In 2023, the NASA SnowEx campaign focuses on the tundra and boreal forest regions of Alaska to collect observations of snow in these unique environments. This effort takes place over the winter season starting in the fall of 2022 through spring 2023, and includes a no-/low-snow data acquisition in October 2022, and a snow-on campaign in March 2023 with airborne radar, radiometer, LiDAR and stereophotogrammetry observations, and a snow melt campaign to collect hyperspectral data in April 2023.

SnowEx 2021 was a continuation of the Time Series (TS) campaign from SnowEx 2020 and included measurements at a subset of the sites from the 2020 campaign in Idaho, Utah, and Colorado, as well as an additional prairie site in central Montana. Baseline measurements began in December of 2020 and extended into April 2021 for most sites, providing observations of seasonal melt in some cases.
SnowEx 2021 snow pit measurements were central to the ground sampling strategy and matched the experiment design from the 2020 campaign. However, the interval board sampling, or weekly measurements of new snowfall and SWE, expanded at most locations. In 2020 most interval boards were co-located with a snow pit, while for 2021 most sites distributed an array of 5-8 boards to sample a range of elevations and aspects. Interval boards are an important ground validation observation to pair with the airborne UAVSAR data. Unused flight hours from SnowEx 2020 (due to the Covid-19 pandemic) were applied to weekly observations of 2021 TS sites. The SnowEx 2021 TS campaign also included albedo measurements taken in Colorado using AVIRIS-NG, a visible/infrared imaging spectrometer.

2020 Time Series Western U.S.
The Time Series Campaign focused on calibration and validation of a SWE retrieval approach using L-band InSAR, leveraging the NASA JPL airborne UAVSAR and several existing study sites throughout the western US. Baseline TS measurements began in December 2019, with weekly measurements occurring from January - March 2020, with two sites extending into the melt season and ending in early May 2020.
2020 Intensive Observation Period Grand Mesa, CO
The primary objectives of the Grand Mesa IOP are to test and validate SWE retrieval from active and passive microwave sensors, and to quantify subpixel variability in thermal IR signatures to assess the value of kilometer-scale satellite IR observations (e.g., GOES-16) for snow energy balance modeling.

SnowEx 2017 was the first in a multi-year series of airborne remote sensing campaigns, designed to address gaps in snow retrieval techniques in preparation for a future snow satellite mission. This field campaign targeted the impact of increasing forest density on both snow remote sensing uncertainty and on snowpack processes. A variety of sensor types were flown to collect multi-sensor airborne data.