Julián Ädem: Thermodynamic Model Climate

Julian Adem and climate

Francisco Javier Chaín Revuelta

On Tuesday October 13, 2015 the Journal of Xalapa published (without credit) in its culture section and page 3E Science and Light what titled "Contributions of Julian Adem to world science" and adding three subtitle "Author model Thermodynamic Climate (MTC) originated in the early 1960s and still valid today "" it's one of the few climate models with such a long history and variety of applications, "" Julian Adem Chahín born in Tuxpan, Veracruz January 8, 1924 "I transcribe to allow credit to their authors Alfredo Diaz Martinez Barradas and Adalberto Tejeda.

Thermodynamic Model Climate

Alfredo Ruiz Barradas * and Adalberto Martínez Tejeda **

League: http://www.uv.mx/cienciauv/blog/aportacionesjulianademacienciamundial/ 

Don Julian Adem Chahín born in Tuxpan, Veracruz, on January 8, 1924. His legacy exceeds evaluations from dating to his scientific work, which in itself denote its contribution to the advancement of atmospheric sciences in the world . In our country it is invaluable also its momentum to meteorology and modern climatology through the founding of the Center for Atmospheric Sciences of the UNAM, the Geophysics Mexican Union, the Bachelor of Atmospheric Sciences at the Universidad Veracruzana and the creation of the International Geophysics and Atmospheric scientific journals.

Together with other brilliant minds such as the Swedish Carl-Gustaf Rossby, father of modern meteorology and the leading US climatologist Jerome namias He was in the battlefront of the great discoveries that allowed during the second half of the twentieth century, make substantial progress in the understanding of the atmosphere in particular and the general climate system.

Initial work

Initial work -in 1956 Adem atmospheric vortices, in 1962 on the general circulation of the atmosphere in 1963 and 1964 around the computational simulation and production of the atmosphere and of Climate system contributed to meteorology and weather pass a descriptive level to one based on physics, with deterministic toils, which ultimately made it possible, within certain limits, weather forecasting and climate with physical-mathematical models. Within the latter it emphasizes its work summit, Climate Thermodynamic Model (MTC), born at the beginning of the 1960s and continues to be used and refined to this day.

The successful path that Julian Adem transited in the field of atmospheric sciences, which beginning in 1956 describing the behavior of the atmosphere in a theoretical way. Using equations incorporating the most important able to induce changes in the atmosphere and devised a novel way to solve these equations allowing to simulate and predict the behavior of tropical cyclones to move under the influence of changing the Earth's rotation mechanisms.

From this work, Adem it focused increasingly understand and represent through a physical-mathematical model of how the atmosphere -part of Climate essential system responded to the incident solar radiation on the planet; in other words, how thermodynamic processes gave way to dynamic processes in the atmosphere. For this task, in 1962, support the basic principle of conservation of thermal energy and thus modeled for the atmosphere the basic mechanisms of heat exchange of solar radiation and land, and energy transfer between the tropics and midlatitudes , required to induce daily atmospheric circulation.

The basis of his masterpiece

ADEM in 1963 applied the principle-energy- conservation into the atmosphere with the inclusion of a layer of clouds, oceans and continents, thus laying the foundation of its MTC. The transfer of energy from some other latitudes through cyclones and anticyclones of, remained a fundamental part of the model, and established the basis of a predictive model not only descriptive-and seasonal temperatures of the atmosphere, understanding that for a prediction seasonal satisfactory was needed at the start of the season with ocean temperatures, given the ability of the latter to store energy.

The achievements of this model, which until then spatially only considered the geographical latitude, motivated ADEM in 1964 to extend in the longitudinal direction and thus make the distinction between ocean and continent for a better simulation of normal (average or) temperature the atmosphere and its anomalies (or deviations from normal) in the Northern Hemisphere. The results obtained with this approach -using the conservation equations of thermal energy as predictive equations for the climate system and estacionales- monthly scales showed the usefulness of the model to simulate global temperature patterns and predict abnormalities temperature troposphere average data from the previous month ocean temperatures and middle troposphere itself as well as the distribution of the layers of ice and snow.

Applications and research

The development of MTC Adem as a tool to simulate the climate system gave foot in the decades to several applications and research, such as simulating the current climate and the last great ice age, predicting the temperature anomalies and precipitation in the northern Hemisphere with verification of the United States and Mexico, predicting drought in northern Africa in the 1980s, the simulation of the current cycle of temperatures in the Gulf of Mexico, experiments on the effect on climate atmospheric or increased atmospheric carbon dioxide humidity, and even use as part of stochastic climate models. Currently the MTC continues to develop in many directions one of which is its extension to a global model and another to an interactive coupling of the atmosphere and ocean.

In short, the model of the climate system devised by Adem consists of an atmospheric layer about 10 kilometers containing a layer of clouds, an ocean layer varies from 50 to 100 meters deep, and continental layer of negligible thickness by its inability to storing thermal energy, the model also incorporates a layer of ice and snow on oceans and continents.

Thus conceived, includes approaches of dynamic processes in the atmosphere and ocean, solar and terrestrial radiation on the surface, atmosphere and clouds, energy flows between the various elements of the system, as well as feedback processes framed all within conservation of thermal energy. The MTC is perhaps one of the few, apart from the so-called General Circulation with a long history and variety of applications. Its use as a research tool has not been exclusive to Mexican institutions such as the UNAM, but has spread to scientific groups from the United States, Belgium, Germany and Russia.

in memoriam

Dr. Julian Adem died on September 9, 2015 in Mexico City, but left an extraordinary legacy and raised many ideas that will further improve our understanding of atmospheric environment and climate system.

* Student and collaborator of Dr. Adem in the 1990s at the Center for Atmospheric Sciences of the UNAM, is currently a research associate in the Department of Science of the Atmosphere and Ocean University of Maryland, United States .

** Student Doctor ADEM in the late 1980s, is currently a researcher at the Universidad Veracruzana. Mail: atejedamartínez@gmail.com

references:
http://cronistadetuxpan.blogspot.mx/2011/05/auditorium-del-centro-de-estudios-de-la.html
http://www.math.cinvestav.mx/joseadem
http://www.expresodetuxpan.com/?p=972
http://www.atmosfera.unam.mx/directorio/adem_j.html
http://www.uv.mx/universo/326/central/central.htm
http://www.uv.mx/gaceta/Gaceta55-56/55-56/mar/mar1.htm
https://es.wikipedia.org/wiki/Juli%C3%A1n_Adem

http://100.unam.mx/images/stories/universitarios/dhc/PDF/adem-chahin-julian.pdf