Validation of CYGNSS Surface Winds using In Situ Marine Observations in the Maritime Continent Region

Surface wind plays a crucial role in many local/regional weather and climate processes and helps to shape the global climate system, particularly the exchanges of energy, mass and momentum across the Earth’s surface. However, there is a lack of consistent high-quality observations, especially over the tropical ocean. The recently launched NASA Cyclone Global Navigation Satellite System (CYGNSS) mission remotely measures near surface wind speed over the tropical ocean with high sampling rates both temporally and spatially. In the early phase of the mission, validation is a critical task, and over-ocean validation is typically challenging due to a lack of robust validation resources that cover a variety of environmental conditions. Moreover, it can also be challenging to obtain in-situ observation resources with co-located CYGNSS records for some of the more scientifically interesting regions, such as the Maritime Continent (MC). The MC is regarded as a key tropical driver for the mean global circulation as well as important large-scale circulation variability such as the Madden-Julian Oscillation (MJO). The focus of this project and analysis is to take advantage of local in-situ resources from the MC regions (e.g. volunteer shipping and the Year of Maritime Continent (YMC) campaign) in order to quantitatively characterize and validate the CYGNSS derived winds in the MC region, which in turn work to unravel the complex multi-scale interactions that occur in MC, including the diurnal cycle, synoptic variations, MJO, ENSO, etc. This presentation will show preliminary results of a comparison between the CYGNSS derived wind speed with land/ship-based surface wind measurements focusing on the MC region. The quality of surface winds will be further assessed with the Advanced Scatterometer (ASCAT) under different precipitation conditions characterized by the Global Precipitation Measurement GPM. Details about the validation methods and challenges associated with the current results will be discussed in this presentation.