A life cycle perspective of the climate forcing from black carbon emissions of Starship and Falcon 9 launchers

The Earth is currently experiencing a significant growth of the space industry resulting from the introduction of cheaper reusable launch vehicles and broad range of new space applications. In parallel, the world is experiencing a severe climate crisis as a result of land use practices and anthropogenic emissions of greenhouse gases (GHG) and aerosols such as black carbon (BC). As a key component of the global economy and the only human activity emitting in all atmospheric layers, the space industry is at an inflexion point where it could become a significant driver of global climate change, or a unique tool to help the world understand, adapt or even de-carbonize the energy system. BC emissions from spaceflight activities have been analyzed in the past with General Circulation Models (GCMs) showing potentially significant radiative forcing in the stratosphere. Given the potential significant growth in intense space activities made possible by heavy launchers (as Starship), it is important to further assess these emissions within a life-cycle perspective, merging with the developments within the space based Life Cycle Assessment(LCA) communities to further understand its role in future climate change, identify the suitability of different launch vehicle technologies and enable a sustainable design of spacecrafts which considers the associated impacts in the high atmosphere. This study firstly derived GWP like metrics from black carbon and other rocket exhaust emissions in the stratosphere from past literature studies, which can be used to compare the climate change impacts of BC emissions with life cycle CO2 emissions within an LCA process. After it, the BC exhaust emission profiles from different launch scenarios with Starship and Falcon 9 vehicles were obtained with an empirical plume post-combustion model, showing a peak in emissions both for ascent and return at around 50 km of altitude, in contrast with past studies. These results were then used within the asteroidImpact GCM model to explore the potential climate forcing signature identified in past studies. Nevertheless, no significant impact was obtained, which might be a consequence of different modelling parameters as the assumed emission altitudes, pulse emission scenario, particle size distribution, and reflectivity properties. These results can be augmented with future studies on the atmospheric perturbations of different propulsive technologies, as those resulting from stratospheric water emissions, NOx and induced cloudiness. The metric derivation process may be extended for stratospheric ozone loss from emitted launch vehicle species for the successful development of an LCA process for space transportation which can ensure eco-design while preventing burden shifting

Toward More Realistic Simulation and Prediction of Dust Storms on Mars

Global dust storms have major implications for the past and present climate, geologic history, habitability, and future exploration of Mars. Yet their mysterious origins mean we remain unable to realistically simulate or predict them. We identify four key Knowledge Gaps and make four Recommendations to make progress in the next decade

Coupled WRF-OpenFOAM study of wind flow over complex terrain

peer reviewedA search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets

Atmospheric transport of subsurface, sporadic, time-varying methane releases on Mars

This study is devoted to the general circulation modeling (GCM) of methane transport in the Martian atmosphere. A localized source originating from a near-subsurface methane reservoir is considered in the GCM simulations, which are performed with a modified version of the Weather Research and Forecasting (WRF) model, MarsWRF. The localized strength of a methane source varies with time, based on a 1-D near-subsurface diffusive transport. Time-varying surface release scenarios are also compared with an instantaneous release scenario. After release from the surface, the methane transport is investigated in the GCM as a passive scalar over time scales varying between 15 and 60 days, much shorter than the photochemical lifetime. Different emission scenarios of various duration and source intensity, as well as multiple locations with different elevation and terrain complexity are considered, to reproduce the substantial concentrations of methane (up to 50 ppb) observed in the northern hemisphere of Mars in 2003 (Mumma et al., 2009). Among the scenarios considered, the observations are reproduced best for an emission scenario of 45 sols duration, during which a total amount of about 90,000 metric tons of methane is released. The results reveal that observed Mars methane plumes in the northern hemisphere of Mars by Mumma et al. (2009) can be reproduced using a localized, time-varying methane source, consistent with a near surface methane reservoir

Spectral analysis of the Martian atmospheric turbulence: InSight observations

In this study, we perform a detailed spectral analysis of the turbulent energy cascade using the in-situ observations by NASA's InSight lander on Mars. A recent study on the daytime Martian boundary layer using the InSight observations showed that the conventional Kolmogorov energy cascade of inertial sub-range fails to predict the spectral density of pressure. Here we extend this by investigating diurnal and seasonal variations in the spectral density of pressure, as the indicator of the Martian atmospheric turbulence. We show distinct spectral behaviours for the daytime and nighttime conditions. Moreover, we report the important effects of regional dust storms, gravity waves, bore and solitary waves on the turbulent energy cascade. Our results show that the presence of a dust storm and gravity wave activity can enhance the turbulence of the nighttime boundary layer of Mars despite the extreme stably stratified conditions compared to the terrestrial case