Arctic Amplification metrics

Davy, Richard and Chen, Linling and Hanna, Edward (2018) Arctic Amplification metrics. International Journal of Climatology, 38 (12). pp. 4384-4394. ISSN 0899-8418

Full content URL: http://doi.org/10.1002/joc.5675

Documents
Arctic Amplification metrics
[img]
[Download]
[img]
Preview
PDF
__network.uni_staff_S1_ehanna_Downloads_AAmetrics.pdf - Whole Document

1MB
Item Type:Article
Item Status:Live Archive

Abstract

One of the defining features of both recent and historical cases of global climate change is Arctic Amplification (AA). This is the more rapid change in the surface air temperature (SAT) in the Arctic compared to some wider reference region, such as the Northern Hemisphere (NH) mean. Many different metrics have been developed to quantify the degree of AA based on SAT anomalies, trends and variability. The use of different metrics, as well as the choice of dataset to use can affect conclusions about the magnitude and temporal variability of AA. Here we review the established metrics of AA to see how well they agree upon the temporal signature of AA, such as the multi-decadal variability, and
16 assess the consistency in these metrics across different commonly-used datasets which cover both the early and late 20th century warming in the Arctic. We find the NOAA 20th Century Reanalysis most closely matches the observations when using metrics based upon SAT trends (A2), variability (A3) and regression (A4) of the SAT anomalies, and the ERA 20th 19 Century Reanalysis is closest to the observations in the SAT anomalies (A1) and variability of SAT anomalies (A3). However, there are large seasonal differences in the consistency between datasets. Moreover, the largest differences between the century-long reanalysis products and observations are during the early warming period, likely due to the sparseness of the observations in the Arctic at that time. In the modern warming period, the high density of observations strongly constrains all the reanalysis products, whether they include satellite observations or only surface observations. Thus, all the reanalysis and observation products produce very similar magnitudes and temporal variability in the degree of AA during the recent warming period.

Keywords:Arctic amplification, Northern Hemisphere, metrics, reanalysis, surface-based observations, climate, atmosphere
Subjects:F Physical Sciences > F860 Climatology
Divisions:College of Science > School of Geography
Related URLs:
ID Code:31738
Deposited On:20 Apr 2018 14:31

Repository Staff Only: item control page