Cloud, precipitation, and water vapor
Cloud micro- and macro- physics play a pivotal role in weather and climate systems. We aim to contribute to the development of next generation of cloud and precipitation physics schemes. Observations from different platforms are used to constrain those schemes in weather prediction and climate models.
Impact of Cloud Ice Particle Size on Climate
Ice particle size is pivotal to determining ice cloud radiative effect and precipitating rate. We conducted a modeling assessment of the climatic effects of ice particle size and found that both climate mean state and climate sensitivity are subject to cloud ice particle size. We also estimate the impact of a proposed satellite mission concept on the climate projection.
Insight of Physical Biases Using Simpler GCM
Marine boundary-layer clouds remain poorly predicted in global climate models due to multiple entangled uncertainty sources. Our recent ACP paper uses the in situ observations from a recent field campaign to constrain and evaluate cloud physics in a simplified version of climate model. Progress and remaining issues in the cloud physics parameterizations are identified. We systematically evaluate the impacts of large-scale forcing, microphysical scheme, and aerosol concentrations on the cloud property.
Stratospheric Water Vapor and Surface Temperature
As an important greenhouse gas, water vapor has great potential to modulate global climate by altering the infrared opacity of the atmosphere. We assess the interactions between stratospheric water vapor and surface temperature using satellite observations and the coupled CESM. Sensitivity experiments show that SWV follows closely with tropical SST on the seasonal time scale, and the response of global mean surface temperature to SWV perturbations over the extratropics is larger than that over the tropics.
Compensating Errors in Latest Climate Simulations
Cloud and radiation biases over the Southern Ocean have been a long-lasting problem in the past generations of global climate models. Our recent paper on Adv. Atmo. Sci. examines the latest CMIP6 climate models and shows compensating errors in the cloud physical properties in spite of overall improvement of radiation simulation over the Southern Ocean. Our study urges the model developers to improve model physical processes — rather than merely focusing on the mean state performance.