A baseline evaluation of oceanographic and sea ice conditions in the Hudson Bay Complex during 2016-2018

In this paper, we examine sea surface temperatures (SSTs) and sea ice conditions in the Hudson Bay Complex as a baseline evaluation for the BaySys 2016–2018 field program time frame. Investigated in particular are spatiotemporal patterns in SST and sea ice state and dynamics, with rankings of the latter to highlight extreme conditions relative to the examined 1981–2010 climatology. Results from this study show that SSTs in northwestern Hudson Bay from May to July, 2016–2018, are high relative to the climatology for SST (1982–2010). SSTs are also warmer in 2016 and 2017 than in 2018 relative to their climatology. Similarly, unusually low sea ice cover existed from August to December of 2016 and July to September of 2017, while unusually high sea ice cover existed in January, February, and October of 2018. The ice-free season was approximately 20 days longer in 2016 than in 2018. Unusually high ice-drift speeds occurred in April of 2016 and 2017 and in May of 2018, coinciding with strong winds in 2016 and 2018 and following strong winds in March 2017. Strong meridional circulation was observed in spring of 2016 and winter of 2017, while weak meridional circulation existed in 2018. In a case study of an extreme event, a blizzard from 7 to 9 March 2017, evaluated using Lagrangian dispersion statistics, is shown to have suppressed sea ice deformation off the coast of Churchill. These results are relevant to describing and planning for possible future pathways and scenarios under continued climate change and river regulation

A baseline evaluation of atmospheric and river discharge conditions in the Hudson Bay Complex during 2016-2018

In this article, we examine atmospheric and river discharge conditions within the Hudson Bay Complex for the BaySys 2016–2018 field program time frame. Investigated in particular is a subset of European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis - Interim (ERA-Interim) atmospheric forcing variables, namely 2-m surface temperature, 10-m surface winds, precipitation, and sea-level pressure, in addition to river discharge. Results from this assessment show that 2016 was characterized by unusually warm conditions (terrestrial and marine) throughout the annual cycle; 2017 by strong cyclone activity in March and high precipitation in January, October, and November; and 2018 by cold and windy conditions throughout the annual cycle. Evaluation of terrestrial conditions showed higher than normal land surface temperatures (the Hudson Bay physical watershed) for all of the 2016–2018 period (excluding a colder than normal spell August–November 2018), particularly in January (2016 and 2017), higher than normal precipitation in October (2016 and 2017), and higher than normal terrestrial discharge to the Hudson Bay Complex in March (2016 and 2017), with drier than average June through October (2016–2018)

Soil Carbon Accumulation in Old-Growth Forests

This chapter investigates the effect of forest age on soil carbon storage, clarifying if old-growth forests still store soil carbon despite the ecological theory that old-growth forests are carbon neutral. In the first section, a general overview of carbon storage is given, and key areas where forest age could affect carbon storage are described. In the second section, the existing literature is reviewed, elaborating the effect of these factors on carbon storage in old-growth forests. Finally a case study of a temperate broadleaf forest site is given. The results demonstrate that old-growth forests are still able to store carbon in the soil; however, litter quality, i.e. acid-generating conifer needles, may also negatively influence soil carbon storage. Most interestingly, the amount of stored carbon depends strongly on the methods applied. Chronosequence approaches generally gain only a few grams of carbon per year and square metre, whereas repeated sampling yields several tens of grams

Changing freshwater contributions to the Arctic : A 90-year trend analysis (1981-2070)

The pan-Arctic domain is undergoing some of Earth's most rapid and significant changes resulting from anthropogenic and climate-induced alteration of freshwater distribution. Changes in terrestrial freshwater discharge entering the Arctic Basin from pan-Arctic watersheds significantly impact oceanic circulation and sea ice dynamics. Historical streamflow records in high-latitude basins are often discontinuous (seasonal or with large temporal gaps) or sparse (poor spatial coverage), however, making trends from observed records difficult to quantify. Our objectives were to generate a more continuous 90-year record (1981-2070) of spatially distributed freshwater flux for the Arctic Basin (all Arctic draining rivers, including the Yukon), suitable for forcing ocean models, and to analyze the changing simulated trends in freshwater discharge across the domain. We established these data as valid during the historical period (1971-2015) and then used projected futures (preserving uncertainty by running a coupled climate-hydrologic ensemble) to analyze long-term (2021-2070) trends for major Arctic draining rivers. When compared to historic trends reported in the literature, we find that trends are projected to nearly double by 2070, with river discharge to the Arctic Basin increasing by 22% (on average) by 2070. We also find a significant trend toward earlier onset of spring freshet and a general flattening of the average annual hydrograph, with a trend toward decreasing seasonality of Arctic freshwater discharge with climate change and regulation combined. The coupled climate-hydrologic ensemble was then used to force an ocean circulation model to simulate freshwater content and thermohaline circulation. This research provides the marine research community with a daily time series of historic and projected freshwater discharge suitable for forcing sea ice and ocean models. Although important, this work is only a first step in mapping the impacts of climate change on the pan-Arctic region

The Unravelling of the Genetic Architecture of Plasminogen Deficiency and its Relation to Thrombotic Disease

Although plasminogen is a key protein in fibrinolysis and several mutations in the plasminogen gene (PLG) have been identified that result in plasminogen deficiency, there are conflicting reports to associate it with the risk of thrombosis. Our aim was to unravel the genetic architecture of PLG in families with plasminogen deficiency and its relationship with spontaneous thrombotic events in these families. A total of 13 individuals from 4 families were recruited. Their genetic risk profile of thromboembolism was characterized using the Thrombo inCode kit. Only one family presented genetic risk of thromboembolism (homozygous carrier of F12 rs1801020 and F13A1 rs5985). The whole PLG was tested using Next Generation Sequencing (NGS) and 5 putative pathogenic mutations were found (after in silico predictions) and associated with plasminogen deficiency. Although we can not find genetic risk factors of thrombosis in 3 of 4 families, even the mutations associated with plasminogen deficiency do not cosegregated with thrombosis, we can not exclude plasminogen deficiency as a susceptibility risk factor for thrombosis, since thrombosis is a multifactorial and complex disease where unknown genetic risk factors, in addition to plasminogen deficiency, within these families may explain the thrombotic tendency

Molecular and clinical spectrum of type I plasminogen deficiency: a series of 50 patients

Severe type I plasminogen (PLG) deficiency has been causally linked to a rare chronic inflammatory disease of the mucous membranes that may be life threatening. Here we report clinical manifestations, PLG plasma levels, and molecular genetic status of the PLG gene of 50 patients. The most common clinical manifestations among these patients were ligneous conjunctivitis (80%) and ligneous gingivitis (34%), followed by less common manifestations such as ligneous vaginitis (8%), and involvement of the respiratory tract (116%), the ears (14%), or the gastrointestinal tract (2%). Four patients showed congenital occlusive hydrocephalus, 2 with Dandy-Walker malformation of cerebellum. Venous thrombosis was not observed. In all patients, plasma PLG levels were markedly reduced. In 38 patients, distinct mutations in the PLG gene were identified. The most common genetic alteration was a K19E mutation found in 34% of patients. Transient in vitro expression of PLG mutants R134K, delK212, R216H, P285T P285A, T319_N320insN, and R776H in transfected COS-7 cells revealed significantly impaired secretion and increased degradation of PLG. These results demonstrate impaired secretion of mutant PLG proteins as a common molecular pathomechanism in type I PLG deficiency.Wo