Monday, 13 January 2020
Hall B1 (Boston Convention and Exhibition Center)
While the Earth’s climate is often represented by changes in average temperature, there are many feedback processes that exhibit strong influences on the full climate system, including coverage of ice at the poles, oceanic circulation, biomass distribution, cloud coverage and other atmospheric phenomena. Because the poles are the least regularly observed region on the globe yet are vital for understanding the current and future state of the climate, the Ice, Cloud, and Land-Elevation Satellite-2 (ICESat-2) launched in September 2018 and is providing frequent high-resolution observations of polar ice and its changes over various timescales. Several of the benefits of this satellite is that it also provides information regarding atmospheric cloud and aerosol layers, ocean wave conditions, and vegetation distribution in locations where present observations are sparse or non-existent.
For this study, we are exploring the effects of clouds and aerosols on the ICESat-2 return signal rate for various surface types. Because of the laser wavelength, the ICESat-2 science team expected a significant decrease in signal return rates in the presence of clouds. The effect of clouds, which is dependent on thickness and height, is to detrimentally impact the surface determination, with higher difficulty on less reflective surfaces. However, the data show that surface signal is being returned even under a multitude of cloud types. The goal here is to determine the representative cloud optical depths relative to photon density within cloud layers over various surface types, including snow/ice, land (with and without vegetation), and water (ocean/lakes). An analysis of the surface return rates for each type will then be computed as a function of cloud optical depth. Individual cloud layer optical depths are not currently being produced for ICESat-2, but if we have a better understanding of this relationship, we can assess the limitations of the various data products that would be used for future applications. Combination with other satellite cloud data, such as CloudSat or MODIS, are used as validation for the cloud properties determined from ICESat-2.
For this study, we are exploring the effects of clouds and aerosols on the ICESat-2 return signal rate for various surface types. Because of the laser wavelength, the ICESat-2 science team expected a significant decrease in signal return rates in the presence of clouds. The effect of clouds, which is dependent on thickness and height, is to detrimentally impact the surface determination, with higher difficulty on less reflective surfaces. However, the data show that surface signal is being returned even under a multitude of cloud types. The goal here is to determine the representative cloud optical depths relative to photon density within cloud layers over various surface types, including snow/ice, land (with and without vegetation), and water (ocean/lakes). An analysis of the surface return rates for each type will then be computed as a function of cloud optical depth. Individual cloud layer optical depths are not currently being produced for ICESat-2, but if we have a better understanding of this relationship, we can assess the limitations of the various data products that would be used for future applications. Combination with other satellite cloud data, such as CloudSat or MODIS, are used as validation for the cloud properties determined from ICESat-2.
- Indicates paper has been withdrawn from meeting
- Indicates an Award Winner