Decadal changes in the leading patterns of sea level pressure  in the Arctic and their impacts on the sea ice variability  in boreal summer

Abstract. Besides its negative trend, the interannual and the interdecadal changes in the Arctic sea ice have also been pronounced in recent decades. The three leading modes in the sea level pressure (SLP) variability in the Arctic (70–90∘ N) – the Arctic Oscillation (AO), the Arctic Dipole (AD), and the third mode (A3) – are analyzed to understand the linkage between sea ice variability and large-scale atmospheric circulation in boreal summer (June–August). This study also compares the decadal changes of the modes between the early (1982–1997) and the recent (1998–2017) periods and their influences on the Arctic sea ice extent (SIE). Only the AD mode shows a significant correlation increase with SIE in summer (JJA) from −0.05 in the early period to 0.57 in the recent period. The AO and the A3 modes show a less significant relationship with SIE for the two periods. The AD is characterized by a dipole pattern of SLP, which modulates the strength of meridional surface winds and the Transpolar Drift Stream (TDS). The major circulation change in the late 1990s is that the direction of the wind has been changed more meridionally over the exit region of the Fram Strait, which causes sea ice drift and discharge through that region. In addition, the response of surface albedo and the net surface heat flux becomes larger and much clearer, suggesting a positive sea-ice–albedo feedback in the sea ice variability associated with the AD. The analysis also reveals that the zonal shift of the centers of SLP anomalies and associated circulation change affects a significant reduction in sea ice concentration over the Pacific sector of the Arctic Ocean. This study further suggests that the Pacific Decadal Oscillation (PDO) phase change could influence the spatial pattern change in the AD.

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Decadal Changes in the Leading Patterns of Sea Level Pressure in the Arctic and Their Impacts on the Sea Ice Variability in Boreal Summer

10.5194/tc-2019-18 ◽

2019 ◽

Author(s):

Nakbin Choi ◽

Kyu-Myong Kim ◽

Young-Kwon Lim ◽

Myong-In Lee

Keyword(s):

Sea Ice ◽

Sea Level ◽

Arctic Sea Ice ◽

The Arctic ◽

Boreal Summer ◽

Sea Level Pressure ◽

Level Pressure ◽

The Pacific ◽

Circulation Change ◽

Arctic Sea

Abstract. Besides its negative trend, the interannual and the interdecadal changes in the Arctic sea ice are also pronounced in recent decades. The three leading modes in the sea level pressure (SLP) variability in the Arctic (70°–90 °N) – the Arctic Oscillation (AO), the Arctic Dipole (AD), and the third mode (A3) – are analyzed to understand the linkage between sea ice variability and large-scale atmospheric circulation in boreal summer (June–August). This study also compares the decadal changes of the modes between the early (1982–1997) and the recent (1998–2017) periods and their influences on the Arctic sea ice extent (SIE). Only the AD mode shows a significant correlation increase with SIE from −0.05 in the early period to 0.57 in the recent period. The AO and the A3 modes show a less significant relationship with SIE for the two periods. The AD is characterized by a dipole pattern of SLP, which modulates the strength of meridional surface winds and the transpolar drift stream (TDS). The major circulation change in the late 1990s is that the direction of the wind has been changed more meridionally over the exit region of the Fram Strait, which causes sea ice drift and discharge through that region. The analysis also reveals that the zonal shift of the centers of SLP anomalies and associated circulation change affects a significant reduction in sea ice concentration over the Pacific sector of the Arctic Ocean. This study further suggests that the Pacific Decadal Oscillation (PDO) phase change could influence the spatial pattern change in the AD.

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The Arctic sea ice extent change connected to Pacific decadal variability

The Cryosphere ◽

10.5194/tc-14-693-2020 ◽

2020 ◽

Vol 14 (2) ◽

pp. 693-708

Author(s):

Xiao-Yi Yang ◽

Guihua Wang ◽

Noel Keenlyside

Keyword(s):

Sea Ice ◽

Sea Level ◽

Annual Cycle ◽

Bering Sea ◽

Arctic Sea Ice ◽

The Arctic ◽

Sea Ice Extent ◽

Sea Level Pressure ◽

Level Pressure ◽

Arctic Sea

Abstract. After an unprecedented retreat, the total Arctic sea ice cover for the post-2007 period is characterized by low extent and a remarkable increase in annual cycle amplitude. We have identified the leading role of spring Bering Sea ice in explaining the changes in the amplitude of the annual cycle of total Arctic sea ice. In particular, these changes are related to the recent occurrence of multiyear variability in spring Bering Sea ice extent. This is due to the phase-locking of the North Pacific Gyre Oscillation (NPGO) and the Pacific Decadal Oscillation (PDO) after about 2007, with a correlation coefficient reaching −0.6. Furthermore, there emerge notable changes in the sea level pressure and sea surface temperature patterns associated with the NPGO in the recent decade. After 2007, the NPGO is related to a quadrupole of sea level pressure (SLP) anomalies that is associated with the wind stress curl and Ekman pumping rate anomalies in the Bering deep basin; these account for the change in Bering Sea subsurface variability that contribute to the decadal oscillation of the spring Bering Sea ice extent.

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Supplementary material to "Decadal Changes in the Leading Patterns of Sea Level Pressure in the Arctic and Their Impacts on the Sea Ice Variability in Boreal Summer"

10.5194/tc-2019-18-supplement ◽

2019 ◽

Author(s):

Nakbin Choi ◽

Kyu-Myong Kim ◽

Young-Kwon Lim ◽

Myong-In Lee

Keyword(s):

Sea Ice ◽

Sea Level ◽

The Arctic ◽

Boreal Summer ◽

Sea Level Pressure ◽

Level Pressure ◽

Supplementary Material

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Outflow of Arctic Ocean Sea Ice into the Greenland and Barents Seas: 1979–2007

Journal of Climate ◽

10.1175/2008jcli2819.1 ◽

2009 ◽

Vol 22 (9) ◽

pp. 2438-2457 ◽

Cited By ~ 135

Author(s):

R. Kwok

Keyword(s):

Sea Ice ◽

Sea Level ◽

Arctic Sea Ice ◽

The Arctic ◽

Positive Trend ◽

Fram Strait ◽

Sea Level Pressure ◽

Level Pressure ◽

Franz Josef Land ◽

The Mean

Abstract Twenty-nine years of Arctic sea ice outflow into the Greenland and Barents Seas are summarized. Outflow is computed at three passages: Fram Strait, between Svalbard and Franz Josef Land (S–FJL), and between Franz Josef Land and Severnaya Zemlya (FJL–SZ). Ice drift at the flux gates has been reprocessed using a consistent and updated time series of passive microwave brightness temperature and ice concentration (IC) fields. Over the record, the mean annual area outflow at the Fram Strait is 706(113) × 103 km2; it was highest in 1994/95 (1002 × 103 km2) when the North Atlantic Oscillation (NAO) index was near its 29-yr peak. The strength of the “Transpolar Drift Stream” (TDS) was high during the late 1980s through the mid-1990s. There is no statistically significant trend in the Fram Strait area flux. Even though there is a positive trend in the gradient of cross-strait sea level pressure, the outflow has not increased because of a negative trend in IC. Seasonally, the area outflow during recent summers (in 2005 and 2007) has been higher (> 2σ from the mean) than average, contributing to the decline of summer ice coverage. Without updated ice thickness estimates, the best estimate of mean annual volume flux (between 1991 and 1999) stands at ∼2200 km3 yr−1 (∼0.07 Sv: Sv ≡ 106 m3 s−1). Net annual outflow at the S–FJL passage is 37(39) × 103 km2; the large outflow of multiyear ice in 2002–03, marked by an area and volume outflow of 141 × 103 km2 and ∼300 km3, was unusual over the record. At the FJL–SZ passage, there is a mean annual inflow of 103(93) × 103 km2 of seasonal ice into the Arctic. While the recent pattern of winter Arctic circulation and sea level pressure (SLP) has nearly reverted to its conditions typical of the 1980s, the summer has not. Compared to the 1980s, the recent summer SLP distributions show much lower SLPs (2–3 hPa) over much of the Arctic. Overall, there is a strengthening of the summer TDS. Examination of the exchanges between the Pacific and Atlantic sectors shows a long-term trend that favors the summer advection of sea ice toward the Atlantic associated with a shift in the mean summer circulation patterns.

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Patterns of Sea Ice Retreat in the Transition to a Seasonally Ice-Free Arctic

Journal of Climate ◽

10.1175/jcli-d-15-0733.1 ◽

2016 ◽

Vol 29 (19) ◽

pp. 6993-7008 ◽

Cited By ~ 16

Author(s):

Patricia DeRepentigny ◽

L. Bruno Tremblay ◽

Robert Newton ◽

Stephanie Pfirman

Keyword(s):

Sea Ice ◽

Sea Level ◽

Large Scale ◽

System Model ◽

The Arctic ◽

Sea Level Pressure ◽

Level Pressure ◽

The Pacific ◽

Ice Retreat ◽

Sea Ice Retreat

Abstract The patterns of sea ice retreat in the Arctic Ocean are investigated using two global climate models (GCMs) that have profound differences in their large-scale mean winter atmospheric circulation and sea ice drift patterns. The Community Earth System Model Large Ensemble (CESM-LE) presents a mean sea level pressure pattern that is in general agreement with observations for the late twentieth century. The Community Climate System Model, version 4 (CCSM4), exhibits a low bias in its mean sea level pressure over the Arctic region with a deeper Icelandic low. A dynamical mechanism is presented in which large-scale mean winter atmospheric circulation has significant effect on the following September sea ice extent anomaly by influencing ice divergence in specific areas. A Lagrangian model is used to backtrack the 80°N line from the approximate time of the melt onset to its prior positions throughout the previous winter and quantify the divergence across the Pacific and Eurasian sectors of the Arctic. It is found that CCSM4 simulates more sea ice divergence in the Beaufort and Chukchi Seas and less divergence in the Eurasian seas when compared to CESM-LE, leading to a Pacific-centric sea ice retreat. On the other hand, CESM-LE shows a more symmetrical retreat between the Pacific, Eurasian, and Atlantic sectors of the Arctic. Given that a positive trend in the Arctic Oscillation (AO) index, associated with low sea level pressure anomalies in the Arctic, is a robust feature of GCMs participating in phase 5 of the Coupled Model Intercomparison Project (CMIP5), these results suggest that the sea ice retreat in the Pacific sector could be amplified during the transition to a seasonal ice cover.

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A study of arctic sea ice and sea‐level pressure using POP and neural network methods

ATMOSPHERE-OCEAN ◽

10.1080/07055900.1994.9649510 ◽

1994 ◽

Vol 32 (3) ◽

pp. 507-529 ◽

Cited By ~ 9

Author(s):

Benyang Tang ◽

Gregory M. Flato ◽

Greg Holloway

Keyword(s):

Neural Network ◽

Sea Ice ◽

Sea Level ◽

Arctic Sea Ice ◽

Sea Level Pressure ◽

Level Pressure ◽

Arctic Sea ◽

Network Methods ◽

And Sea Level

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Record high Pacific Arctic seawater temperatures and delayed sea ice advance in response to episodic atmospheric blocking

Scientific Reports ◽

10.1038/s41598-020-77488-y ◽

2020 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

Tsubasa Kodaira ◽

Takuji Waseda ◽

Takehiko Nose ◽

Jun Inoue

Keyword(s):

Sea Ice ◽

Arctic Region ◽

Arctic Sea Ice ◽

Sea Surface ◽

The Arctic ◽

Atmospheric Blocking ◽

Sea Ice Extent ◽

The Pacific ◽

Arctic Sea ◽

Highly Correlated

AbstractArctic sea ice is rapidly decreasing during the recent period of global warming. One of the significant factors of the Arctic sea ice loss is oceanic heat transport from lower latitudes. For months of sea ice formation, the variations in the sea surface temperature over the Pacific Arctic region were highly correlated with the Pacific Decadal Oscillation (PDO). However, the seasonal sea surface temperatures recorded their highest values in autumn 2018 when the PDO index was neutral. It is shown that the anomalous warm seawater was a rapid ocean response to the southerly winds associated with episodic atmospheric blocking over the Bering Sea in September 2018. This warm seawater was directly observed by the R/V Mirai Arctic Expedition in November 2018 to significantly delay the southward sea ice advance. If the atmospheric blocking forms during the PDO positive phase in the future, the annual maximum Arctic sea ice extent could be dramatically reduced.

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Variability of Arctic Sea Ice Based on Quantile Regression and the Teleconnection with Large-Scale Climate Patterns

Journal of Climate ◽

10.1175/jcli-d-19-0375.1 ◽

2020 ◽

Vol 33 (10) ◽

pp. 4009-4025

Author(s):

Shuyu Zhang ◽

Thian Yew Gan ◽

Andrew B. G. Bush

Keyword(s):

Sea Ice ◽

Quantile Regression ◽

Large Scale ◽

Southern Oscillation ◽

Arctic Sea Ice ◽

The Arctic ◽

Climate Indices ◽

The Pacific ◽

Arctic Sea ◽

Climate Patterns

AbstractUnder global warming, Arctic sea ice has declined significantly in recent decades, with years of extremely low sea ice occurring more frequently. Recent studies suggest that teleconnections with large-scale climate patterns could induce the observed extreme sea ice loss. In this study, a probabilistic analysis of Arctic sea ice was conducted using quantile regression analysis with covariates, including time and climate indices. From temporal trends at quantile levels from 0.01 to 0.99, Arctic sea ice shows statistically significant decreases over all quantile levels, although of different magnitudes at different quantiles. At the representative extreme quantile levels of the 5th and 95th percentiles, the Arctic Oscillation (AO), the North Atlantic Oscillation (NAO), and the Pacific–North American pattern (PNA) have more significant influence on Arctic sea ice than El Niño–Southern Oscillation (ENSO), the Pacific decadal oscillation (PDO), and the Atlantic multidecadal oscillation (AMO). Positive AO as well as positive NAO contribute to low winter sea ice, and a positive PNA contributes to low summer Arctic sea ice. If, in addition to these conditions, there is concurrently positive AMO and PDO, the sea ice decrease is amplified. Teleconnections between Arctic sea ice and the climate patterns were demonstrated through a composite analysis of the climate variables. The anomalously strong anticyclonic circulation during the years of positive AO, NAO, and PNA promotes more sea ice export through Fram Strait, resulting in excessive sea ice loss. The probabilistic analyses of the teleconnections between the Arctic sea ice and climate patterns confirm the crucial role that the climate patterns and their combinations play in overall sea ice reduction, but particularly for the low and high quantiles of sea ice concentration.

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Inter-Relations between the Arctic Sea Ice and the General Circulation of the Atmosphere (Abstract)

Annals of Glaciology ◽

10.3189/s0260305500000963 ◽

1987 ◽

Vol 9 ◽

pp. 252-252

Author(s):

G. Wendler ◽

M. Jeffries ◽

Y. Nagashima

Keyword(s):

Sea Ice ◽

General Circulation ◽

Arctic Sea Ice ◽

The Arctic ◽

Zonal Circulation ◽

The Pacific ◽

Arctic Sea ◽

Ice Conditions ◽

The Pacific Ocean ◽

Opposing Effects

Satellite imagery has substantially improved the quality of sea-Ice observation over the last decades. Therefore, for a 25-year period, a statistical study based on the monthly Arctic sea-ice data and the monthly mean 700 mbar maps of the Northern Hemisphere was carried out to establish the relationships between sea-ice conditions and the general circulation of the atmosphere. It was found that sea-ice conditions have two opposing effects on the zonal circulation intensity, depending on the season. Heavier than normal ice in winter causes stronger than normal zonal circulation in the subsequent months, whereas heavier than normal ice in the summer–fall causes weaker zonal circulation in the subsequent months. Analyzing the two sectors, the Atlantic and Pacific ones separately, a negative correlation was found, which means a heavy ice year in the Atlantic Ocean is normally associated with a light one in the Pacific Ocean and vice versa.

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