CMSS student Oscar Garcia used altimetry data from a new satellite to explore links between sea surface anomalies and hurricane tracks during his summer at the NASA Goddard Space Flight Center

The goal of the project was to use ICESat data altimetry as a new tool to analyze hurricanes. The birth of a hurricane, called cyclogenesis, occurs when an atmospheric cyclone is created as air is warmed by anomalously warm sea surface temperatures, exceeding 26° Celsius. As the air rises, an atmospheric low pressure cell is created in such a way that if this low pressure cell is near the equator, it will produce counter-clock wise rotating winds around the low pressure center, an effect of the Earth's rotation. As warm water temperatures persist, heat and moisture continue to be transferred from the ocean to the atmosphere allowing hurricanes make progress on their paths. Additionally, the intensification of hurricanes involves a combination of favorable atmospheric conditions such as trough interactions and vertical shear. For a long time the upper ocean thermal structure was thought to play only a marginal role in hurricane intensification. However, after a series of events where the sudden intensification of hurricanes occurred when their paths passed over oceanic warm features, it is now important to consider that the upper ocean plays a crucial role in this process. The ICESat laser altimeter, with a footprint of 70 m provides data much closer to the coast. Therefore, the purpose of this study was to analyze the ICESat satellite ocean product (GLA 15) and compare it to the radar altimeter data from TOPEX/Jason.  While the main objective is to supplement the radar altimeter measurements of oceanic mesoscale variability, the initial objective is to investigate whether anomalies in the surface topography could be detected satisfactorily by the ICESat Geoscience laser altimeter for identifying zones where intensification of hurricanes occurred. In the region bounded by 100° to 60° west longitude and from 0° to 40° North latitude the GLAS data is compared to radar altimetry.

The nature of data coming from ICESat allows identification of Sea Level Anomalies. ICESat calculations of sea level and mesoscale variability are demonstrated and compared to calculations from TOPEX/POSEIDON and JASON Satellites. A systematic error from 20 to 30 cm between ICESat altimetry and Jason Sea Level Anomalies was observed and could be explained by the differences in the geoid and tide models used for each satellite. After fixing this difference, ICESat is able to match TOPEX/POSEIDON and Jason detection of major sea level anomaly and mesoscale variability features in the area under study.

Satellite laser ranging uses lasers to measure ranges from ground stations to satellite borne retro-reflectors to the millimeter level. The primary mission of the ILRS as stated in the organization's Terms of Reference is "to support, through satellite and lunar laser tracking data and related products, geodetic and geophysical research activities."

Oscar Garcia is one of the members of our first CMSS class.  He is a Mexican National from Tampico.  Oscar holds a Masters Degree in Quality Systems from the Instituto de Estudios Superiores de Tamaulipas, Mexico (2003) and a Bachelor of Engineering in Electronics degree from the Instituto Tecnologico de Ciudad Madero, Mexico (1996).  Gary Jeffress is co-chair of his graduate advisory committee and tentative other members of his committee include Pablo Tarazaga and Ian MacDonald.  At the end of his first year of studies at TAMU-CC Oscar was invited to an 11 week internship at the NASA Goddard Space Flight Center in Greenbelt, Maryland (NASA Graduate Student Summer Program at the Goddard Earth Sciences and Technology Center (GEST)).  There he worked with mentor Dr. Daniel Jacob as part of the Laboratory of Hydrospheric and Biospheric Sciences.

Read Oscar's research paper