Nick Cowan (Northwestern) Potenal for Characterizaon of Transing Planets with JWST Study Analysis Group 10 (SAG-X)

1. What is the full diversity of planet properes needed to characterize and understand the climate of short- period ? 2. Which measurement suites and how much observing me are needed to characterize the climate of transing planets? 3. Will JWST be able to characterize the atmospheres of transing terrestrial planets? 4. Which crical measurements will be too expensive or inaccessible to JWST, and can these be obtained with planned observatories?

SAG-X Parcipants (so far) Daniel Angerhausen (RPI), Natasha Batalha (Penn State), Adrian Belu (Bordeaux), Knicole Colon (Lehigh), Bill Danchi (Goddard), Pieter Deroo (JPL), Jonathan Fortney (UCSC), Sco Gaudi (Ohio State), Tom Greene (Ames), Ma Greenhouse (Goddard), Joe Harrington (UCF), Lisa Kaltenegger (MPIA), Nikole Lewis (MIT), Chuck Lillie (Lillie Consulng), Mercedes Lopez-Morales (CfA), Avi Mandell (Goddard), Emily Rauscher (Princeton), Aki Roberge (Goddard), Franck Selsis (Bordeaux), Kevin Stevenson (Chicago), Mark Swain (JPL)

1D Climate Cartoon

Tstrat

Stratosphere

Tropopause

Height Thermal Emission Probes Near Tropopause Γ Troposphere

Reflected Light Probes Near Surface

Temperature Tsurf 1D Climate Cartoon

Increase Insolaon and/or Decrease Albedo Height

Temperature 1D Climate Cartoon

Increase Longwave Opacity Height

Temperature 1D Climate Cartoon Height Decrease Specific Heat Capacity

Temperature 2D Climate Cartoon (eg: height + latude)

Unfortunately we don’t have To learn from exoplanets, robust predicve models for: we need to measure: • Clouds • Planetary Albedo • Atmospheric Loss Height • Albedo Gradients • Photochemistry • Eming Temperature • Geochemical Cycling • Temperature Gradients Advecon • Wind Velocies (vercal and horizontal)

Temperature Predicng vs Measuring Planetary Climate

Model Inputs Model Outputs • Insolaon • Eming Temperature • Eccentricity • Temperature Gradients • Obliquity • Diurnal Response • Surface Albedo • Seasonal Response • Greenhouse Gases • Cloudiness • Specific Heat Capacity • Surface Temperature • • • Surface Pressure Precipitaon • Thermal Inera Transit Phase Variaons Archetypal Short-Period Planets

Hot Earth (CoRoT-7b, Kepler 10b, α Cen Bb)

Temperate Super-Earth (HD 85512 b, GJ 163 c)

Warm Neptune (GJ 1214b, GJ 436b)

Hot Jupiter (HD 209458b, HD 189733b, WASP-12b) Transit Thermal Light Curve Brightness

100%

2 99% Transit Depth = (Rp/R*) Transit

Time Some Transit Depths

Warm Neptune: 2.7E-2

Hot Jupiter: 8.8E-3

Temperate Super-Earth: 7.3E-3

Hot Earth: 7.3E-5 Thermal Light Curve Brightness 2 Annulus/Stellar Area = 2RpH/R* (where scale height H = kBT/μg) 100% Transit 99%

Transit depth is different at different wavelengths

Time Some Transit Spectral Features

Warm Neptune: 2.4E-4

Hot Jupiter: 1.2E-4

Temperate Super-Earth: 6.5E-6

Hot Earth: 2.0E-6 Eclipse Thermal Light Curve

Brightness + Planet Star 100.3% 100% Eclipse

Eclipse Depth ≈ (R /R )2 (T /T ) 99% p * * Transit

Time Some Eclipse Depths

Warm Neptune: 8.1E-3

Hot Jupiter: 4.0E-3

Temperate Super-Earth: 7.0E-4

Hot Earth: 3.3E-5 Thermal Light Curve

Brightness Star + Planet Star 100.3% 100% Transit Eclipse depth is different at different wavelengths 99%

2 Eclipse Spectrum ≈ (Rp/R*) (Tsurf - Ttrop)/T*

Time Thermal Phases Thermal Light Curve

Star + Planet Brightness Star 2 Phase Amplitude ≈ (Rp/R*) (Tday - Tnight)/T* 100.3%

100.1% 100% Eclipse Transit

Time Eclipse Spectroscopy vs. Phase Variaons

• Differences in temperature – Vercal (33-200 K) – Zonal (60-2000 K) • Spectroscopy has to achieve S/N with relavely narrow bandwidth (R>10) • Phase variaons require long-term stability Predicng vs Measuring Planetary Climate

Model Inputs Model Outputs • Insolaon • Eming Temperature • Eccentricity • Temperature Gradients • Obliquity • Diurnal Response • Surface Albedo • Seasonal Response • Greenhouse Gases • Cloudiness • Specific Heat Capacity • Surface Temperature • Surface Gravity • • Surface Pressure Precipitaon • Thermal Inera