Dynamic ocean topography of the northern Nordic seas: a comparison between satellite altimetry and ocean modeling
<p>The dynamic ocean topography (DOT) of the polar seas can be described by satellite altimetry sea surface height observations combined with geoid information as well as by ocean models. The altimetry observations are characterized by an irregular sampling and seasonal sea ice coverage compli...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-02-01
|
| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/13/611/2019/tc-13-611-2019.pdf |
| Summary: | <p>The dynamic ocean topography (DOT) of the polar seas can be
described by satellite altimetry sea surface height observations combined
with geoid information as well as by ocean models. The altimetry observations are
characterized by an irregular sampling and seasonal sea ice coverage
complicating reliable DOT estimations. Models display various spatiotemporal
resolutions but are limited to their computational and mathematical context
and introduced forcing models. In the present paper, ALES+ retracked
altimetry ranges and derived along-track DOT heights of ESA's Envisat and
water heights of the Finite Element Sea Ice-Ocean Model (FESOM)
are compared to investigate similarities and discrepancies. The goal of the present paper is to
identify to what extent pattern and variability of the northern Nordic seas derived from
measurements and model agree with each other, respectively.
The study period covers the years 2003–2009. An assessment analysis regarding seasonal
DOT variabilities shows good agreement and confirms the dominant impact of the annual
signal in both datasets. A comparison based on estimated regional annual signal components
shows 2–3 times stronger amplitudes of the observations but good agreement of the phase.
Reducing both datasets by constant offsets and the annual signal reveals small regional
residuals and highly correlated DOT time series (Pearson linear correlation coefficient of at
least 0.67). The highest correlations can be found in areas that are ice-free and affected by
ocean currents. However, differences are visible in sea-ice-covered shelf regions. Furthermore,
remaining constant artificial elevations in the observational data can be
attributed to an insufficient
representation of the used geoid. In general, the comparison results in good agreement between
simulated and altimetry-based descriptions of the DOT in the northern Nordic seas.</p> |
|---|---|
| ISSN: | 1994-0416 1994-0424 |