Improvements in Sub-Catchment Fractional Snowpack and Snowmelt Parameterizations and Hydrologic Modeling for Climate Change Assessments in the Western Himalayas

The present work proposes to improve estimates of snowpack and snowmelt and their assessment in the steep Himalayan ranges at the sub-catchment scale. Temporal variability of streamflow and the associated distribution of accumulated snow in catchments with glacier presence in the Himalayas illustrates how changes in snowpack and snowmelt can affect the water supply for local water management. The primary objective of this study is to assess the role of elevation, temperature lapse rate (TLR), and precipitation lapse rate (PLR) in the computation of snowpack (or snowfall) and snowmelt in sub-catchments of the Satluj River basin. Modeling of snowpack and snowmelt was constructed using the Soil Water Assessment Tool (SWAT) in both historical (1991–2008) and near-time scenarios (2011–2030) by implementing real-time hydrometeorological, snow-hydrological parameters, and Global Circulation Model (GCM) datasets. The modeled snowmelt-induced streamflow showed a good agreement with the observed streamflow (~60%), calibrated and validated at three gauges. A Sequential Uncertainty Parameter Fitting (SUFI2) method (SUFI2) resulted that the curve number (CN2) was found to be significantly sensitive during calibration. The snowmelt hydrological parameters such as snowmelt factor maximum (SMFMX) and snow coverage (SNO50COV) significantly affected objective functions, such as R2 and NSE, during the model optimization. For the validation of snowpack and snowmelt, the results have been contrasted with previous studies and found comparable. The computed snowpack and snowmelt were found highly variable over the Himalayan sub-catchments, as also reported by previous researchers. The magnitude of snowpack change consistently decreases across all the sub-catchments of the Satluj river catchment (varying between 4% and 42%). The highest percentage of changes in the snowpack was observed over high-elevation sub-catchments.

Advance forecasting of cyclone track over north Indian Ocean using a global circulation model

& m".kdfVca/kh; pØokr lewps fo’o esa vf/kdka’k rVorhZ {ks=ksa esa xaHkhj vkSj fodjky Mj mRiUu djrs jgrs gSaA blfy, m".kdfVca/kh; pØokrksa ds laca/k esa vf/kd lVhd vkSj yEch vof/k ds iwokZuqeku dh ek¡x c<+rh tk jgh gSA ;|fi dkQh le; ls lhfer {ks= fun’kZ ¼,y- ,- ,e-½ m".kdfVca/kh; pØokrksa ds xfrdh; iwokZuqeku ds fy, ijEijkxr lk/ku jgs gSa fQj Hkh bl ckr ls Hkh badkj ugh fd;k tk ldrk gS fd pØokrksa dh xfrdh; izÑfr ds izLrqrhdj.k esa HkweaMyh; ifjlapj.k fun’kkZsa ¼th- lh- ,e-½ ds mi;ksx ds Qy Lo:Ik dkQh lq/kkj vk;k gSA mnkgj.k ds fy, caxky dh [kkM+h ds dqN pØokr rks caxky dh [kkM+h esa gh fodflr gksrs gSa fdarq cgqr ls pØokr [kkM+h ds iwoZ dh rjQ cus fuEu nkc {ks= ds l?ku gksus vkSj [kkM+h dh vksj c<+us ds dkj.k curs gSa ftlls ;g Li"V gS fd pØokr ds iwokZuqeku ds fy, pØokr ds mRiUu gksus ds foLr`r {ks= dks 'kkfey djus dh vko’;drk gSA bl 'kks/k&i= esa geus crk;k gS fd ,y- ,- ,e- vkSj th- lh- ,e- dh la;qDr fo’ks"krk rqyukRed :Ik ls uohu Js.kh ds HkweaMyh; ekWMyksa ¼th- lh- ,e-½ ls pØokr ds ekxZ vkSj mldh rhozrk tSls dqN vR;ar egRoiw.kZ y{k.kksa ds laca/k eas yEch vof/k ds vkSj vf/kd lVhd rjg ds iwokZuqeku nksuksa miyC/k djk ldrs gSaA lkr pØokrksa ls lacaf/kr fofHkUu LFkkuksa] _rqvksa] o"kZ vkSj mudh rhozrk] izfr:fir ekxksZa vkSj pØokrksa ds ySaMQky ds LFkyksa ds ik¡p fnuksa ls Hkh vf/kd le; igys dh mudh vkjafHkd voLFkkvksa vkSj muds laca/k esa leqnz lrg rkieku ¼,l- ,l- Vh-½ ds ekfld tyok;q foKku ds 48 ?kaVs igys tkjh fd, x, gSaA buesa rkRdkfyd izpkyukRed iwokZuqeku ds leku gh =qfV;k¡ ikbZ xbZ gSaA Tropical cyclones pose a serious and growing threat to many coastal areas world over; there is increasing demand for better accuracy as well as longer range for tropical cyclone forecasts. While the traditional tool for dynamical forecasting of tropical cyclones has been Limited Area Models (LAM), there are reasons to believe that use of Global Circulation Models (GCM) may result in improved representation of cyclone dynamics. Over Bay of Bengal, for example, while some cyclones develop in situ, many result from intensification of low pressure system that travel from the east, implying need for consideration of a large domain. We show here that a relatively new class of Global Circulation Models (GCM), combining the advantages of LAMs and GCMs, can provide both longer range and better accuracy for such critical parameters like track and intensity. For seven cyclones representing different locations, seasons, years and strength, simulated tracks and land-fall locations show, with initial condition more than 5 days ahead and only monthly climatology of sea surface temperature (SST), errors comparable to those from current operational forecast 48 hours in advance.

Latent negative precipitation for the delineation of a zero-precipitation area in spatial interpolations

The spatial interpolation of precipitation has been employed in a number of fields, including by spatially downscaling the Global Circulation Model (GCM) to a finer scale. Most precipitation events become more sporadic when the coverage area increases (i.e., a portion of the points experience zero precipitation). However, spatial interpolations of precipitation generally ignore these dry areas, and the interpolated grids are filled with certain precipitation amounts. Subsequently, no delineation of dry and wet regions can be made. Therefore, the current study suggested a novel approach to determine dry areas in spatial interpolations of precipitation events by assigning latent negative precipitation (LNP) to points with observed precipitation values of zero. The LNP-assigned points are then employed in a spatial interpolation. After that, the dry region can be determined using the negative region (i.e., points with zero precipitation). The magnitude of LNP can be defined by multiplying the precipitation values of neighboring stations by a tuning parameter. The LNP method and the tuning parameter are tested on weather stations covering South Korea. The results indicate that the proposed LNP method can be suitable for the spatial interpolation of precipitation events by delineating dry and wet regions. Additionally, the tuning parameter plays a special role in that it increases in value with longer precipitation durations and denser networks. A value of 0.5–1.5 can be suggested for the tuning parameter as a rule of thumb when high accuracy for final products of interpolated precipitation is not critical. For future studies, the LNP model derived herein can be tested over much larger areas, such as the United States, and the model can also be easily adopted for other variables with spatially sporadic values.

Polar tongue of ionisation during geomagnetic superstorm

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.

A global model of meteoric metals in the atmosphere of Mars

&lt;p&gt;Here we report a global model of meteoric metals including Mg, Fe and Na in the Laboratoire de M&amp;#233;t&amp;#233;orologie Dynamique (LMD) Mars global circulation model (termed as LMD-Mars-Metals), following on similar work as we have done for the Earth&amp;#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&lt;sup&gt;-8&lt;/sup&gt; 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 CO&lt;sub&gt;2&lt;/sub&gt; 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 CO&lt;sub&gt;2&lt;/sub&gt; 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&lt;sup&gt;+&lt;/sup&gt; observations from IUVS (Imaging UV Spectrometer) and NGIMS (Neutral Gas Ion Mass Spectrometer) instruments on NASA&amp;#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. &amp;#160;&lt;/p&gt;

Exploring the formation of the Arsia Mons Elongated Cloud on Mars

&lt;p&gt;In a recently published paper, we reported the existence and properties of the Arsia Mons Elongated Cloud (AMEC; Hern&amp;#225;ndez-Bernal et al., 2021). We are now exploring models for the theoretical understanding of this outstanding phenomenon.&lt;/p&gt; &lt;p&gt;The AMEC forms at sunrise over the western slope of the Arsia Mons volcano, and for ~3 hours expands to the west following zonal winds, leaving behind a characteristic white bright tail. This process repeats in a daily cycle for a long season around the southern solstice. According to observations in MY34, the AMEC reaches a length of up to 1800 km, and expands at a velocity of around 170 m/s (~130 m/s in other years) at ~45 km in altitude. In comparison, winds predicted by the Global Circulation Model LMD-MCD are ~60m/s (Millour et al. 2018).&lt;/p&gt; &lt;p&gt;The cloud is clearly driven by upward winds forced by the topography of the volcano. We are analysing from the theoretical perspective the formation and particular features of this cloud.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt; &lt;p&gt;Hern&amp;#225;ndez&amp;#8208;Bernal, J., S&amp;#225;nchez&amp;#8208;Lavega, A., del R&amp;#237;o&amp;#8208;Gaztelurrutia, T., Ravanis, E., Cardes&amp;#237;n&amp;#8208;Moinelo, A., Connour, K., ... &amp; Hauber, E. (2021). An extremely elongated cloud over Arsia Mons volcano on Mars: I. Life cycle. &lt;em&gt;Journal of Geophysical Research: Planets&lt;/em&gt;, &lt;em&gt;126&lt;/em&gt;(3), e2020JE006517.&lt;/p&gt; &lt;p&gt;Millour, E., F. Forget,A. Spiga, et al.&amp;#160; &quot;Mars climate database. (Version 5.3)&quot; From Mars Express to ExoMars (2018)&lt;/p&gt;

Synergistic studies enhanced through data assimilation: combining multiple retrievals with a Mars Global Circulation Model

&lt;div&gt; &lt;p&gt;&lt;span data-contrast=&quot;auto&quot;&gt;The wealth of observations now available from multiple spacecraft in orbit around Mars and rovers/landers on the surface provides information on several aspects of the atmosphere, although they are restricted in space and time. Most of the observational datasets are largely complementary, so an efficient method to combine them in a physically consistent way will lead to more constrained studies of the evolution of the global martian atmosphere. Data assimilation is one such method, combining multiple retrievals with a Mars Global Circulation Model (GCM) while accounting for errors in both sources of information and producing an optimal representation of the evolving martian surface and atmosphere. Data assimilation is a powerful tool in that multiple parameters each observed independently by different instruments (e.g. water vapour, ozone, carbon monoxide, dust opacity, temperature) are all realistically constrained and physically consistent at the same time, and unobserved parameters can also be influenced by assimilated data (e.g. water vapour assimilation will impact on the water ice distribution). It also allows for study of atmospheric features that change significantly between observations and identifying processes that lead to the observed changes.&lt;/span&gt;&lt;span data-ccp-props=&quot;{&amp;quot;335551550&amp;quot;:6,&amp;quot;335551620&amp;quot;:6}&quot;&gt;&amp;#160;&lt;/span&gt;&lt;/p&gt; &lt;/div&gt; &lt;div&gt; &lt;p&gt;&lt;span data-contrast=&quot;auto&quot;&gt;Data assimilation studies are prevalent on Earth and are becoming more mainstream for Mars, with several different Mars GCMs now capable of assimilating retrievals using different assimilation schemes. The Open University (OU) ExoMars modelling group Mars GCM has been combined with several retrieval datasets via data assimilation to study features of the ozone, carbon monoxide, water and dust cycles alongside dynamical features such as the polar vortices, surface warming during a global dust storm and planetary waves. OpenMARS (Open access to Mars Assimilated Remote Soundings), a publicly available global reanalysis dataset from 1999-2015, was also created using the OU assimilation system.&lt;/span&gt;&lt;span data-ccp-props=&quot;{&amp;quot;335551550&amp;quot;:6,&amp;quot;335551620&amp;quot;:6}&quot;&gt;&amp;#160;&lt;/span&gt;&lt;/p&gt; &lt;/div&gt; &lt;div&gt; &lt;p&gt;&lt;span data-contrast=&quot;auto&quot;&gt;This talk will give a brief overview of the benefits and limitations of data assimilation for Mars, and will demonstrate how combining retrievals of different atmospheric parameters with a Mars GCM via data assimilation leads to a better constrained analysis of the martian atmosphere than is possible with retrievals or GCMs alone.&lt;/span&gt;&lt;span data-ccp-props=&quot;{&amp;quot;335551550&amp;quot;:6,&amp;quot;335551620&amp;quot;:6}&quot;&gt;&amp;#160;&lt;/span&gt;&lt;/p&gt; &lt;/div&gt;

Impact of Climate Change on Some Agricultural Crops Distribution and Productivity in Georgia

Under the increase of the concern for food security in the world, mainly caused by water resources shortages, the forecast and determination of crop yield at regional scale has been considered as a strategic topic. This study has been conducted to assess the possible impacts of the climate change on cereal crops productivity and irrigation requirement for two main producing regions of Georgia, according to the current crop pattern, and for the 2050s periods. With this aim, water-driven FAO-AquaCrop model has been used. Furthermore, ongoing and forecasted changes, up to the end of the century, in agro-climatic zones relevant for cereals production have been assessed. The climate change data was generated for RCP4.5 scenario through the global circulation model ECHAM4.1, dynamically downscaled on the region via regional climate model (RegCM4.1). Results show overall increase in cereal crop yields, but also enhancement in water shortages even considering optimum management practices under rainfed conditions. Based on the results obtained, recommendations have been developed for adaptation measures to the climate change for the Georgia Agriculture sector.

Polar tongue of ionisation during geomagnetic superstorm

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 mid-latitude SED anomaly. It is suggested that better representation of the high-latitude plasma convection is needed. The results are discussed in the context of space weather modelling.

Simulating effects of the 774 AD solar proton event on atmospheric electricity

&lt;p&gt;High energy cosmic rays of galactic and solar origin, natural radioactivity, lighting in thunderstorms and electrified shower clouds, produce ion clusters and charge the whole atmosphere causing a ubiquitous potential difference between the ionosphere and the surface. This Global Electric Circuit (GEC) allows the flow of charges to the surface in the fair-weather regions of the globe. Here, we simulate the effect of highly energetic particle radiation, in particular the 774 AD solar proton event, on the GEC with the aid of the global circulation model EMAC/MESSy. The simulations assume pre-industrial atmospheric conditions and the coupling of aerosol and atmospheric electricity schemes allows for ion-ion and ion-aerosol capture reactions. We discuss effects in fair weather current and atmospheric conductivity at different latitudinal bands. &lt;/p&gt;