Revisiting the contemporary sea-level budget on global and regional scales
<jats:p>Dividing the sea-level budget into contributions from ice sheets and glaciers, the water cycle, steric expansion, and crustal movement is challenging, especially on regional scales. Here, Gravity Recovery And Climate Experiment (GRACE) gravity observations and sea-level anomalies from altimetry are used in a joint inversion, ensuring a consistent decomposition of the global and regional sea-level rise budget. Over the years 2002–2014, we find a global mean steric trend of 1.38 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 0.16 mm/y, compared with a total trend of 2.74 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 0.58 mm/y. This is significantly larger than steric trends derived from in situ temperature/salinity profiles and models which range from 0.66 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 0.2 to 0.94 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 0.1 mm/y. Mass contributions from ice sheets and glaciers (1.37 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 0.09 mm/y, accelerating with 0.03 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 0.02 mm/y<jats:sup>2</jats:sup>) are offset by a negative hydrological component (−0.29 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 0.26 mm/y). The combined mass rate (1.08 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 0.3 mm/y) is smaller than previous GRACE estimates (up to 2 mm/y), but it is consistent with the sum of individual contributions (ice sheets, glaciers, and hydrology) found in literature. The altimetric sea-level budget is closed by coestimating a remaining component of 0.22 ± 0.26 mm/y. Well above average sea-level rise is found regionally near the Philippines (14.7 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 4.39 mm/y) and Indonesia (8.3 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 4.7 mm/y) which is dominated by steric components (11.2 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 3.58 mm/y and 6.4 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 3.18 mm/y, respectively). In contrast, in the central and Eastern part of the Pacific, negative steric trends (down to −2.8 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 1.53 mm/y) are detected. Significant regional components are found, up to 5.3 <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mo>±</m:mo></m:math></jats:inline-formula> 2.6 mm/y in the northwest Atlantic, which are likely due to ocean bottom pressure variations.</jats:p>