Comparing Palmer Drought Severity Index drought assessments using the traditional offline approach with direct climate model outputs Hydrology and Earth System Sciences DOI 10.5194/hess-24-2921-2020 11 June 2020 Many previous studies using offline drought indices report that future warming will increase worldwide drought. However, this contradicts observations/projections of vegetation greening and increased runoff. We resolved this paradox by re-calculating the same drought indices using direct climate model outputs and find no increase in future drought as the climate warms. We also find that accounting for the impact of CO 2 on plant transpiration avoids the previous overestimation of drought. Read more
N2O isotopocule measurements using laser spectroscopy: analyzer characterization and intercomparison Atmospheric Measurement Techniques DOI 10.5194/amt-13-2797-2020 10 June 2020 The latest commercial laser spectrometers have the potential to revolutionize N 2 O isotope analysis. However, to do so, they must be able to produce trustworthy data. Here, we test the performance of widely used laser spectrometers for ambient air applications and identify instrument-specific dependencies on gas matrix and trace gas concentrations. We then provide a calibration workflow to facilitate the operation of these instruments in order to generate reproducible and accurate data. Read more
Model-based climatology of diurnal variability in stratospheric ozone as adata analysis tool Atmospheric Measurement Techniques DOI 10.5194/amt-13-2733-2020 10 June 2020 We use the NASA GEOS-GMI chemistry climate model to construct a climatology of stratospheric ozone diurnal variations as a function of latitude, pressure and month, which can be used in a variety of data analysis tasks involving ozone observations made at different times of the day. The climatology compares well with previous modeling simulations and available observations, and to the authors’ knowledge is the first characterization of the diurnal cycle available for general ozone data analyses. Read more
Present and future changes in winter climate indices relevant for access disruptions in Troms, northern Norway Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-1847-2020 9 June 2020 We have studied changes in winter weather known to trigger road closures and isolation of small seaside communities in northern Norway. We find that snow amounts and heavy snowfall events have increased in the past, while future projections for 2040–2100 show a decrease in snow-related indices. Events of heavy water supply and zero crossings are expected to increase. Our results imply fewer dry-snow-related access disruptions in the future, while wet-snow avalanches and slushflows may increase. Read more
Simultaneous measurements of the relative-humidity-dependent aerosol lightextinction, scattering, absorption, and single-scattering albedo with ahumidified cavity-enhanced albedometer Atmospheric Measurement Techniques DOI 10.5194/amt-13-2623-2020 4 June 2020 We report the first demonstration of a humidified cavity-enhanced albedometer (H-CEA) that combines a broadband cavity-enhanced aerosol albedometer with a humidigraph system for simultaneous and accurate measurements of multiple optical hygroscopic parameters ( f (RH)ext,scat,abs,ω) at λ = 532 nm. The instrument is suitable for operating under high RH-conditions and has sampling advantages over independent measurements of different parameters with different instruments. Read more
Network-risk: an open GIS toolbox for estimating the implications of transportation network damage due to natural hazards, tested for Bucharest, Romania Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-1421-2020 4 June 2020 Natural hazards have an increasing impact on transportation networks. In order to analyze it we developed Network-risk – an open toolbox for ArcGIS. The toolbox links input data such as network datasets (also OpenStreetMap – OSM – data), traffic values or segments which can be affected, determining the difficulty to reach an area and enabling evaluation of socioeconomic implications. By testing Network-risk for Bucharest we show areas difficult to reach by emergency units in earthquakes. Read more
Effects of upwelling duration and phytoplankton growth regime on dissolved-oxygen levels in an idealized Iberian Peninsula upwelling system Nonlinear Processes in Geophysics DOI 10.5194/npg-27-277-2020 2 June 2020 The oceans are losing oxygen, and future changes may worsen this problem. We performed computer simulations of an idealized Iberian Peninsula upwelling system to identify the main fine-scale processes driving dissolved oxygen variability as well as study the response of oxygen levels to changes in wind patterns and phytoplankton species. Our results suggest that oxygen levels would decrease if the wind blows for long periods of time or if phytoplankton is dominated by species that grow slowly. Read more
Exploration of oxidative chemistry and secondary organic aerosol formation in the Amazon during the wet season:explicit modeling of the Manaus urban plume with GECKO-A Atmospheric Chemistry and Physics DOI 10.5194/acp-20-5995-2020 2 June 2020 The GoAmazon 2014/5 field campaign took place near the city of Manaus, Brazil, isolated in the Amazon rainforest, to study the impacts of urban pollution on natural air masses. We simulated this campaign with an extremely detailed organic chemistry model to understand how the city would affect the growth and composition of natural aerosol particles. Discrepancies between the model and the measurements indicate that the chemistry of naturally emitted organic compounds is still poorly understood. Read more
Wetropolis extreme rainfall and flood demonstrator: from mathematical design to outreach Hydrology and Earth System Sciences DOI 10.5194/hess-24-2483-2020 28 May 2020 Wetropolis is a table-top demonstration model with extreme rainfall and flooding, including random rainfall, river flow, flood plains, an upland reservoir, a porous moor, and a city which can flood. It lets the viewer experience extreme rainfall and flood events in a physical model on reduced spatial and temporal scales with an event return period of 6.06 min rather than, say, 200 years. We disseminate its mathematical design and how it has been shown most prominently to over 500 flood victims. Read more
Rapid collaborative knowledge building via Twitter after significantgeohazard events Geoscience Communication DOI 10.5194/gc-3-129-2020 28 May 2020 Among social media platforms, Twitter is valued by scholars to disseminate scientific information. Using two 2018 geohazard events as examples, we show that collaborative open data sharing and discussion on Twitter promote very rapid building of knowledge. This breaks down the traditional ivory tower of academia, making science accessible to nonacademics who can follow the discussion. It also presents the opportunity for a new type of scientific approach within global virtual teams. Read more
