bluewave

The record breaking IO standing wave is making headlines again. Now it looks like it’s producing an early September pattern resembling MJO phase 1. So this translates into the big ridge along the West Coast and trough over the MW/GL. It will limit our early September 90° potential.

It really depends on how long the ridge says locked in along the West Coast. This hasn’t been our typical September pattern during the last decade. There has usually been a trough out there with a ridge over New England.

I agree that the MYI loss is the big story. https://climate.nasa.gov/news/2817/with-thick-ice-gone-arctic-sea-ice-changes-more-slowly/ With thick ice gone, Arctic sea ice changes more slowly The Arctic Ocean's blanket of sea ice has changed since 1958 from predominantly older, thicker ice to mostly younger, thinner ice, according to new research published by NASA scientist Ron Kwok of the Jet Propulsion Laboratory, Pasadena, California. With so little thick, old ice left, the rate of decrease in ice thickness has slowed. New ice grows faster but is more vulnerable to weather and wind, so ice thickness is now more variable, rather than dominated by the effect of global warming. Working from a combination of satellite records and declassified submarine sonar data, NASA scientists have constructed a 60-year record of Arctic sea ice thickness. Right now, Arctic sea ice is the youngest and thinnest its been since we started keeping records. More than 70 percent of Arctic sea ice is now seasonal, which means it grows in the winter and melts in the summer, but doesn't last from year to year. This seasonal ice melts faster and breaks up easier, making it much more susceptible to wind and atmospheric conditions. Working from a combination of satellite records and declassified submarine sonar data, NASA scientists have constructed a 60-year record of Arctic sea ice thickness. Right now, Arctic sea ice is the youngest and thinnest its been since we started keeping records. More than 70 percent of Arctic sea ice is now seasonal, which means it grows in the winter and melts in the summer, but doesn't last from year to year. This seasonal ice melts faster and breaks up easier, making it much more susceptible to wind and atmospheric conditions. Kwok's research, published today in the journal Environmental Research Letters, combined decades of declassified U.S. Navy submarine measurements with more recent data from four satellites to create the 60-year record of changes in Arctic sea ice thickness. He found that since 1958, Arctic ice cover has lost about two-thirds of its thickness, as averaged across the Arctic at the end of summer. Older ice has shrunk in area by almost 800,000 square miles (more than 2 million square kilometers). Today, 70 percent of the ice cover consists of ice that forms and melts within a single year, which scientists call seasonal ice. Sea ice of any age is frozen ocean water. However, as sea ice survives through several melt seasons, its characteristics change. Multiyear ice is thicker, stronger and rougher than seasonal ice. It is much less salty than seasonal ice; Arctic explorers used it as drinking water. Satellite sensors observe enough of these differences that scientists can use spaceborne data to distinguish between the two types of ice. Thinner, weaker seasonal ice is innately more vulnerable to weather than thick, multiyear ice. It can be pushed around more easily by wind, as happened in the summer of 2013. During that time, prevailing winds piled up the ice cover against coastlines, which made the ice cover thicker for months. The ice's vulnerability may also be demonstrated by the increased variation in Arctic sea ice thickness and extent from year to year over the last decade. In the past, sea ice rarely melted in the Arctic Ocean. Each year, some multiyear ice flowed out of the ocean into the East Greenland Sea and melted there, and some ice grew thick enough to survive the melt season and become multiyear ice. As air temperatures in the polar regions have warmed in recent decades, however, large amounts of multiyear ice now melt within the Arctic Ocean itself. Far less seasonal ice now thickens enough over the winter to survive the summer. As a result, not only is there less ice overall, but the proportions of multiyear ice to seasonal ice have also changed in favor of the young ice. Seasonal ice now grows to a depth of about six feet (two meters) in winter, and most of it melts in summer. That basic pattern is likely to continue, Kwok said. "The thickness and coverage in the Arctic are now dominated by the growth, melting and deformation of seasonal ice." The increase in seasonal ice also means record-breaking changes in ice cover such as those of the 1990s and 2000s are likely to be less common, Kwok noted. In fact, there has not been a new record sea ice minimum since 2012, despite years of warm weather in the Arctic. "We've lost so much of the thick ice that changes in thickness are going to be slower due to the different behavior of this ice type," Kwok said. Kwok used data from U.S. Navy submarine sonars from 1958 to 2000; satellite altimeters on NASA's ICESat and the European CryoSat-2, which span from 2003 to 2018; and scatterometer measurements from NASA's QuikSCAT and the European ASCAT from 1999 to 2017.

Updated for July 2020. 7....2020...EWR...5...NYC...7...LGA...1.....JFK...4...BDR....1...ISP....4

Updated for the 3.17 in Montclair, NJ with Tropical Storm Fay. 7/11/2020 8:00 AM NJ-ES-31 Montclair 0.7 N 3.17 NA | NA NA | NA NJ Essex

Updated for June 2020 6....2020...EWR..10..LGA...3...BDR...5.....ISP....5

Updated for the 3.99 at Bridgeport on July 3rd.

This record +AO pattern was more like something we saw around 1990. https://nsidc.org/arcticseaicenews/ Previous studies, led by University of Washington scientist Ignatius Rigor (e.g., Rigor et al., 2002), suggest that a positive winter phase of the Arctic Oscillation favors low sea ice extent the subsequent September. Wind patterns “flush” old, thick ice out of the Arctic Ocean through the Fram Strait and promote the production of thin ice along the Eurasian coast that is especially prone to melting out in summer. However, in recent years, this relationship has not been as clear (Stroeve et al., 2011). The potential effects this winter’s positive AO on the summer evolution of ice extent and the September 2020 minimum bears watching.

If the rate of warming since 1980 continues, then we are on track for +1.5 C of warming around 2035.

Updated for top 10 warmth in February 2020. 2....2020...EWR...6...NYC...6...LGA....8...JFK...4...BDR...5....iSP...3

Updated for the top10 warmth in January 2020. 1....2020...EWR...9...NYC...9...LGA....7...JFK...6...BDR...3....ISP...6

2nd warmest year for the Arctic behind 2016.

Record low Arctic sea ice extent for the Chukchi Sea in 2019.

Updated for 3.44 in Woodbury, NY. https://nwschat.weather.gov/p.php?pid=201912141224-KOKX-NOUS41-PNSOKX WOODBURY 3.44 704 AM 12/14 CWOP

The record amount of open water for the Chukchi Sea continues to be one of the big stories this year.

That was a very cold -NAO/+PNA pattern for the first week of December 2003. It was the snowiest first week of December and the 11th coldest for NYC.

Another recent paper highlighted how unusual the initiation of the March 2015 unprecedented MJO event in phase 4 was. This helped trigger the 2015-2016 super El Niño event. https://www.nature.com/articles/srep46692 The emergence of this convection–circulation pattern signaled the onset of an MJO that later strengthened to an unprecedented amplitude (MJO real-time multivariate index24 of 4.62 on March 16, 2015 compared with the previous record of 4.02 on February 14, 1985; http://www.bom.gov.au/climate/mjo/) during its eastward propagation over the tropical Pacific in March (Fig. 2c)13. In contrast to the canonical MJOs, which typically originate in the tropical IO, the MJO in spring 2015 initiated in the western Pacific. Our analysis revealed that only 3 out of the 75 large-amplitude MJOs (occurring in 1975, 2013, and 2015; approximately 4%) during 1974–2015 initiated in the western Pacific (i.e., phase 4 of the MJO index24, Supplementary Figure 2). Notably, only in 2015, the MJO preceded the onset of an El Niño event. No eastward-propagating tropical signals from the west but strong extratropical perturbations were observed preceding the 2015 MJO event; this lead–lag relationship implies the potential extratropical effect on triggering the MJO. Furthermore, the percentile values reported in Figs 1 and 2 show the unprecedented amplitudes of the extratropical SLP, northerly, WWB, tropical SLP anomaly crossing the central and eastern equatorial Pacific (Fig. 1c), and the MJO strength. This observation revealed the distinct characteristics associated with this MJO: the effect of extratropical forcing, atypical genesis location and timing, and the extremity of amplitudes in many aspects. The warm ocean surface in the equatorial western Pacific might be another favorable condition conducive to MJO occurrence. A vertical cross section of the monthly ocean temperature along the equator (Supplementary Figure 3) revealed that the upper ocean in the central Pacific was approximately 1.5 K warmer in February–April 2015 than the long-term mean. This warming in the central Pacific was markedly higher than that during the onset of the 1997–98 El Niño. A previous study13 reported the effect of this warm water on MJO development in early spring 2015. An analysis of the SST evolution since early 2014 indicated that the warm SST in the central Pacific was primarily the remaining positive SST anomaly from the aborted 2014 El Niño (data not shown). The extratropical forcing in late February likely triggered the anomalous convection over this warm water and initiated the rigorous atmosphere–ocean interaction in the tropical western and central Pacific and onset of a strong MJO event. Conclusion and Discussion An atypical MJO initiated to the west of the dateline in early March 2015 and rapidly amplified to an unprecedented magnitude over the warm SST in the central and eastern Pacific on March 16. Following the MJO, the SST in the equatorial central–eastern Pacific encountered rapid growth and ultimately evolved to a strong El Niño comparable with the 1982–83 and 1997–98 events. Before the MJO onset, we observed a persisting high-pressure system accompanied by strong cold northerly in the extratropical western North Pacific. On the basis of data diagnostics and numerical experiments, we identified an atypical effect of extratropical perturbations in the western North Pacific on triggering the onset of the MJO in March 2015 and indirectly contributing to the onset of the 2015–16 El Niño. The main results are summarized as follows: 1 Observational analysis indicated that the strong cold northerly, which was associated with a persisting high-pressure system in the extratropical western North Pacific, penetrated southward to the tropical western Pacific and triggered the tropical convective instability that led to the onset of the MJO at an atypical location, namely west of the dateline. The critical effect of the extratropical disturbances on the MJO onset was confirmed by numerical experiments by using an atmospheric general circulation model coupled with an ocean mixed layer model. 2 The MJO developed rapidly to an extreme magnitude because of the favorable ocean conditions: a warm upper ocean temperature in the equatorial central and western Pacific remaining from the aborted 2014 El Niño. 3 Both data diagnostics and numerical experiments revealed that the strong WWB associated with the MJO triggered the first pulse of downwelling Kelvin wave-like perturbations that later induced the onset of the 2015–16 El Niño. Extratropical forcing was the unique characteristic of the reported MJO–El Niño event. The onset of El Niño by an MJO has been observed often. However, according to our review of relevant literature, the present study is the first to report the onset of an El-Niño-inducing MJO in the western Pacific triggered by extratropical perturbations. Extremity was another unique characteristic. Several aspects of perturbations, such as extratropical and tropical SLP, northerly, and the MJO reached unprecedented amplitudes. The reasons for these unique characteristics remain unknown. However, our study revealed the possible effect of extratropical forcing, which has not been considered previously, on the onset of MJO and El Niño. Such a mechanism, although it might not occur frequently, warrants further attention and may elucidate the onset of an MJO and its potential effect on El Niño.

https://www.nature.com/articles/s41586-019-1764-4 Article Published: 27 November 2019 Twofold expansion of the Indo-Pacific warm pool warps the MJO life cycle Nature volume 575, pages647–651(2019)Cite this article Article metrics 23 Altmetric Metrics details M. K. Roxy, Panini Dasgupta, Michael J. McPhaden, Tamaki Suematsu, Chidong Zhang & Daehyun Kim Abstract The Madden–Julian Oscillation (MJO) is the most dominant mode of subseasonal variability in the tropics, characterized by an eastward-moving band of rain clouds. The MJO modulates the El Niño Southern Oscillation1, tropical cyclones2,3 and the monsoons4,5,6,7,8,9,10, and contributes to severe weather events over Asia, Australia, Africa, Europe and the Americas. MJO events travel a distance of 12,000–20,000 km across the tropical oceans, covering a region that has been warming during the twentieth and early twenty-first centuries in response to increased anthropogenic emissions of greenhouse gases11, and is projected to warm further. However, the impact of this warming on the MJO life cycle is largely unknown. Here we show that rapid warming over the tropical oceans during 1981–2018 has warped the MJO life cycle, with its residence time decreasing over the Indian Ocean by 3–4 days, and increasing over the Indo-Pacific Maritime Continent by 5–6 days. We find that these changes in the MJO life cycle are associated with a twofold expansion of the Indo-Pacific warm pool, the largest expanse of the warmest ocean temperatures on Earth. The warm pool has been expanding on average by 2.3 × 105 km2 (the size of Washington State) per year during 1900–2018 and at an accelerated average rate of 4 × 105 km2(the size of California) per year during 1981–2018. The changes in the Indo-Pacific warm pool and the MJO are related to increased rainfall over southeast Asia, northern Australia, Southwest Africa and the Amazon, and drying over the west coast of the United States and Ecuador. Fig. 1: A twofold expansion of the warm pool. Fig. 2: Changes in the MJO life cycle. Fig. 3: Correlation between MJO phase duration and ocean–atmosphere conditions. Fig. 4: Changes in global rainfall in response to the changes in MJO phase duration. Extended Data Fig. 1 Typical life cycle of the MJO. Extended Data Fig. 2 Annual average period of MJO events. Extended Data Fig. 3 Warm pool area in multiple datasets and breakpoint analysis. Extended Data Fig. 4 Correlation between MJO phase duration and ocean–atmosphere conditions, without removing the trends.

Every month since April has featured top 3 warmth in the Arctic. This is a first for April through October. https://www.esrl.noaa.gov/psd/data/timeseries/

Similar to the findings in this recent paper. https://advances.sciencemag.org/content/4/8/eaat6773 DISCUSSION Implications and outlook The doubling of BG halocline heat content over the past three decades appears attributable to a warming of the source waters that ventilate the layer, where this warming is due to sea ice losses in the Chukchi Sea that leave the surface ocean more exposed to incoming solar radiation in summer. The effects of an efficient local ice-albedo feedback are thus not confined to the surface ocean/sea ice heat budget but, in addition, lead to increased heat accumulation in the ocean interior that has consequences far beyond the summer season. Strong stratification and weak mechanical mixing in the BG halocline ensure that significant summertime heat remains in the halocline through the winter. With continued sea ice losses in the Chukchi Sea, additional heat may continue to be archived in the warm halocline. This underscores the far-reaching implications of changes to the dynamical ice-ocean system in the Chukchi Sea region. However, there is a limit to this: Once the source waters for the halocline become warm enough that their buoyancy is affected, ventilation can be shut off. Efficient summertime subduction relies on the lateral surface front in the NCS region between warm, salty water that is denser to the south and cooler, fresher water that is less dense to the north. For longer-duration solar warming (that is, longer-duration ice-free conditions in the region), SSTs on the south side of the front may become warm enough (around 13°C, under the assumption of a 1.5-month ice-free period dominated by solar absorption) that the lateral density gradient is eliminated [see (24)]. It remains to be seen how continued sea ice losses will fundamentally change the water column structure and dynamics of the Arctic halocline. In the coming years, however, excess BG halocline heat will give rise to enhanced upward heat fluxes year-round, creating compound effects on the system by slowing winter sea ice growth.

Updated for the 9th warmest October at EWR and 7th warmest at ISP.

According to the NSIDC data, October 2019 beat 2012 for the lowest monthly average extent. This makes the 3rd new lowest monthly extent record for 2019. It’s also the 10th new lowest monthly extent since 2016. ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/Sea_Ice_Index_Monthly_Data_with_Statistics_G02135_v3.0.xlsx 1 2019 5.66 2 2012 5.89 NSIDC lowest average monthly extents Jan...2018 Feb...2018 Mar...2017 Apr....2019 May...2016 Jun....2016 Jul.....2019 Aug...2012 Sep...2012 Oct...2019 Nov...2016 Dec...2016

While the ESS is finally freezing up, Chukchi extent remains at record low levels for the end of October.