Abstract
Falling snow is a key component of the Earth’s water cycle, and space-based observations provide the best current capability to evaluate it globally. The Cloud Profiling Radar (CPR) on board CloudSat is sensitive to snowfall, and other satellite missions and climatological models have used snowfall properties measured by it for evaluating and comparing against their snowfall products. Since a battery anomaly in 2011, the CPR has operated in a Daylight-Only Operations (DO-Op) mode, in which it makes measurements primarily during only the daylit portion of its orbit. This work provides estimates of biases inherent in global snowfall amounts derived from CPR measurements due to this shift to DO-Op mode. We use CloudSat’s snowfall measurements during its Full Operations (Full-Op) period prior to the battery anomaly to evaluate the impact of the DO-Op mode sampling. For multi-year global mean values, the snowfall fraction during DO-Op changes by −10.16% and the mean snowfall rate changes by −8.21% compared with Full-Op. These changes are driven by the changes in sampling in DO-Op and are very little influenced by changes in meteorology between the Full-Op and DO-Op periods. The results highlight the need to sample consistently with the CloudSat observations or to adjust snowfall estimates derived from CloudSat when using DO-Op data to evaluate other precipitation products.
Highlights
Facing a warming climate, increasingly detailed and complete information is necessary to understand changes in the water and energy budgets and reduce uncertainties in predictions of future climate
This study compares CloudSat snowfall measurements taken during the Full Operations (Full-Op) period against those taken during the Daylight-Only Operations (DO-Op) period to assess the impact of this change in sampling on snowfall properties estimated from the CloudSat snowfall product
The analyses focus on the 2C-SNOW-PROFILE (2CSP) version R05 CloudSat product [20]
Summary
Increasingly detailed and complete information is necessary to understand changes in the water and energy budgets and reduce uncertainties in predictions of future climate. This study compares CloudSat snowfall measurements taken during the Full-Op period against those taken during the DO-Op period to assess the impact of this change in sampling on snowfall properties estimated from the CloudSat snowfall product. These impacts have the potential to influence the interpretation of comparisons against model simulations and other snowfall products and so need to be quantified. After a data and methods section (Section 2), this study describes the spatial and temporal sampling biases common to all CloudSat products due to the transition from Full-Op to DO-Op (Section 3) and focuses on the impact of the transition on estimates of longer-term variations in snowfall detection and quantification (Section 4).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
