Identifying Robust Cloud Feedbacks in Observations and Models

To reduce the substantial uncertainties associated with long-term climate-change, we will undertake a multi-faceted collaborative research effort to identify robust cloud feedbacks in today’s climate models, and constrain them with available observations. Key aspects of the proposed work include identification of cloud feedbacks in today’s climate models that exhibit similarity in the contexts of current-climate variability and climate-change ("timescale invariant feedbacks"), and the mechanisms leading to the similarities. We will also identify the observations that can constrain these feedbacks quantitatively. To allow for a variety of relevant mechanisms, we will undertake separate analyses of feedbacks associated with:

  1. Stratocumulus
  2. High clouds
  3. Middle-latitude clouds
  4. Polar clouds.

Because of the anticipated importance of marine stratocumulus feedbacks for overall cloud feedback, we will apply a mixed-layer model forced by climate model boundary conditions to diagnose the simulated mechanisms underpinning simulated stratocumulus variability and change. Finally, through the use of a perturbed physics ensemble technique, we will determine how cloud-process parameterizations are related to the "timescale invariant" feedbacks we diagnose in the rest of the project. This is a critical step in discovering how to actually construct a comprehensive climate model that more realistically represents cloud feedbacks.

Project Term: 
2010 to 2014
Project Type: 
Laboratory Funded Research

Publications:

An Observational Radiative Constraint on Hydrologic Cycle Intensification
Analyzing the Dependence of Global Cloud Feedback on the Spatial Pattern of Sea Surface Temperature Change with A Green's Function Approach
Analyzing the Dependence of Global Cloud Feedback on the Spatial Pattern of Sea Surface Temperature Change with A Green's Function Approach
Clearing Clouds of Uncertainty
Cloud feedback mechanisms and their representation in global climate models
Constraining the Low-Cloud Optical Depth Feedback at Middle and High Latitudes using Satellite Observations
Diagnosing the Average Spatio-Temporal Impact of Convective Systems – Part 1: A methodology for evaluating climate models
Emergent Constraints for Cloud Feedbacks
Evidence for Climate Change in the Satellite Cloud Record
External Influences on Modeled and Observed Cloud Trends
Impact of Decadal Cloud Variations on the Earth’s Energy Budget
Impact of decadal cloud variations on the Earth’s energy budget
Importance of Vegetation Processes for Model Spread in the Fast Precipitation Response to CO2 Forcing
Importance of Vegetation Processes for Model Spread in the Fast Precipitation Response to CO2 Forcing
Insights from a Refined Decomposition of Cloud Feedbacks
Low-Cloud Feedbacks from Cloud-Controlling Factors: A Review
Low-Cloud Feedbacks from Cloud-Controlling Factors: A Review
Low-Cloud Optical Depth Feedback in Climate Models
On the Spread of Changes in Marine Low Cloud Cover in Climate Model Simulations of the 21st Century
Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Oscillation
Positive Tropical Marine Low-Cloud Cover Feedback Inferred from Cloud-Controlling Factors
Positive Tropical Marine Low-Cloud Cover Feedback Inferred from Cloud-Controlling Factors
Quantifying Components of Aerosol-Cloud-Radiation Interactions in Climate Models
Quantifying the Sources of Inter-Model Spread in Equilibrium Climate Sensitivity
Shallowness of Tropical Low Clouds as a Predictor of Climate Models' Response to Warming
Statistical Significance of Climate Sensitivity Predictors Obtained by Data Mining
The Cloud Feedback Model Intercomparison Project (CFMIP) contribution to CMIP6
The Relationship between Interannual and Long-Term Cloud Feedbacks
The Response of the Southern Hemispheric Eddy-Driven Jet to Future Changes in Shortwave Radiation in CMIP5
The Strength of the Tropical Inversion and its Response to Climate Change in 18 CMIP5 Models

Research Highlights:

A Novel Technique to Diagnose the Spatio-Temporal Impact of Convective Systems Highlight Presentation
An Observational Radiative Constraint on Hydrologic Cycle Intensification Highlight Presentation
Assessing Model Simulations of Deep Convection: A Novel Compositing Approach Highlight Presentation
Cirrus Clouds Represent An Important Component of the Cloud Feedback Highlight Presentation
Clearing Clouds of Uncertainty Highlight Presentation
CMIP3 Climate Models May Overestimate Global Warming by Underestimating Future Low Cloudiness Highlight
Dependence of Cloud Feedback on the Spatial Pattern of Sea Surface Warming Highlight Presentation
Detailing Aerosol-Cloud-Radiation Interactions using Simple Diagnostics Highlight Presentation
Do Emergent Constraints Help Predict Future Climate? Highlight Presentation
Evidence for Climate Change in Satellite Cloud Record Highlight Presentation
Evidence that relationship between low-level cloud reflectivity and temperature in the current climate can predict the climate change response Highlight Presentation
Higher climate sensitiviity is linked to a shallower tropical low clouds Highlight Presentation
Identifying the Human Fingerprint in Observed Cloud Trends Highlight Presentation
Impact of Decadal Cloud Variations on the Earth’s Energy Budget Highlight Presentation
Insights from a Refined Decomposition of Cloud Feedbacks Highlight Presentation
Model Spread in the Fast Response of Global Precipitation Highlight Presentation
Observations Indicate that the Low-Cloud Feedback is Positive Highlight Presentation
Positive Tropical Marine Low-Cloud Cover Feedback Inferred from Cloud-Controlling Factors Highlight Presentation
Review of Cloud Feedbacks in Climate Models Highlight Presentation
The Relationship between Interannual and Long-Term Cloud Feedbacks Highlight Presentation
The Role of Clouds in Shifting the Mid-Latitude Jet Highlight Presentation
The Tropical Inversion will Strengthen in a Warming Climate Highlight Presentation
Why do Climate Models Disagree? Highlight
Will Low-level Clouds Reflect More Sunlight with Warming? Highlight Presentation