Fluorometric method for the determination of gas-phase hydrogen peroxide

The fluorometric gas-phase hydrogen peroxide procedure is based on the technique used by Lazrus et. al. for the determination of H2O2 in the liquid phase. The analytical method utilizes the reaction of H2O2 with horseradish peroxidase and p-hydroxphenylacetic acid (POPHA) to form the fluorescent dimer of POPHA. The analytical reaction responds stoichiometrically to both H2O2 and some organic hydroperoxides. To discriminate H2O2 from organic hydroperoxides, catalase is used to preferentially destroy H2O2. Using a dual-channel flow system the H2O2 concentration is determined by difference

Characterizing the potential for drought action from combined hydrological and societal perspectives

Drought is a function of both natural and human influences, but fully characterizing the interactions between human and natural influences on drought remains challenging. To better characterize parts of the drought feedback loop, this study combines hydrological and societal perspectives to characterize and quantify the potential for drought action. For the hydrological perspective, we examine historical groundwater data, from which we determine the decadal likelihoods of exceeding hydrologic thresholds relevant to different water uses. Stakeholder interviews yield data about how people rate the importance of water for different water uses. We combine these to quantify the Potential Drought Action Indicator (PDAI). The PDAI is demonstrated for a study site in south-central Oklahoma, where water availability is highly influenced by drought and management of water resources is contested by local stakeholders. For the hydrological perspective, we find that the historical decadal likelihood of exceedance for a moderate threshold associated with municipal supply has ranged widely: from 23&thinsp;% to 75&thinsp;%, which corresponds well with natural drought variability in the region. For the societal perspective, stakeholder interviews reveal that people value water differently for various uses. Combining this information into the PDAI illustrates that potential drought action increases as the hydrologic threshold is exceeded more often; this occurs as conditions get drier and when water use thresholds are more moderate. The PDAI also shows that for water uses where stakeholders have diverse views of importance, the PDAI will be diverse as well, and this is exacerbated under drier conditions. The variability in stakeholder views of importance is partially explained by stakeholders' cultural worldviews, pointing to some implications for managing water when drought risks threaten. We discuss how the results can be used to reduce potential disagreement among stakeholders and promote sustainable water management, which is particularly important for planning under increasing drought.</p

Drought-Ready Communities: A Guide to Community Drought Preparedness

Table of Contents Introduction to Drought-Ready Communities........................................................ 4 Section 1. Getting Started: Invite the Community to Participate, Commit to the Process...................... 7 1.1 Establish a leadership team that includes individuals with responsibility for monitoring, communication, and implementation .............................................. 7 1.2 Identify stakeholders or groups in the community that may need additional resources to participate in the Drought-Ready Communities process .................... 8 1.3 Include government agencies and regulators ....................................... 9 1.4 Develop a contact list ................................................................ 9 1.5 Gather community perceptions of drought .................................................. 10 Section 2. Information Gathering: Understand Water Sources and Uses, Develop a Drought History . 11 2.1 Identify water sources and uses ....................................................... 11 2.2 Learn how drought has affected the community in the past ........................ 12 2.3 Gather data on water and climate ................................................................. 13 2.4 List factors that affect the severity of drought impacts ..................................... 1

Gas emission strength and evolution of the molar ratio of BrO/SO2 in the plume of Nyiragongo in comparison to Etna

Airborne and ground-based differential optical absorption spectroscopy observations have been carried out at the volcano Nyiragongo (Democratic Republic of Congo) to measure SO2 and bromine monoxide (BrO) in the plume in March 2004 and June 2007, respectively. Additionally filter pack and multicomponent gas analyzer system (Multi-GAS) measurements were carried out in June 2007. Our measurements provide valuable information on the chemical composition of the volcanic plume emitted from the lava lake of Nyiragongo. The main interest of this study has been to investigate for the first time the bromine emission flux of Nyiragongo (a rift volcano) and the BrO formation in its volcanic plume. Measurement data and results from a numerical model of the evolution of BrO in Nyiragongo volcanic plume are compared with earlier studies of the volcanic plume of Etna (Italy). Even though the bromine flux from Nyiragongo (2.6t/d) is slightly greater than that from Etna (1.9t/d), the BrO/SO2 ratio (maximum 7x10(-5)) is smaller than in the plume of Etna (maximum 2.1x10(-4)). A one-dimensional photochemical model to investigate halogen chemistry in the volcanic plumes of Etna and Nyiragongo was initialized using data from Multi-GAS and filter pack measurements. Model runs showed that the differences in the composition of volcanic volatiles led to a smaller fraction of total bromine being present as BrO in the Nyiragongo plume and to a smaller BrO/SO2 ratio

Bringing Indigenous and Earth Sciences, Knowledges, and Practices Together to Understand and Respond to COVID-19

COVID-19 is having specific and devastating impacts, yet it is spurring resilient responses among Indigenous populations due to unique histories, cultures, geographies, and capacities. The Working Group on Indigenous and Earth Sciences Knowledges and Practices in Response to COVID-19 came together to foreground Indigenous perspectives in defining research questions for potential intercultural collaboration between Indigenous and Earth sciences to drive urgent, culturally relevant, and appropriate responses to COVID-19. The Working Group included intercultural, intergenerational, and interdisciplinary representatives from the Rising Voices Center for Indigenous and Earth Sciences, a nation-wide network of scientists, educators, students, and community leaders and organizers. To identify priority research areas and emerging questions, the Working Group hosted a webinar discussion and fielded a questionnaire with the Rising Voices community as well as utilized their own perspectives and expertise. The results highlighted four dynamics that many Indigenous Peoples are presently facing with the COVID-19 pandemic, including food security and safety; pre-existing conditions; turning to resilience and wisdom; and emerging questions at the nexus of Indigenous wisdom and knowledge and Earth sciences. Valuing Indigenous observations, knowledges, wisdom, and practices equally with Earth Sciences, this work contributes to decolonizing Earth Sciences, disaster management, and public health. It works to mitigate the particular threats and impacts that Indigenous communities and populations face from COVID-19 and the increasing spread of infectious diseases. Doing so addresses injustices in Earth Sciences and disaster management and the disproportionately adverse impacts of COVID-19 on Indigenous communities