A global model of meteoric metals in the atmosphere of Mars

Here we report a global model of meteoric metals including Mg, Fe and Na in the Laboratoire de M&#233;t&#233;orologie Dynamique (LMD) Mars global circulation model (termed as LMD-Mars-Metals), following on similar work as we have done for the Earth&#8217;s atmosphere. The model has been developed by combining three components: the state-of-the-art LMD-Mars model covering the whole atmosphere from the surface to the upper thermosphere (up to ~ 2 x10-8 Pa or 240 km), a description of the neutral and ion-molecule chemistry of Mg, Fe and Na in the Martian atmosphere (where the high CO2 abundance produces a rather different chemistry from the terrestrial atmosphere), and a treatment of injection of the metals into the atmosphere as a result of the ablation of cosmic dust particles. The LMD-Mars model contains a detailed treatment of atmospheric physics, dynamics and chemistry from the lower atmosphere to the ionosphere. The model also includes molecular diffusion and considers the chemistry of the C, O, H and N families and major photochemical ion species in the upper atmosphere, as well as improved treatments of the day-to-day variability of the UV solar flux and 15 mm CO2 cooling under non-local thermodynamic equilibrium conditions. So far, we have incorporated the chemistries of Mg, Fe and Na into LMD-Mars because these metals have different chemistries which control the characteristic features of their ionized and neutral layers in the Martian atmosphere. The Mg chemistry has 4 neutral and 6 ionized Mg-containing species, connected by 25 neutral and ion-molecule reactions. The corresponding Fe chemistry has 39 reactions with 14 Fe-containing species. Na chemistry has 7 neutral and only 2 ionized Na-containing species, with 32 reactions. The injection rate of these metals as a function of height is pre-calculated from the Leeds Chemical Ablation Model (CABMOD) combined with an astronomical model which predicts the dust from Jupiter Family and Long Period comets, as well as the asteroid belt, in the inner solar system. The LMD-Mars-Metals model has been run for several full Martian years under different surface dust scenarios to investigate the impact of high atmospheric dust loadings on the modelled metal layers. The model has been evaluated against Mg+ observations from IUVS (Imaging UV Spectrometer) and NGIMS (Neutral Gas Ion Mass Spectrometer) instruments on NASA&#8217;s Mars Atmosphere and Volatile Evolution Mission (MAVEN) spacecraft. We have also carried out other sensitivity experiments with different seasonality/altitude/latitudinal varying of Meteoric Input Function (MIF) of these metals in the model. These sensitivity results will be discussed. &#160;

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Impact of gradients at the Martian terminator on the retrieval of ozone from TGO/NOMAD-UVIS

10.5194/epsc2020-670 ◽

2020 ◽

Author(s):

Arianna Piccialli ◽

Ann Carine Vandaele ◽

Yannick Willame ◽

Shohei Aoki ◽

Cedric Depiesse ◽

...

Keyword(s):

Radiative Transfer ◽

Circulation Model ◽

Atmospheric Composition ◽

Global Circulation Model ◽

Model Calculations ◽

Global Circulation ◽

Retrieval Technique ◽

Solar Occultation ◽

Composition And Structure ◽

The Impact

1. IntroductionRapid variations in species concentration at the terminator have the potential to cause asymmetries in the species distributions along the line of sight (LOS) of a solar occultation experiment. Ozone, in particular, displays steep gradients across the terminator of Mars due to photolysis [1]. Nowadays, most of the retrieval algorithms for solar and stellar occultations rely on the assumption of a spherically symmetrical atmosphere. However, photochemically induced variations near sunrise/sunset conditions need to be taken into account in the retrieval process in order to prevent inaccuracies.Here, we investigated the impact of gradients along the LOS of the solar occultation experiment TGO/NOMAD-UVIS for the retrieval of ozone under sunrise/sunset conditions. We used the diurnal variations in the ozone concentration obtained from photochemical model calculations together with an adapted radiative transfer code.2. The NOMAD UVIS channelNOMAD is a spectrometer composed of 3 channels: 1) a solar occultation channel (SO) operating in the infrared (2.3-4.3 &#956;m); 2) a second infrared channel LNO (2.3-3.8 &#956;m) capable of doing nadir, as well as solar occultation and limb; and 3) an ultraviolet/visible channel UVIS (200-650 nm) that can work in the three observation modes [2,3].The UVIS channel has a spectral resolution <1.5 nm. In the solar occultation mode it is mainly devoted to study the climatology of ozone and aerosols content [4].Since the beginning of operations, on 21 April 2018, NOMAD UVIS acquired more than 3000 solar occultations with an almost complete coverage of the planet.3. Retrieval techniqueNOMAD-UVIS spectra are simulated using the line-by-line radiative transfer code ASIMUT-ALVL developed at IASB-BIRA [5]. In a preliminary study based on SPICAM-UV solar occultations (see [6]), ASIMUT was modified to take into account the atmospheric composition and structure at the day-night terminator. As input for ASIMUT, we used gradients predicted by the 3D GEM-Mars v4 Global Circulation Model (GCM) [7,8]. UVIS ozone profiles will also be compared to SPICAM-UV retrievals. 4. Summary and future workWe will present ozone vertical profiles retrieved from the first Martian year of observations from TGO/NOMAD-UVIS. In addition, we plan to compare our retrievals to SPICAM-UV observations. As first step, we will retrieve O3 profiles without taking in account gradients. Then, we will investigate the effects of ozone density gradients on the retrieval of ozone.References[1] Lef&#232;vre, F., Bertaux, J.L., Clancy, R. T., Encrenaz, T., Fast, K., Forget, F., Lebonnois, S., Montmessin, F., Perrier, S., Aug. 2008. Heterogeneous chemistry in the atmosphere of Mars. Nature 454, 971&#8211;975.[2] Vandaele, A.C., et al., Planetary and Space Science, Vol. 119, pp. 233&#8211;249, 2015.[3] Neefs, E., et al., Applied Optics, Vol. 54 (28), pp. 8494-8520, 2015.[4] M.R. Patel et al., In: Appl. Opt. 56.10 (2017), pp. 2771&#8211;2782. DOI: 10.1364/AO.56.002771.[5] Vandaele, A.C., et al., JGR, 2008. 113 doi:10.1029/2008JE003140.[6] Piccialli, A., Icarus, 2019, [7] Neary, L., and F. Daerden (2018), Icarus, 300, 458&#8211;476, doi:10.1016/j.icarus.2017.09.028.[8] Daerden et al., 2019, Icarus 326, https://doi.org/10.1016/j.icarus.2019.02.030 How to cite: Piccialli, A., Vandaele, A. C., Willame, Y., Aoki, S., Depiesse, C., Trompet, L., Neary, L., Viscardy, S., Daerden, F., Erwin, J., Thomas, I. R., Ristic, B., Mason, J. P., Patel, M., Bellucci, G., and Lopez-Moreno, J.-J.: Impact of gradients at the Martian terminator on the retrieval of ozone from TGO/NOMAD-UVIS, Europlanet Science Congress 2020, online, 21 September&#8211;9 Oct 2020, EPSC2020-670, 2020

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Gravity wave drag in a global circulation model of the Martian atmosphere: Parameterisation and validation

Advances in Space Research ◽

10.1016/s0273-1177(97)00277-9 ◽

1997 ◽

Vol 19 (8) ◽

pp. 1245-1254 ◽

Cited By ~ 20

Author(s):

M. Collins ◽

S.R. Lewis ◽

P.L. Read

Keyword(s):

Gravity Wave ◽

Circulation Model ◽

Martian Atmosphere ◽

Wave Drag ◽

Global Circulation Model ◽

Global Circulation

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Runoff trends analysis and future projections of hydrological patterns in small forested catchments

Soil and Water Research ◽

10.17221/110/2013-swr ◽

2014 ◽

Vol 9 (No. 4) ◽

pp. 169-181 ◽

Cited By ~ 7

Author(s):

A. Lamačová ◽

J. Hruška ◽

P. Krám ◽

E. Stuchlík ◽

A. Farda ◽

...

Keyword(s):

Climate Change ◽

Climate Model ◽

Regional Climate ◽

Circulation Model ◽

Monitoring Network ◽

Annual Runoff ◽

Global Circulation Model ◽

Forested Catchments ◽

Ipcc Sres ◽

The Impact

The aims of the present study were (i) to evaluate trends in runoff from small forested catchments of the GEOMON (GEOchemical MONitoring) network during the period 1994–2011, and (ii) to estimate the impact of anticipated climate change projected by ALADIN-Climate/CZ regional climate model coupled to ARPEGE-Climate global circulation model and forced with IPCC SRES A1B emission scenario on flow patterns in the periods 2021–2050 and 2071–2100. There were no general patterns found indicating either significant increases or decreases in runoff on either seasonal or annual levels across the investigated catchments within 1994–2011. Annual runoff is projected to decrease by 15% (2021–2050) and 35% (2071–2100) with a significant decrease in summer months and a slight increase in winter months as a result of expected climate change as simulated by the selected climate model.

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Mutual Interference of Local Gravity Wave Forcings in the Stratosphere

Atmosphere ◽

10.3390/atmos11111249 ◽

2020 ◽

Vol 11 (11) ◽

pp. 1249

Author(s):

Nadja Samtleben ◽

Aleš Kuchař ◽

Petr Šácha ◽

Petr Pišoft ◽

Christoph Jacobi

Keyword(s):

Gravity Wave ◽

Rocky Mountains ◽

Middle Atmosphere ◽

East Asian ◽

Polar Vortex ◽

Circulation Model ◽

Global Circulation Model ◽

Mean Flow ◽

Destructive Effect ◽

The Impact

Gravity wave (GW) breaking and associated GW drag is not uniformly distributed among latitudes and longitudes. In particular, regions of enhanced GW breaking, so-called GW hotspots, have been identified, major Northern Hemisphere examples being located above the Rocky Mountains, the Himalayas and the East Asian region. These hotspots influence the middle atmosphere circulation both individually and in combination. Their interference is here examined by performing simulations including (i) the respective single GW hotspots, (ii) two GW hotspots, and (iii) all three GW hotspots with a simplified global circulation model. The combined GW hotspots lead to a modification of the polar vortex in connection with a zonal mean flow decrease and an increase of the temperature at higher latitudes. The different combinations of GW hotspots mainly prevent the stationary planetary wave (SPW) 1 from propagating upward at midlatitudes leading to a decrease in energy and momentum transfer in the middle atmosphere caused by breaking SPW 1, and in turn to an acceleration of the zonal mean flow at lower latitudes. In contrast, the GW hotspot above the Rocky Mountains alone causes an increase in SPW 1 amplitude and Eliassen–Palm flux (EP flux), inducing enhanced negative EP divergence, decelerating the zonal mean flow at higher latitudes. Consequently, none of the combinations of different GW hotspots is comparable to the impact of the Rocky Mountains GW hotspot alone. The reason is that the GW hotspots mostly interfere nonlinearly. Depending on the longitudinal distance between two GW hotspots, the interference between the combined Rocky Mountains and East Asian GW hotspots is more additive than the interference between the combined Rocky Mountains and Himalaya GW hotspots. While the Rocky Mountains and the East Asian GW hotspots are longitudinally displaced by 105°, the Rocky Mountains are shifted by 170° to the Himalayas. Moreover, while the East Asian and the Himalayas are located side by side, the interference between these GW hotspots is the most nonlinear because they are latitudinally displaced by 20°. In general, the SPW activity, e.g., represented in SPW amplitudes, EP flux or Plumb flux, is strongly reduced, when the GW hotspots are interacting with each other. Thus, the interfering GW hotspots mostly have a destructive effect on SPW propagation and generation.

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Coupling a multi-layered snow model with a GCM

Annals of Glaciology ◽

10.3189/s0260305500013811 ◽

1997 ◽

Vol 25 ◽

pp. 66-72 ◽

Cited By ~ 25

Author(s):

Eric Brun ◽

Eric Martin ◽

Valery Spiridonov

Keyword(s):

Snow Cover ◽

Circulation Model ◽

Surface Fluxes ◽

Coupling Scheme ◽

Global Circulation Model ◽

Time Step ◽

Global Circulation ◽

Climate Simulations ◽

Snow Model ◽

The Impact

A multi-layered snow model, including most physical processes governing the evolution of snowpacks, has been coupled to a global circulation model (GCM) to improve the representation of snow cover in climate simulations. The snow model (Crocus) includes original features to simulate the evolution of snowpack layering that allows a realistic calculation of snow albedo as a function of the type and size of the crystals of the surface layer. The coupling scheme is based on a synchronous run of the GCM and of the snow model with an exchange of the surface fluxes at every time-step. It was tested in a five-year run at a T42 resolution. The impact on the atmosphere was important over most snow-covered regions and the snowpacks simulated in the different regions present a layering that is realistic and very variable in connection with the climate. The simulated snow cover compares satisfactorily with the present snow climatology.

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A global circulation model for the asteroid impact simulations

10.5194/egusphere-egu2020-10832 ◽

2020 ◽

Author(s):

Hakan Sert ◽

Orkun Temel ◽

Cem Berk Senel ◽

Ozgur Karatekin

Keyword(s):

Ocean Circulation ◽

Three Dimensional ◽

Circulation Model ◽

Co2 Concentration ◽

Atmospheric Model ◽

Global Circulation Model ◽

Asteroid Impact ◽

Global Circulation ◽

Impact Simulations ◽

The Impact

In this study, we present a three-dimensional global circulation model (GCM) to investigate the environmental effects of an asteroid impact on the global Earth system. The model is applied to model the atmospheric response of the Cretaceous&#8211;Paleogene (K&#8211;Pg) extinction event which took place 66 million years ago and resulted in the mass extinction of various animal and plant species. The atmospheric model is developed based on the planetWRF model. First, the paleoclimate model is validated using the proxy data. Then, the sensitivity to atmospheric co2 concentration is investigated. The radiation parameterization scheme of the planetWRF model is modified to include the effect of various climate-active aerosols and gases released after the impact event. The model is also coupled both to a simple one-dimensional ocean mixed layer and a three-dimensional ocean circulation model. Both the atmospheric and oceanic response is investigated.

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Assessing the impact of Laurentide Ice Sheet topography on glacial climate

Climate of the Past ◽

10.5194/cp-10-487-2014 ◽

2014 ◽

Vol 10 (2) ◽

pp. 487-507 ◽

Cited By ~ 56

Author(s):

D. J. Ullman ◽

A. N. LeGrande ◽

A. E. Carlson ◽

F. S. Anslow ◽

J. M. Licciardi

Keyword(s):

Boundary Condition ◽

Boundary Conditions ◽

Ice Sheet ◽

Circulation Model ◽

Meridional Overturning Circulation ◽

Laurentide Ice Sheet ◽

Global Circulation Model ◽

Northeastern Asia ◽

The Impact ◽

Ice Sheet Topography

Abstract. Simulations of past climates require altered boundary conditions to account for known shifts in the Earth system. For the Last Glacial Maximum (LGM) and subsequent deglaciation, the existence of large Northern Hemisphere ice sheets caused profound changes in surface topography and albedo. While ice-sheet extent is fairly well known, numerous conflicting reconstructions of ice-sheet topography suggest that precision in this boundary condition is lacking. Here we use a high-resolution and oxygen-isotope-enabled fully coupled global circulation model (GCM) (GISS ModelE2-R), along with two different reconstructions of the Laurentide Ice Sheet (LIS) that provide maximum and minimum estimates of LIS elevation, to assess the range of climate variability in response to uncertainty in this boundary condition. We present this comparison at two equilibrium time slices: the LGM, when differences in ice-sheet topography are maximized, and 14 ka, when differences in maximum ice-sheet height are smaller but still exist. Overall, we find significant differences in the climate response to LIS topography, with the larger LIS resulting in enhanced Atlantic Meridional Overturning Circulation and warmer surface air temperatures, particularly over northeastern Asia and the North Pacific. These up- and downstream effects are associated with differences in the development of planetary waves in the upper atmosphere, with the larger LIS resulting in a weaker trough over northeastern Asia that leads to the warmer temperatures and decreased albedo from snow and sea-ice cover. Differences between the 14 ka simulations are similar in spatial extent but smaller in magnitude, suggesting that climate is responding primarily to the larger difference in maximum LIS elevation in the LGM simulations. These results suggest that such uncertainty in ice-sheet boundary conditions alone may significantly impact the results of paleoclimate simulations and their ability to successfully simulate past climates, with implications for estimating climate sensitivity to greenhouse gas forcing utilizing past climate states.

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Changes of Early Summer Precipitation in the Korean Peninsula and Nearby Regions Based on RCP Simulations

Journal of Climate ◽

10.1175/jcli-d-14-00504.1 ◽

2015 ◽

Vol 28 (9) ◽

pp. 3557-3578 ◽

Cited By ~ 22

Author(s):

Ja-Young Hong ◽

Joong-Bae Ahn

Keyword(s):

Korean Peninsula ◽

Large Scale ◽

Climate Model ◽

Circulation Model ◽

Regional Model ◽

Horizontal Resolution ◽

Early Summer ◽

Lower Atmosphere ◽

Convective Precipitation ◽

Global Circulation Model

Abstract In this study, the projected regional precipitation changes over northeast Asia (NEA) during early summer [May–July (MJJ)] for the late twenty-first century (2071–2100) were investigated using a high-resolution regional climate model (WRF3.4) based on the representative concentration pathways (RCPs) induced by the global circulation model (HadGEM2-AO). The increased horizontal resolution of the regional model with a 12.5-km horizontal resolution enabled it to reproduce the terrain-following features reasonably well compared to low-resolution reanalysis and HadGEM2-AO model data. The results of a regionally downscaled historical (1981–2010) experiment (D_Historical) demonstrated the model’s ability to capture the spatial and temporal variations of rainband migrating meridionally during MJJ over NEA. According to the regional model projection, intensive precipitation will increase and the rainband will affect the Korean Peninsula approximately 10 days earlier than in the D_Historical cases in both RCP4.5 and RCP8.5 (2071–2100). The precipitation will also increase in most of the domain, particularly in the southern Korean Peninsula and Kyushu, Japan. These increases in precipitation are attributed to increases in the northward moist transport coming from the lower latitudes and moist static instability in the lower atmosphere. According to this study, the convective precipitation contributes mainly to the increase in total precipitation. On the other hand, the large-scale nonconvective precipitation related to the stationary front will not change significantly but even tends to decrease approximately from the middle of July. The extreme precipitation intensity is also projected to increase by at least 22% (38%) in RCP4.5 (RCP8.5).

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Polar tongue of ionisation during geomagnetic superstorm

Annales Geophysicae ◽

10.5194/angeo-39-833-2021 ◽

2021 ◽

Vol 39 (5) ◽

pp. 833-847

Author(s):

Dimitry Pokhotelov ◽

Isabel Fernandez-Gomez ◽

Claudia Borries

Keyword(s):

High Latitude ◽

Geomagnetic Storms ◽

Circulation Model ◽

Convection Flow ◽

Electron Content ◽

Global Circulation Model ◽

Plasma Convection ◽

Total Electron ◽

Ionospheric Plasma Density ◽

The Impact

Abstract. During the main phase of geomagnetic storms, large positive ionospheric plasma density anomalies arise at middle and polar latitudes. A prominent example is the tongue of ionisation (TOI), which extends poleward from the dayside storm-enhanced density (SED) anomaly, often crossing the polar cap and streaming with the plasma convection flow into the nightside ionosphere. A fragmentation of the TOI anomaly contributes to the formation of polar plasma patches partially responsible for the scintillations of satellite positioning signals at high latitudes. To investigate this intense plasma anomaly, numerical simulations of plasma and neutral dynamics during the geomagnetic superstorm of 20 November 2003 are performed using the Thermosphere Ionosphere Electrodynamics Global Circulation Model (TIE-GCM) coupled with the statistical parameterisation of high-latitude plasma convection. The simulation results reproduce the TOI features consistently with observations of total electron content and with the results of ionospheric tomography, published previously by the authors. It is demonstrated that the fast plasma uplift, due to the electric plasma convection expanded to subauroral mid-latitudes, serves as a primary feeding mechanism for the TOI anomaly, while a complex interplay between electrodynamic and neutral wind transports is shown to contribute to the formation of a mid-latitude SED anomaly. This contrasts with published simulations of relatively smaller geomagnetic storms, where the impact of neutral dynamics on the TOI formation appears more pronounced. It is suggested that better representation of the high-latitude plasma convection during superstorms is needed. The results are discussed in the context of space weather modelling.

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An introduction to stable water isotopes in climate models: benefits of forward proxy modelling for paleoclimatology

Climate of the Past Discussions ◽

10.5194/cpd-5-1697-2009 ◽

2009 ◽

Vol 5 (3) ◽

pp. 1697-1729 ◽

Cited By ~ 4

Author(s):

C. Sturm ◽

Q. Zhang ◽

D. Noone

Keyword(s):

Climate Models ◽

Circulation Model ◽

Sensitivity Study ◽

Water Isotopes ◽

Global Circulation Model ◽

Stable Water Isotopes ◽

Wide Range ◽

Precipitation Seasonality ◽

The Impact ◽

Isotopic Signal

Abstract. Stable water isotopes have been measured in a wide range of climate archives, with the purpose of reconstructing regional climate variations. Yet the common assumption that the isotopic signal is a direct indicator of temperature proves to be misleading under certain circumstances, since its relationship with temperature also depends on e.g. atmospheric circulation and precipitation seasonality. The present article introduces the principles, benefits and caveats of using climate models with embedded water isotopes as a support for the interpretation of isotopic climate archives. A short overview of the limitations of empirical calibrations of isotopic proxy records is presented, with emphasis on the physical processes that infirm its underlying hypotheses. The simulation of climate and its associated isotopic signal, despite difficulties related to downscaling and intrinsic atmospheric variability, can provide a "transfer function" between the isotopic signal and the considered climate variable. The multi-proxy data can then be combined with model output to produce a physically consistent climate reconstruction and its confidence interval. A sensitivity study with the isotope-enabled global circulation model CAM3iso under idealised present-day, pre-industrial and mid-Holocene is presented to illustrate the impact of a changing climate on the isotope-temperature relationship.

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