Using Sentinel-3 Satellite Imagery for Cyanobacteria Development Monitoring

Great Lakes basins and inland waterways experience increased harmful algal bloom (HAB) production as a result of eutrophication– excess nutrient loading into waterways from agriculture and urbanization. Muskegon Lake, an estuary located on the eastern coast of Lake Michigan, was classified as a Great Lakes Area of Concern in 1985 due to severe HABs from several impairments including agricultural runoff and industrial waste dumping. Because of the ecosystem and human health threats posed by HABs such as wildlife and human illness and drinking water contamination, monitoring the abundance of HABs in inland waterways is imperative. The goal of this study was to evaluate the application and validity of remote sensing cyanobacteria abundance in Muskegon Lake using Sentinel-3 Ocean and Land Color Instrument (OLCI) satellite imagery from 2016-2021. Results show that the cyanobacteria quantification algorithm calculated high cell densities up to 1.25 million compared to in situ measurements up to 25,000 from a phycocyanin probe on the Muskegon Lake Buoy Observatory. However, remotely sensed cyanobacteria densities follow the same growth and die-off trends as calculated by the Buoy phycocyanin probe. Moreover, the results of this study display that remote sensing cyanobacteria HABs can supplement field data in flagging high HAB days for public health monitoring as well as documenting historical growth trends

Astro2020 Science White Paper: The Local Relics of of Supermassive Black Hole Seeds

We have compelling evidence for stellar-mass black holes (BHs) of ~5-80 M_sun that form through the death of massive stars. We also have compelling evidence for so-called supermassive BHs (10^5-10^10 M_sun) that are predominantly found in the centers of galaxies. We have very good reason to believe there must be BHs with masses in the gap between these ranges: the first ~10^9 M_sun BHs are observed only hundreds of millions of years after the Big Bang, and all theoretically viable paths to making supermassive BHs require a stage of "intermediate" mass. However, no BHs have yet been reliably detected in the 100-10}^5 M_sun mass range. Uncovering these intermediate-mass BHs of 10^3-10^5 M_sun is within reach in the coming decade. In this white paper we highlight the crucial role that 30-m class telescopes will play in dynamically detecting intermediate-mass black holes, should they exist.Comment: Science White Paper Submitted for the Astro2020 Decadal Survey on Astronomy and Astrophysic

Modeling the uptake of plug-in vehicles in a heterogeneous car market using a consumer segmentation approach

There is broad agreement on the need for substantial use of low carbon vectors in the long term in the transport sector. Electrification, via mass market adoption of plug-in vehicles (i.e. battery electric and plug-in hybrid electric vehicles), has emerged as a front runner for road transport across the globe, but there are concerns that the pace and extent implied by many modelling studies is problematic and that assessment of (a) the heterogeneity in the market, (b) other low carbon vectors (e.g. conventional hybrids, hydrogen fuel cell) and (c) life cycle energy and environmental impacts have been relatively neglected. This paper aims to fill these gaps by examining the timing, scale and impacts of the uptake of plug-in vehicles in the heterogeneous UK car market from a consumer perspective. To achieve this aim it (a) brings together a bespoke disaggregated model of the transport-energy-environment system (the UK Transport Carbon Model) with previous work by the authors on heterogeneity in the demand for and supply of plug-in vehicles and (b) applies the improved model to develop future low carbon scenarios that assess the potential impact of different investment pathways and policy approaches to the electrification of cars with the view to meeting the UK’s legally binding carbon budgets to 2050. The results show the importance of accounting for the heterogeneity in and dynamic nature of the car market in terms of new technology adoption by private consumers, so called ‘user choosers’ and fleet managers, as well as accounting for potential effects on wider life cycle emissions resulting from different uptake pathways. It allows an assessment of the effectiveness of different policy instruments, market conditions (vehicle supply, private vs fleet market, vehicle segments) and social factors (consumer awareness, range “anxiety”, perceived charging requirements) on different consumer segments, thus providing more policy-focused conclusions on the likely pathways to high penetration of plug-in vehicles that may be required to meet future carbon and air quality targets

Electromagnetic Window into the Dawn of Black Holes

The origin of massive black holes in the early universe is one of the major puzzles in astrophysics. Future X-ray surveys can detect BHs with mass M &lt; 105 M☉ at z &gt; 10, and OIR observations can characterize their immediate environment. These observations will open a window into the "Dawn of Black Holes" and distinguish models of their origin. <p/