scholarly journals Long-term trends of global marine primary and secondary aerosol production during the recent global warming hiatus (2000–2015)

2018 ◽  
Author(s):  
Sang-Keun Song ◽  
Zang-Ho Shon ◽  
Yu-Na Choi ◽  
Young-Baek Son ◽  
Minsung Kang ◽  
...  
Keyword(s):  
Global Warming ◽  
Pacific Ocean ◽  
Southern Ocean ◽  
Atmospheric Aerosol ◽  
Sea Surface ◽  
Aerosol Loading ◽  
Global Warming Hiatus ◽  
Long Term Trends ◽  
Warming Hiatus

Abstract. Long-term trends in global sea spray aerosol (SSA) emissions and dimethyl sulfide (DMS) fluxes from sea to air during the recent global warming hiatus (2000–2015) were analyzed using satellite observations and modelling data. The SSA emissions were estimated using a widely used whitecap method with sea surface temperature (SST) dependence. In addition, sea-to-air DMS fluxes were also used to quantify the secondary contributions of DMS through its sequential oxidation and gas-to-particle conversion. Aerosol optical depth (AOD) was estimated by an aerosol optical model using the number concentration of SSA and non-sea-salt sulfate from DMS. The estimated AOD, which was derived from the SSA and DMS emitted from the sea surface, was compared with satellite-derived AOD to quantify its (primary and secondary) contribution to atmospheric aerosol loading (i.e., observed AOD). Yearly global mean anomalies in DMS fluxes and AOD derived from SSA showed statistically significant downward trends during the recent global warming hiatus, whereas SSA emissions and AOD derived from DMS oxidation did not. In terms of regional trends, the decreases in SSA emissions during 2000–2015 occurred over the central Pacific Ocean, the Indian Ocean, and the Caribbean Sea, whereas upward trends in SSA emissions occurred over the tropical southeastern Pacific Ocean, the Southern Ocean, and the North Atlantic Ocean. DMS fluxes during the study period showed a clear downward trend over most regions of the global ocean. The estimates of the contributions of SSA (primary) and DMS (secondary) to atmospheric aerosol loading were 23–62% and 26–38%, respectively, with the largest primary contribution (~90%) over the Southern Ocean.

scholarly journals Tracking the Missing Heat from the Global Warming Hiatus

Eos ◽  
2015 ◽  
Vol 96 ◽  
Author(s):  
Christina Reed
Keyword(s):  
Global Warming ◽  
Pacific Ocean ◽  
Indian Ocean ◽  
Surface Heat ◽  
The Pacific ◽  
Global Warming Hiatus ◽  
The Indian Ocean ◽  
The Pacific Ocean ◽  
Warming Hiatus

Despite indications that the Pacific Ocean is helping to take up the world's missing surface heat, it is not storing the heat; oceanographers now find the ocean has moved heat over to the Indian Ocean.

scholarly journals Reconstructed 3-D Ocean Temperature Derived from Remotely Sensed Sea Surface Measurements for Mixed Layer Depth Analysis

2019 ◽  
Vol 11 (24) ◽  
pp. 3018 ◽  
Author(s):  
Yubeen Jeong ◽  
Jihyun Hwang ◽  
Jinku Park ◽  
Chan Joo Jang ◽  
Young-Heon Jo
Keyword(s):  
Global Warming ◽  
Spatial Resolution ◽  
Linear Trend ◽  
Mixed Layer Depth ◽  
Sea Surface ◽  
Layer Depth ◽  
Thermal Structures ◽  
Global Warming Hiatus ◽  
Surface Measurements ◽  
Warming Hiatus

The mixed layer depth (MLD) is generally estimated using in situ or model data. However, MLD analyses have limitations due to the sparse resolution of the observed data. Therefore, this study reconstructs three-dimensional (3D) ocean thermal structures using only satellite sea surface measurements for a higher spatial and longer temporal resolution than that of Argo and diagnoses the decadal variation of global MLD variability. To simulate the ocean thermal structures, the relationship between the ocean subsurface temperature and the sea surface fields was computed based on gridded Argo data. Based on this relationship, high spatial resolution and extended periods of satellite-derived altimeter, sea surface temperature (SST), and wind stress data were used to estimate the 3D ocean thermal structures with 0.25° spatial resolution and 26 standard depth levels (5–2000 m) for 24 years (1993–2016). Then, the MLD was calculated using a temperature threshold method (∆T = 0.2 °C) and correlated reasonably well (>0.9) with other MLD datasets. The extended 24-year data enabled us to analyze the decadal variability of the MLD. The global linear trend of the 24-year MLD is −0.110 m yr−1; however, from 1998 to 2012, the linear trend is −0.003 m yr−1 which is an order of magnitude smaller than that of other periods and corresponds to a global warming hiatus period. Via comparisons between the trends of the SST anomalies and the MLD anomalies, we tracked how the MLD trend changes in response to the global warming hiatus.

scholarly journals Recent changes (2013-2017) in scyphomedusan fauna in the Boka Kotorska Bay, Montenegro (Southeast Adriatic)

2019 ◽  
Vol 60 (1) ◽  
pp. 25-39
Author(s):  
Ivana Violić ◽  
Davor Lučić ◽  
Ivona Milić Beran ◽  
Vesna Mačić ◽  
Branka Pestorić ◽  
...  
Keyword(s):  
Time Series ◽  
Global Warming ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Water Column ◽  
Sea Surface ◽  
Long Term Trends ◽  
Sst Anomalies ◽  
Chrysaora Hysoscella

A semi- quantitative time series (2013-2017) was used to present the recent events of scyphomedusae appearance and abundance in the Boka Kotorska Bay, Montenegro, Southeast Adriatic. Six meroplanktonic species were recorded: Aurelia spp, Chrysaora hysoscella, Cotylorhiza tuberculata ̧ Discomedusa lobata, Drymonema dalmatinum and Rhizostoma pulmo. Among them, C. hysoscella and D. lobata dominated in the water column during winter and spring, forming dense aggregations in March and May, and February to May, respectively. Our description of the D. lobata blooms are actually the first known records of blooms for this species. C. tuberculata was observed in the Bay principally in August and September. The bloom was occurred only in 2017, being the first information of C. tuberculata mass appearance in this area. We hypothesized that global warming phenomena could trigger the observed changes, and in this respect, long-term trends of sea surface temperature (SST) fluctuations were analysed. The scyphomedusae blooms coincided with high positive SST anomalies, noted in the last seven years for this area. To better understand the mechanisms underlying changes in their phenology and abundance, detailed studies on benthic stages in the Bay are essential.

Stable Isotope Evidence for Recent Global Warming Hiatus

2020 ◽  
Author(s):  
Rui Wang ◽  
Zhongfang Liu
Keyword(s):  
Global Warming ◽  
Air Temperature ◽  
Surface Air Temperature ◽  
Stable Isotopic ◽  
Global Warming Hiatus ◽  
Isotope Evidence ◽  
Warming Hiatus ◽  
Open Question ◽  
New Evidence

<p>Global mean surface air temperature (SAT) has remained relative stagnant since the late 1990s, a phenomenon known as global warming hiatus. Despite widespread concern and discussion, there is still an open question about whether this hiatus exists, partly due to the biases in observations. The stable isotopic composition of precipitation in mid- and high-latitude continents closely tracks change of the air temperature, providing an alternative to evaluate global warming hiatus. Here we use the long-term precipitation δ<sup>18</sup>O records available to investigate changes in SAT over the period 1970–2016. The results reveal slight decline in δ<sup>18</sup>O anomaly from 1998 to 2012, with a slope of -0.0004‰ decade<sup>-1 </sup>which is significantly different from that of pre-1998 interval. This downward δ<sup>18</sup>O anomaly trend suggests a slight cooling for about -0.001°C decade<sup>-1</sup>, corroborating the recent hiatus in global warming. Our work provides new evidence for recent global warming hiatus and highlights the potential of utilizing precipitation isotope for tracking climate changes.</p>

The IOD-ENSO precursory teleconnection over the tropical Indo-Pacific Ocean: dynamics and long-term trends under global warming

2018 ◽  
Vol 36 (1) ◽  
pp. 4-19 ◽  
Author(s):  
Dongliang Yuan ◽  
Xiaoyue Hu ◽  
Peng Xu ◽  
Xia Zhao ◽  
Yukio Masumoto ◽  
...  
Keyword(s):  
Global Warming ◽  
Pacific Ocean ◽  
Ocean Dynamics ◽  
Long Term Trends
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