Low-frequency variability of surface air temperature over the Barents Sea: causes and mechanisms

2015 ◽  
Vol 47 (3-4) ◽  
pp. 1247-1262 ◽  
Author(s):  
Eveline C. van der Linden ◽  
Richard Bintanja ◽  
Wilco Hazeleger ◽  
Rune G. Graversen
Keyword(s):  
Air Temperature ◽  
Barents Sea ◽  
Low Frequency ◽  
Surface Air Temperature ◽  
The Barents Sea ◽  
Low Frequency Variability

COMPARATIVE ANALYSIS OF SPECTRA OF THE 2000-YEAR NORTHERN HEMISPHERE AVERAGE SURFACE AIR TEMPERATURE RECONSTRUCTIONS

2021 ◽  
pp. 5-13
Author(s):  
N. M. DATSENKO ◽  
◽  
D. M. SONECHKIN ◽  
B. YANG ◽  
J.-J. LIU ◽  
...  
Keyword(s):  
High Resolution ◽  
Northern Hemisphere ◽  
Air Temperature ◽  
Wavelet Transforms ◽  
Spectral Composition ◽  
Low Frequency ◽  
Surface Air Temperature ◽  
Temporal Variations ◽  
Continuous Wavelet Transforms ◽  
Stable Estimation

The spectral composition of temporal variations in the Northern Hemisphere mean surface air temperature is estimated and compared in 2000-year paleoclimatic reconstructions. Continuous wavelet transforms of these reconstructions are used for the stable estimation of energy spectra. It is found that low-frequency parts of the spectra (the periods of temperature variations of more than 100 years) based on such high-resolution paleoclimatic indicators as tree rings, corals, etc., are similar to the spectrum of white noise, that is never observed in nature. This seems unrealistic. The famous reconstruction called “Hockey Stick” is among such unrealistic reconstructions. Reconstructions based not only on high-resolution but also on low-resolution indicators seem to be more realistic, since the low-frequency parts of their spectra have the pattern of red noise. They include the “Boomerang” reconstruction showing that some warm periods close to the present-day one were observed in the past.

The Role of Moist Intrusions in Winter Arctic Warming and Sea Ice Decline

2016 ◽  
Vol 29 (12) ◽  
pp. 4473-4485 ◽  
Author(s):  
Cian Woods ◽  
Rodrigo Caballero
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Surface Air Temperature ◽  
The Arctic ◽  
Positive Trend ◽  
Sea Ice Concentration ◽  
Local Conditions ◽  
The Barents Sea ◽  
Strong Inversion ◽  
Ice Concentration

Abstract This paper examines the trajectories followed by intense intrusions of moist air into the Arctic polar region during autumn and winter and their impact on local temperature and sea ice concentration. It is found that the vertical structure of the warming associated with moist intrusions is bottom amplified, corresponding to a transition of local conditions from a “cold clear” state with a strong inversion to a “warm opaque” state with a weaker inversion. In the marginal sea ice zone of the Barents Sea, the passage of an intrusion also causes a retreat of the ice margin, which persists for many days after the intrusion has passed. The authors find that there is a positive trend in the number of intrusion events crossing 70°N during December and January that can explain roughly 45% of the surface air temperature and 30% of the sea ice concentration trends observed in the Barents Sea during the past two decades.

scholarly journals Estimates of low frequency natural variabilit in near-surface air temperature

The Holocene ◽  
1996 ◽  
Vol 6 (3) ◽  
pp. 255-263 ◽  
Author(s):  
T.P. Barnett ◽  
B.D. Santer ◽  
P.D. Jones ◽  
R.S. Bradley ◽  
K.R. Briffa
Keyword(s):  
Air Temperature ◽  
Low Frequency ◽  
Surface Air Temperature ◽  
Near Surface

scholarly journals Climatic variability in Princess Elizabeth Land (East Antarctica) over the last 350 years

2017 ◽  
Vol 13 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Alexey A. Ekaykin ◽  
Diana O. Vladimirova ◽  
Vladimir Y. Lipenkov ◽  
Valérie Masson-Delmotte
Keyword(s):  
Air Temperature ◽  
Climatic Variability ◽  
Low Frequency ◽  
Surface Air Temperature ◽  
Temperature Variability ◽  
East Antarctica ◽  
Global Changes ◽  
Temperature Record ◽  
Isotopic Records ◽  
The Antarctic

Abstract. We use isotopic composition (δD) data from six sites in Princess Elizabeth Land (PEL) in order to reconstruct air temperature variability in this sector of East Antarctica over the last 350 years. First, we use the present-day instrumental mean annual surface air temperature data to demonstrate that the studied region (between Russia's Progress, Vostok and Mirny research stations) is characterized by uniform temperature variability. We thus construct a stacked record of the temperature anomaly for the whole sector for the period of 1958–2015. A comparison of this series with the Southern Hemisphere climatic indices shows that the short-term inter-annual temperature variability is primarily governed by the Antarctic Oscillation (AAO) and Interdecadal Pacific Oscillation (IPO) modes of atmospheric variability. However, the low-frequency temperature variability (with period  >  27 years) is mainly related to the anomalies of the Indian Ocean Dipole (IOD) mode. We then construct a stacked record of δD for the PEL for the period of 1654–2009 from individual normalized and filtered isotopic records obtained at six different sites (PEL2016 stacked record). We use a linear regression of this record and the stacked PEL temperature record (with an apparent slope of 9 ± 5.4 ‰ °C−1) to convert PEL2016 into a temperature scale. Analysis of PEL2016 shows a 1 ± 0.6 °C warming in this region over the last 3 centuries, with a particularly cold period from the mid-18th to the mid-19th century. A peak of cooling occurred in the 1840s – a feature previously observed in other Antarctic records. We reveal that PEL2016 correlates with a low-frequency component of IOD and suggest that the IOD mode influences the Antarctic climate by modulating the activity of cyclones that bring heat and moisture to Antarctica. We also compare PEL2016 with other Antarctic stacked isotopic records. This work is a contribution to the PAGES (Past Global Changes) and IPICS (International Partnerships in Ice Core Sciences) Antarctica 2k projects.

Observed Trends in Canada’s Climate and Influence of Low-Frequency Variability Modes

2015 ◽  
Vol 28 (11) ◽  
pp. 4545-4560 ◽  
Author(s):  
L. A. Vincent ◽  
X. Zhang ◽  
R. D. Brown ◽  
Y. Feng ◽  
E. Mekis ◽  
...  
Keyword(s):  
Snow Cover ◽  
Large Scale ◽  
Low Frequency ◽  
Surface Air Temperature ◽  
Spring Precipitation ◽  
The North ◽  
Temperature And Precipitation ◽  
Low Frequency Variability ◽  
Hydroclimatic Variables

Abstract Trends in Canada’s climate are analyzed using recently updated data to provide a comprehensive view of climate variability and long-term changes over the period of instrumental record. Trends in surface air temperature, precipitation, snow cover, and streamflow indices are examined along with the potential impact of low-frequency variability related to large-scale atmospheric and oceanic oscillations on these trends. The results show that temperature has increased significantly in most regions of Canada over the period 1948–2012, with the largest warming occurring in winter and spring. Precipitation has also increased, especially in the north. Changes in other climate and hydroclimatic variables, including a decrease in the amount of precipitation falling as snow in the south, fewer days with snow cover, an earlier start of the spring high-flow season, and an increase in April streamflow, are consistent with the observed warming and precipitation trends. For the period 1900–2012, there are sufficient temperature and precipitation data for trend analysis for southern Canada (south of 60°N) only. During this period, temperature has increased significantly across the region, precipitation has increased, and the amount of precipitation falling as snow has decreased in many areas south of 55°N. The results also show that modes of low-frequency variability modulate the spatial distribution and strength of the trends; however, they alone cannot explain the observed long-term trends in these climate variables.

scholarly journals Climatic variability in Princess Elizabeth Land (East Antarctica) over the last 350 years

2016 ◽  
Author(s):  
Alexey A. Ekaykin ◽  
Diana O. Vladimirova ◽  
Vladimir Ya. Lipenkov ◽  
Valérie Masson-Delmotte
Keyword(s):  
Air Temperature ◽  
Climatic Variability ◽  
Low Frequency ◽  
Surface Air Temperature ◽  
Frequency Component ◽  
Temperature Variability ◽  
East Antarctica ◽  
Temperature Record ◽  
Atmospheric Variability ◽  
Isotopic Records

Abstract. We use isotopic composition (δD) data from 6 sites in Princess Elisabeth Land (PEL) in order to reconstruct the air temperature variability in this sector of East Antarctica for the last 350 years. First, we use the present-day instrumental mean annual surface air temperature data to demonstrate that the studied region (between Russian research stations Progress, Vostok and Mirny) is characterized by uniform temperature variability. We thus construct the stacked record of the temperature anomaly for the whole sector for the period 1958–2015. A comparison of this series with the Southern Hemisphere climatic indices shows that the short-term inter-annual temperature variability is primarily governed by Antarctic Oscillation (AAO) and Interdecadal Pacific Oscillation (IPO) modes of atmospheric variability. However, the low-frequency temperature variability (with period > 27 years) is mainly related to the anomalies of Indian Ocean Dipole (IOD) mode. Then we construct the stacked record of δD for the PEL for the period 1654–2009 from individual normalized and filtered isotopic records obtained at 6 different sites ('PEL2016' stacked record). We use a significant relationship between this record and the stacked PEL temperature record (with an apparent slope of 9 ‰ °C−1) to convert 'PEL2016' into temperature scale. Analysis of 'PEL2016' shows a 1 °C warming in this region over the last three centuries, with a particularly cold period from mid-18th to mid-19th century. A peak of cooling occurred in the 1840s – a feature previously observed in other Antarctic records. We reveal that 'PEL2016' correlates with a low-frequency component of IOD. We suggest that the IOD mode influences the Antarctic climate by modulating the activity of cyclones that bring heat and moisture to Antarctica. We also compare 'PEL2016' with other Antarctic stacked isotopic records. This work is a contribution to PAGES and IPICS Antarctica 2k projects.

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