PO.DAAC

The Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission, a joint partnership between NASA and the German Research Centre for Geosciences (GFZ), launched on 22 May 2018. It uses twin satellites to accurately map month-to-month variations in the Earth's gravity field and surface mass changes. It will continue the legacy data record of the first Gravity Recovery and Climate Experiment (GRACE) mission (2002-2017).

Conceptually very similar to the original GRACE mission, GRACE-FO consists of two identical satellites flying in formation around Earth at an initial altitude of approximately 490 kilometers and a nominal separation distance of 220+/-50 kilometers. Instruments on board the satellites precisely measure changes in the distance between them due to orbital perturbations caused by geographical and temporal variations in Earth's gravity field.

GRACE-FO will expand GRACE's legacy of scientific achievements. These include tracking mass changes in Earth's polar ice sheets and mountain glaciers (which impacts global sea level); estimating total water storage on land (from groundwater changes in deep aquifers to changes in soil moisture and surface water); inferring changes in deep ocean currents, a driving force in climate; and even measuring changes within the solid Earth itself, such as postglacial rebound and the impact of major earthquakes.

Figure 1. The global monthly mass anomalies distribution for Jan-2019 from GRACE-FO Level-3 Release-06 data

GRACE-FO mission datasets are archived and distributed by the PO.DAAC. The TELLUS GRACE-FO Level-3 Release-06 (RL06) datasets are described and discoverable via the PO.DAAC dataset information pages.  The dataset information pages also provide access to the technical documentation, GRACE-FO Level-3 User Handbook, and guidance on how to cite the data.

The SPURS (Salinity Processes in the Upper Ocean Regional Study) project is a NASA-funded oceanographic process study and associated field program that aims to elucidate key mechanisms responsible for near-surface salinity variations in the oceans. SPURS employs a suite of state-of-the-art in-situ sampling technologies that, combined with remotely sensed salinity fields from the Aquarius/SAC-D, SMAP and SMOS satellites, provide a detailed characterization of salinity structure over a continuum of spatio-temporal scales. While SPURS-1 focused on the salinity maximum region of the sub-tropical N. Atlantic, SPURS-2 concentrated on the dynamic and seasonally variable, rainfall-dominated region of the eastern tropical Pacific centered at 10°N, 125°W.  The SPURS-2 campaign involved two month-long cruises by the R/V Revelle in August-September 2016 and October-November 2017 combined with complementary sampling on a more continuous basis over this period by the schooner Lady Amber.

This second SPURS-2 data release includes an additional six of what will ultimately be a total of twenty eight in-situ datasets produced during the SPURS-2 field campaign that will be archived and distributed by the PO.DAAC.  Datasets comprising this release include: salinity snake, waveglider, rawinsonde, underway CTD (UCTD), underway surface profiling system (USPS) and associated thermosalinograph (TSG) data, and continuous flux technique (CFT) video imagery data.  Sample data plots of several of these datasets are illustrated in figure 1 below.

SPURS-2 Resources at PO.DAAC:

• PODAAC SPURS Mission Page: https://podaac.jpl.nasa.gov/spurs
• SPURS2 Dataset Landing Pages: https://podaac.jpl.nasa.gov/datasetlist?search=SPURS2

Figure 1.  A+B) Rawinsonde trajectory map and temperature profile time series, C+D) Salinity snake mapped SSS + temperature, time series, E+F) Waveglider salinity at 2m trajectory and times series, G+H) uCTD temperature time series and vertical profile series.