Jiachen Liu
@jiachenliu.bsky.social
PhD candidate at Peking University (she/her) | working on atmospheres on Earth, terrestrial planets, and sub-Neptunes! https://jiachenliu-atmos.github.io/
Reposted by Jiachen Liu
w/ Oli Shorttle, @johannateske.bsky.social & Eliza Kempton we reviewed our current understanding and prospects for peaking on the inside of small #exoplanets in "Constraining exoplanet interiors using observations of their atmospheres": www.science.org/stoken/autho... & arxiv.org/abs/2510.08844 🔭🧪⚒️☄️
October 13, 2025 at 12:27 PM
w/ Oli Shorttle, @johannateske.bsky.social & Eliza Kempton we reviewed our current understanding and prospects for peaking on the inside of small #exoplanets in "Constraining exoplanet interiors using observations of their atmospheres": www.science.org/stoken/autho... & arxiv.org/abs/2510.08844 🔭🧪⚒️☄️
Reposted by Jiachen Liu
We observed the habitable zone planet TRAPPIST-1e with JWST to search for an atmosphere.
You've seen the headlines, now let's dive into the science! 🧪
THREAD (1/N)
#Exoplanets 🔭
You've seen the headlines, now let's dive into the science! 🧪
THREAD (1/N)
#Exoplanets 🔭
A rocky planet in its star’s ‘habitable zone’ could be the first known to have an atmosphere – here’s what we found
The largest telescope in space has been trained on a rocky exoplanet.
theconversation.com
September 9, 2025 at 11:14 PM
We observed the habitable zone planet TRAPPIST-1e with JWST to search for an atmosphere.
You've seen the headlines, now let's dive into the science! 🧪
THREAD (1/N)
#Exoplanets 🔭
You've seen the headlines, now let's dive into the science! 🧪
THREAD (1/N)
#Exoplanets 🔭
Reposted by Jiachen Liu
Update on the atmosphere vs no atmosphere debate for TRAPPIST-1 b and c -- here's a nice and (IMO) conclusive result from Gillon and Ducrot et al.: no thick atmosphere on either planet. arxiv.org/pdf/2509.02128
arxiv.org
September 3, 2025 at 7:11 AM
Update on the atmosphere vs no atmosphere debate for TRAPPIST-1 b and c -- here's a nice and (IMO) conclusive result from Gillon and Ducrot et al.: no thick atmosphere on either planet. arxiv.org/pdf/2509.02128
Reposted by Jiachen Liu
Happy to share the first paper from the SPACE Program, led by my student Angelique Kahle! she observed a hot little sub-Neptune, HD 86226c (Rp = 2.3 Re; equilibrium temp = 1300 K). arxiv.org/pdf/2507.13439
The spectrum is *really* flat ! here's the amplitude compared to other gaseous planets.
The spectrum is *really* flat ! here's the amplitude compared to other gaseous planets.
July 21, 2025 at 11:26 AM
Happy to share the first paper from the SPACE Program, led by my student Angelique Kahle! she observed a hot little sub-Neptune, HD 86226c (Rp = 2.3 Re; equilibrium temp = 1300 K). arxiv.org/pdf/2507.13439
The spectrum is *really* flat ! here's the amplitude compared to other gaseous planets.
The spectrum is *really* flat ! here's the amplitude compared to other gaseous planets.
Reposted by Jiachen Liu
My paper with Tom Evans-Soma and Nathan Mayne on magnetic drag models is now accepted and up on the arXiv. For a quick summary, look at the PDF of my Exoclimes poster that I shared last week.
www.arxiv.org/abs/2507.08511
www.arxiv.org/abs/2507.08511
Geometric Considerations in Hot Jupiter Magnetic Drag Models
Magnetic fields are expected to impact the atmospheric dynamics of hot and ultra-hot Jupiters due to their increased ionization fractions, compared to that of cooler exoplanets, but our ability to mod...
www.arxiv.org
July 14, 2025 at 7:43 AM
My paper with Tom Evans-Soma and Nathan Mayne on magnetic drag models is now accepted and up on the arXiv. For a quick summary, look at the PDF of my Exoclimes poster that I shared last week.
www.arxiv.org/abs/2507.08511
www.arxiv.org/abs/2507.08511
Just finished answering questions from my 10pm (local time) Exoclimes talk #ExoclimesVII — been following sessions into the night all week due to Canada time zone.
Thanks to the LOC for enabling live audio & remote presentation. It eased the pain of missing in-person due to visa issues.
Thanks to the LOC for enabling live audio & remote presentation. It eased the pain of missing in-person due to visa issues.
July 10, 2025 at 10:12 PM
Just finished answering questions from my 10pm (local time) Exoclimes talk #ExoclimesVII — been following sessions into the night all week due to Canada time zone.
Thanks to the LOC for enabling live audio & remote presentation. It eased the pain of missing in-person due to visa issues.
Thanks to the LOC for enabling live audio & remote presentation. It eased the pain of missing in-person due to visa issues.
Reposted by Jiachen Liu
I recommend giving this paper by @jiachenliu.bsky.social, @astroduncan.bsky.social, and Jun Yang a close read: arxiv.org/abs/2506.23891. Sub-Neptunes like K2-18b lie in an interesting regime where both the radiative feedback and mixing of chemical tracers is important, I’m looking forward to Part 2!
Three-dimensional Transport-induced Chemistry on Temperate sub-Neptune K2-18b, Part I: the Effects of Atmospheric Dynamics
The low equilibrium temperatures of temperate sub-Neptunes lead to extremely long chemical timescales in their upper atmospheres, causing the abundances of chemical species to be strongly shaped by at...
arxiv.org
July 1, 2025 at 2:25 PM
I recommend giving this paper by @jiachenliu.bsky.social, @astroduncan.bsky.social, and Jun Yang a close read: arxiv.org/abs/2506.23891. Sub-Neptunes like K2-18b lie in an interesting regime where both the radiative feedback and mixing of chemical tracers is important, I’m looking forward to Part 2!
Reposted by Jiachen Liu
Jiachen Liu (@jiachenliu.bsky.social) has a very interesting paper out where she looks at the dynamics of K2-18b, modelled as a mini-Neptune.
www.arxiv.org/abs/2506.23891
www.arxiv.org/abs/2506.23891
Three-dimensional Transport-induced Chemistry on Temperate sub-Neptune K2-18b, Part I: the Effects of Atmospheric Dynamics
The low equilibrium temperatures of temperate sub-Neptunes lead to extremely long chemical timescales in their upper atmospheres, causing the abundances of chemical species to be strongly shaped by at...
www.arxiv.org
July 1, 2025 at 10:26 AM
Jiachen Liu (@jiachenliu.bsky.social) has a very interesting paper out where she looks at the dynamics of K2-18b, modelled as a mini-Neptune.
www.arxiv.org/abs/2506.23891
www.arxiv.org/abs/2506.23891
My new paper, co-authored with Duncan Christie and Jun Yang, on 3D chemical kinetics simulations of K2-18b has been accepted by MNRAS!
This is Part I of a series. In Part I, we examine the planet's atmospheric dynamics and its impact on the transport of passive tracers.
arxiv.org/abs/2506.23891
This is Part I of a series. In Part I, we examine the planet's atmospheric dynamics and its impact on the transport of passive tracers.
arxiv.org/abs/2506.23891
Three-dimensional Transport-induced Chemistry on Temperate sub-Neptune K2-18b, Part I: the Effects of Atmospheric Dynamics
The low equilibrium temperatures of temperate sub-Neptunes lead to extremely long chemical timescales in their upper atmospheres, causing the abundances of chemical species to be strongly shaped by at...
arxiv.org
July 1, 2025 at 8:28 AM
My new paper, co-authored with Duncan Christie and Jun Yang, on 3D chemical kinetics simulations of K2-18b has been accepted by MNRAS!
This is Part I of a series. In Part I, we examine the planet's atmospheric dynamics and its impact on the transport of passive tracers.
arxiv.org/abs/2506.23891
This is Part I of a series. In Part I, we examine the planet's atmospheric dynamics and its impact on the transport of passive tracers.
arxiv.org/abs/2506.23891
Reposted by Jiachen Liu
"The possible elimination of the lab, called GFDL, in concert with potential cuts to other NOAA operations, threatens irreparable harm not only to global understanding of climate change and long-range scenarios for the planet but to the country’s safety, competitiveness and national security."
White House Proposal Could Gut Climate Modeling the World Depends On
Potential funding cuts for NOAA and its research partners threaten irreparable harm not only to climate research but to American safety, competitiveness, and national security.
www.propublica.org
April 24, 2025 at 1:55 PM
"The possible elimination of the lab, called GFDL, in concert with potential cuts to other NOAA operations, threatens irreparable harm not only to global understanding of climate change and long-range scenarios for the planet but to the country’s safety, competitiveness and national security."
Reposted by Jiachen Liu
𝗡𝗼, 𝗮 𝗯𝗶𝗼𝘀𝗶𝗴𝗻𝗮𝘁𝘂𝗿𝗲 𝘄𝗮𝘀 𝗻𝗼𝘁 𝗷𝘂𝘀𝘁 𝗱𝗲𝘁𝗲𝗰𝘁𝗲𝗱 𝗶𝗻 𝗞𝟮-𝟭𝟴𝗯'𝘀 𝗮𝘁𝗺𝗼𝘀𝗽𝗵𝗲𝗿𝗲.
K2-18b is back in the news, now with a bold claim that biosignature molecules (DMS and/or DMDS) have been 'detected at 3σ'.
Most exoplanet astronomers are extremely sceptical about these claims, let's see why (1/n).
🔭🧪🪐 #exoplanet
K2-18b is back in the news, now with a bold claim that biosignature molecules (DMS and/or DMDS) have been 'detected at 3σ'.
Most exoplanet astronomers are extremely sceptical about these claims, let's see why (1/n).
🔭🧪🪐 #exoplanet
April 17, 2025 at 4:08 PM
𝗡𝗼, 𝗮 𝗯𝗶𝗼𝘀𝗶𝗴𝗻𝗮𝘁𝘂𝗿𝗲 𝘄𝗮𝘀 𝗻𝗼𝘁 𝗷𝘂𝘀𝘁 𝗱𝗲𝘁𝗲𝗰𝘁𝗲𝗱 𝗶𝗻 𝗞𝟮-𝟭𝟴𝗯'𝘀 𝗮𝘁𝗺𝗼𝘀𝗽𝗵𝗲𝗿𝗲.
K2-18b is back in the news, now with a bold claim that biosignature molecules (DMS and/or DMDS) have been 'detected at 3σ'.
Most exoplanet astronomers are extremely sceptical about these claims, let's see why (1/n).
🔭🧪🪐 #exoplanet
K2-18b is back in the news, now with a bold claim that biosignature molecules (DMS and/or DMDS) have been 'detected at 3σ'.
Most exoplanet astronomers are extremely sceptical about these claims, let's see why (1/n).
🔭🧪🪐 #exoplanet
Reposted by Jiachen Liu
An astonishing headline reporting on new observations from a team led to Nikku Madhusudhan claims they’ve found ‘hints of life’ on a planet orbiting a dwarf star some 124 light years away. What’s going on? (1/n) www.bbc.co.uk/news/article... 🔭 🧪
Promising hints of life found on distant planet K2-18b
Scientists find new but tentative evidence that a faraway world orbiting another star may be home to life.
www.bbc.co.uk
April 17, 2025 at 3:24 AM
An astonishing headline reporting on new observations from a team led to Nikku Madhusudhan claims they’ve found ‘hints of life’ on a planet orbiting a dwarf star some 124 light years away. What’s going on? (1/n) www.bbc.co.uk/news/article... 🔭 🧪
Reposted by Jiachen Liu
Shared some (highly skeptical) thoughts on today’s “habitable planet” #K218b news. Thank you @npr.org for the responsible reporting on this topic!
"I think this is one of those situations where extraordinary claims require extraordinary evidence": Laura Kreidberg
@mpi-astro.bsky.social about signs of life beyond our #solarsystem.
npr.org/2025/04/16/n... #exoplanets #K218b @npr.org @lkreidberg.bsky.social
@mpi-astro.bsky.social about signs of life beyond our #solarsystem.
npr.org/2025/04/16/n... #exoplanets #K218b @npr.org @lkreidberg.bsky.social
Is this a hint of life on another world, or just a lot of hot air?
The James Webb Space Telescope may have detected life-associated gas in the atmosphere of a far-off planet. The news is being greeted with both enthusiasm and skepticism.
npr.org
April 17, 2025 at 6:47 AM
My new paper with Feng Ding and Jun Yang has been accepted at ApJ: arxiv.org/abs/2504.05233.
In this study, we find that lower-tropospheric radiative heating is necessary but not independently sufficient to form the NAIV. Instead, the dynamic heating induced by large-scale subsidence is essential.
In this study, we find that lower-tropospheric radiative heating is necessary but not independently sufficient to form the NAIV. Instead, the dynamic heating induced by large-scale subsidence is essential.
Formation of Near-surface Atmospheric Inversion and Surface Inversion in Hothouse Climates
A hothouse climate may develop throughout Earth's history and its warming future and on potentially habitable exoplanets near the inner edge of the habitable zone. Previous studies suggested that near...
arxiv.org
April 8, 2025 at 6:52 AM
My new paper with Feng Ding and Jun Yang has been accepted at ApJ: arxiv.org/abs/2504.05233.
In this study, we find that lower-tropospheric radiative heating is necessary but not independently sufficient to form the NAIV. Instead, the dynamic heating induced by large-scale subsidence is essential.
In this study, we find that lower-tropospheric radiative heating is necessary but not independently sufficient to form the NAIV. Instead, the dynamic heating induced by large-scale subsidence is essential.