2023 AMSS Abstract Book

Bering Sea | Climate and Oceanography

A simplistic forecast for Alexandrium in the Gulf of Alaska based on Sea Surface Temperature Presenter: Timothy Wynne , timothy.wynne@noaa.gov , NOAA Steve Kibler , steve.kibler@noaa.gov , NOAA Kaytee Pokrzywinski , kaytee.pokrzywinski@noaa.gov , NOAA Alexandrium has been routinely observed in the Gulf of Alaska in concentrations high enough to cause human health risks due to their ability to produce potent saxitoxins. Here we will create a forecast product based on a habitat suitability model. There have been a number of published studies that indicate that either warming temperatures and/ or a certain temperature threshold range is preferred by Alexandrium. Satellite derived Sea-Surface Temperature (SST) data from the Visible Infrared Imaging Radiometer Suite (VIIRS) will be downloaded and processed at its native 750- meter pixel size from the start of the mission (2012) through the present. The initial forecast will be based on three separate SST products. The first product is based on a preferred temperature range reported to be between 7o C and 15o C. The second product will be a monthly climatological anomaly. A climatological mean will be processed for each month. Individual months will then be subtracted from the monthly climatology to create a monthly SST anomaly. The third product that will be considered will be created in a similar fashion but using a 10-day climatological mean. For each 10-day period a climatological mean will be calculated. Each 10-day mean will then be subtracted from the 10-day climatological mean to create a 10-day anomaly. Each subsequent 10-day time period will be assigned a score between 0 and three. If the SST is between 7o C and 15o C, one point will be given. If the monthly climatological anomaly is positive an additional point will be given. If the 10-day SST anomaly is positive an additional point will be given. In this fashion a score of zero (bloom unlikely, i.e. none of the three conditions were met) to three (bloom likely, i.e. all three conditions were met) will be assigned. Future work will attempt to incorporate remotely sensed chlorophyll into the forecast.

Alaska Marine Science Symposium 2023 30 7

Made with FlippingBook flipbook maker