Article
Meteorology & Atmospheric Sciences
Edward W. Doddridge, John Marshall, Hajoon Song, Jean-Michel Campin, Maxwell Kelley
Summary: Observational records show an upward trend in summertime westerly winds over the Southern Ocean, associated with cold sea surface temperature anomalies. This trend may be linked to enhanced vertical mixing, which moves heat downward and cools the sea surface while warming the subsurface waters. The main driver of surface cooling remains uncertain, with the relative importance of advective and mixing contributions varying depending on the model used.
JOURNAL OF CLIMATE
(2021)
Article
Geosciences, Multidisciplinary
Kazutoshi Sato, Jun Inoue
Summary: The study found that the distribution of low-tropospheric ice clouds in Antarctica and the Southern Ocean is influenced by temperature, with marine aerosols acting as ice-nucleating particles in both summer and winter.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
Alex D. Crawford, Jennifer Lukovich, Michelle R. McCrystall, Julienne C. Stroeve, David G. Barber
Summary: This study found evidence that reduced sea ice in winter and spring strengthens Arctic cyclones and increases precipitation. However, there is a weaker connection between sea ice reduction in autumn and storm intensity. The relationship between sea ice and cyclone intensification is also influenced by wind shear.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Ruonan Zhang, James A. Screen, Renhe Zhang
Summary: A series of extreme cold events occurred across Eurasia and North America during winter 2020/21. Reduced Arctic sea ice, La Nina, and a sudden stratospheric warming were identified as factors contributing to the extreme cold wave in February 2021. The Arctic and Pacific Ocean surface conditions in winter 2020/21 increased the probability of cold days by approximately 17%-43%.
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2022)
Article
Geosciences, Multidisciplinary
R. L. Atlas, C. S. Bretherton, M. F. Khairoutdinov, P. N. Blossey
Summary: This article examines the impact of the process of liquid droplets colliding with ice crystals, producing ice splinters, on clouds. It is found that this process reduces cloud reflectivity and shortens cloud lifetimes. Through simulations and observations, the researchers validate this impact and demonstrate the key role of global storm-resolving models in understanding the effects of clouds on Earth's climate.
Article
Geosciences, Multidisciplinary
Felix Pithan, Marylou Athanase, Sandro Dahlke, Antonio Sanchez-Benitez, Matthew D. Shupe, Anne Sledd, Jan Streffing, Gunilla Svensson, Thomas Jung
Summary: Comparing climate model output to observations is crucial for model assessment. By nudging the large-scale atmospheric circulation, climate model output can be compared to local observations for short-term campaigns. Nudging simplifies and accelerates the process of model improvement and extends the range of observations suitable for evaluation.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2023)
Article
Oceanography
Yusuke Kawaguchi, Zoe Koenig, Daiki Nomura, Mario Hoppmann, Jun Inoue, Ying-Chih Fang, Kirstin Schulz, Michael Gallagher, Christian Katlein, Marcel Nicolaus, Benjamin Rabe
Summary: This study examines the mixing processes and sea ice drift in the ice-ocean boundary layer (IOBL) near the geographic North Pole. Measurements of ice motion, currents, hydrography, and turbulence were conducted to quantify the transport of momentum, heat, and salt in the IOBL. The study provides important insights into Arctic climate change.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Meteorology & Atmospheric Sciences
Yu Liang, Haibo Bi, Ruibo Lei, Timo Vihma, Haijun Huang
Summary: By investigating the patterns of horizontal atmospheric latent energy (LE) transport towards the Arctic, this study identified four primary transport pathways and observed their interannual variability. The results indicate that these pathways are significantly modulated by cyclones, especially the northern Europe and Greenland Sea pathways. The study also provides insights into the relationship between atmospheric LE transport and air temperature, moisture, surface heat flux, and sea ice anomalies over the Arctic Ocean in winter. Through thermodynamic analysis, it argues that the enhanced local atmosphere-ice interactions caused by poleward LE transport contribute to the loss of Arctic sea ice.
JOURNAL OF CLIMATE
(2023)
Article
Oceanography
A. Klocker, A. C. Naveira Garabato, F. Roquet, C. de Lavergne, S. R. Rintoul
Summary: The formation of the Southern Ocean's internal pycnocline is closely related to sea ice-ocean interactions, with strong salinity-based stratification created at the base of the winter mixed layer due to persistent sea-ice melt. These highly stratified sheets then descend into the ocean interior at fronts of the Antarctic Circumpolar Current and connect seamlessly to the internal pycnocline in areas further north. These findings highlight the important role of localized sea ice-ocean interactions in shaping the vertical structure of the Southern Ocean.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Geosciences, Multidisciplinary
Wenli Zhong, Sylvia T. Cole, Jinlun Zhang, Ruibo Lei, Michael Steele
Summary: The ocean-to-ice heat flux in the Beaufort Gyre region of the Arctic Ocean has increased during winter due to thinner and less compact sea ice, leading to enhanced ice growth and stronger vertical convection and subsurface heat entrainment. The contribution of Ekman upwelling to the heat flux changes was found to be secondary.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Engineering, Environmental
Megan O'Sadnick, Chris Petrich, Jofrid Skarohamar
Summary: Ice in the fjords of northern Norway undergoes temperature fluctuations throughout winter, making it difficult to track conditions at the ice-ocean interface. However, ice samples gathered from fjords allow for studying the connection between ice properties and environmental conditions. Using a developed method, the growth rate and water composition at the interface were determined for ice samples from six fjords in March 2018. The results showed variations in seawater content and brine volume fraction in the ice.
COLD REGIONS SCIENCE AND TECHNOLOGY
(2023)
Article
Meteorology & Atmospheric Sciences
Yajuan Song, Fangli Qiao, Jiping Liu, Qi Shu, Ying Bao, Meng Wei, Zhenya Song
Summary: The Southern Ocean exhibits the most pronounced sea spray effects, which enhance heat and water exchange at the air-sea interface. The inclusion of sea spray effects in climate models can mitigate biases and improve simulations and predictions. Current climate models still have deficiencies in reproducing the climatological features of the Southern Ocean, but consideration of sea spray effects can help address these issues.
JOURNAL OF CLIMATE
(2022)
Article
Engineering, Environmental
Megan O'Sadnick, Chris Petrich, Camilla Brekke, Jofrid Skarohamar, Oystein Kleven
Summary: This study monitored seven fjords in Norway over three winter seasons and found significant variations in ice conditions between fjords and years. Factors such as weather, runoff, and snow cover were identified as potential drivers of ice formation.
COLD REGIONS SCIENCE AND TECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
Meenakshi Sreejith, P. G. Remya, B. Praveen Kumar, Abhijith Raj, T. M. Balakrishnan Nair
Summary: This study analyzes the influence of Southern Ocean sea ice concentration on wave fields in the north Indian Ocean. The results show that neglecting the sea ice concentration can lead to significant errors in simulating wave height and period, and may result in false swell alerts along the southeastern Australian coasts. Including the Southern Ocean sea ice concentration in wave models is crucial for accurately predicting wave conditions in the North Indian Ocean.
SCIENTIFIC REPORTS
(2022)
Article
Meteorology & Atmospheric Sciences
Yazhe Hu, Bart Geerts, Min Deng, Coltin Grasmick, Yonggang Wang, Christian Philipp Lackner, Yishi Hu, Zachary J. Lebo, Damao Zhang
Summary: This study investigates the vertical structure of postfrontal shallow clouds in the Southern Ocean. The study focuses on cloud phase and the associated growth mechanisms of precipitation. Analysis of data from the MARCUS field campaign reveals that the majority of clouds are shallow and precipitating, with weak vertical motions and temperatures ranging from -18 to -10 degrees Celsius. An experimental cloud-phase algorithm classifies two-thirds of clouds in the 0 to -5 degrees Celsius layer as containing ice, indicating that cold-cloud processes contribute significantly to precipitation growth.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2023)
Article
Meteorology & Atmospheric Sciences
Jennifer E. Kay, Casey Wall, Vineel Yettella, Brian Medeiros, Cecile Hannay, Peter Caldwell, Cecilia Bitz
JOURNAL OF CLIMATE
(2016)
Article
Meteorology & Atmospheric Sciences
Casey J. Wall, Dennis L. Hartmann, Po-Lun Ma
JOURNAL OF CLIMATE
(2017)
Article
Meteorology & Atmospheric Sciences
Tsubasa Kohyama, Dennis L. Hartmann
JOURNAL OF CLIMATE
(2017)
Article
Meteorology & Atmospheric Sciences
Tsubasa Kohyama, Dennis L. Hartmann, David S. Battisti
JOURNAL OF CLIMATE
(2017)
Article
Geosciences, Multidisciplinary
Tsubasa Kohyama, Dennis L. Hartmann, David S. Battisti
GEOPHYSICAL RESEARCH LETTERS
(2018)
Article
Geosciences, Multidisciplinary
Casey J. Wall, Dennis L. Hartmann
GEOPHYSICAL RESEARCH LETTERS
(2018)
Article
Meteorology & Atmospheric Sciences
Casey J. Wall, Dennis L. Hartmann, Mandana M. Thieman, William L. Smith, Patrick Minnis
JOURNAL OF CLIMATE
(2018)
Article
Geosciences, Multidisciplinary
Casey J. Wall, Dennis L. Hartmann, Joel R. Norris
GEOPHYSICAL RESEARCH LETTERS
(2019)
Article
Geosciences, Multidisciplinary
Daisuke Takasuka, Tsubasa Kohyama, Hiroaki Miura, Tamaki Suematsu
Summary: The formation of Madden-Julian Oscillation (MJO) clouds can be initiated by the amplification of upper-level mixed Rossby-gravity waves (MRGs) above the western Indian Ocean (WIO) and subsequent dispersion downward to form low-level MRG wave packets. Additionally, upper-level circumnavigating Kelvin waves can assist in this process by promoting MRG wave accumulation in the WIO. The proposed mechanism has been theoretically plausible and supported by observations, but further evaluation with more data is needed.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Multidisciplinary Sciences
Tsubasa Kohyama, Yoko Yamagami, Hiroaki Miura, Shoichiro Kido, Hiroaki Tatebe, Masahiro Watanabe
Summary: Observations and model simulations show that sea surface temperatures along the Gulf Stream and the Kuroshio Current synchronize at decadal time scales, associated with meridional migrations of the atmospheric jet stream. Changes in ocean currents due to jet shifts lead to temperature synchronicity, indicating that BCS is an interbasin air-sea coupled mode. Air temperature patterns similar to BCS have been repeatedly observed, demonstrating the presence of this synchronization phenomenon.
Article
Meteorology & Atmospheric Sciences
Tsubasa Kohyama, Tamaki Suematsu, Hiroaki Miura, Daisuke Takasuka
Summary: This study focuses on the downward branch of the Walker circulation above the Indian Ocean, noting its interactions with planetary-scale climate circulations. The presence of the Wall is mainly influenced by the Asian Summer Monsoon and seasonal changes in zonal winds. Additionally, vertical mixing forced by East African topography is found to be crucial for sustaining the Wall.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Meteorology & Atmospheric Sciences
Amane Nakamura, Tsubasa Kohyama
Summary: This study compares the validity of using mean and mode as reference states for the analysis of El Nino-Southern Oscillation (ENSO) phenomena. The results indicate that the mode is more stable and able to emphasize the relationship between ENSO amplitude and zonal shifts of ENSO anomalies.
Article
Meteorology & Atmospheric Sciences
Shion Sekizawa, Tsubasa Kohyama
Summary: On January 15, 2022, the eruption of the Hunga Tonga volcano resulted in observed sea-level fluctuations in Japan. These fluctuations were likely meteotsunamis caused by atmospheric pressure disturbances rather than tectonic activity. Using a simple shallow-water model, this study found that the observed sea-level changes were consistent with changes forced by atmospheric conditions. The experiments also highlighted the importance of underwater topography and continental slopes in amplifying these changes, while deeper trenches had a lesser impact.