Southern Ocean cloud and aerosol data: a compilation of measurements from the 2018 Southern Ocean Ross Sea Marine Ecosystems and Environment voyage

Due to its remote location and extreme weather conditions, atmospheric in situ measurements are rare in the Southern Ocean. As a result, aerosol–cloud interactions in this region are poorly understood and remain a major source of uncertainty in climate models. This, in turn, contributes substantially to persistent biases in climate model simulations such as the well-known positive shortwave radiation bias at the surface, as well as biases in numerical weather prediction models and reanalyses. It has been shown in previous studies that in situ and ground-based remote sensing measurements across the Southern Ocean are critical for complementing satellite data sets due to the importance of boundary layer and low-level cloud processes. These processes are poorly sampled by satellite-based measurements and are often obscured by multiple overlying cloud layers. Satellite measurements also do not constrain the aerosol–cloud processes very well with imprecise estimation of cloud condensation nuclei. In this work, we present a comprehensive set of ship-based aerosol and meteorological observations collected on the 6-week Southern Ocean Ross Sea Marine Ecosystem and Environment voyage (TAN1802) voyage of RV Tangaroa across the Southern Ocean, from Wellington, New Zealand, to the Ross Sea, Antarctica. The voyage was carried out from 8 February to 21 March 2018. Many distinct, but contemporaneous, data sets were collected throughout the voyage. The compiled data sets include measurements from a range of instruments, such as (i) meteorological conditions at the sea surface and profile measurements; (ii) the size and concentration of particles; (iii) trace gases dissolved in the ocean surface such as dimethyl sulfide and carbonyl sulfide; (iv) and remotely sensed observations of low clouds. Here, we describe the voyage, the instruments, and data processing, and provide a brief overview of some of the data products available. We encourage the scientific community to use these measurements for further analysis and model evaluation studies, in particular, for studies of Southern Ocean clouds, aerosol, and their interaction. The data sets presented in this study are publicly available at https://doi.org/10.5281/zenodo.4060237 (Kremser et al., 2020)

Use of chromoendoscopy versus white light endoscopy for colorectal cancer surveillance in inflammatory bowel disease patients with primary sclerosing cholangitis; a six year experience

Background: Patients with inflammatory bowel disease (IBD) are at increased risk for development of dysplasia and colorectal cancer (CRC), with a further 6-fold increased risk in those with primary sclerosing cholangitis (PSC) versus their non-PSC-IBD counterparts. Preneoplastic tissue in IBD patients is often flat and multifocal and may not be appreciated in up to one-third of colonoscopies. The dysplasia yield from surveillance colonoscopy can be improved by spraying dyes that highlight subtle changes in the architecture of the colonic mucosa. Limited data exists on outcomes of chromoendoscopy in PSC-IBD population. Our aim was to audit the endoscopic outcomes of CRC surveillance in PSC-IBD patients, comparing chromoendoscopy (CE) versus white-light endoscopy (WLE), over a six-year period. Methods: Retrospective study analyzing our Oxford PSC database to identify patients actively followed up since January 1st, 2010. Patients were excluded who did not have a diagnosis of IBD, had a colectomy prior to January 1st, 2010, or did not under go endoscopic surveillance at our institution. Endoscopic and histological findings were recorded from endoscopic electronic reporting systems (EndoBase and UNISOFT), and histology reports from NHS Casenotes. Procedures were excluded if bowel preparation was inadequate or evidence of moderate inflammation. Results: 140 PSC patients were followed up during study period, of which 58 PSC-IBD patients attended our institution for their endoscopic surveillance (38 UC, 10 Crohn's disease, and 10 IBD-U). The median disease duration at time of colonoscopy was 12.4 years (7.3–24.5). 178 colonoscopies were performed on this population, of which 57 were excluded due to poor prep and active inflammation. 122 procedures were analysed. 74 were performed with CE while 48 with WLE. High definition scope was more likely to be used at CE than WLE procedures (58.3% versus 28.2%, p=0.005). Targeted biopsies were taken at time of 23/74 (31.1%) CE procedures (one high grade dysplasia (HGD), two low grade dysplasia (LGD), one indefinite for dysplasia (IFD), one sessile serrated polyp (SSP), and three hyperplastic changes (all right colon)) versus 1/48 (2.2%) WLE procedures (normal) (p&lt;0.001). More visible lesions were identified at chromoendoscopy (p=0.04), with 78 identified in CE procedures (one HGD, two LGD, one IFD, three SSP, 24 hyperplastic polyps (15 right sided), and 5 adenomatous polyps) versus 18 in WLE procedures (no dysplastic lesions, five hyperplastic (two right sided)). Premalignant lesions were more likely to be detected at CE (p=0.006). Conclusions: This study shows evolving clinical practice at a single centre with increased detection of premalignant lesions with CE versus WLE for PSC-IBD patients.</p

Use of chromoendoscopy versus white light endoscopy for colorectal cancer surveillance in inflammatory bowel disease patients with primary sclerosing cholangitis cohort: A six year experience

Patients with inflammatory bowel disease (IBD) are at increased risk for development of dysplasia and colorectal cancer (CRC), with a further 6-fold increased risk in those with primary sclerosing cholangitis (PSC) versus their non-PSC-IBD counterparts. Preneoplastic tissue in IBD patients is often flat and multifocal and may not be appreciated in up to one-third of colonoscopies. The dysplasia yield from surveillance colonoscopy can be improved by spraying dyes that highlight subtle changes in the architecture of the colonic mucosa. Limited data exists on outcomes of chromoendoscopy in PSC-IBD population

Use of chromoendoscopy versus white light endoscopy for colorectal cancer surveillance in inflammatory bowel disease patients with primary sclerosing cholangitis; a six year experience

Patients with inflammatory bowel disease (IBD) are at increased risk for development of dysplasia and colorectal cancer (CRC), with a further 6-fold increased risk in those with primary sclerosing cholangitis (PSC) versus their non-PSC-IBD counterparts. Preneoplastic tissue in IBD patients is often flat and multifocal and may not be appreciated in up to one-third of colonoscopies. The dysplasia yield from surveillance colonoscopy can be improved by spraying dyes that highlight subtle changes in the architecture of the colonic mucosa. Limited data exists on outcomes of chromoendoscopy in PSC-IBD population

Use of chromoendoscopy versus white light endoscopy for colorectal cancer surveillance in inflammatory bowel disease patients with primary sclerosing cholangitis cohort: A six year experience

Patients with inflammatory bowel disease (IBD) are at increased risk for development of dysplasia and colorectal cancer (CRC), with a further 6-fold increased risk in those with primary sclerosing cholangitis (PSC) versus their non-PSC-IBD counterparts. Preneoplastic tissue in IBD patients is often flat and multifocal and may not be appreciated in up to one-third of colonoscopies. The dysplasia yield from surveillance colonoscopy can be improved by spraying dyes that highlight subtle changes in the architecture of the colonic mucosa. Limited data exists on outcomes of chromoendoscopy in PSC-IBD population

Constraining the Surface Flux of Sea Spray Particles From the Southern Ocean

Modeling the shortwave radiation balance over the Southern Ocean region remains a challenge for Earth system models. To investigate whether this is related to the representation of aerosol-cloud interactions, we compared measurements of the total number concentration of sea spray-generated particles within the Southern Ocean region to model predictions thereof. Measurements were conducted from a container laboratory aboard the R/V Tangaroa throughout an austral summer voyage to the Ross Sea. We used source-receptor modeling to calculate the sensitivity of our measurements to upwind surface fluxes. From this approach, we could constrain empirical parameterizations of sea spray surface flux based on surface wind speed and sea surface temperature. A newly tuned parameterization for the flux of sea spray particles based on the near-surface wind speed is presented. Comparisons to existing model parameterizations revealed that present model parameterizations led to overestimations of sea spray concentrations. In contrast to previous studies, we found that including sea surface temperature as an explanatory variable did not substantially improve model-measurement agreement. To test whether or not the parameterization may be applicable globally, we conducted a regression analysis using a database of in situ whitecap measurements. We found that the key fitting parameter within this regression agreed well with the parameterization of sea spray flux. Finally, we compared calculations from the best model of surface flux to boundary layer measurements collected onboard an aircraft throughout the Southern Ocean Clouds, Radiation, Aerosol Transport Experimental Study (SOCRATES), finding good agreement overall

Constraining the Surface Flux of Sea Spray Particles From the Southern Ocean

International audience• Current-era GCMs overestimate sea spray concentrations relative to measurements in the Ross Sea • Better constraints for sea spray flux were found by tuning wind-speed based parameterizations to these observations • Variations in sea surface temperature did not explain further variability within the temperature range studie