Community climate simulations to assess avoided impacts in 1.5 and 2 ∘C futures Earth System Dynamics DOI 10.5194/esd-8-827-2017 19 September 2017 We present the results of a set of climate simulations designed to simulate futures in which the Earth’s temperature is stabilized at the levels referred to in the 2015 Paris Agreement. We consider the necessary future emissions reductions and the aspects of extreme weather which differ significantly between the 2 and 1.5 °C climate in the simulations. Read more
Combining ground-based microwave radiometer and the AROME convective scale model through 1DVAR retrievals in complex terrain: an Alpine valley case study Atmospheric Measurement Techniques DOI 10.5194/amt-10-3385-2017 18 September 2017 Microwave radiometers have the capability of observing temperature and humidity profiles with a few minute time resolution. This study investigates the potential benefit of this instrument to improve weather forecasts thanks to a better initialization of the model. Our results show that a significant improvement can be expected in the model initialization in the first 3 km with potential impacts on weather forecasts. Read more
A national-scale seasonal hydrological forecast system: development and evaluation over Britain Hydrology and Earth System Sciences DOI 10.5194/hess-21-4681-2017 15 September 2017 The research presented here provides the first evaluation of the skill of a seasonal hydrological forecast for the UK. The forecast scheme combines rainfall forecasts from the Met Office GloSea5 forecast system with a national-scale hydrological model to provide estimates of river flows 1 to 3 months ahead. The skill in the combined model is assessed for different seasons and regions of Britain, and the analysis indicates that Autumn/Winter flows can be forecast with reasonable confidence. Read more
Astronomical calibration of the Ypresian timescale: implications for seafloor spreading rates and the chaotic behavior of the solar system? Climate of the Past DOI 10.5194/cp-13-1129-2017 11 September 2017 We assembled a very accurate geological timescale from the interval 47.8 to 56.0 million years ago, also known as the Ypresian stage. We used cyclic variations in the data caused by periodic changes in Earthäs orbit around the sun as a metronome for timescale construction. Our new data compilation provides the first geological evidence for chaos in the long-term behavior of planetary orbits in the solar system, as postulated almost 30 years ago, and a possible link to plate tectonics events. Read more
An update on ozone profile trends for the period 2000 to 2016 Atmospheric Chemistry and Physics DOI 10.5194/acp-17-10675-2017 11 September 2017 Thanks to the 1987 Montreal Protocol and its amendments, ozone-depleting chlorine (and bromine) in the stratosphere has declined slowly since the late 1990s. Improved and extended long-term ozone profile observations from satellites and ground-based stations confirm that ozone is responding as expected and has increased by about 2 % per decade since 2000 in the upper stratosphere, around 40 km altitude. At lower altitudes, however, ozone has not changed significantly since 2000. Read more
Extracting real-crack properties from non-linear elastic behaviour of rocks: abundance of cracks with dominating normal compliance and rocks with negative Poisson ratios Nonlinear Processes in Geophysics DOI 10.5194/npg-24-543-2017 5 September 2017 A new method of analysing pressure wave dependences is presented and tested against the published experimental data. Upon the results of examination of more than 90 rock samples, it was found that a significant portion of rocks (~ 45 %) exhibit negative Poisson ratios at lower pressures. Such a significant number of naturally auxetic rocks suggests that the occurrence of negative Poisson ratios is not as exotic as assumed previously. Read more
JRAero: the Japanese Reanalysis for Aerosol v1.0 Geoscientific Model Development DOI 10.5194/gmd-10-3225-2017 4 September 2017 A global aerosol reanalysis product named the Japanese Reanalysis for Aerosol (JRAero) was constructed by the Meteorological Research Institute (MRI) of the Japan Meteorological Agency. The reanalysis employs a global aerosol transport model developed by MRI and a two-dimensional variational data assimilation method. It assimilates maps of aerosol optical depth (AOD) from MODIS onboard the Terra and Aqua satellites every 6 h and has a TL159 horizontal resolution (approximately 1.1° × 1.1°). Read more
The electric current approach in the solar–terrestrial relationship Annales Geophysicae DOI 10.5194/angeo-35-965-2017 21 August 2017 The sequence of phenomena consisting of solar flares, coronal mass ejections (CMEs), auroral substorm, and geomagnetic storms is mostly a manifestation of electromagnetic energy dissipation. Thus, first of all, it is natural to consider each of them in terms of a sequence of power supply (dynamo), power transmission (electric currents/circuits), and dissipation (mostly observed phenomena), i.e., as an input–output process and the electric current line approach. Read more
Simultaneous measurements of new particle formation at 1 s time resolution at a street site and a rooftop site Atmospheric Chemistry and Physics DOI 10.5194/acp-17-9469-2017 8 August 2017 This study reports the distinct effects of street canyons on new particle formation (NPF) under warm or cold ambient temperature conditions because of on-road vehicle emissions; i.e., stronger condensation sinks are responsible for the reduced NPF in the springtime, but efficient nucleation and partitioning of gaseous species contribute to the enhanced NPF in the wintertime. The oxidization of biogenic organics is suggested to play an important role in growing new particles. Read more
Has dyke development in the Vietnamese Mekong Delta shifted flood hazard downstream? Hydrology and Earth System Sciences DOI 10.5194/hess-21-3991-2017 7 August 2017 In this study we provide a numerical quantification of changes in flood hazard in the Vietnamese Mekong Delta as a result of dyke development. Other important drivers to the alteration of delta flood hazard are also investigated, e.g. tidal level. The findings of our study are substantial valuable for the decision makers in Vietnam to develop holistic and harmonized floods and flood-related issues management plan for the whole delta. Read more