توسعه و ارزیابی هسته دینامیکی ناآب‌ایستایی مدل جهانی جوی دانشگاه تهران (NH-UTGAM)

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه فیزیک فضا، مؤسسه ژئوفیزیک، دانشگاه تهران، تهران، ایران.

2 گروه علوم دریایی، دانشکده ناوبری و فرماندهی کشتی، دانشگاه علوم و فنون دریایی امام خمینی نوشهر، نوشهر، ایران.

چکیده

در این مقاله، تغییرات انجام‌شده برای ساخت هسته دینامیکی ناآب‌ایستایی کاملاً تراکم‌پذیر NH-UTGAM ارائه می‌شود. این مدل در واقع توسعه هسته دینامیکی مدل جوی آب‌ایستایی دانشگاه تهران برپایه الگوریتم DCASL است. همچون مدل آب‌ایستایی، مدل جدید از مختصه قائم تعمیم‌یافته بهره می‌برد و با تعریف جدید سیگما برحسب فشار آب‌ایستایی هر دو امکان سیگما-تتا و سیگما-پی را فراهم می‌کند. بنابراین مدل به‌راحتی می‌تواند با کمترین تغییر و با حفظ اصالت خود، در حل معادلات از حالت ناآب‌ایستایی به آب‌ایستایی و به‌عکس تغییر یابد. بدین منظور، در راستای قائم برای مهار انتشار قائم امواج صوتی از روش ضمنی و در راستای افقی از روش صریح استفاده شده است. برای بررسی عملکرد مدل جدید در هر دو مقیاس همدیدی و میانی، پس از ارائه فرمول‌بندی و تغییرات صورت‌گرفته، به‌ترتیب از آزمون‌های آرمانی موج کژفشار یابلونوسکی-ویلیامسون و موج کوهستان استفاده شد. به‌طور کلی، نتایج حاصل از این آزمون‌ها قابل مقایسه با مدل‌های مطرح جهانی بوده و بیانگر درستی عملکرد هسته دینامیکی مدل جدید است. در پایان، با کاربست مجموعه‌ای از طرحواره‌های پارامترسازی فیزیک کامل، مبادرت به ارزیابی مدل ناآب‌ایستایی در یک پیش‌بینی پنج‌روزه وضع هوا شد. مقایسه‌ای با دو مدل جهانی مرجع GFS با تفکیک افقی 5/0 درجه و داده‌های بازتحلیل ERA5 از ECMWF با تفکیک افقی 25/0 درجه نیز انجام شد. عملکرد مدل توسعه‌یافته در مقایسه با مدل‌های مرجع، با درنظر گرفتن تفکیک مکانی به مراتب بالاتر آنها و نیز تنظیمات دقیق­تر موارد فیزیکی مدل همچون لایه مرزی، شارهای تلاطم سطح و همرفت کومه‌ای، قابل قبول است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Development and assessment of the non-hydrostatic dynamical core of the University of Tehran Global Atmospheric Model (NH-UTGAM)

نویسندگان [English]

  • Reza Laghaeizadeh 1
  • Ali Reza Mohebalhojeh 1
  • Farhang Ahmadi-Givi 1
  • Mohammad Mirzaei 1
  • Ali Mohammadi 2
1 Department of Space Physics, Institute of Geophysics, University of Tehran, Tehran, Iran.
2 Department of Marine Sciences, Faculty of Navigation and Ship Command, Imam Khomeini Naval University of Noshahr, Noshahr, Iran.
چکیده [English]

The changes made to build a fully compressible global atmospheric model are presented. The non-hydrostatic dynamical core named NH-UTGAM is based on the atmospheric and hydrostatic model developed by University of Tehran, built on the DCASL algorithm for its dynamical core. The distinct feature of the DCASL algorithm is the simultaneous use of a contour and a grid representation for a potential vorticity (PV) like variable, enabling it to achieve effective resolutions for the PV-like vaiable much higher than that of conventional grid-based algorithms. With the inclusion of non-hydrostatic processes, this model is able to represent scales as small as kilometer in horizontal direction. Like the hydrostatic model, the new model uses the hybrid generalized vertical coordinate, with the definition of sigma in terms of hydrostatic pressure, which provides both the possibility of sigma-theta and sigma-pressure vertical coordinates. Therefore, while maintaining its originality, the model will be able to switch from non-hydrostatic to hydrostatic and vice versa with minimal changes. For this purpose, in the vertical direction, an implicit method is used to suppress the vertical propagation of sound waves, which is combined with an explicit method in the horizontal direction, leading to the HEVI (Horizontally Explicit-Vertically Implicit) scheme. After presenting the formulation and the changes made, as a first assessment, the way the new model works in simulating the evolution of synoptic-scale Rossby waves in mid-latitudes is discussed. This is done through implementation of the (dry) Jablonowski–Williamson baroclinic wave test. The performance of the models constructed are then investigated in the face of meso-scale waves such as the mountain wave. This is done by simulating non-hydrostatic gravity waves through the ideal test of the mountain wave presented in the reference tests of the Dynamical Core Model Intercomparison Project (DCMIP). The results obtained for this test are comparable to those by the world-famous models available and indicate the power of the dynamical core of the new model in the detection and time evolution of meso-scale and non-hydrostatic scale waves. Finally, by using a set of full physics parameterization schemes, the non-hydrostatic model has been evaluated in a five-day weather forecast. The output of the rainfall field as a clear example of the model's performance and rainfall forecast has been compared with the results obtained from the hydrostatic version of the model with similar horizontal and vertical resolution. Comparison with two global reference models has also been carried out: GFS (Global Forecast System) with horizontal resolution of 0.5 degrees and ERA5 reanalysis data from ECMWF (European Centre for Medium Range Weather Forecasts) with horizontal resolution of 0.25 degrees. In general, the performance of the developed UTGAM model is acceptable compared to the reference models given their much higher spatial resolution and more accurate settings related to the physical parametrizations of the model such as the boundary layer, surface turbulence fluxes, and cumulus convection.

کلیدواژه‌ها [English]

  • Non-hydrostatic atmospheric model
  • DCASL algorithm
  • Jablonowski–Williamson baroclinic wave test
  • mountain wave test
  • physical parameterization
Brinkop, S., & Roeckner, E. (1995). Sensitivity of a general circulation model to parameterizations of cloud–turbulence interactions in the atmospheric boundary layer. Tellus A, 47(2), 197–220.
Chen, C., Li, X., Xiao, F., & and Shen, X. (2023). A nonhydrostatic atmospheric dynamical core on cubed sphere using multi-moment finite-volume method. Journal of Computational Physics, 473, 111717.
Dritschel, D. G., & Ambaum, M. H. P. (1997). A contour-advective semi-Lagrangian numerical algorithm for simulating fine-scale conservative dynamical fields. Quarterly Journal of the Royal Meteorological Society, 123, 1097–1130.
Dritschel, D. G., & Ambaum, M. H. P. (2006). The diabatic contour advective semi-Lagrangian model. Monthly Weather Review, 134, 2503–2514.
Dritschel, D. G., Polvan, L. M., & Mohebalhojeh, A. R. (1999). The contour-advective semi-Lagrangian algorithm for the shallow-water equations. Monthly Weather Review, 127, 1551–1565.
Durran, D. R. (2010). Numerical Methods for Fluid Dynamics: With Applications to Geophysics. New York, NY: Springer New York.
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz-Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmons, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., De Chiara, G., Dahlgre, P., Dee, D. P., Diamantakis, M., Dragani, R., Flemming, J., Forbes, R. M., Fuentes, M., Geer, M., Haimberger, L., Healy, S., Hogan, R., Holm, E., Janiskova, M., Keeley, S., Laloyaux, P., Lopez, P., Lupu, C., Radnoti, G., de Rosnay, P., Roznum, I., Vamborg, F., Sebastien, V., & Thépaut, J., (2020). The ERA5 global reanalysis. Quarterly Journal of the Royal Meteorological Society, 146, 1999–2049.
Iacono, M. J., Delamere, J. S., Mlawer, E. J., Clough, S. A., Morcrette, J. J., & Hou, Y. T. (2004). Development and evaluation of RRTMG_SW, a shortwave radiative transfer model for general circulation model applications. In Proceedings of the 14th atmos. radiation measurement (ARM) science team meeting, Albuquerque, New Mexico, March (p. 22–26).
Iacono, M. J., Mlawer, E. J., Clough, S. A., & Morcrette, J. J. (2000). Impact of an improved longwave radiation model, RRTM, on the energy budget and thermodynamic properties of the NCAR community climate model, CCM3. Journal of Geophysical Research: Atmospheres, 105(D11), 14873–14890.‏
Jablonowski, C., & Williamson, D. L. (2006). A baroclinic instability test case for atmospheric model dynamical cores. Quarterly Journal of the Royal Meteorological Society, 132, 2943–2975.
Kaviani, M., Ahmadi-Givi, F., Mohebalhojeh, A. R., & Yazgi, D. (2020). A quantitative assessment of the impact of increase in CO2 concentration on baroclinic instability. In EGU General Assembly Conference Abstracts (p. 682).
Konor, C. S., & Arakawa, A. (1997). Design of an atmospheric model based on a generalized vertical coordinate. Monthly Weather Review, 125, 1649–1673.
Kühnlein, C., Deconinck, W., Klein, R., Malardel, S., Piotrowski, Z. P., Smolarkiewicz, P. K., Szmelter, J., & Wedi, N. P. (2019). FVM 1.0: a nonhydrostatic finite-volume dynamical core for the IFS. Geoscientific Model Development, 12(2), 651–676.
Klemp, J. B., Skamarock, W. C., & Park, S. H. (2015). Idealized global nonhydrostatic atmospheric test cases on a reduced‐radius sphere. Journal of Advances in Modeling Earth Systems, 7(3), 1155–1177.
Klemp, J. B., Skamarock, W. C., & Ha, S. (2018). Damping acoustic modes in compressible horizontally explicit vertically implicit (HEVI) and split-explicit time integration schemes. Monthly Weather Review, 146, 1911–1923.
Laghaeizadeh, R., Joghataei, M., Yazgi, D., & Mohebalhojeh, A. R. (2020). The diabatic contour‐advective semi‐Lagrangian algorithms for the dynamical core of global models in terrain‐following isentropic and pressure vertical coordinates. Quarterly Journal of the Royal Meteorological Society, 146(733), 3715-3728.
Laprise, R. (1992). The Euler equations of motion with hydrostatic pressure as an independent variable. Monthly weather review, 120(1), 197–207.
Lohmann, U., & Roeckner, E. (1996). Design and performance of a new cloud microphysics scheme developed for the ECHAM general circulation model. Climate Dynamics, 12, 557-572.
Mirzaei, M., Mohebalhojeh, A. R., & Ahmadi-Givi, F. (2012). On imbalance generated by vortical flows in a two-layer spherical Boussinesq primitive equation model. Journal of the Atmospheric Sciences, 69(9), 2819-2834.
Mohebalhojeh, A. R., & Dritschel, D. G. (2004). Contour‐advective semi‐Lagrangian algorithms for many‐layer primitive‐equation models. Quarterly Journal of the Royal Meteorological Society, 130(596), 347-364.
Mohebalhojeh, A. R., & Dritschel, D. G. (2007). Assessing the numerical accuracy of complex spherical shallow-water flows. Monthly Weather Review, 135(11), 3876-3894.
Mohebalhojeh, A.R., & Dritschel, D. G. (2009) The diabatic contour-advective semi-Lagrangian algorithms for the spherical shallow-water equations. Monthly Weather Review, 137, 2979–2994.
Mohebalhojeh, A. R., Joghataei, M., & Dritschel, D. G. (2016). Toward a PV-based algorithm for the dynamical core of hydrostatic global models. Monthly Weather Review, 144, 2481–2502.
Nakajima, K., & Matsuno, T. (1988). Numerical experiments concerning the origin of cloud clusters in the tropical atmosphere. Journal of the Meteorological Society of Japan. Ser. II, 66(2), 309-329.‏
Nordeng, T.E., (1994). Extended versions of the convective parametrization scheme at ECMWF and their impact on the mean and transient activity of the model in the tropics. Research Department Technical Memorandum, 206, 1-41.
Satoh, M., Matsuno, T., Tomita, H., Miura, H., Nasuno, T., & Iga, S. I. (2008). Nonhydrostatic icosahedral atmospheric model (NICAM) for global cloud resolving simulations. Journal of Computational Physics, 227(7), 3486-3514.
Simmons, A. J. and Burridge, D. M. (1981) An energy and angular-momentum conserving vertical finite-difference scheme and hybrid vertical coordinates. Monthly Weather Review, 109, 748–766.
Skamarock, W. C., Klemp, J. B., Duda, M. G., Fowler, L. D., Park, S. H., & Ringler, T. D. (2012). A multiscale nonhydrostatic atmospheric model using centroidal Voronoi tesselations and C-grid staggering. Monthly Weather Review, 140(9), 3090–3105.
Skamarock, W. C., Ong, H., & Klemp, J. B. (2021). A fully compressible nonhydrostatic deep-atmosphere equations solver for MPAS. Monthly Weather Review, 149(2), 571-583.
Stevens, B., Giorgetta, M., Esch, M., Mauritsen, T., Crueger, T., Rast, S., Salzmann, M., Schmidt, H., Bader, J., Block, K., Brokopf, R., Fast, I., Kinne, S., Kornblueh, L., Lohmann, U., Pincus, R., Reichler, R., & Roeckner, E. (2013). Atmospheric component of the MPI-M Earth System Model: ECHAM6. Journal of Advances in Modeling Eearth Systems, 5, 146–172.
Stevens, B., Satoh, M., Auger, L., Biercamp, J., Bretherton, C. S., Chen, X., Duben, P., Judt, F., Khairoutdinov, M., Klocke, D., Kodama, C., Kornblueh, C.., Lin, S., Neumann, P., Putman, W. M., Rober, N., Shibuya, R., Vanniere, B., Vidale, P. L., Wedi, N., & Zhou, L. (2019). DYAMOND: the DYnamics of the Atmospheric general circulation Modeled On Non-hydrostatic Domains. Progress in Earth and Planetary Science, 6(1), 1–17.
Sundqvist, H., Berge, E., & Kristjánsson, J. E. (1989). Condensation and cloud parameterization studies with a mesoscale numerical weather prediction model.
Tiedtke, M. (1989). A comprehensive mass flux scheme for cumulus parameterization in large-scale models. Monthly Weather Review, 117(8), 1779–1800.
Tompkins, A. M. (2002). A prognostic parameterization for the subgrid-scale variability of water vapor and clouds in large-scale models and its use to diagnose cloud cover. Journal of the Atmospheric Sciences, 59(12), 1917–1942.
Toy, M. D. (2013). A supercell storm simulation using a nonhydrostatic cloud-resolving model based on a hybrid isentropic-sigma vertical coordinate. Monthly Weather Review, 141, 1204–1215.
Ullrich, P. A., Jablonowski, C., Kent, J., Lauritzen, P. H., Nair, R. D., & Taylor, M. A. (2012). Dynamical core model intercomparison project (DCMIP) test case document. DCMIP Summer School, 83 pp.
Zhang, Y., Li, J., Yu, R., Zhang, S., Liu, Z., Huang, J., & Zhou, Y., (2018). A layer‐averaged nonhydrostatic dynamical framework on an unstructured mesh for global and regional atmospheric modeling: Model description, baseline evaluation, and sensitivity exploration. Journal of Advances in Modeling Earth Systems. 11, 1685–1714.