ترغب بنشر مسار تعليمي؟ اضغط هنا

A theoretical model for realistic local climates

233   0   0.0 ( 0 )
 نشر من قبل Gabriele Di Bona
 تاريخ النشر 2019
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

We write a nonlinear model that predicts the climate (temperature and humidity) on the surface of a small region on Earth, perform numerical investigations using the model, and compare the results to real climate on a variety of regions on Earth. It the parameters are chosen keeping into consideration the climatic Koppen zone to which the region belongs, the numerical model accurately reproduces the real climate. The model takes into account the doubly-periodic forcing of the solar radiation (annual and daily), the laws of irradiance, the fact that the Earth has land and oceans with different thermic inertia, and the humidity of the air due to evaporation. This enables us to reproduce remarkable features of Earths climate such as lag of seasons, lag of noons, and asymmetric evolution of daily temperatures. The model can easily be adapted to planets with non-terrestrial astronomic parameters. We conclude this article with an investigation of an Earth with eccentricity higher than real.

قيم البحث

اقرأ أيضاً

We perform a first experimental test of a local realistic model, recently proposed, based on the Wigner function as probability distribution for the hidden variable. Our results disfavour the model and confirm standard quantum mechanics predictions.
We present the results of full new calculation of radiocarbon 14C production in the Earth atmosphere, using a numerical Monte-Carlo model. We provide, for the first time, a tabulated 14C yield function for the energy of primary cosmic ray particles r anging from 0.1 to 1000 GeV/nucleon. We have calculated the global production rate of 14C, which is 1.64 and 1.88 atoms/cm2/s for the modern time and for the pre-industrial epoch, respectively. This is close to the values obtained from the carbon cycle reservoir inventory. We argue that earlier models overestimated the global 14C production rate because of outdated spectra of cosmic ray heavier nuclei. The mean contribution of solar energetic particles to the global 14C is calculated as about 0.25% for the modern epoch. Our model provides a new tool to calculate the 14C production in the Earths atmosphere, which can be applied, e.g., to reconstructions of solar activity in the past.
75 - Nicola Scafetta 2013
Power spectra of global surface temperature (GST) records reveal major periodicities at about 9.1, 10-11, 19-22 and 59-62 years. The Coupled Model Intercomparison Project 5 (CMIP5) general circulation models (GCMs), to be used in the IPCC (2013), are analyzed and found not able to reconstruct this variability. From 2000 to 2013.5 a GST plateau is observed while the GCMs predicted a warming rate of about 2 K/century. In contrast, the hypothesis that the climate is regulated by specific natural oscillations more accurately fits the GST records at multiple time scales. The climate sensitivity to CO2 doubling should be reduced by half, e.g. from the IPCC-2007 2.0-4.5 K range to 1.0-2.3 K with 1.5 C median. Also modern paleoclimatic temperature reconstructions yield the same conclusion. The observed natural oscillations could be driven by astronomical forcings. Herein I propose a semi empirical climate model made of six specific astronomical oscillations as constructors of the natural climate variability spanning from the decadal to the millennial scales plus a 50% attenuated radiative warming component deduced from the GCM mean simulation as a measure of the anthropogenic and volcano contributions to climatic changes. The semi empirical model reconstructs the 1850-2013 GST patterns significantly better than any CMIP5 GCM simulation. The model projects a possible 2000-2100 average warming ranging from about 0.3 C to 1.8 C that is significantly below the original CMIP5 GCM ensemble mean range (1 K to 4 K).
Just a few decades after the discovery of the Charon Relay, and the ensuing First Contact War, relatively little is known about the population of planets linked by the Prothean mass relays. Understanding the nature of these systems and how they may d iffer from the broader population of planetary systems in our galaxy is key to both continued human habitation across the broader Galaxy, as well as to our understanding of the Prothean civilization. What factors motivated their choices of planetary systems? Characterizing these systems allows us to peer into Prothean society and culture, and make inferences about the preferences that drove their expansion throughout the Galaxy. In this study, we undertake a broad analysis of the systems recorded in the Systems Alliance Planetary Survey, examining their dynamical stability, orbital properties, and the climates of the inhabited worlds. We find that the Alliance data is inconsistent with both a modern understanding of planetary system dynamics, as well as with our understanding of Earth-like climate dynamics. We suggest this is due in part to security-related data obfuscation by the Alliance, and in part due to the real preferences of the Protheans.
There is a subclass of the X-ray jets from young stellar objects which are heated very close to the footpoint of the jets, particularly DG Tau jets. Previous models attribute the strong heating to shocks in the jets. However, the mechanism that local izes the heating at the footpoint remains puzzling. We presented a different model of such X-ray jets, in which the disk atmosphere is magnetically heated. Our disk corona model is based on the so-called nanoflare model for the solar corona. We show that the magnetic heating near the disks can result in the formation of a hot corona with a temperature of > 10^6 K even if the average field strength in the disk is moderately weak, > 1 G. We determine the density and the temperature at the jet base by considering the energy balance between the heating and cooling. We derive the scaling relations of the mass loss rate and terminal velocity of jets. Our model is applied to the DG Tau jets. The observed temperature and estimated mass loss rate are consistent with the prediction of our model in the case of the disk magnetic field strength of ~20 G and the heating region of < 0.1 au. The derived scaling relation of the temperature of X-ray jets could be a useful tool to estimate the magnetic field strength. We also found that the jet X-ray can have a significant impact on the ionization degree near the disk surface and the dead-zone size.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا