scholarly journals The ground-based FTIR network's potential for investigating the atmospheric water cycle

2010 ◽  
Vol 10 (7) ◽  
pp. 3427-3442 ◽  
Author(s):  
M. Schneider ◽  
K. Yoshimura ◽  
F. Hase ◽  
T. Blumenstock
Keyword(s):  
General Circulation ◽  
Water Cycle ◽  
Circulation Model ◽  
Hadley Circulation ◽  
Reanalysis Data ◽  
The Arctic ◽  
Atmospheric Water ◽  
Arctic Oscillation Index ◽  
Northern Atlantic ◽  
The Arctic Oscillation

Abstract. We present tropospheric H216O and HD16O/H216O vapour profiles measured by ground-based FTIR (Fourier Transform Infrared) spectrometers between 1996 and 2008 at a northern hemispheric subarctic and subtropical site (Kiruna, Northern Sweden, 68° N and Izaña, Tenerife Island, 28° N, respectively). We compare these measurements to an isotope incorporated atmospheric general circulation model (AGCM). If the model is nudged towards meteorological fields of reanalysis data the agreement is very satisfactory on time scales ranging from daily to inter-annual. Taking the Izaña and Kiruna measurements as an example we document the FTIR network's unique potential for investigating the atmospheric water cycle. At the subarctic site we find strong correlations between the FTIR data, on the one hand, and the Arctic Oscillation index and the northern Atlantic sea surface temperature, on the other hand. The Izaña FTIR measurements reveal the importance of the Hadley circulation and the Northern Atlantic Oscillation index for the subtropical middle/upper tropospheric water balance. We document where the AGCM is able to capture these complexities of the water cycle and where it fails.

scholarly journals The ground-based FTIR network's potential for investigating the atmospheric water cycle

2009 ◽  
Vol 9 (6) ◽  
pp. 26199-26235 ◽  
Author(s):  
M. Schneider ◽  
K. Yoshimura ◽  
F. Hase ◽  
T. Blumenstock
Keyword(s):  
Water Transport ◽  
General Circulation ◽  
Water Cycle ◽  
Lower Troposphere ◽  
Circulation Model ◽  
Hadley Circulation ◽  
The Arctic ◽  
Atmospheric Water ◽  
Transport Pathways ◽  
Northern Atlantic

Abstract. We present tropospheric H216O and HD16O/H216O vapour profiles measured by ground-based FTIR (Fourier Transform Infrared) spectrometers between 1996 and 2008 at a northern hemispheric subarctic and subtropical site (Kiruna, Northern Sweden, 68° N and Izaña, Tenerife Island, 28° N, respectively). We compare these measurements to an isotope incorporated atmospheric general circulation model (AGCM). If the model is nudged towards meteorological fields of reanalyses data the agreement is very satisfactory on time scales ranging from daily to inter-annual which demonstrates the good quality of the FTIR data. Taking the Izaña and Kiruna measurements as an example we document the FTIR network's unique potential for investigating the atmospheric water cycle. For the subtropical site the FTIR observations confirm the central role of the Hadley circulation, but in addition they reveal a strong connection between the Northern Atlantic Oscillation (NAO) and the middle/upper tropospheric water vapour transport pathways. Concerning the subarctic site the observations indicate that water transport to the lower troposphere is affected by the northern Atlantic sea surface temperature and correlated to the Arctic Oscillation (AO). For the middle troposphere we observe that spring and autumn water transport pathways are different. We document in detail where the AGCM is able to capture these complexities of the water cycle and where it fails.

A Closer Comparison of Early and Late-Winter Atmospheric Trends in the Northern Hemisphere

2005 ◽  
Vol 18 (16) ◽  
pp. 3204-3216 ◽  
Author(s):  
Yongyun Hu ◽  
Ka Kit Tung ◽  
Jiping Liu
Keyword(s):  
Northern Hemisphere ◽  
General Circulation ◽  
Polar Vortex ◽  
Circulation Model ◽  
Hadley Circulation ◽  
Reanalysis Data ◽  
Hadley Cell ◽  
The Arctic ◽  
Late Winter ◽  
Positive Trend

Abstract Decadal trends are compared in various fields between Northern Hemisphere early winter, November–December (ND), and late-winter, February–March (FM), months using reanalysis data. It is found that in the extratropics and polar region the decadal trends display nearly opposite tendencies between ND and FM during the period from 1979 to 2003. Dynamical trends in late winter (FM) reveal that the polar vortex has become stronger and much colder and wave fluxes from the troposphere to the stratosphere are weaker, consistent with the positive trend of the Arctic Oscillation (AO) as found in earlier studies, while trends in ND appear to resemble a trend toward the low-index polarity of the AO. In the Tropics, the Hadley circulation shows significant intensification in both ND and FM, with stronger intensification in FM. Unlike the Hadley cell, the Ferrel cell shows opposite trends between ND and FM, with weakening in ND and strengthening in FM. Comparison of the observational results with general circulation model simulations is also discussed.

scholarly journals Seasonal Forecasting with a Simple General Circulation Model: Predictive Skill in the AO and PNA

2005 ◽  
Vol 18 (4) ◽  
pp. 597-609 ◽  
Author(s):  
Jacques Derome ◽  
Hai Lin ◽  
Gilbert Brunet
Keyword(s):  
General Circulation ◽  
Initial Conditions ◽  
Circulation Model ◽  
Atmospheric Model ◽  
The Arctic ◽  
Small Perturbations ◽  
Predictive Skill ◽  
The Pacific ◽  
The Arctic Oscillation ◽  
Environmental Prediction

Abstract A primitive equation dry atmospheric model is used to perform ensemble seasonal predictions. The predictions are done for 51 winter seasons [December–January–February (DJF)] from 1948 to 1998. Ensembles of 24 forecasts are produced, with initial conditions of 1 December plus small perturbations. The model uses a forcing field that is calculated empirically from the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalyses. The forcing used to forecast a given winter is the sum of its winter climatological forcing plus an anomaly. The anomalous forcing is obtained as that of the month prior to the start of the forecast (November), which is also calculated from NCEP data. The predictions are thus made without using any information about the season to be predicted. The ensemble-mean predictions for the 51 winters are verified against the NCEP–NCAR reanalyses. Comparisons are made with the results obtained with a full GCM. It is found that the skill of the simple GCM is comparable in many ways to that of the full GCM. The skill in predicting the amplitude of the main patterns of Northern Hemisphere mean-seasonal variability, the Arctic Oscillation (AO) and the Pacific–North American (PNA) pattern is also discussed. The simple GCM has skill not only in predicting the PNA pattern during winters with strong ENSO forcing, but it also has skill in predicting the AO in winters without appreciable ENSO forcing.

scholarly journals RELATIONSHIP OF THE GREENLAND HALIBUT STOCKS IN THE OKHOTSK SEA WITH ENVIRONMENTAL FACTORS

2020 ◽  
Vol 200 ◽  
pp. 58-81
Author(s):  
V. V. Kulik ◽  
S. V. Prants ◽  
M. V. Budyansky ◽  
M. Yu. Uleysky ◽  
P. A. Fayman ◽  
...  
Keyword(s):  
Time Lag ◽  
Additive Model ◽  
Circulation Model ◽  
The Arctic ◽  
Okhotsk Sea ◽  
Greenland Halibut ◽  
Arctic Oscillation Index ◽  
Western Kamchatka ◽  
Arrival Times ◽  
The Arctic Oscillation

Dynamics of the greenland halibut biomass in the fishery districts of the Okhotsk Sea (or subzones) is considered. The biomass variation in the East-Sakhalin subzone has a significant (p < 0.05) negative correlation with the number of 3+ fish in other subzones, with the time lag of 3 years (r = –0.53) and 4 years (r = –0.49), that is interpreted as alternative distribution of the halibut recruitment from the common spawning area either to this district or other ones. From other hand, the recruits abundance in other districts is significantly and positively associated (r = 0.52, p < 0.05) with the index of zonal atmosphere transfer in January and with the index of meridional atmosphere transfer in March of the years of hatching. The recruitment dependence on the spawning stock could be explained by Beaverton-Holt equation with the residuals significantly and positively (r = 0.64, p = 0.03) related with the Arctic Oscillation index. Transport of the eggs, larvae and juveniles of greenland halibut from the spawning grounds at western Kamchatka to the western Okhotsk Sea is considered as the mechanism of its recruitment distribution between the districts in relation with atmospheric indices. The transport was simulated for 1993–2017 using the circulation model JCOPE2 as the movement of 250,000 artificial passive particles, imitating eggs and larvae, with water flows at the depth 40–50 m where their main aggregations are supposed. The particles were released in the area at western Kamchatka where the maximal concentration of spawning females occurred. Number of the particles reached the sections off eastern Sakhalin and their arrival times were computed, their pathways were tracked. The portion of particles released in December and reached northern Sakhalin within 150 days changed in significant positive correlation (r = 0.44, p < 0.05) with dynamics of the halibut stock in the East-Sakhalin subzone, with the time lag 6 years. Even closer correlation (r = 0.94, p < 0.05) could be found for the optimum income of the particles released in October or November in the general additive model of the stock. Using the model results for the recent years, the greenland halibut stock decreasing in the East-Sakhalin subzone is forecasted for the next 6 years.

scholarly journals A Numerical Sensitivity Study of the Influence of Siberian Snow on the Northern Annular Mode

2012 ◽  
Vol 25 (2) ◽  
pp. 592-607 ◽  
Author(s):  
Y. Peings ◽  
D. Saint-Martin ◽  
H. Douville
Keyword(s):  
General Circulation ◽  
Arctic Oscillation ◽  
Polar Vortex ◽  
Circulation Model ◽  
Sensitivity Study ◽  
The Arctic ◽  
Annular Mode ◽  
Northern Annular Mode ◽  
Model Free ◽  
The Arctic Oscillation

Abstract The climate version of the general circulation model Action de Recherche Petite Echelle Grande Echelle (ARPEGE-Climat) is used to explore the relationship between the autumn Siberian snow and the subsequent winter northern annular mode by imposing snow anomalies over Siberia. As the model presents some biases in the representation of the polar vortex, a nudging methodology is used to obtain a more realistic but still interactive extratropical stratosphere in the model. Free and nudged sensitivity experiments are compared to discuss the dependence of the results on the northern stratosphere climatology. For each experiment, a positive snow mass anomaly imposed from October to March over Siberia leads to significant impacts on the winter atmospheric circulation in the extratropics. In line with previous studies, the model response resembles the negative phase of the Arctic Oscillation. The well-documented stratospheric pathway between snow and the Arctic Oscillation operates in the nudged experiment, while a more zonal propagation of the signal is found in the free experiment. Thus, the study provides two main findings: it supports the influence of Siberian snow on the winter extratropical circulation and highlights the importance of the northern stratosphere representation in the models to capture this teleconnection. These findings could have important implications for seasonal forecasting, as most of the operational models present biases similar to those of the ARPEGE-Climat model.

A Predictability Measure Applied to Seasonal Predictions of the Arctic Oscillation

2007 ◽  
Vol 20 (18) ◽  
pp. 4733-4750 ◽  
Author(s):  
Youmin Tang ◽  
Hai Lin ◽  
Jacques Derome ◽  
Michael K. Tippett
Keyword(s):  
Confidence Level ◽  
General Circulation ◽  
Arctic Oscillation ◽  
A Priori ◽  
Circulation Model ◽  
The Arctic ◽  
Ensemble Prediction ◽  
Central Pacific ◽  
The Arctic Oscillation ◽  
Sst Anomalies

Abstract In this study, ensemble seasonal predictions of the Arctic Oscillation (AO) were conducted for 51 winters (1948–98) using a simple global atmospheric general circulation model. A means of estimating a priori the predictive skill of the AO ensemble predictions was developed based on the relative entropy (R) of information theory, which is a measure of the difference between the forecast and climatology probability density functions (PDFs). Several important issues related to the AO predictability, such as the dominant precursors of forecast skill and the degree of confidence that can be placed in an individual forecast, were addressed. It was found that R is a useful measure of the confidence that can be placed on dynamical predictions of the AO. When R is large, the prediction is likely to have a high confidence level whereas when R is small, the prediction skill is more variable. A small R is often accompanied by a relatively weak AO index. The value of R is dominated by the predicted ensemble mean. The relationship identified here, between model skills and the R of an ensemble prediction, offers a practical means of estimating the confidence level of a seasonal forecast of the AO using the dynamical model. Through an analysis of the global sea surface temperature (SST) forcing, it was found that the winter AO-related R is correlated significantly with the amplitude of the SST anomalies over the tropical central Pacific and the North Pacific during the previous October. A large value of R is usually associated with strong SST anomalies in the two regions, whereas a poor prediction with a small R indicates that SST anomalies are likely weak in these two regions and the observed AO anomaly in the specific winter is likely caused by atmospheric internal dynamics.

scholarly journals Influence of atmospheric internal variability on the long-term Siberian water cycle during the past 2 centuries

2018 ◽  
Vol 9 (2) ◽  
pp. 497-506 ◽  
Author(s):  
Kazuhiro Oshima ◽  
Koto Ogata ◽  
Hotaek Park ◽  
Yoshihiro Tachibana
Keyword(s):  
General Circulation ◽  
Large Scale ◽  
Water Cycle ◽  
Circulation Model ◽  
Internal Variability ◽  
The Arctic ◽  
The Past ◽  
Term Variation ◽  
East West

Abstract. River discharges from Siberia are a large source of freshwater into the Arctic Ocean, whereas the cause of the long-term variation in Siberian discharges is still unclear. The observed river discharges of the Lena in the east and the Ob in the west indicated different relationships in each of the epochs during the past 7 decades. The correlations between the two river discharges were negative during the 1980s to mid-1990s, positive during the mid-1950s to 1960s, and became weak after the mid-1990s. More long-term records of tree-ring-reconstructed discharges have also shown differences in the correlations in each of the epochs. It is noteworthy that the correlations obtained from the reconstructions tend to be negative during the past 2 centuries. Such tendency has also been obtained from precipitations in observations, and in simulations with an atmospheric general circulation model (AGCM) and fully coupled atmosphere–ocean GCMs conducted for the Fourth Assessment Report of the IPCC. The AGCM control simulation further demonstrated that an east–west seesaw pattern of summertime large-scale atmospheric circulation frequently emerges over Siberia as an atmospheric internal variability. This results in an opposite anomaly of precipitation over the Lena and Ob and the negative correlation. Consequently, the summertime atmospheric internal variability in the east–west seesaw pattern over Siberia is a key factor influencing the long-term variation in precipitation and river discharge, i.e., the water cycle in this region.

scholarly journals Influence of atmospheric internal variability on the long-term Siberian water cycle during the past two centuries

2017 ◽  
Author(s):  
Kazuhiro Oshima ◽  
Koto Ogata ◽  
Hotaek Park ◽  
Yoshihiro Tachibana
Keyword(s):  
General Circulation ◽  
Water Cycle ◽  
Circulation Model ◽  
Internal Variability ◽  
The Arctic ◽  
Coupled Models ◽  
The Past ◽  
Term Variation ◽  
East West

Abstract. River discharges from Siberia are a large source of freshwater into the Arctic Ocean, although the cause of the long-term variation in discharge is still unclear. The observed river discharges of the Lena in the east and the Ob in the west indicated different relationships in each of the epochs during the past seven decades. The correlations between the two river discharges were negative during the 1980s to mid-1990s, positive during the mid-1950s to 1960s, and became weak after the mid-1990s. Long-term records of tree-ring-reconstructed discharges during the past two centuries have also shown differences in the correlations in each epoch. However, it is noteworthy that the correlations obtained from the reconstructions tend to be negative. Such negative correlations have also been obtained from precipitations over the Lena and Ob in observation, and in simulations with an atmospheric general circulation model (AGCM) and multi-coupled models conducted for the Fourth Assessment Report of the IPCC. The AGCM control simulation further demonstrated that an east–west seesaw pattern of summertime atmospheric large-scale circulation frequently emerges over Siberia as an atmospheric internal variability, resulting in the negative correlation between the Lena and Ob. Consequently, the summertime atmospheric internal variability of east–west seesaw pattern over Siberia is a key factor influencing the long-term variation in precipitation and river discharge, i.e., the water cycle in this region.

scholarly journals Sea ice and climate in 20th- and 21st-century simulations with a global atmosphere-ocean-ice model

2001 ◽  
Vol 33 ◽  
pp. 521-524 ◽  
Author(s):  
John W. Weatherly ◽  
Julie M. Arblaster
Keyword(s):  
Sea Ice ◽  
Greenhouse Gases ◽  
General Circulation ◽  
Circulation Model ◽  
Warming Trend ◽  
Solar Flux ◽  
Global Temperature ◽  
The Arctic ◽  
The North ◽  
The Arctic Oscillation

AbstractA global atmosphere-ocean-sea-ice general circulation model (GCM) is used in simulations of climate with greenhouse gas concentrations and sulfate aerosols prescribed from observational data (1870−1995) and future projections (1995−2100). Simulations that include the variability in solar flux from 1870 through 1995 are also performed. The variation in solar flux of ± 2 W m−2 produces a global temperature change of ± 0.2°C in the model. The more recent simulated warming trend produced by increasing greenhouse gases exceeds this solar-flux warming, although the solar flux contributes to some of the simulated present-day warm temperatures. The future increases in greenhouse gases produce an increase in global temperature of 1.2°C over 70 years, with significant decreases in Arctic ice thickness and area. The model exhibits an atmospheric pressure mode similar to the Arctic Oscillation, with different correlation indices between the North Atlantic and North Pacific pressure anomalies.

Sign in / Sign up

Export Citation Format

Share Document