration ◽  
Lead Time ◽  
Initial Conditions ◽  
Lead Times ◽  
Calibration Model ◽  
Forecast System ◽  
Feasible Method ◽  
River Stage ◽  
Short Lead Time

Abstract One element of a complete verification system is the ability to determine why forecasts behave as they do. This paper describes and demonstrates an operationally feasible method for conducting this type of diagnostic verification analysis. Hindcasts are generated using different configurations of the forecast system and then the skill of the generated hindcasts is compared. The hindcasts and comparisons are constructed to isolate individual elements of the forecast process. The approach is used to evaluate the role of model calibration, model initial conditions, and precipitation forecasts in generating skill for deterministic river forecasts. The authors find that calibration and initial conditions provide skill for the short lead-time forecasts, with precipitation forecasts providing the majority of the skill in forecasts of high stages at longer lead times. At all lead times, this study shows model calibration is essential, as the calibration makes forecasts reliable.

scholarly journals The role of convective overshooting clouds in tropical stratosphere–troposphere dynamical coupling

2015 ◽  
Vol 15 (12) ◽  
pp. 6767-6774 ◽  
Author(s):  
K. Kodera ◽  
B. M. Funatsu ◽  
C. Claud ◽  
N. Eguchi
Keyword(s):  
Deep Convection ◽  
Correlation Coefficients ◽  
Longwave Radiation ◽  
Convective Activity ◽  
Convective Clouds ◽  
Circulation Change ◽  
Tropospheric Circulation ◽  
Dynamical Coupling ◽  
The Tropics

Abstract. This paper investigates the role of deep convection and overshooting convective clouds in stratosphere–troposphere dynamical coupling in the tropics during two large major stratospheric sudden warming events in January 2009 and January 2010. During both events, convective activity and precipitation increased in the equatorial Southern Hemisphere as a result of a strengthening of the Brewer–Dobson circulation induced by enhanced stratospheric planetary wave activity. Correlation coefficients between variables related to the convective activity and the vertical velocity were calculated to identify the processes connecting stratospheric variability to the troposphere. Convective overshooting clouds showed a direct relationship to lower stratospheric upwelling at around 70–50 hPa. As the tropospheric circulation change lags behind that of the stratosphere, outgoing longwave radiation shows almost no simultaneous correlation with the stratospheric upwelling. This result suggests that the stratospheric circulation change first penetrates into the troposphere through the modulation of deep convective activity.

Interactions between Physics Diversity and Multiscale Initial Condition Perturbations for Storm-Scale Ensemble Forecasting

2020 ◽  
Vol 148 (8) ◽  
pp. 3549-3565
Author(s):  
Aaron Johnson ◽  
Xuguang Wang
Keyword(s):  
Spatial Scale ◽  
Lead Time ◽  
Cold Pool ◽  
Small Scale ◽  
Lead Times ◽  
Synoptic Scale ◽  
Convective Initiation ◽  
Forecast Performance ◽  
Forecast Lead Time

Abstract This study investigates impacts on convection-permitting ensemble forecast performance of different methods of generating the ensemble IC perturbations in the context of simultaneous physics diversity among the ensemble members. A total of 10 convectively active cases are selected for a systematic comparison of different methods of perturbing IC perturbations in 10-member convection-permitting ensembles, both with and without physics diversity. These IC perturbation methods include simple downscaling of coarse perturbations from a global model (LARGE), perturbations generated with ensemble data assimilation directly on the multiscale domain (MULTI), and perturbations generated using each method with small scales filtered out as a control. MULTI was found to be significantly more skillful than LARGE at early lead times in all ensemble physics configurations, with the advantage of MULTI gradually decreasing with increasing forecast lead time. The advantage of MULTI, relative to LARGE, was reduced but not eliminated by the presence of physics diversity because of the extra ensemble spread that the physics diversity provided. The advantage of MULTI, relative to LARGE, was also reduced by filtering the IC perturbations to a commonly resolved spatial scale in both ensembles, which highlights the importance of flow-dependent small-scale (<~10 m) IC perturbations in the ensemble design. The importance of the physics diversity, relative to the IC perturbation method, depended on the spatial scale of interest, forecast lead time, and the meteorological characteristics of the forecast case. Such meteorological characteristics include the strength of synoptic-scale forcing, the role of cold pool interactions, and the occurrence of convective initiation or dissipation.

Skill of the MJO and Northern Hemisphere Blocking in GEFS Medium-Range Reforecasts

2014 ◽  
Vol 142 (2) ◽  
pp. 868-885 ◽  
Author(s):  
Thomas M. Hamill ◽  
George N. Kiladis
Keyword(s):  
Northern Hemisphere ◽  
Lead Time ◽  
Decadal Variability ◽  
Longwave Radiation ◽  
Lead Times ◽  
Atlantic Sector ◽  
Tropical Precipitation ◽  
Predictive Skill ◽  
Perfect Model ◽  
Medium Range

Abstract Forecast characteristics of Northern Hemisphere atmospheric blocking and the Madden–Julian oscillation (MJO) were diagnosed using an extensive time series (December–February 1985–2012) of daily medium-range ensemble reforecasts based on a version of the NCEP Global Ensemble Forecast System (GEFS). For blocking, (i) interannual variability of analyzed blocking frequency was quite large, (ii) the GEFS slightly underforecasted blocking frequency at longer leads in the Euro-Atlantic sector, (iii) predictive skill of actual blocking was substantially smaller than its perfect-model skill, (iv) block onset and cessation were forecast less well than overall blocking frequency, (v) there was substantial variability of blocking skill between half-decadal periods, and (vi) the reliability of probabilistic blocking forecasts degraded with increasing lead time. For the MJO, (i) forecasts of strong Indian Ocean MJOs propagated too slowly, especially the component associated with outgoing longwave radiation (OLR), that is, convection; (ii) tropical precipitation was greatly overforecast at early lead times; (iii) the ensemble predictions were biased and/or underdispersive, manifested in U-shaped rank histograms of MJO indices (magnitude forecasts were especially U shaped); (iv) MJO correlation skill was larger for its wind than for its OLR component, and was larger for the higher-amplitude MJO events; (v) there was some half-decadal variability in skill; and (vi) probabilistic skill of the MJO forecast was modest, and skill was larger when measured relative to climatology than when measured relative to a lagged persistence forecast. For longer-lead forecasts, the GEFS demonstrated little ability to replicate the changes in blocking frequency due to a strong MJO that were noted in analyzed data.

scholarly journals The critical role of cloud–infrared radiation feedback in tropical cyclone development

2020 ◽  
Vol 117 (45) ◽  
pp. 27884-27892
Author(s):  
James H. Ruppert ◽  
Allison A. Wing ◽  
Xiaodong Tang ◽  
Erika L. Duran
Keyword(s):  
Tropical Cyclones ◽  
Infrared Radiation ◽  
Critical Role ◽  
Tropical Storms ◽  
Rapid Intensification ◽  
Societal Challenge ◽  
Tc Prediction ◽  
Transverse Circulation ◽  
Radiation Feedback

The tall clouds that comprise tropical storms, hurricanes, and typhoons—or more generally, tropical cyclones (TCs)—are highly effective at trapping the infrared radiation welling up from the surface. This cloud–infrared radiation feedback, referred to as the “cloud greenhouse effect,” locally warms the lower–middle troposphere relative to a TC’s surroundings through all stages of its life cycle. Here, we show that this effect is essential to promoting and accelerating TC development in the context of two archetypal storms—Super Typhoon Haiyan (2013) and Hurricane Maria (2017). Namely, this feedback strengthens the thermally direct transverse circulation of the developing storm, in turn both promoting saturation within its core and accelerating the spin-up of its surface tangential circulation through angular momentum convergence. This feedback therefore shortens the storm’s gestation period prior to its rapid intensification into a strong hurricane or typhoon. Further research into this subject holds the potential for key progress in TC prediction, which remains a critical societal challenge.

The Role of the SLP in Autism Spectrum Disorder Screening and Assessment

2008 ◽  
Vol 15 (2) ◽  
pp. 50-59 ◽  
Author(s):  
Amy Philofsky
Keyword(s):  
Language Development ◽  
Critical Role ◽  
Children With Autism ◽  
Autism Spectrum ◽  
Children With Asd ◽  
Prevalence Estimates ◽  
Notable Increase ◽  
Screening Assessment ◽  
Critical Components

AbstractRecent prevalence estimates for autism have been alarming as a function of the notable increase. Speech-language pathologists play a critical role in screening, assessment and intervention for children with autism. This article reviews signs that may be indicative of autism at different stages of language development, and discusses the importance of several psychometric properties—sensitivity and specificity—in utilizing screening measures for children with autism. Critical components of assessment for children with autism are reviewed. This article concludes with examples of intervention targets for children with ASD at various levels of language development.

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