The Mars general circulation model is the result of a research project by

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

to understand the nature of the general circulation of the

atmosphere of Mars The atmosphere of Mars is the layer of gases surrounding Mars. It is primarily composed of carbon dioxide (95%), molecular nitrogen (2.85%), and argon (2%). It also contains trace levels of water vapor, oxygen, carbon monoxide, hydrogen, and nob ...

, how that circulation is driven and how it affects the

climate of Mars The climate of Mars has been a topic of scientific curiosity for centuries, in part because it is the only terrestrial planet whose surface can be easily directly observed in detail from Earth with help from a telescope. Although Mars is small ...

in the long term.

How it works

This Mars climate model is a complex 3-dimensional (height, latitude, longitude) model, which represents the processes of atmospheric heating by gases and ground-air heat transfer, as well as large-scale atmospheric motions. The model also uses geophysical boundaries which are taken from spacecraft observation. These boundaries can include Martian topography, albedo, or thermal inertia. By solving the dynamics and physics of the model an overall understanding of the planets processes can be estimated. The current model has not been modified for use with distributed computing systems like

BOINC The Berkeley Open Infrastructure for Network Computing (BOINC, pronounced rhymes with "oink") is an open-source middleware system for volunteer computing (a type of distributed computing). Developed originally to support SETI@home, it became the ...

History

A first attempt at a Mars general circulation model was created by Leovy and Mintz who used an Earth model and adapted it to Martian conditions. This preliminary model had the capability to predict atmospheric condensation of carbon dioxide and the presence of transient baroclinic waves in the winter mod-latitudes. After this NASA Ames Research Center started adding more data to improve the model and gain more insight into Martian weather and climate. Mars

climate simulation Numerical climate models (or climate system models) are mathematical models that can simulate the interactions of important drivers of climate. These drivers are the atmosphere, oceans, land surface and ice. Scientists use climate models to stu ...

models date as far back as the Viking missions to

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

. Most Mars climate simulation models were written by individual researchers that were never reused or open-sourced. By the 1990s the need for a unified model codebase came into being, due to the general impact of the internet on climate modelling and research. This current Mars climate simulation model has its origins with the internet era. In 2007, Jeff Hollingsworth took leadership of the Ames Mars GCM group. With the aid of NASA HQ a Mars Climate Modeling Center (MCMC) was created in order to provide more services to the community. Since 2019, Melinda Kahre spearheads the leadership of MCMC and has aided in developing a new cubed-sphere finite volume (FV3-based) Mars general circulation model to provide higher resolution modeling. The new FV3-based model replaced the older latitude-longitude dynamical core (Legacy Mars GCM). Other improvements has been made in order to allow public access to older and newer models of Mars' general circulation. MCMC has recently presented a community analysis pipeline (CAP) which is an open-source tool for analyzing and visualizing the Mars general circulation model. The project hopes to streamline and increase access to Mars data. This goal of increasing accessibility is to provide scientist and researcher more opportunity to contribute to data from Mars missions.

Research using the Mars general circulation model

The Mars general circulation model has been a tool used by researchers to better understand the planet. The model includes various Martian cycles including active carbon dioxide, pressure, dust, and water cycles. These elements combined provide insight into the planet's atmospheric chemistry. The model is used as an aid in interpreting as well as analyzing the data received from spacecraft and applies to numerous disciplines that have lingering questions about the planet. Some of the recent research using the model is determining the processes that caused an abundance of high-altitude water vapor during the 2018 global dust storm, interpreting Martian thermospheric waves, effects of any orbital changes to the planets circulator and climate system, and much more. In 2016 the

ExoMars ExoMars (Exobiology on Mars) is an astrobiology programme of the European Space Agency (ESA). The goals of ExoMars are to search for signs of past life on Mars, investigate how the Martian water and geochemical environment varies, investigate ...

Trace Gas Orbiter was launched with hopes of looking for evidence of methane and other trace elements that could be signature of biological and/or geological processes. The NOMAD spectrometer instrument onboard

will rely on the Mars general circulation model for much of the data interpretation and analysis. Other spacecraft instruments have been compared to the circulation model such as water-ice and dust results from

Maven MAVEN is a NASA spacecraft orbiting Mars to study the loss of that planet's atmospheric gases to space, providing insight into the history of the planet's climate and water. The name is an acronym for "Mars Atmosphere and Volatile Evolution" w ...

's Imaging Ultraviolet Spectrograph (IUVS). With the continuous additions of new spacecraft being sent the Mars, the data is rapidly updating making the Martian model highly advanced.

Methane on Mars

The

Martian atmosphere The atmosphere of Mars is the layer of gases surrounding Mars. It is primarily composed of carbon dioxide (95%), molecular nitrogen (2.85%), and argon (2%). It also contains trace levels of water vapor, oxygen, carbon monoxide, hydrogen, and nob ...

contains 10 nmol/ mol methane (CH₄). In 2014, NASA reported that the ''Curiosity'' rover detected a tenfold increase ('spike') in methane in the atmosphere around it in late 2013 and early 2014. Four measurements taken over two months in this period averaged 7.2 ppb, implying that Mars is episodically producing or releasing methane from an unknown source. Before and after that, readings averaged around one-tenth that level. On 7 June 2018, NASA announced a cyclical seasonal variation in the background level of atmospheric methane. The principal candidates for the origin of Mars' methane include non-biological processes such as

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

-rock reactions,

radiolysis Radiolysis is the dissociation of molecules by ionizing radiation. It is the cleavage of one or several chemical bonds resulting from exposure to high-energy flux. The radiation in this context is associated with ionizing radiation; radiolysis is ...

of water, and

pyrite The mineral pyrite ( ), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic luster and pale brass-yellow hue ...

formation, all of which produce H₂ that could then generate methane and other hydrocarbons via Fischer–Tropsch synthesis with CO and CO₂. It has also been shown that methane could be produced by a process involving water, carbon dioxide, and the mineral

olivine The mineral olivine () is a magnesium iron Silicate minerals, silicate with the chemical formula . It is a type of Nesosilicates, nesosilicate or orthosilicate. The primary component of the Earth's upper mantle (Earth), upper mantle, it is a com ...

, which is known to be common on Mars. Living

microorganism A microorganism, or microbe, is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen ...

s, such as

methanogen Methanogens are anaerobic archaea that produce methane as a byproduct of their energy metabolism, i.e., catabolism. Methane production, or methanogenesis, is the only biochemical pathway for Adenosine triphosphate, ATP generation in methanogens. A ...

s, are another possible source, but no evidence for the presence of such organisms has been found on Mars.

Other planets

There are global climate simulation models that have been written for

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined a ...

Saturn Saturn is the sixth planet from the Sun and the second largest in the Solar System, after Jupiter. It is a gas giant, with an average radius of about 9 times that of Earth. It has an eighth the average density of Earth, but is over 95 tim ...

Neptune Neptune is the eighth and farthest known planet from the Sun. It is the List of Solar System objects by size, fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 t ...

and

Venus Venus is the second planet from the Sun. It is often called Earth's "twin" or "sister" planet for having almost the same size and mass, and the closest orbit to Earth's. While both are rocky planets, Venus has an atmosphere much thicker ...

References