Validating Sea Ice Forecasts
IASOA observations for validation of sea ice forecasting
Stakeholders in the Arctic whose seasonal activities are determined by localized timing of freeze-up require detailed information about short-term changes in sea
ice conditions. To address this need, the Polar Observations and Processes group within the Physical Science Division (PSD) at NOAA Earth System Research Laboratory (ESRL) is conducting an experimental sea ice forecast using a dynamically coupled ocean-atmosphere-sea ice-land model called RASM-ESRL. The model is run with 10 km horizontal resolution and 40 vertical levels. The coupled system uses state of the art components (WRF, CICE5, CLM) and is forced at the lateral boundaries with GFS forecast fields. The objective of the experiment is to first validate and then improve the representation of cloud-atmospheric boundary layer-surface interactions to improve sea ice forecasts on sub-seasonal-to-seasonal time scales.
The project is partnered with IASOA to carry out model validation of atmospheric and land surface variables, including cloud properties, surface radiation fluxes, and meteorology. Measurements from Barrow, Oliktok Point, Tiksi, Alert, NyÅlesund and Eureka are incorporated. In addition to the IASOA network, validations will also be conducted using observations over the sea ice region
from the Ice Mass Buoy Program (IMB) and the upcoming SeaState campaign to be carried out in the Beaufort and Chuckchi seas as the sea ice freezes in autumn 2015.
One of the most important aspects of the validation efforts is timeliness of data accessibility. RASM-ESRL is being operated experimentally from mid-summer through autumn 2015 and observation-based evaluations conducted in parallel allow the forecast team to better interpret model output and identify problems in advance of the autumn freeze-up during which team members on board the Sikuliaq will use RASM-ESRL forecasts. Data acquisition and accessibility is made possible through the efforts of IASOA, NOAA PSD, NOAA NWS, the US Dept. of Energy (DOE) Atmospheric Radiation Measurement Program (ARM), the Arctic and Antarctic Research Institute (AARI), Environment Canada, and the Cold Regions Research and Engineering Laboratory (CRREL).
The sea ice forecast experiment web page can be accessed here: http://www.esrl.noaa.gov/psd/forecasts/seaice/. Example validation plots from Barrow are also available on the forecast website, here: http://www.esrl.noaa.gov/psd/people/amy.solomon/hindcasts.html. To highlight the value of multi-site comparisons to model output, preliminary plots below show comparisons of relative humidity between radiosoundings from Barrow, Oliktok Point, Alert, Eureka, and Ny-Alesund and RASM-ESRL for the nearest model point to each station.