# Máté Ádámkovics¶

mate@berkeley.edu

# Planetary Atmospheres¶

The Sunlight that we can observe illuminating a planet carries information about the distant atmosphere. We know that a diverse range of exotic physical environments exist among the planets and their moons. I study these places with telescopes on Earth and instruments on spacecraft. Using infrared spectroscopy, we can study the atmospheric physics of clouds, precipation, and circulation in a wide variety circumstances. A few specific examples what I've worked on are described below:

# Titan¶

The weather is a daily reminder of the changes in our environment, and can inspire the search for a deeper understanding of our physical world. From the local weekly weather forecast, to knowledge of regional and seasonal conditions, to predicting the global climate response of our atmosphere in the coming decades due to significant anthropogenic changes, there are intriguing challenges in understanding our atmosphere.

An example of how I made measurements using two of the largest optical/IR telescopes in the world, together with data from the Cassini spacecraft, to measure the methane humidity variation on Titan is described in Ádámkovics et al. (2015).

### From the literature:¶

Ádámkovics et al. (2015) - Methane humidity variation

Mitchell et al. (2011) - Precipitation and waves

Ádámkovics et al. (2010) - A stationary mid-latitude cloud system

# Giant Planets¶

Clouds are a visual diagnostic of horizontal motions on the giant planets, and spectroscopy can be used to determine the altitude structure. Measurements of both images and spectra — sometimes referred to as hyper-spectral data, integral-field spectral cubes, or spatially-resolved spectra — can provide a 3-dimensional picture of the fluid motions in the atmospheres of giant planets.

#### From the literature:¶

Bjoraker et al., (2015) - Jupiter's deep cloud structure

Luszcz-Cook et al. (2010) - Clouds at Neptune's south pole

de Pater et al. (2011) - Jupiter's north polar cap

At near-infrared wavelengths, in the cold outer solar system, the dominant processes for altering the rays of Sunlight as they travel through an atmosphere are absorption by gas molecules and scattering by particles, such as clouds (big droplets or crystals) and aerosols (small hydrocarbons, usually). The physics can be written down in a straightfoward way, and models of the atmosphere can be created. The azimuthally-averaged radiative transfer equation for discrete layers, $i$, along the path $\mu$ is

$I(\tau_i,\mu) = I(\tau_{i+1},\mu) \, e^{-\delta\tau_i/\mu} + \int\limits\limits_{0}^{\delta\tau_i} S(\tau',\mu) e^{-\tau'/\mu} \frac{d\tau'}{\mu}$

where the source function is

$S(\tau',\mu) = \overbrace{ \frac{\tilde{\omega}}{4\pi} \, (\pi F_0) \, P(\mu,-\mu_0) \, e^{-\tau/\mu_0} }^{\mathrm{single \; scattering}} + \overbrace{ \int\limits\limits_{-1}^1 \frac{\tilde\omega}{2} \, I(\tau,\mu') \, P(\mu,\mu')\, d\mu' }^{\mathrm{multiple \; scattering}}$

In the top expression, the first term in the is the direct contribution of gas and particle absorption, and the second (integral) term is the diffuse contribution from scattering. Solving this problem numerically is used to calculate spectra from atmospheric models that are compared to observations.

The code for my models is available on github.

If you find the code useful, please cite my 2015 paper where this particular code is first described, and if you encounter problems, email me mate@berkeley.edu.

# Protoplanetary Disk Atmospheres¶

The flared disk of material around young stars is observed to have a gaseous atmosphere evidenced by atomic ion and molecular emission lines. Temperatures of a few thousand Kelvin are indicated by CO, as well as temperatures of several hundred by the observations of water and small organic molecules. These gas temperatures can be much hotter than the dust continuum emission. One guess about the mechanism that is responsbile for producing such high temperatures is represented by an equation for accretion heating,

$\hspace{2cm}\Lambda_{\rm acc} = 9\alpha_{h} \rho c^2 \Omega/4.$

However, a problem exists in that $\alpha_h$ is not directly constrained by observations, nor is it unambiguously determined by theory. In fact, it's not all that clear that this equation correctly represents all of the most relevant physics. Recently, we been exploring the relative roles of FUV and accretion heating in disks.

## Thermal-chemical models & disk structure¶

We explore the various heating (and cooling) mechanisms in disks that together with the relevent chemistry determines the vertical structure of temperatures and molecular abundances, shown in the figure below.

The layered structure of the disk is illustrated by the shaded regions that highlight layers with different temperatures. The molecular emission from these layers is a characteristic diagnostic of the inner planet-forming regions of diks.

Recently, we've been working on understanding hot molecular hydrogen emission, which depends strongly on Lyman-$\alpha$ radiation. Our revised manuscript is back to ApJ and should be accepted soon, Ádámkovics, Najita & Glassgold (2015, preprint).

### From the literature:¶

Ádámkovics, Glassgold & Najita (2014) - Water and FUV radiation

Ádámkovics, Glassgold & Meijerink (2011) - X-ray ionization

Najita, Ádámkovics & Glassgold (2011) - Formation of organic molecules