This seminar will be Zoom only.
Zoom Info: If you’re interested in attending virtually, please contact Jem Averyt: Jem.Averyt@lasp.colorado.edu
Abstract: The two active sensors belong to NASA A-train mission, i.e., Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) lidar aboard Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) and Cloud Profiling Radar (CPR) radar aboard CloudSat have provided detailed information about the cloud structures. In this study, we combine CALIPSO and CloudSat (CALCS) active sensor measurements to examine cloud volume changes over the Pacific and compare the results with Moderate Resolution Imaging Spectroradiometer (MODIS) passive measurements. It is shown that CALCS and MODIS capture similar features of cloud volumes related to El Niño–Southern Oscillation (ENSO) events. Over the eastern Pacific during the El Niño season, increased relative humidity (RH) anomalies caused the increase of mid and high cloud volumes. However, MODIS often misses thin cirrus cloud changes in high altitudes and mid-level clouds are overestimated. As a result, the correlation between RH and cloud volume anomalies is higher when CALCS observations are used, compared to MODIS. Both MODIS and CALCS low cloud anomalies are well explained by estimated inversion strength (EIS) and sea surface temperature (SST) anomalies. However, larger fluctuations are noted in MODIS low cloud anomalies, partly due to the overlapping cloud effects in passive measurements. Also, the cloud base heights of mid and high-level clouds are underestimated by MODIS retrievals, causing smaller impacts on the low troposphere cloud amounts. However, CALCS measurements indicate that cloud base heights of mid/high-level clouds are often below 3 km, and the changes of mid/high clouds are largely compensated with low-level cloud changes.
Zoom Info: If you’re interested in attending virtually, please contact Jem Averyt to be added to the mailing list: Jem.Averyt@lasp.colorado.edu
Address Info:
LASP – Space Science Building
SPSC-W120
3665 Discovery Drive, Boulder, CO 80303
The Physics Frontiers Centers (PFC) program supports university-based centers and institutes where the collective efforts of a larger group of individuals can enable transformational advances in the most promising research areas. The program is designed to foster major breakthroughs at the intellectual frontiers of physics by providing needed resources such as combinations of talents, skills, disciplines, and/or specialized infrastructure, not usually available to individual investigators or small groups, in an environment in which the collective efforts of the larger group can be shown to be seminal to promoting significant progress in the science and the education of students. PFCs also include creative, substantive activities aimed at enhancing education, broadening participation of traditionally underrepresented groups, and outreach to the scientific community and general public.