Publications Highlight articles

European Geosciences Union

www.egu.eu

Highlight articles

Some features of our web site require JavaScript to function properly. Please enable JavaScript in your browser.

2045 items found

10 20 50

Rainbow color map distorts and misleads research in hydrology – guidance for better visualizations and science communication

We found with a scientific paper survey (~ 1000 papers) that 45 % of the papers used rainbow color maps or red–green visualizations. Those rainbow visualizations, although attracting the media’s attention, will not be accessible for up to 10 % of people due to color vision deficiency. The rainbow color map distorts and misleads scientific communication. The study gives guidance on how to avoid, improve and trust color and how the flaws of the rainbow color map should be communicated in science.

Milankovitch, the father of paleoclimate modeling

The history of the long-term variations in the astronomical elements used in paleoclimate research shows that, contrary to what might be thought, Milutin Milankovitch is not the father of the astronomical theory but he is definitely the father of paleoclimate modeling. He did not calculate these long-term variations himself but used them extensively for calculating the “secular march” of incoming solar radiation. He advanced our understanding of Quaternary climate variations by two important and original contributions fully described in his Canon of insolation. These are the definition and use of caloric seasons and the concept of the “mathematical climate”. How his mathematical model allowed him to give the caloric summer and winter insolation a climatological meaning is illustrated.

Rapid measurement of RH-dependent aerosol hygroscopic growth using a humidity-controlled fast integrated mobility spectrometer (HFIMS)

In this study, we present a newly developed instrument, the humidity-controlled fast integrated mobility spectrometer (HFIMS), for fast measurements of aerosol hygroscopic growth. The HFIMS can measure the distributions of particle hygroscopic growth factors at six diameters from 35 to 265 nm under five RH levels from 20 to 85 % within 25 min. The HFIMS significantly advances our capability of characterizing the hygroscopic growth of atmospheric aerosols over a wide range of relative humidities.

Dynamics of salt intrusion in the Mekong Delta: results of field observations and integrated coastal–inland modelling

Increased salt intrusion jeopardizes freshwater supply to the Mekong Delta, and the current trends are often inaccurately associated with sea level rise. Using observations and models, we show that salinity is highly sensitive to ocean surge, tides, water demand, and upstream discharge. We show that anthropogenic riverbed incision has significantly amplified salt intrusion, exemplifying the importance of preserving sediment budget and riverbed levels to protect deltas against salt intrusion.

The long-term transport and radiative impacts of the 2017 British Columbia pyrocumulonimbus smoke aerosols in the stratosphere

Interactions of extreme fires with weather systems can produce towering smoke plumes that inject aerosols at very high altitudes (> 10 km). Three such major injections, largest at the time in terms of emitted aerosol mass, took place over British Columbia, Canada, in August 2017. We model the transport and impacts of injected aerosols on the radiation balance of the atmosphere. Our model results match the satellite-observed plume transport and residence time at these high altitudes very closely.

The nano-scanning electrical mobility spectrometer (nSEMS) and its application to size distribution measurements of 1.5–25 nm particles

We present the design, modeling, and experimental characterization of the nano-scanning electrical mobility spectrometer (nSEMS), a recently developed instrument that probes particle physical properties in the 1.5–25 nm range. The nSEMS has proven to be extremely powerful in examining atmospheric nucleation and the subsequent growth of nanoparticles in the CERN CLOUD experiment, which provides a valuable asset to study atmospheric nanoparticles and to evaluate their impact on climate.

Physical characteristics of frozen hydrometeors inferred with parameter estimation

Satellite observations sensitive to cloud and precipitation help improve the quality of weather forecasts. However, they are sensitive to things that models do not forecast, such as the shapes and sizes of snow and ice particles. These details can be estimated from the observations themselves and then incorporated in the satellite simulators used in weather forecasting. This approach, known as parameter estimation, will be increasingly useful to build models of poorly known physical processes.

Influence of the representation of convection on the mid-Holocene West African Monsoon

This paper investigates the impact of explicitly resolving convection on the mid-Holocene West African Monsoon rain belt by employing the ICON climate model in high resolution. While the spatial distribution and intensity of the precipitation are improved by this technique, the monsoon extents further north and the mean summer rainfall is higher in the simulation with parameterized convection.

Iodide CIMS and m∕z 62: the detection of HNO3 as NO3− in the presence of PAN, peroxyacetic acid and ozone

We demonstrate in laboratory experiments that the formation of IOx anions (formed in reactions of I− with O3) or acetate anions (formed e.g. by the reaction of I− with peracetic acid) results in unexpected sensitivity of an iodide chemical ionisation mass spectrometer (I-CIMS) to HNO3 at a mass-to-charge ratio of 62. This helps explain observations of apparent high daytime levels of N2O5. Airborne measurements using I-CIMS confirm these conclusions.

Recent degradation of interior Alaska permafrost mapped with ground surveys, geophysics, deep drilling, and repeat airborne lidar

The Cryosphere
DOI 10.5194/tc-15-3555-2021
10 September 2021

Permafrost is actively degrading across high latitudes due to climate warming. We combined thousands of end-of-summer active layer measurements, permafrost temperatures, geophysical surveys, deep borehole drilling, and repeat airborne lidar to quantify permafrost warming and thawing at sites across central Alaska. We calculate the mass of permafrost soil carbon potentially exposed to thaw over the past 7 years (0.44 Pg) is similar to the yearly carbon dioxide emissions of Australia.

Spatial and temporal subsidence characteristics in Wuhan (China), during 2015–2019, inferred from Sentinel-1 synthetic aperture radar (SAR) interferometry

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-21-2285-2021
8 September 2021

We mapped the subsidence of Wuhan using Sentinel-1 synthetic aperture radar (SAR) images acquired during 2015–2019. Overall subsidence coincides with the distribution of engineered geological regions with soft soils, while the subsidence centers shifted with urban construction activities. Correlation between karst subsidence and concentrated rainfall was identified in Qingling–Jiangdi. Results indicate that interferometric SAR can be employed to routinely monitor and identify geohazards.

Better representation of dust can improve climate models with too weak an African monsoon

Earth system models have persistent biases that impinge on our ability to make robust future regional predictions of precipitation. For the last 15 years, there has been little improvement in these biases. This work presents an accurate representation of dust absorption based upon observed dust mineralogical composition and size distribution. The striking result is that this more accurate representation improves tropical precipitations for climate models with too weak an African monsoon.

Characterization of dark current signal measurements of the ACCDs used on board the Aeolus satellite

This paper reports on dark current signal anomalies of the detectors used on board the ESA’s Earth Explorer satellite Aeolus during the first 1.5 years in orbit. After introducing sophisticated algorithms to classify dark current anomalies according to their characteristics, the impact of the different kinds of anomalies on wind measurements is discussed. In addition, mitigation approaches for the wind retrieval are presented and potential root causes are discussed.

Drought effects on leaf fall, leaf flushing and stem growth in the Amazon forest: reconciling remote sensing data and field observations

Satellite images show that the Amazon forest has greened up during past droughts. Measurements of tree stem growth and leaf litterfall upscaled using machine-learning algorithms show that leaf flushing at the onset of a drought results in canopy rejuvenation and green-up during drought while simultaneously trees excessively shed older leaves and tree stem growth declines. Canopy green-up during drought therefore does not necessarily point to enhanced tree growth and improved forest health.

Steepening of magnetosonic waves in the inner coma of comet 67P/Churyumov–Gerasimenko

Plasma waves are an integral part of cometary physics, as they facilitate the transfer of energy and momentum. From intermediate to strong activity, nonlinear asymmetric plasma and magnetic field enhancements dominate the inner coma of 67P/CG. We present a statistical survey of these structures from December 2014 to June 2016, facilitated by Rosetta’s unprecedented long mission duration. Using a 1D MHD model, we show they can be described as a combination of nonlinear and dissipative effects.

Controls on the rates and products of particle attrition by bed-load collisions

The authors of this paper conducted experiments to investigate the mechanics of sediment attrition due to collisions with the channel bed during downstream transport. During this process, the grains become rounder and smaller, changing the overall distribution of sediment in the river. In this work the authors examine how material properties play a role in the breakdown of sediment due to energetic collisions and the fine particles that are produced when chipped off of larger grains.

fv3gfs-wrapper: a Python wrapper of the FV3GFS atmospheric model

FV3GFS is a weather and climate model written in Fortran. It uses Fortran so that it can run fast, but this makes it hard to add features if you do not (or even if you do) know Fortran. We have written a Python interface to FV3GFS that lets you import the Fortran model as a Python package. We show examples of how this is used to write “model” scripts, which reproduce or build on what the Fortran model can do. You could do this same wrapping for any compiled model, not just FV3GFS.

Invited perspectives: The ECMWF strategy 2021–2030 challenges in the area of natural hazards

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-21-2163-2021
23 August 2021

The European Centre for Medium-Range Weather Forecasts mission is to deliver high-quality global medium‐range (3–15 d ahead of time) weather forecasts and monitoring of the Earth system. We have published a new strategy, and in this paper we discuss what this means for forecasting and monitoring natural hazards.

Nonstationary weather and water extremes: a review of methods for their detection, attribution, and management

Weather and water extremes have devastating effects each year. One of the principal challenges for society is understanding how extremes are likely to evolve under the influence of changes in climate, land cover, and other human impacts. This paper provides a review of the methods and challenges associated with the detection, attribution, management, and projection of nonstationary weather and water extremes.

Thaw-driven mass wasting couples slopes with downstream systems, and effects propagate through Arctic drainage networks

Climate-driven landslides are transforming glacially conditioned permafrost terrain, coupling slopes with aquatic systems, and triggering a cascade of downstream effects. Nonlinear intensification of thawing slopes is primarily affecting headwater systems where slope sediment yields overwhelm stream transport capacity. The propagation of effects across watershed scales indicates that western Arctic Canada will be an interconnected hotspot of thaw-driven change through the coming millennia.