Abstract The Community Earth System Model version 2 (CESM2) simulates a high equilibrium climate sensitivity (ECS > 5°C) and Last Glacial Maximum (LGM) that is substantially colder than proxy temperatures. In this study, we examine the role of cloud parameterizations in simulating LGM cooling CESM2. Through substituting different versions schemes atmosphere model, attribute excessive to new CESM2 microphysics ice nucleation. Further exploration suggests removing an inappropriate limiter...

Mixed-phase clouds play an important role in determining Arctic warming, but are parametrized models and difficult to constrain with observations. We use two satellite-derived cloud phase metrics investigate the vertical structure of global climate that Community Atmosphere Model version 6 (CAM6) atmospheric component. report a model error limiting ice nucleation, produce set Arctic-constrained runs by adjusting microphysical variables match metrics, evaluate feedbacks for all simulations....

Abstract. Infrared spectral radiation fields observed by satellites make up an information-rich, multi-decade record with continuous coverage of the entire planet. As direct observations, are also largely free from uncertainties that accumulate during geophysical retrieval and data assimilation processes. Comparing these observations earth system models (ESMs), however, is hindered definitional differences between observe those generated models. Here, we present a flexible, computationally...

Abstract Clouds are the main source of uncertainties when projecting climate change. Mixed-phase clouds that contain ice and supercooled-liquid particles especially hard to constrain, models neither agree on their phase nor spatial extent. This is problematic, as underestimate contemporary in mixed-phase will future warming. Furthermore, it has recently been shown water not homogeneously-mixed, vertically horizontally. However, while there have attempts at observationally constraining...

Abstract Clouds are parameterized in climate models using quantities on the model grid‐scale to approximate cloud cover and impact radiation. Because of complexity processes involved with clouds, these parameterizations one key challenges modeling. Differences clouds among main contributors spread sensitivity across models. In this work, three generations an atmosphere lineage evaluated against satellite observations. Satellite simulators used within provide appropriate comparison individual...

We demonstrate the use of a flexible digital servo system for optical stabilization both repetition rate and carrier-envelope offset frequency laser comb. The is based entirely on low-cost field programmable gate array, simple electronic components, existing open-source software. Utilizing slow fast feedback actuators commercial mode-locked comb, we maintain cycle-slip free locking optically-derived beatnotes over 30 hour period measure residual phase noise at or below ~0.1 rad,...

Abstract Ice nucleation in mixed‐phase clouds has been identified as a critical factor projections of future climate. Here we explore how this process influences climate sensitivity using the Community Earth System Model 2 (CESM2). We find that ice affects simulated cloud feedbacks over most regions and levels troposphere, not just extratropical low clouds. However, with present‐day global mean phase adjusted to replicate satellite retrievals, similar total feedback is attained whether...

Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Geophysical Research Letters. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing an older version [v1]Go new versionUsing satellite observations evaluate model representation of Arctic mixed-phase cloudsAuthorsJonah KShawiDZacharyMcGrawOlimpiaBrunoiDTrudeStorelvmoStefanHoferSee all authors...

Mixed-phase clouds play an important role in determining Arctic warming, but are parametrized models and difficult to constrain with observations. We use two satellite-derived cloud phase metrics investigate the vertical structure of global climate that Community Atmosphere Model version 6 (CAM6) atmospheric component. report a model error limiting ice nucleation, produce set Arctic-constrained runs by adjusting microphysical variables match metrics, evaluate feedbacks for all simulations....

Earth and Space Science Open Archive This work has been accepted for publication in Journal of Advances Modeling Systems (JAMES). Version RecordESSOAr is a venue early communication or feedback before peer review. Data may be preliminary. Learn more about preprints. preprintOpen AccessYou are viewing the latest version by default [v1]LGM paleoclimate constraints inform cloud parameterizations equilibrium climate sensitivity CESM2AuthorsJiangZhuBette LOtto-BliesneriDEsther...

We present a new modality for infrared, hyperspectral microscopy using dual-comb, electro-optic sampling of octave-spanning infrared frequency combs. obtain images SU8 test patterns on Si wafers with spatial resolution 12 µm.

Mixed-phase clouds greatly affect projections of future climate, with recent evaluations highlighting the influence ice nucleation process in these clouds. Here we explore how this affects climate sensitivity using simulations Community Earth System Model version 2 (CESM2). Ice is found to simulated cloud feedbacks not just over extratropical low but most regions and levels troposphere. However, otherwise major on total feedback negated when holding global mean phase observed levels. In...

Ice nucleation in mixed-phase clouds has recently been identified as a critical factor projections of future climate. Here we explore how this process influences climate sensitivity using the Community Earth System Model 2 (CESM2). We find that ice affects simulated cloud feedbacks over most regions and levels troposphere, not just extratropical low clouds. nucleation’s impact on is found to primarily operate through process’s role setting global-scale phase. Conversely, whether treated...

<title>Abstract</title> Clouds are the main source of uncertainties when projecting climate change. Mixed-phase clouds (MPCs) that contain ice and supercooled-liquid particles especially hard to constrain, models neither agree on their phase nor spatial extent. This is problematic, as underestimate contemporary in MPCs will future warming. Furthermore, it has recently been shown water not homogeneously-mixed, vertically horizontally. However, while there have attempts at observationally...

Abstract Most observed patterns of recent Arctic surface warming and sea ice loss lie outside unforced internal climate variability. In contrast, human influence on related changes in outgoing longwave radiation has not been assessed. Outgoing captures the flow thermal energy from through atmosphere to space, making it an essential indicator change. Furthermore, satellites have measured pan-Arctic for two decades while temperature observations remain spatially temporally sparse. Here, model...

We present a new modality for infrared, hyperspectral microscopy using dual-comb, electro-optic sampling of octave-spanning infrared frequency combs. obtain images SU8 test patterns on Si wafers with spatial resolution $12 \mu \text{m}$.

We demonstrate the use of a flexible digital servo system for optical stabilization both repetition rate and carrier-envelope offset frequency laser comb. The is based entirely on low-cost field programmable gate array, simple electronic components, existing open-source software. Utilizing slow fast feedback actuators commercial mode-locked comb, we maintain cycle-slip free locking optically-derived beatnotes over 30 hour period, measure residual phase noise at or below ~0.1 rad,...