Land Surface Climate in the Regional Arctic System Model

The article of record as published may be found at http://dx.doi.org/10.1175/JCLI-D-15-0415.1The Regional Arctic System Model (RASM) is a fully coupled, regional Earth system model applied over the pan-Arctic domain. This paper discusses the implementation of the Variable Infiltration Capacity land surface model (VIC) in RASM and evaluates the ability of RASM, version 1.0, to capture key features of the land surface climate and hydrologic cycle for the period 1979-2014 in comparison with uncoupled VIC simulations, reanalysis datasets, satellite measurements, and in situ observations. RASM reproduces the dominant features of the land surface climatology in the Arctic, such as the amount and regional distribution of precipitation, the partitioning of precipitation between runoff and evapotranspiration, the effects of snow on the water and energy balance, and the differences in turbulent fluxes between the tundra and taiga biomes. Surface air temperature biases in RASM, compared to reanalysis datasets ERA-Interim and MERRA, are generally less than 2 degrees C; however, in the cold seasons there are local biases that exceed 6 degrees C. Compared to satellite observations, RASM captures the annual cycle of snow-covered area well, although melt progresses about two weeks faster than observations in the late spring at high latitudes. With respect to derived fluxes, such as latent heat or runoff, RASM is shown to have similar performance statistics as ERA-Interim while differing substantially from MERRA, which consistently overestimates the evaporative flux across the Arctic region.U.S. Department of Energy (DOE) [DE-FG02-07ER64460, DE-SC0006856, DE-SC0006178]; DO

SB04-22/23: Resolution Authorizing Approval of Staff Senate Signature of Bear Necessities Statement to University Administration

Passed during May 10, 2023 Staff Senate meeting. Documents from the May 10, 2023 meeting of the University of Montana S by University of Montana--Missoula. Staff Senate (umt.edu) Resolution authorizing approval of Staff Senate to sign support to the ASUM Bear Necessities statement to the University of Montana Administration. Resolution Authored by Kat Cowley. Additional Authors, including Cowley, listed for letter. Letter discusses concerns regarding the status of marginalized and vulnerable student populations and offers suggestions on some ways the University of Montana can support students at a basic human level. These include continued advocacy for increase support from the State of Montana, increased housing availability, meal plan affordability, open education resources, campus accessibility, and addressing staffing issues

Evaluation of the atmosphere–land–ocean–sea ice interface processes in the Regional Arctic System Model version 1 (RASM1) using local and globally gridded observations

The Regional Arctic System Model version 1 (RASM1) has been developed to provide high-resolution simulations of the Arctic atmosphere–ocean–sea ice–land system. Here, we provide a baseline for the capability of RASM to simulate interface processes by comparing retrospective simulations from RASM1 for 1990–2014 with the Community Earth System Model version 1 (CESM1) and the spread across three recent reanalyses. Evaluations of surface and 2 m air temperature, surface radiative and turbulent fluxes, precipitation, and snow depth in the various models and reanalyses are performed using global and regional datasets and a variety of in situ datasets, including flux towers over land, ship cruises over oceans, and a field experiment over sea ice. These evaluations reveal that RASM1 simulates precipitation that is similar to CESM1, reanalyses, and satellite gauge combined precipitation datasets over all river basins within the RASM domain. Snow depth in RASM is closer to upscaled surface observations over a flatter region than in more mountainous terrain in Alaska. The sea ice–atmosphere interface is well simulated in regards to radiation fluxes, which generally fall within observational uncertainty. RASM1 monthly mean surface temperature and radiation biases are shown to be due to biases in the simulated mean diurnal cycle. At some locations, a minimal monthly mean bias is shown to be due to the compensation of roughly equal but opposite biases between daytime and nighttime, whereas this is not the case at locations where the monthly mean bias is higher in magnitude. These biases are derived from errors in the diurnal cycle of the energy balance (radiative and turbulent flux) components. Therefore, the key to advancing the simulation of SAT and the surface energy budget would be to improve the representation of the diurnal cycle of radiative and turbulent fluxes. The development of RASM2 aims to address these biases. Still, an advantage of RASM1 is that it captures the interannual and interdecadal variability in the climate of the Arctic region, which global models like CESM cannot do

Clinical Outcomes in 3343 Children and Adults with Rheumatic Heart Disease from 14 Low and Middle Income Countries: 2-Year Follow-up of the Global Rheumatic Heart Disease Registry (the REMEDY study)

Background: There are few contemporary data on the mortality and morbidity associated with rheumatic heart disease or information on their predictors. We report the 2-year follow-up of individuals with rheumatic heart disease from 14 low- and middle-income countries in Africa and Asia. Methods: Between January 2010 and November 2012, we enrolled 3343 patients from 25 centers in 14 countries and followed them for 2 years to assess mortality, congestive heart failure, stroke or transient ischemic attack, recurrent acute rheumatic fever, and infective endocarditis. Results: Vital status at 24 months was known for 2960 (88.5%) patients. Two-thirds were female. Although patients were young (median age, 28 years; interquartile range, 18–40), the 2-year case fatality rate was high (500 deaths, 16.9%). Mortality rate was 116.3/1000 patient-years in the first year and 65.4/1000 patient-years in the second year. Median age at death was 28.7 years. Independent predictors of death were severe valve disease (hazard ratio [HR], 2.36; 95% confidence interval [CI], 1.80–3.11), congestive heart failure (HR, 2.16; 95% CI, 1.70–2.72), New York Heart Association functional class III/IV (HR, 1.67; 95% CI, 1.32–2.10), atrial fibrillation (HR, 1.40; 95% CI, 1.10–1.78), and older age (HR, 1.02; 95% CI, 1.01–1.02 per year increase) at enrollment. Postprimary education (HR, 0.67; 95% CI, 0.54–0.85) and female sex (HR, 0.65; 95% CI, 0.52–0.80) were associated with lower risk of death. Two hundred and four (6.9%) patients had new congestive heart failure (incidence, 38.42/1000 patient-years), 46 (1.6%) had a stroke or transient ischemic attack (8.45/1000 patient-years), 19 (0.6%) had recurrent acute rheumatic fever (3.49/1000 patient-years), and 20 (0.7%) had infective endocarditis (3.65/1000 patient-years). Previous stroke and older age were independent predictors of stroke/transient ischemic attack or systemic embolism. Patients from low- and lower-middle–income countries had significantly higher age- and sex-adjusted mortality than patients from upper-middle–income countries. Valve surgery was significantly more common in upper-middle–income than in lower-middle– or low-income countries. Conclusions: Patients with clinical rheumatic heart disease have high mortality and morbidity despite being young; those from low- and lower-middle–income countries had a poorer prognosis associated with advanced disease and low education. Programs focused on early detection and the treatment of clinical rheumatic heart disease are required to improve outcomes. </jats:sec

Effects of Projected Twenty-First Century Sea Level Rise, Storm Surge, and River Flooding on Water Levels in Puget Sound Floodplains and Estuaries

Thesis (Master's)--University of Washington, 2012Near coastal environments have been identified as some of the most likely to be impacted by climate change. Observed changes in Puget Sound sea level and flood magnitudes are in line with those projected by previous climate change impacts studies. Current understanding of the combined effects of these changes is relatively low and has prompted us to explore the ways in which their co-occurrence will influence near coastal ecosystems and infrastructure. This project examines the effects of climate change on the lower reaches of Puget Sound rivers by investigating changes in storm surge, sea level rise, and riverine flooding. The project utilizes numerical models to quantify the shifts in hydraulic conditions expected in the Skagit and Nisqually river basins. Global climate model simulations from the ECHAM-5 climate model were used as the climate forcings and were 1) statistically downscaled using the hybrid delta method, and 2) dynamically downscaled using the WRF regional climate model. Naturalized flows produced using the Variable Infiltration Capacity hydrology model were used to drive reservoir models that simulate flood control operations. Storm surge was calculated using a regression approach that included anomalous atmospherics forcings simulated by the WRF model. A 2D hydrodynamic model was used to estimate water surface elevations in the Skagit and Nisqually River estuaries using resampled hourly hydrographs keyed to regulated daily flood flows produced by a daily time step reservoir simulation model and tide predictions adjusted for SLR and storm surge. Combining peak annual storm surge with expected sea level rise, the historic (1970-1999) 100-yr peak tidal anomaly is found to be exceeded every year by the 2020s. By the 2050s, the extrapolated 100-yr riverine flood events are found to increase by 30% and 25% in the Skagit and Nisqually Rivers, respectively. In the Skagit River, the combined effect of sea level rise and larger floods yields increased areal flood inundation up to 80% relative to the present "100-year" flood

Understanding the Arctic Hydroclimate Using the Regional Arctic System Model

Thesis (Ph.D.)--University of Washington, 2016-10The importance of understanding the Arctic climate system is underscored by the recent and unprecedented observed changes in key climatic processes across the region, and the potential for these changes to impact natural and human activities in coming decades. Warming associated with global climate change is expected to bring further changes to the Arctic cryosphere as well as the broader regional and global climate systems. My research has focused on the development and application the Regional Arctic System Model (RASM). RASM is a fully-coupled regional Earth system model (ESM) applied over a large Pan- Arctic domain. The development of RASM has been motivated by the need to improve multi-decadal simulations of high-latitude climate and to advance our understanding of the coupled interactions between individual components within the Arctic climate system. In this dissertation, I present analysis related to the development, evaluation, and application of the components of RASM that simulate land surface processes with the overarching goal of better understanding the Arctic hydroclimate. This dissertation was made up of three core chapters. In Chapter 3, I introduce a novel coupling of the Variable Infiltration Capacity (VIC) model within RASM, evaluating the performance of the VIC compared to observations and other model based datasets. In Chapter 4, I present a new river routing scheme (RVIC) for earth system models, again evaluating the model in comparison to in situ observations and model based datasets. This chapter also presents the development of a new coastal streamflow dataset for ocean modeling applications. Finally, in Chapter 5, RASM was used to evaluate how changes in the sea ice cover in the Arctic Ocean impacted precipitation patterns over land