Extreme Cold Waves Research Articles

Extreme Cold Wave over East Asia in January 2016: A Possible Response to the Larger Internal Atmospheric Variability Induced by Arctic Warming

It is argued that anthropogenic global warming may decrease the global occurrence of cold waves. However, a historical record-extreme cold wave, popularly called the “boss level” cold wave, attacked East Asia in January 2016, which gives rise to the discussion of why this boss-level cold wave occurred during the winter with the warmest recorded global mean surface air temperature (SAT). To explore the impacts of human-induced global warming and natural internal atmosphere variability, we investigated the cold-wave-related circulation regime (i.e., the large-scale atmospheric circulation pattern) and compared the observation with the large ensemble simulations of the MIROC5 model. Our results showed that this East Asian extreme cold-wave-related atmospheric circulation regime mainly exhibited an extremely strong anomaly of the Ural blocking high (UBH) and a record-breaking anomaly of the surface Siberian high (SH), and it largely originated from the natural internal atmosphere variability. However, because of the dynamic effect of Arctic amplification, anthropogenic global warming may increase the likelihood of extreme cold waves through shifting the responsible natural atmospheric circulation regime toward a stronger amplitude. The probability of occurrence of extreme anomalies of UBH, SH, and the East Asia area mean SAT have been increased by 58%, 57%, and 32%, respectively, as a consequence of anthropogenic global warming. Therefore, extreme cold waves in East Asia, such as the one in January 2016, may be an enhanced response to the larger internal atmospheric variability modulated by human-induced global warming.

Daily‐scale planetary wave patterns and the modulation of cold season weather in the northern extratropics

AbstractTropospheric planetary waves, often linked to asymmetries in lower boundary forcing, significantly modulate atmospheric blocking and storm track structures that are, in turn, linked to extreme surface weather events. Day‐to‐day variability in the planetary scale circulation, taken as wave numbers 1 to 5 in the daily 500 hPa geopotential heights, and the associated impact on storm tracks and regional weather are studied for the period 1950–2005. Six boreal cold‐season distinct planetary wave patterns are identified via hierarchical cluster analysis. The first, second, and sixth patterns feature a prominent zonal wave number 1 structure, while the fourth and fifth patterns resemble the negative and positive phases of northern annular mode, respectively. The second pattern represents an amplification of the climatological mean wave structure, while the third pattern resembles the zonal wave number 3 pattern. A multitaper spectral analysis of the daily projection indices indicates that the planetary wave patterns are primarily intraseasonal in nature. The first (sixth) pattern combines the positive (negative) phase of the Pacific‐North American teleconnection pattern and negative (positive) phase of the North Atlantic Oscillation, inducing poleward (equatorward) shifts in the Pacific storm track and a weakened (strengthened) Atlantic storm track. In contrast, the fourth (fifth) pattern results in a simultaneous equatorward (poleward) displacement of both storm tracks. Extreme cold waves over the continental United States (U.S.) are favored during occurrences of the fourth and sixth patterns. During episodes of the first pattern, increased rainfall prevails over much of the U.S., while precipitation anomalies induced by the other patterns are more regional in nature.

The structure and large-scale organization of extreme cold waves over the conterminous United States

Extreme cold waves (ECWs) occurring over the conterminous United States (US) are studied through a systematic identification and documentation of their local synoptic structures, associated large-scale meteorological patterns (LMPs), and forcing mechanisms external to the US. Focusing on the boreal cool season (November–March) for 1950‒2005, a hierarchical cluster analysis identifies three ECW patterns, respectively characterized by cold surface air temperature anomalies over the upper midwest (UM), northwestern (NW), and southeastern (SE) US. Locally, ECWs are synoptically organized by anomalous high pressure and northerly flow. At larger scales, the UM LMP features a zonal dipole in the mid-tropospheric height field over North America, while the NW and SE LMPs each include a zonal wave train extending from the North Pacific across North America into the North Atlantic. The Community Climate System Model version 4 (CCSM4) in general simulates the three ECW patterns quite well and successfully reproduces the observed enhancements in the frequency of their associated LMPs. La Nina and the cool phase of the Pacific Decadal Oscillation (PDO) favor the occurrence of NW ECWs, while the warm PDO phase, low Arctic sea ice extent and high Eurasian snow cover extent (SCE) are associated with elevated SE-ECW frequency. Additionally, high Eurasian SCE is linked to increases in the occurrence likelihood of UM ECWs.

An Analysis of a Winter-time Temperature Change and an Extreme Cold Waves Frequency in Korea

An Analysis of a Winter-time Temperature Change and an Extreme Cold Waves Frequency in Korea

Woodland Mediterranean birds can resist a dry extreme cold wave

Abstract The ecological consequences of climate extreme events are still poorly understood, especially those related to cold episodes. Winter cold spells might imperil the energy balance of small passerines, thus compromising their survivorship. Here we analyze how the abundance and habitat use of three tree-gleaning passerine species wintering in a montane oakwood of central Spain at ca. 1,300 m a.s.l. was influenced by the cold wave that hit Europe in February 2012. We monitored temperature, wind and the relative abundance of great tit Parus major, blue tit Cyanistes caeruleus and long-tailed tit Aegithalos caudatus in 15 plots throughout three periods: before, during and after the cold wave. Our results clearly rule out widespread mortality and temporal migration of the studied passerine populations, as the abundance of these species did not diminish during the cold wave. Moreover, the species usually foraging higher in the tree canopy -and thus more exposed to wind-moved to the less windy woodland plots (long-tailed tit) and reduced their foraging height above ground during the cold wave (long-tailed tit and blue tit), probably to mitigate the deleterious effects of wind chill. Therefore, these forest birds were able to cope with a dry cold wave that was statistically extreme in terms of temperature and wind chill, according to the historic climate records of the region. It seems that, at least when foraging substrates are not heavily covered by snow or ice, Mediterranean birds can resist an extreme cold wave [Current Zoology 60 (4): 429–437, 2014].

An Analysis of the Impact of Extreme Climate Events on Agriculture in Korea

This paper analyses the impact of extreme climate events' annual variation in temperature and precipitation on agricultural land values with a panel data of 49 municipalities for 1992-2010 based upon a Ricardian approach in order to consider the short and long-term impacts of climate change. The estimates indicate that heavy rainfall-related extreme climate events negatively affect agricultural land values. However, summer-related extreme events in temperature are negatively related to agricultural land values, while winter-related ones in temperature have a positive impact on them except for extreme cold wave in the daytime. This result confirms that temperature-related variables are more significant than precipitation-related ones in explaining and measuring the economic effect of global warming and extreme climate events on agriculture in Korea.

Reconstructing the 20th century high‐resolution climate of the southeastern United States

We dynamically downscale the 20th Century Reanalysis (20CR) to a 10‐km grid resolution from 1901 to 2008 over the southeastern United States and the Gulf of Mexico using the Regional Spectral Model. The downscaled data set, which we call theFlorida Climate Institute‐Florida State University Land‐Atmosphere Reanalysis for theSoutheastern United States at 10‐km resolution (FLAReS1.0), will facilitate the study of the effects of low‐frequency climate variability and major historical climate events on local hydrology and agriculture. To determine the suitability of the FLAReS1.0 downscaled data set for any subsequent applied climate studies, we compare the annual, seasonal, and diurnal variability of temperature and precipitation in the model to various observation data sets. In addition, we examine the model's depiction of several meteorological phenomena that affect the climate of the region, including extreme cold waves, summer sea breezes and associated convective activity, tropical cyclone landfalls, and midlatitude frontal systems. Our results show that temperature and precipitation variability are well‐represented by FLAReS1.0 on most time scales, although systematic biases do exist in the data. FLAReS1.0 accurately portrays some of the major weather phenomena in the region, but the severity of extreme weather events is generally underestimated. The high resolution of FLAReS1.0 makes it more suitable for local climate studies than the coarser 20CR.