The Atmospheric Infrared Sounder (AIRS) on the Aqua platform has observed temperature and water vapor since 2002, while CloudSat and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) have simultaneously observed cloud vertical structure collocated to AIRS for over two years. This talk is partitioned into two primary themes that address (1) the patterns of relative humidity within and outside of ice clouds, and (2) the characteristics of small-scale temperature, water vapor, and cloud water content structures. Both of these issues are of primary concern in climate modeling efforts because more precise and extensive observations like these will be helpful to address deficiencies in climate model representations of upper tropospheric physical processes and sub-grid scale cloud parameterizations.

We find that AIRS shows the highest humidity (RHI), as well as increased frequency of supersaturation with respect to ice, to be coincident or nearly coincident with cirrus cloudiness in the upper troposphere. Cloudy and clear RHI fields show strong seasonal, latitudinal, and height dependences. The modulation of these dependences by dynamical processes is investigated using AIRS temperature variance. We show that the spatial and temporal variability of temperature variance explains a significant portion of the spatial and temporal variability of RHI variance. Therefore, the dynamical processes that modulate the magnitude of temperature variance may hinder the inference of ice nucleation mechanisms from cloudy RHI distributions (as suggested by previous studies).

Furthermore, we present results of variance length scaling within the troposphere using derived temperature and water vapor profiles from AIRS. We show that temperature has a power law exponent closer to -3 in the midlatitudes at length scales > 800 km or so, but closer to -5/3 at scales < 500 km, as observed by various aircraft campaigns and shown by numerical modeling and theoretical studies. The temperature exponent in the tropics at all length scales becomes less negative and is larger than -5/3. For water vapor, the scaling relationships are vastly different from temperature with -5/3 observed in the midlatitudes, and less than -2 in parts of the tropics and subtropics, with little to no scale break observed. Lastly, we investigate the statistical moments of cloud water content (CWC) fields observed by Cloudsat for multiple cloud-types coincident to AIRS. The various moments of CWC distributions reveal coherent altitude, latitudinal, and cloud-type structures that will be useful to constrain assumptions about sub-grid scale distributions of cloud properties in statistical climate model parameterizations.