Mutual information forecasts for optimal adaptive sampling guidance

Analysis and Forecasts for 29 Jun 0000Z to 06 Jul 0000Z 2025, Issued 29 Jun 2025

Measuring T,S    Verifying against σ_T

We use our mutual information (MI) forecasts between candidate observation locations and future regional field or variables of interest (target or verification field/variables) to predict the most informative future data locations. We use our MIT MSEAS ensemble forecast to predict these MI fields.

For the MI fields that we show in the table below, the goal is to predict the location of candidate future glider observations (temperature and salinity profiles) on different days (00Z June 29 to 00Z July 6) that are the most informative about the target σ_T, on 00Z July 7, 2025, in the region of the forecast neck of the LC and its uncertainty.

• The candidate glider observations at each location in the domain occur at the times indicated in the headers of each MI plot. These glider temperature (T) and salinity (S) profiles are assumed taken at the 0m, 50m, 150m, 300m and 500m depths, unless these depths are below the topography, in which case the depths are equally redistributed.
• The target (verification) variables are the σ_T fields in the region of the forecast neck of the LC and its uncertainty at 00Z on June 28, 2025. These fields are defined by σ_T profiles at all the locations shown by green stars taken together, at 00Z on July 7, 2025, at 150m, 300m, and 500m depths (in the region of the forecast neck of the LC and its uncertainty).

The locations with highest MI (bright yellow) on each day indicate where glider T and S profile observations are predicted to be most informative about the neck of the LC and its uncertainty at 00Z on July 7, 2025. The results indicate that initially sampling in northwest corner of the neck array is best. As the measurement time gets closer to the verification time, the best sampling region moves southeast with the whole array emphasized.

00Z June 29 2025	00Z June 30 2025	00Z July 1 2025
00Z July 2 2025	00Z July 3 2025	00Z July 4 2025
00Z July 5 2025	00Z July 6 2025