Including a Cold Pool Representation in a Convection Parameterization and Simulating Its Impacts on the Spatial and Temporal Variability of the Precipitation in the NASA GEOS GCM

We developed and implemented a simple representation of a cold pool in the Grell-Freitas (GF) convection parameterization. The cold pool parameterization is based on the observation that convective-scale downdrafts produce a local deficit of the moist static energy (MSE). This information is advected and becoming downwind available to trigger and intensify new convection. The cold pool is dissipated by a simple exponential decay using a lifetime of a few hours, or by interacting with the underneath surface by exchanging latent and sensible heat fluxes. Preliminary results show some improvement of the simulation of the diurnal cycle of the precipitation over the land, mainly during the nighttime

A New Look at Some Old Animals

How the tiny marine animalTrichoplax adhaerens is related to other animals has long puzzled researchers studying the origin of metazoans. An ambitious "total evidence" study provides careful analysis of this question and reveals some surprises

Structure, Photophysics and the Order-Disorder Transition to the Beta Phase in Poly(9,9-(di -n,n-octyl)fluorene)

X-ray diffraction, UV-vis absorption and photoluminescence (PL) spectroscopy have been used to study the well-known order-disorder transition (ODT) to the beta phase in poly(9,9-(di n,n-octyl)fluorene)) (PF8) thin film samples through combination of time-dependent and temperature-dependent measurements. The ODT is well described by a simple Avrami picture of one-dimensional nucleation and growth but crystallization, on cooling, proceeds only after molecular-level conformational relaxation to the so called beta phase. Rapid thermal quenching is employed for PF8 studies of pure alpha phase samples while extended low-temperature annealing is used for improved beta phase formation. Low temperature PL studies reveal sharp Franck-Condon type emission bands and, in the beta phase, two distinguishable vibronic sub-bands with energies of approximately 199 and 158 meV at 25 K. This improved molecular level structural order leads to a more complete analysis of the higher-order vibronic bands. A net Huang-Rhys coupling parameter of just under 0.7 is typically observed but the relative contributions by the two distinguishable vibronic sub-bands exhibit an anomalous temperature dependence. The PL studies also identify strongly correlated behavior between the relative beta phase 0-0 PL peak position and peak width. This relationship is modeled under the assumption that emission represents excitons in thermodynamic equilibrium from states at the bottom of a quasi-one-dimensional exciton band. The crystalline phase, as observed in annealed thin-film samples, has scattering peaks which are incompatible with a simple hexagonal packing of the PF8 chains.Comment: Submitted to PRB, 12 files; 1 tex, 1 bbl, 10 eps figure

Subseasonal Forecasting with an Icosahedral, Vertically Quasi-Lagrangian Coupled Model. Part I: Model Overview and Evaluation of Systematic Errors

The atmospheric hydrostatic Flow-Following Icosahedral Model (FIM), developed for medium-range weather prediction, provides a unique three-dimensional grid structurea quasi-uniform icosahedral horizontal grid and an adaptive quasi-Lagrangian vertical coordinate. To extend the FIM framework to subseasonal time scales, an icosahedral-grid rendition of the Hybrid Coordinate Ocean Model (iHYCOM) was developed and coupled to FIM. By sharing a common horizontal mesh, airsea fluxes between the two models are conserved locally and globally. Both models use similar adaptive hybrid vertical coordinates. Another unique aspect of the coupled model (referred to as FIMiHYCOM) is the use of the GrellFreitas scale-aware convective scheme in the atmosphere. A multiyear retrospective study is necessary to demonstrate the potential usefulness and allow for immediate bias correction of a subseasonal prediction model. In these two articles, results are shown based on a 16-yr period of hindcasts from FIMiHYCOM, which has been providing real-time forecasts out to a lead time of 4 weeks for NOAAs Subseasonal Experiment (SubX) starting July 2017. Part I provides an overview of FIMiHYCOM and compares its systematic errors at subseasonal time scales to those of NOAAs operational Climate Forecast System version 2 (CFSv2). Part II uses bias-corrected hindcasts to assess both deterministic and probabilistic subseasonal skill of FIMiHYCOM. FIMiHYCOM has smaller biases than CFSv2 for some fields (including precipitation) and comparable biases for other fields (including sea surface temperature). FIMiHYCOM also has less drift in bias between weeks 1 and 4 than CFSv2. The unique grid structure and physics suite of FIMiHYCOM is expected to add diversity to multimodel ensemble forecasts at subseasonal time scales in SubX

X-ray Raman scattering study of aligned polyfluorene

We present a non-resonant inelastic x-ray scattering study at the carbon K-edge on aligned poly[9,9-bis(2-ethylhexyl)-fluorene-2,7-diyl] and show that the x-ray Raman scattering technique can be used as a practical alternative to x-ray absorption measurements. We demonstrate that this novel method can be applied to studies on aligned $\pi$-conjugated polymers complementing diffraction and optical studies. Combining the experimental data and a very recently proposed theoretical scheme we demonstrate a unique property of x-ray Raman scattering by performing the symmetry decomposition on the density of unoccupied electronic states into $s$- and $p$-type symmetry contributions.Comment: 19 pages, 8 figure

Comparison of observed and model-computed low frequency circulation and hydrography on the New England Shelf

Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 113 (2008): C09015, doi:10.1029/2007JC004394.The finite volume coastal ocean model (FVCOM) is configured to study the interannual variability of circulation in the Gulf of Maine (GoM) and Georges Bank. The FVCOM-GoM system incorporates realistic time-dependent surface forcing derived from a high-resolution mesoscale meteorological model (MM5) and assimilation of observed quantities including sea surface temperature and salinity and temperature fields on the open boundary. An evaluation of FVCOM-GoM model skill on the New England shelf is made by comparison of computed fields and data collected during the Coastal Mixing and Optics (CMO) Program (August 1996–June 1997). Model mean currents for the full CMO period compare well in both magnitude and direction in fall and winter but overpredict the westward flow in spring. The direction and ellipticity of the subtidal variability correspond but computed magnitudes are around 20% below observed, partially due to underprediction of the variability by MM5. Response of subtidal currents to wind-forcing shows the model captures the directional dependence, as well as seasonal variability of the lag. Hydrographic results show that FVCOM-GoM resolves the spatial and temporal evolution of the temperature and salinity fields. The model-computed surface salinity field compares well, except in May when there is no indication of the fresh surface layer from the Connecticut River discharge noted in the observations. Analysis of model-computed results indicates that the plume was unable to extend to the mooring location due to the presence of a westward mean model-computed flow during that time that was stronger than observed. Overall FVCOM-GoM captures well the dynamics of the mean and subtidal flow on the New England shelf.G. Cowles was supported by the Massachusetts Marine Fisheries Institute (MFI) through NOAA grants DOC/NOAA/ NA04NMF4720332 and DOC/NOAA/NA05NMF4721131, S. Lentz by the NSF Ocean Sciences Division through grants OCE-841292 and OCE- 848961, C. Chen and Q. Xu through the NSF/NOAA GLOBEC/Northwest Atlantic/Georges Bank Program under NSF grants OCE-0234545 and OCE-0227679 and NOAA grants NA-16OP2323, and R. Beardsley through NOAA grant NA-17RJ1223

Evaluation of uncertainties in regional climate change simulations

We have run two regional climate models (RCMs) forced by three sets of initial and boundary conditions to form a 2×3 suite of 10-year climate simulations for the continental United States at approximately 50 km horizontal resolution. The three sets of driving boundary conditions are a reanalysis, an atmosphere-ocean coupled general circulation model (GCM) current climate, and a future scenario of transient climate change. Common precipitation climatology features simulated by both models included realistic orographic precipitation, east-west transcontinental gradients, and reasonable annual cycles over different geographic locations. However, both models missed heavy cool-season precipitation in the lower Mississippi River basin, a seemingly common model defect. Various simulation biases (differences) produced by the RCMs are evaluated based on the 2×3 experiment set in addition to comparisons with the GCM simulation. The RCM performance bias is smallest, whereas the GCM-RCM downscaling bias (difference between GCM and RCM) is largest. The boundary forcing bias (difference between GCM current climate driven run and reanalysis-driven run) and intermodel bias are both largest in summer, possibly due to different subgrid scale processes in individual models. The ratio of climate change to biases, which we use as one measure of confidence in projected climate changes, is substantially larger than 1 in several seasons and regions while the ratios are always less than 1 in summer. The largest ratios among all regions are in California. Spatial correlation coefficients of precipitation were computed between simulation pairs in the 2×3 set. The climate change correlation is highest and the RCM performance correlation is lowest while boundary forcing and intermodel correlations are intermediate. The high spatial correlation for climate change suggests that even though future precipitation is projected to increase, its overall continental-scale spatial pattern is expected to remain relatively constant. The low RCM performance correlation shows a modeling challenge to reproduce observed spatial precipitation patterns

Quantitative description of temperature induced self-aggregation thermograms determined by differential scanning calorimetry

A novel thermodynamic approach for the description of differential scanning calorimetry (DSC) experiments on self-aggregating systems is derived and presented. The method is based on a mass action model where temperature dependence of aggregation numbers is considered. The validity of the model was confirmed by describing the aggregation behavior of poly(ethylene oxide)-poly(propylene oxide) block copolymers, which are well-known to exhibit a strong temperature dependence. The quantitative description of the thermograms could be performed without any discrepancy between calorimetric and van 't Hoff enthalpies, and moreover, the aggregation numbers obtained from the best fit of the DSC experiments are in good agreement with those obtained by light scattering experiments corroborating the assumptions done in the derivation of the new model

Efficacy and Safety of Nivolumab Plus Ipilimumab vs Nivolumab Alone for Treatment of Recurrent or Metastatic Squamous Cell Carcinoma of the Head and Neck: The Phase 2 CheckMate 714 Randomized Clinical Trial

IMPORTANCE: There remains an unmet need to improve clinical outcomes in patients with recurrent or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). OBJECTIVE: To evaluate clinical benefit of first-line nivolumab plus ipilimumab vs nivolumab alone in patients with R/M SCCHN. DESIGN, SETTING, AND PARTICIPANTS: The CheckMate 714, double-blind, phase 2 randomized clinical trial was conducted at 83 sites in 21 countries between October 20, 2016, and January 23, 2019. Eligible participants were aged 18 years or older and had platinum-refractory or platinum-eligible R/M SCCHN and no prior systemic therapy for R/M disease. Data were analyzed from October 20, 2016 (first patient, first visit), to March 8, 2019 (primary database lock), and April 6, 2020 (overall survival database lock). INTERVENTIONS: Patients were randomized 2:1 to receive nivolumab (3 mg/kg intravenously [IV] every 2 weeks) plus ipilimumab (1 mg/kg IV every 6 weeks) or nivolumab (3 mg/kg IV every 2 weeks) plus placebo for up to 2 years or until disease progression, unacceptable toxic effects, or consent withdrawal. MAIN OUTCOMES AND MEASURES: The primary end points were objective response rate (ORR) and duration of response between treatment arms by blinded independent central review in the population with platinum-refractory R/M SCCHN. Exploratory end points included safety. RESULTS: Of 425 included patients, 241 (56.7%; median age, 59 [range, 24-82] years; 194 males [80.5%]) had platinum-refractory disease (nivolumab plus ipilimumab, n = 159; nivolumab, n = 82) and 184 (43.3%; median age, 62 [range, 33-88] years; 152 males [82.6%]) had platinum-eligible disease (nivolumab plus ipilimumab, n = 123; nivolumab, n = 61). At primary database lock, the ORR in the population with platinum-refractory disease was 13.2% (95% CI, 8.4%-19.5%) with nivolumab plus ipilimumab vs 18.3% (95% CI, 10.6%-28.4%) with nivolumab (odds ratio [OR], 0.68; 95.5% CI, 0.33-1.43; P = .29). Median duration of response for nivolumab plus ipilimumab was not reached (NR) (95% CI, 11.0 months to NR) vs 11.1 months (95% CI, 4.1 months to NR) for nivolumab. In the population with platinum-eligible disease, the ORR was 20.3% (95% CI, 13.6%-28.5%) with nivolumab plus ipilimumab vs 29.5% (95% CI, 18.5%-42.6%) with nivolumab. The rates of grade 3 or 4 treatment-related adverse events with nivolumab plus ipilimumab vs nivolumab were 15.8% (25 of 158) vs 14.6% (12 of 82) in the population with platinum-refractory disease and 24.6% (30 of 122) vs 13.1% (8 of 61) in the population with platinum-eligible disease. CONCLUSIONS AND RELEVANCE: The CheckMate 714 randomized clinical trial did not meet its primary end point of ORR benefit with first-line nivolumab plus ipilimumab vs nivolumab alone in platinum-refractory R/M SCCHN. Nivolumab plus ipilimumab was associated with an acceptable safety profile. Research to identify patient subpopulations in R/M SCCHN that would benefit from nivolumab plus ipilimumab over nivolumab monotherapy is warranted. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02823574