Increased shear in the North Atlantic upper-level jet stream over the past four decades

Earth’s equator-to-pole temperature gradient drives westerly mid-latitude jet streams through thermal wind balance. In the upper atmosphere, anthropogenic climate change is strengthening this meridional temperature gradient by cooling the polar lower stratosphere and warming the tropical upper troposphere acting to strengthen the upper-level jet stream. In contrast, in the lower atmosphere, Arctic amplification of global warming is weakening the meridional temperature gradient acting to weaken the upper-level jet stream. Therefore, trends in the speed of the upper-level jet stream represent a closely balanced tug-of-war between two competing effects at different altitudes. It is possible to isolate one of the competing effects by analysing the vertical shear—the change in wind speed with height—instead of the wind speed, but this approach has not previously been taken. Here we show that, although the zonal wind speed in the North Atlantic polar jet stream at 250 hectopascals has not changed since the start of the observational satellite era in 1979, the vertical shear has increased by 15 per cent (with a range of 11–17 per cent) according to three different reanalysis datasets. We further show that this trend is attributable to the thermal wind response to the enhanced upper-level meridional temperature gradient. Our results indicate that climate change may be having a larger impact on the North Atlantic jet stream than previously thought. The increased vertical shear is consistent with the intensification of shear-driven clear-air turbulence expected from climate change which will affect aviation in the busy transatlantic flight corridor by creating a more turbulent flying environment for aircraft. We conclude that the effects of climate change and variability on the upper-level jet stream are being partly obscured by the traditional focus on wind speed rather than wind shear

Trends and connections across the Antarctic cryosphere

Satellite observations have transformed our understanding of the Antarctic cryosphere. The continent holds the vast majority of Earth’s fresh water, and blankets swathes of the Southern Hemisphere in ice. Reductions in the thickness and extent of floating ice shelves have disturbed inland ice, triggering retreat, acceleration and drawdown of marine-terminating glaciers. The waxing and waning of Antarctic sea ice is one of Earth’s greatest seasonal habitat changes, and although the maximum extent of the sea ice has increased modestly since the 1970s, inter-annual variability is high, and there is evidence of longer-term decline in its extent

Global lake responses to climate change

Climate change is one of the most severe threats to global lake ecosystems. Lake surface conditions, such as ice cover, surface temperature, evaporation and water level, respond dramatically to this threat, as observed in recent decades. In this Review, we discuss physical lake variables and their responses to climate change. Decreases in winter ice cover and increases in lake surface temperature modify lake mixing regimes and accelerate lake evaporation. Where not balanced by increased mean precipitation or inflow, higher evaporation rates will favour a decrease in lake level and surface water extent. Together with increases in extreme-precipitation events, these lake responses will impact lake ecosystems, changing water quantity and quality, food provisioning, recreational opportunities and transportation. Future research opportunities, including enhanced observation of lake variables from space (particularly for small water bodies), improved in situ lake monitoring and the development of advanced modelling techniques to predict lake processes, will improve our global understanding of lake responses to a changing climate

Kondisi Self Disclosure Mahasiswa Bimbingan dan Konseling

<p>Penelitian ini bertujuan untuk mengidentifikasikan kondisi <em>self disclosure</em> mahasiswa Bimbingan dan Konseling berdasarkan dimensi keluasan dan kedalaman. Jenis penelitian ini adalah penelitian deskriptif<em> </em>dengan metode kuantitatif. Instrumen yang digunakan adalah Inventori Pengukuran <em>Self Disclosure</em> Mahasiswa (IPSDM), dengan Sampel sebanyak 85 orang mahasiswa menggunakan teknik <em>Simple Random Sampling</em>. Temuan penelitian mengungkapkan bahwa, 1) Sebanyak 55,29% mahasiswa Bimbingan dan Konseling memiliki kondisi keluasan<em> self disclosure</em> pada kategori tidak luas dan dilihat pada target <em>person </em> menunjukkan bahwa ibu merupakan target <em>person</em> pertama dan paling banyak dipilih responden penelitian (72,16%), 2) Sebanyak 38,82% mahasiswa Bimbingan dan Konseling memiliki kondisi kedalaman<em> self disclosure</em> pada kategori sedang. Penelitian ini merekomendasikan mahasiswa Bimbingan dan Konseling, agar dapat memperluas dan memperdalam kemampuan melakukan <em>self disclosure</em> dan perlu pelayanan Bimbingan dan Konseling untuk memperluas dan memperdalam kemampuan dalam melakukan <em>self disclosure</em>.</p

Unraveling El Nino&apos;s impact on the East Asian Monsoon and Yangtze River summer flooding

Strong El Nino events are followed by massive summer monsoon flooding over the Yangtze River basin (YRB), home to about a third of the population in China. Although the El Nino-Southern Oscillation (ENSO) provides the main source of seasonal climate predictability for many parts of the Earth, the mechanisms of its connection to the East Asian monsoon remain largely elusive. For instance, the traditional Nino3.4 ENSO index only captures precipitation anomalies over East Asia in boreal winter but not during the summer. Here we show that there exists a robust year-round and predictable relationship between ENSO and the Asian monsoon. This connection is revealed by combining equatorial (Nino3.4) and off-equatorial Pacific sea surface temperature anomalies (Nino-A index) into a new metric that captures ENSO&apos;s various aspects, such as its interaction with the annual cycle and its different flavors. This extended view of ENSO complexity improves predictability of YRB summer flooding events.11179Ysciescopu

A combination mode of climate variability responsible for extremely poor recruitment of the Japanese eel (Anguilla japonica)

Satellite data and assimilation products are used to investigate fluctuations in the catch of Japanese eel (Anguilla japonica) in eastern Asian countries. It has been reported that the salinity front has extended farther south, which has shifted the eel’s spawning grounds to a lower latitude, resulting in smaller eel catches in 1983, 1992, and 1998. This study demonstrates that interannual variability in the eel catch is strongly correlated with the combination mode (C-mode), but not with the El Niño–Southern Oscillation. These eels continue to spawn within the North Equatorial Current (NEC), but the salinity front shifts south during a canonical El Niño. On the other hand, the spawning grounds accompanied by the salinity front extend farther south during the C-mode of climate variability, and eel larvae fail to join the nursery in the NEC, resulting in extremely poor recruitment in East Asia. We propose an appropriate sea surface temperature index to project Japanese eel larval catch