Xiquan Dong (PI)
University of North Dakota
dong@aero.und.edu

Comparison of Cloud Fraction, Height/Temperature, and Microphysical Properties Between GISS SCM, NASA MODIS, and DOE ARM SGP Data

This proposed research is in response to the announcement of NASA NN-H-04-Z-YS-008-N, in particular for “a new Cloud Modeling and Analysis Initiative (CMAI)”, using three data sets: NASA GISS Single Column Model (SCM) simulations, NASA MODIS satellite results, and DOE ARM surface data over the ARM Southern Great Plains (SGP) site during the period of 2000-2003. Based on the 4-year three data sets, we propose to provide (1) cloud amount and height/temperature of different kind of clouds, and (2) single-layer low, middle, and high cloud microphysical properties. In the first objective, we will first provide and compare the seasonal/monthly/hourly variations and their corresponding vertical distributions of total cloud amount between three data sets. Then we will further classify the clouds into 10 categories, such as single-layer low (<3km), middle (3-6 km), and high (>6km) cloud amounts, as well as multilayer clouds. Next we will compare the satellite view of low, middle, and high clouds with the surface observations, and study how many (%) low/middle clouds under high clouds were not observed by satellite, and finally reconcile the surface and satellite estimations of cloud amounts.   Eventually we will compare both surface and satellite results with the model simulations, understand the physical processes associated with cloud formation, maintenance, and dissipation, and modify the existing cloud parameterizations if necessary. The cloud height and temperature comparison will help us to identify the reasons why they (3 data sets) agree or do not agree. In the second objective, we will do the similar study to the first objective, but focus on the microphysical/optical properties of single-layer low, middle, and high clouds. From the comparison, we want to know if they agree to each other if all of three data sets have correct cloud microphysical properties. If not, what are the reasons for leading to this discrepancy?  We will simply compare the statistical results over many events, rather than case-to-case comparison. However, we will use the same criteria for three data sets during comparison.         These two objectives will help ESE to partially answer the following three questions:  (1) What are the effects of clouds on Earth’s climate? (2) How can predications of climate variability and change be improved? (3) How well can transient climate variations be understood and predicated? We have set up a permanent website for publishing the results for the scientific community (http://people.aero.und.edu/~dong/result.html). It is our goal to eventually improve the representation of clouds in climate models and to have more accurate climate predications using satellite and surface observations. This research team is unique because we bring to bear documented expertise in the proposed research areas: model (Dr. Del Genio), satellite remote sensing (Dr. Minnis), and surface remote sensing (Dr. Dong), and we are confident that we can complete the proposed research if the proposal is funded.

+ Back to Participant Listing