The toxicity and environmental persistence of anthropogenic per- and poly-fluoroalkyl substances (PFAS) are of global concern. To address legacy PFAS concerns in the United States, industry developed ...numerous replacement PFAS that commonly are treated as confidential information. To investigate the distribution of PFAS in New Jersey, soils collected from across the state were subjected to nontargeted mass-spectral analyses. Ten chloroperfluoropolyether carboxylates were tentatively identified, with at least three congeners in all samples. Nine congeners are ≥(CF
)
Distinct chemical formulas and structures, as well as geographic distribution, suggest airborne transport from an industrial source. Lighter congeners dispersed more widely than heavier congeners, with the most widely dispersed detected in an in-stock New Hampshire sample. Additional data were used to develop a legacy-PFAS fingerprint for historical PFAS sources in New Jersey.
Metastatic castration-resistant prostate cancer (mCRPC) has a highly complex genomic landscape. With the recent development of novel treatments, accurate stratification strategies are needed. Here we ...present the whole-genome sequencing (WGS) analysis of fresh-frozen metastatic biopsies from 197 mCRPC patients. Using unsupervised clustering based on genomic features, we define eight distinct genomic clusters. We observe potentially clinically relevant genotypes, including microsatellite instability (MSI), homologous recombination deficiency (HRD) enriched with genomic deletions and BRCA2 aberrations, a tandem duplication genotype associated with CDK12
and a chromothripsis-enriched subgroup. Our data suggests that stratification on WGS characteristics may improve identification of MSI, CDK12
and HRD patients. From WGS and ChIP-seq data, we show the potential relevance of recurrent alterations in non-coding regions identified with WGS and highlight the central role of AR signaling in tumor progression. These data underline the potential value of using WGS to accurately stratify mCRPC patients into clinically actionable subgroups.
Chemical transport associated with the dynamics of the Asian summer monsoon (ASM) system is investigated using model output from the National Center for Atmospheric Research (NCAR) Whole Atmosphere ...Community Climate Model run in specified dynamics mode. The 3‐D day‐to‐day behavior of modeled carbon monoxide is analyzed together with dynamical fields and transport boundaries to identify preferred locations of uplifting from the boundary layer, the role of subseasonal‐scale dynamics in the upper troposphere and lower stratosphere (UTLS), and the relationship of ASM transport and the stratospheric residual circulation. The model simulation of CO shows the intraseasonal east‐west oscillation of the anticyclone may play an essential role in transporting convectively pumped boundary layer pollutants in the UTLS. A statistical analysis of 11 year CO also shows that the southern flank of the Tibetan plateau is a preferred location for boundary layer tracers to be lofted to the tropopause region. The vertical structure of a model tracer (E90) further shows that the rapid ASM vertical transport is only effective up to the tropopause level (around 400 K). The efficiency of continued vertical transport into the deep stratosphere is limited by the slow ascent associated with the zonal‐mean residual circulation in the lower stratosphere during northern summer. Quasi‐isentropic transport near the 400 K potential temperature level is likely the most effective process for ASM anticyclone air to enter the stratosphere.
Key Points
Model results indicate that there is a preferred location of vertical transport from the boundary layer to UTLS
Subseasonal‐scale dynamics of the Asian monsoon anticyclone is an important driver of UTLS chemical transport
The season's slow ascent in residual circulation limits the efficiency of vertical transport into the stratosphere from the ASM
Winter‐summer differences in the transport of air from the boundary layer to the lower stratosphere at low latitudes are investigated with ensembles of back trajectory calculations that track parcels ...from the 380 K isentropic surface to their convective detrainment in the tropical tropopause layer (TTL) during the winter of 2006–2007 and summer of 2007. Horizontal displacements for the trajectories are calculated from reanalysis data; potential temperature displacements are calculated from radiative heating rates derived from observed cloud, water vapor, ozone, and temperature variations; and the locations' convective detrainments are determined by satellite observations of convective clouds. Weaker upwelling in the TTL during boreal summer compared with that of winter both slows the ascent through the TTL and raises the height threshold that convective detrainment must surpass in order for ascent to occur, restricting the injection of new air into the stratosphere during summer. In addition, anticyclonic circulations associated with convective activity contribute to vertical transport in the TTL by guiding detrained air parcels through regions with the strongest upwelling. These features combine to make monsoon‐related convection over the Indian subcontinent the dominant source of new air during summer. In contrast, winter sources are spread over the southern continents and the western Pacific Ocean. These seasonal differences imply that air entering the tropical stratosphere during summer is older but might nevertheless be more polluted than air entering during winter. While poor data sampling in the TTL makes it difficult to validate our results, they are bolstered by favorable comparisons with previous studies of the TTL, by sensitivity tests that reveal important dynamical influences on surface‐to‐stratospheric transport, and by the robustness of dynamical interactions that systematically associate deep convection with anticyclonic circulations and strong radiative heating in the TTL. Sensitivity experiments suggest that the aforementioned seasonal differences are sensitive to strong “large‐scale” (on global space scales and seasonal time scales) perturbations. In particular, uncertainties in the vertical motion fields constrain our ability to draw definitive conclusions. However, trajectory statistics are not sensitive to small‐scale perturbations, with the encouraging implication that our results are primarily associated with those features of the circulation that are the most likely to be robust.
Key Points
Anticyclonic circulations are important for vertical transport in the TTL
Slow ascent rates make summer TTL transport less efficient than that of winter
Elevated levels of zero heating make summer TTL transport less efficient
The Asian summer monsoon (ASM) creates a hemispheric-scale signature in trace-gas distributions in the upper troposphere and lower stratosphere (UTLS).
Data from satellite retrievals are the best ...source of information for
characterizing these large-scale signatures. Measurements from the Microwave
Limb Sounder (MLS), a limb-viewing satellite sensor, have been the most
widely used retrieval products for these types of studies. This work explores
the information for the ASM influence on UTLS chemical distribution from two
nadir-viewing sensors, the Infrared Atmospheric Sounding Interferometer
(IASI) and the Ozone Monitoring Instrument (OMI), together with the MLS.
Day-to-day changes in carbon monoxide (CO) and ozone (O3) tracer
distributions in response to dynamical variability are examined to assess
how well the data from different sensors provide useful information for
studying the impact of sub-seasonal-scale dynamics on chemical fields. Our
results, using June–August 2008 data, show that although the MLS
provides relatively sparse horizontal sampling on daily timescales,
interpolated daily CO distributions show a high degree of dynamical
consistency with the synoptic-scale structure of and variability in the
anticyclone. Our analysis also shows that the IASI CO retrieval has
sufficient sensitivity to produce upper tropospheric (UT) CO with
variabilities independent from the lower to middle tropospheric CO. The
consistency of IASI CO field with the synoptic-scale anticyclone dynamical
variability demonstrates that the IASI UT CO product is a physically
meaningful dataset. Furthermore, IASI CO vertical cross sections combined
with the daily maps provide the first observational evidence for a model
analyses-based hypothesis on the preferred ASM vertical transport location
and the subsequent horizontal redistribution via east–west eddy shedding.
Similarly, the OMI O3 profile product is shown to be capable of
distinguishing the tropospheric-dominated air mass in the anticyclone from
the stratospheric-dominated background on a daily timescale, providing
consistent and complementary information to the MLS. These results not only
highlight the complementary information between nadir and limb sensors but
also demonstrate the value of “process-based” retrieval evaluation for
characterizing satellite data information content.
The transport of air from the planetary boundary layer (PBL) into the Asian Summer Monsoon anticyclone is investigated using backward trajectories initiated within the anti‐cyclone at 100 mb and 200 ...mb during August 2011. Transport occurs through a well‐defined conduit centered over the southern Tibetan plateau, where convection lofts air parcels into the anticyclone. The conduit, as a dynamical feature, is distinct from the anticyclone. Thus, while the anticyclone influences transport through the upper troposphere and lower stratosphere, it does not by itself define a transport pipeline through that region. To quantify model sensitivities, parcel trajectories are calculated using wind fields from multiple analysis data sets (European Centre for Medium‐Range Weather Forecasts, National Center for Environmental Prediction's Global Forecasting System, and NASA's Modern‐Era Retrospective Analysis for Research and Applications MERRA) and from synthetically modified data sets that explore the roles of vertical motion and horizontal resolution for discrepancies among these calculations. All calculations agree on the relative contributions to PBL sources for the anticyclone from large‐scale regions with Tibetan Plateau and India/SE Asia being the most important. However, they disagree on the total fraction of air within the anticyclone that was recently in the PBL. At 200 mbar, calculations using MERRA are clear outliers due to problematic vertical motion in those data. Large differences among the different data sets at 100 mbar are more closely related to horizontal resolution. It is speculated that this reflects the importance of deep, small‐scale convective updrafts for transport to 100 mbar.
Key Points
Air transport to the Asian anticyclone is confined to a vertical conduitRegional contributions to anticyclone are robustVertical motion explains discrepancies in total fraction of young air
Dispersion of backward air parcel trajectories that are initially tightly grouped near the tropical tropopause is examined using three ensemble approaches: “RANWIND,” in which different ensemble ...members use identical resolved wind fluctuations but different realizations of stochastic, multifractal simulations of unresolved winds; “PERTLOC,” in which members use identical resolved wind fields but initial locations are perturbed 2° in latitude and longitude; and a multimodel ensemble (“MULTIMODEL”) that uses identical initial conditions but different resolved wind fields and/or trajectory formulations. Comparisons among the approaches distinguish, to some degree, physical dispersion from that due to data uncertainty and the impacts of unresolved wind fluctuations from those of resolved variability. Dispersion rates are robust properties of trajectories near the tropical tropopause. Horizontal dispersion rates are typically ~3°/d, which is large enough to spread parcels throughout the tropics within typical tropical tropopause layer transport times (30–60 days) and underscores the importance of averaging large collections of trajectories to obtain reliable parcel source and pathway distributions. Vertical dispersion rates away from convection are ~2–3 hPa/d. Dispersion is primarily carried out by the resolved flow, and the RANWIND approach provides a plausible representation of actual trajectory dispersion rates, while PERTLOC provides a reasonable and inexpensive alternative to RANWIND. In contrast, dispersion from the MULTIMODEL calculations is important because it reflects systematic differences in resolved wind fields from different reanalysis data sets.
Key Points
Dispersion rates are robust properties of trajectories near the tropical tropopause
Dispersion is primarily carried out by the resolved flow
Physical dispersion can be distinguished from trajectory error
Per- and polyfluoroalkyl substances (PFAS) make up a widespread, environmentally persistent class of anthropogenic chemicals that are widely used in industrial and consumer products and frequently ...detected in environmental media. Concerns over potential human health impacts from long-term exposure to legacy PFAS (long-chain perfluoroalkyl acids) resulted in the use of PFAS with alternative structures. Nontargeted environmental monitoring has been crucial in identifying the existence and transport of emerging PFAS in environmental media. Previous work in an industrially impacted region of southwestern New Jersey has shown consistently elevated levels of legacy PFAS, motivating additional examination by nontargeted mass spectrometry to identify emerging PFAS contamination. This study applied nontargeted analysis to water samples collected in Gloucester and Salem counties in southwestern New Jersey, revealing the existence of a series of chloro-perfluoro-polyether carboxylates and related PFAS species, believed to originate from a regional, industrial PFAS user. There is sparse publicly available toxicity information for the emerging chemical species, but estimated concentrations exceeded the state drinking water standards for perfluorooctanoic acid and perfluorononanoic acid. Nontargeted analysis was used to estimate the effectiveness of point-of-entry water treatment systems for removal of the emerging species and reduced the abundance of PFAS by >90%.
Although next-generation per- and polyfluorinated substances (PFAS) were designed and implemented as safer and environmentally degradable alternatives to “forever” legacy PFAS, there is little ...evidence to support the actual transformation of these compounds and less evidence of the safety of transformed products in the environment. Multiple congeners of one such PFAS alternative, the chloro-perfluoropolyether carboxylates (Cl-PFPECAs), have been found in New Jersey soils surrounding a manufacturing facility. These compounds are ideal candidates for investigating environmental transformation due to the existence of potential reaction centers including a chlorinated carbon and ether linkages. Transformation products of the chemical structures of this class of compounds were predicted based on analogous PFAS transformation pathways documented in peer-reviewed literature. Potential reaction products were used as the basis for high-resolution mass-spectrometric suspect screening of the soils. Suspected transformation products of multiple congeners, the Cl-PFPECAs, including H-PFPECAs, epox-PFPECAs, and diOH-PFPECAs, were tentatively observed in these screenings. Although ether linkages have been hypothesized as potential reaction centers under environmental conditions, to date, no documentation of ether scission has been identified. Despite exhaustive scrutiny of the high-resolution data for our Cl-PFPECA-laden soils, we found no evidence of ether scission.
THE NASA AIRBORNE TROPICAL TROPOPAUSE EXPERIMENT Jensen, Eric J.; Pfister, Leonhard; Jordan, David E. ...
Bulletin of the American Meteorological Society,
01/2017, Letnik:
98, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The February–March 2014 deployment of the National Aeronautics and Space Administration (NASA) Airborne Tropical Tropopause Experiment (ATTREX) provided unique in situ measurements in the western ...Pacific tropical tropopause layer (TTL). Six flights were conducted from Guam with the long-range, high-altitude, unmanned Global Hawk aircraft. The ATTREX Global Hawk payload provided measurements of water vapor, meteorological conditions, cloud properties, tracer and chemical radical concentrations, and radiative fluxes. The campaign was partially coincident with the Convective Transport of Active Species in the Tropics (CONTRAST) and the Coordinated Airborne Studies in the Tropics (CAST) airborne campaigns based in Guam using lower-altitude aircraft (see companion articles in this issue). The ATTREX dataset is being used for investigations of TTL cloud, transport, dynamical, and chemical processes, as well as for evaluation and improvement of global-model representations of TTL processes. The ATTREX data are publicly available online (at https://espoarchive.nasa.gov/).
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Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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