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Qué es ENSO - La Oscilación del Sur “El Niño”?

Thursday, January 28, 2016

“El Niño” y “La Niña” son parte de la oscilación del sur El Niño, (ENSO por sus siglas). ENSO es una fluctuación natural de las temperaturas superficiales del mar y la presión superficial del aire del Océano Pacifico Tropical entre el este y oeste.  Durante un evento “El Niño,” los vientos alisios del este se debilitan, permitiendo que el agua superficial más cálida  del Océano Pacifico Tropical del oeste corra  hacia el este.  Durante un evento “La Niña,”  estos vientos alisios se intensifican, causando que el agua cálida del este no pueda correr hacia el oeste y por consiguiente que el agua cálida superficial del este se apile.  Grandes áreas de baja presión superficial del aire y precipitación convectiva siguen el agua cálida al migrar a través del Océano Pacifico Tropical, alterando los patrones de circulación atmosférica (por ejemplo, la Circulación Walker), que pueden influir el tiempo de todo el mundo. (Figura 1)

Figura 1: Eventos El Niño causan que el pasaje invernal de la corriente en chorro  se mueva sobre la región del suroeste, generalmente entregando más lluvia y nieve invernal en la región. Imagen modificada de la Administración Oceánica y Atmosférica Nacional (NOAA).

El Niño Tracker - Jan 2016

Friday, January 22, 2016

El Niño conditions continued for an 11th straight month, putting us squarely in the middle of a strong El Niño event that will be among one of the strongest events on record. Forecasts focused on the persistence of sea surface temperature (SST) anomalies (Figs. 1–2) and weakened trade winds, enhanced convective activity in the central and eastern Pacific, and El Niño-related ocean-atmosphere coupling. Models continue to forecast a strong El Niño event that will last through spring 2016, but we are starting to see signs of decline in the overall strength of the event.

On Jan. 12, the Japan Meteorological Agency identified ongoing El Niño conditions as having reached their “mature stage” in the equatorial Pacific in November–December 2015, with likely gradual weakening during the months ahead. On Jan. 14, the NOAA-Climate Prediction Center (CPC) extended its El Niño advisory and said the current atmospheric and oceanic anomalies reflect a strong El Niño that will persist through most of the spring, transitioning to ENSO-neutral by late spring or early summer. The CPC noted, however, that the “exact timing of the transition is difficult to predict.” On Jan. 19, the Australian Bureau of Meteorology maintained its tracker at official El Niño status, with the event likely having peaked and ocean temperatures showing signs of gradual cooling. On Jan. 21, the International Research Institute for Climate and Society (IRI) and CPC forecasts indicated that all oceanic and atmospheric variables were indicative of a strong El Niño event, with consensus centering on strong El Niño conditions that will persist through spring 2016 (Fig. 3). The IRI/CPC briefing also indicated El Niño strength peaked in November–December, but that this was a “broad peak” with a gradual decline and the El Niño event would remain strong through late spring 2016. The North American multi-model ensemble currently shows a strong event extending into 2016 with gradual weakening heading into spring and summer (Fig. 4).

 

So what does this mean for the region? Even though forecasts are looking at the eventual decline of the El Niño signals, we are in the middle of a strong El Niño event. For the Southwest, the current seasonal forecasts and past events suggest we should see well above-average cumulative precipitation totals throughout our cool season (October–March), but we should also expect periods of inactivity between storms. Even though the 2015–2016 El Niño event “peaked” in November-December, we see impacts in the Southwest as they lag behind this spike in intensity, which means that we look to late winter and early spring as the most likely times to see increased storm activity associated with the El Niño signal. This doesn’t mean we can’t or won’t see increased activity outside of this window, but the default state for the desert Southwest is dry; even a strong El Niño event can only alter that system so much. We won’t be able to fully dissect and judge the 2015–2016 El Niño event until we see just how much rain and snow fell over the entire cool season. Given what we know about past events, our best bets for receiving above-average precipitation will be in February and March, or even April.  


Looking at the 1997–1998 event—the strongest El Niño event on record—most of Arizona and New Mexico received below-average rain and snowfall for all of January before returning to normal or above-normal precipitation in February and March (Figs. 5–8).

Southwest Climate Outlook January 2016

Thursday, January 21, 2016

In this Issue:


Precipitation: Over the past 30 days, the cumulative precipitation totals for Arizona and New Mexico were a mix of above- and below-average values (Fig. 1). Thirty-day averages often span wet and dry periods, while the week-to-week totals show considerably more variability. For example, precipitation totals in southern Arizona were buoyed by a series of storms that brought significant rainfall to the southwestern U.S. in the first week of January, which was preceded by a relatively below-average December and followed by an extended dry period in mid-January (see El Niño Tracker for more commentary and discussion of recent precipitation trends).

Temperature: December cooled off in much of the Southwest. Most of Arizona recorded normal to below-normal temperatures, while New Mexico was mostly normal to above normal, especially along the eastern half of the state (Fig. 2). Globally, 2015 was the warmest year on record and was among the top five warmest years for many western states (Fig. 3), and was the second warmest year on record for the U.S. overall.

Snowpack and Water Supply: Relatively frequent winter storm activity has brought impressive snowpack levels and snow water equivalent (SWE) percent of normal values to much of the western U.S., including above-normal values across almost all of the basins in Arizona and New Mexico (Fig. 4). Increased winter precipitation is an expected pattern given the current strong El Niño event. Later this spring, we will have a more accurate understanding of El Niño’s contribution to winter precipitation and a better sense of how temperature affected patterns of rain and snow and the contributions to water supply (See reservoir totals).

Drought: Long-term drought conditions persist across much of central and eastern Arizona along with the western edge of central New Mexico (Fig. 5). Recent runs of average to above-average precipitation have helped mitigate some of the short-term drought conditions, but we are continually reminded that multi-year droughts, such as those we experienced during much of the 21st century, will require multi-year periods to fully recover. El Niño offers hope for additional drought relief, particularly if above-average precipitation over the winter helps saturate soils and build snowpack in the region, boosting reservoir storage during springtime snowmelt runoff events.

El Niño Tracker: We are in the middle of a strong El Niño event forecast to remain in place through Spring 2016. We can expect variable weather throughout the winter season, but we anticipate more winter precipitation events and a higher cumulative total at the end of the cool season (see El Niño Tracker).

Precipitation & Temperature Forecast: The January 21 NOAA-Climate Prediction Center three month seasonal outlook predicts above-average precipitation for most of the Southwest this winter, with progressively increasing chances of above-average precipitation as you move south (Fig. 6, top). Temperature forecasts are split, with elevated chances for above-average temperatures along the West Coast and the Pacific Northwest, and increased chances for below-average temperatures centered over Texas and and southeastern New Mexico (Fig. 6, bottom).

Introducing the 2016 CLIMAS Climate and Society Graduate Fellows

Wednesday, January 13, 2016

The Climate & Society Graduate Fellows Program supports University of Arizona graduate students whose work connects climate research and decision making. The program is made possible by support from the Climate Assessment for the Southwest (CLIMAS), the International Research Applications Program (IRAP), and the UA Office for Research and Discovery. Fellows receive $5,000 and guidance from members of the CLIMAS research team for one year. The program’s main objective is to train a group of students to cross the traditional boundaries of academic research into use-inspired science and applied research. While CLIMAS research generally occurs in the Southwest U.S., the Fellows program allows students to work anywhere in the world.

Fellows’ projects may follow two tracks. Students who want to conduct collaborative research may use their funding for use-inspired projects. Students who have conducted climate research and want to communicate their findings to audiences outside of academia may use their funding for outreach. Fellows may also use their funding for a combination of the two tracks.

The Climate & Society Graduate Fellows Program helps students address the world’s climate-related problems by funding projects that engage people outside of the university.

The 2016 Climate Assessment for the Southwest (CLIMAS) Climate & Society Graduate Fellows are:

Saleh Ahmed

Developing a Community Hub for Climate Innovations in  Southwest Coastal Bangladesh

Abstract: Bangladesh ranks as one of the countries most vulnerable to the impacts of climate variability and change. A majority of local farmers and fishermen, whose livelihoods are dependent on climate-sensitive sectors, do not receive adequate climate information that can help improve their adaptation decision-making and increase community resilience. However, several evidence suggest that poor and marginalized farmers can improve their adaptation decision-making if they receive the appropriate demand-driven climate information in a timely manner. This motivates to develop a stakeholder-driven and user-inspired community hub for climate innovations in southwest coastal Bangladesh, where the livelihoods of majority of people are dependent on climate-sensitive sectors, and exposed to various adverse impacts caused by climate variability and change. This community hub should play instrumental role in creating opportunities for multi-way interactions and knowledge and information exchange by coproducing climate knowledge among various stakeholders concerning climate-related issues that are directly linked to local livelihoods. Ultimately, this community hub for climate innovations should play critical role promoting various social innovations in the region. The fundamental objective of this project, with the support from CLIMAS, is to develop a stakeholders-driven & use-inspired process of needs assessment that feeds into a development proposal, which can ultimately be scaled-up by national or international development partners for larger impacts across the regions. A small farming community in southwest coastal Bangladesh is the focus of this planned project.


Schuyler Chew

Collaborative Outreach and Climate Adaptation Planning with the Pyramid Lake Paiute Tribe

Abstract: The Pyramid Lake Paiute Tribe (PLPT) in Nevada is deeply connected physically, culturally and spiritually to Pyramid Lake and has made substantial gains to protect this ecosystem. Through collaborative efforts, our research team has been working with PLPT to understand how climate change might impact tribal water resources. We developed a mass-balance approximation tool to simulate Pyramid Lake elevation over time under various climate change scenarios and proposed ten adaptation recommendations that might enhance tribal adaptive capacity. I seek to build on this research endeavor by discussing with PLPT decision makers how to improve the mass-balance tool’s usefulness for water resource planning. I also plan to collaboratively engage with tribal stakeholders to develop a set of guiding principles that the tribe can use to evaluate climate adaptation strategies.


Stina Janssen

Solar Sovereignty: use-inspired collaborative research for affordable off-grid solar on the Navajo Nation

Abstract: The Navajo Nation is experiencing severe and worsening drought conditions exacerbated by climate change. As a CLIMAS Fellow, Stina Janssen will collaborate with Black Mesa Water Coalition (BMWC) to coproduce research usable for the development of off-grid residential solar systems affordable to low income Navajo households. Stina's research will explore constraints and possibilities for finance and community-ownership or community-control structures applicable for BMWC's solar program. 


Sarah Kelly-Richards

Outreach for Small Hydropower Governance in Chile

Abstract: Globally, renewable energy production is promoted as a mitigation strategy for climate change. Supported by a Fulbright Scholarship in Chile, my dissertation research examines the challenges and potential of small hydropower (typically generating between 1 to 20 megawatts) as form of climate change mitigation. As a CLIMAS fellow, I will conduct outreach informed by research findings that is designed to connect local knowledge of small hydropower development with environmental policymaking. Ultimately, my project seeks to support social justice and environmental sustainability within the transition to renewable energy. 


Joy Liu

Dryland conservation in China: local incentives drive collaborative action on regional climate adaptation

Abstract: This project will assess the local incentives that drive collaborative efforts to conserve dryland systems on agricultural landscape in northern China by collaborating with a non-profit organization (NGO) called Green Action Charity Foundation. The Foundation collaborate with two other stakeholders: County-level officials, and village leaders in Shanxi province to develop tree-planting models, and achieve reforestation targets set by the national government. But NGO efforts face the challenge of integrating conservation, local development needs and regional climate adaptation strategies. Data from interviews and ethnographic study conducted during summer 2014 serve as basis to identify possible incentives and disincentives for collaboration among stakeholders. In summer and fall 2016, a comparative community-level climate adaptation profile and drivers for participation in conservation efforts will be documented and analyzed through stakeholder perspectives in two villages in Shanxi and Gansu province, China. These findings will be used by the Foundation and other stakeholders to develop an updated integrative collaborative model that may help us understand what drives dissonance between values and subsequent collaborative behavior in the context of dryland conservation in China. 

Ask an Applied Climatologist - Q&A - How did observed weather correspond to (El Niño) climate predictions?

Tuesday, January 12, 2016

Looking back at Oct-Dec; Did observed weather events correspond with expected (El Niño) climate patterns?

January has kicked off with a bang, and the much anticipated super-mega-Godzilla El Nino is upon us.  El Niño conditions have been in place for months (Figure 1: Oceanic Niño Index), but has this El Niño event been impacting the weather of the Southwest in ways that are expected? Sort of, but not exactly.

This is probably to be expected, as we and others have been saying, no two El Niño events are alike (which means they are hard to compare), AND the October-November-December time period is still very early season for El Niño in the Southwest, so it would be premature to judge it too harshly, or to call this as having gone off the rails.

First off, the October through December time frame is a period of transition for the Southwest where we move from our summer monsoon thunderstorm season into a more westerly upper level circulation pattern and look expectantly for winter storms to bring precipitation to the region. October is also the time where a tropical storm can either directly or indirectly bring a boatload of moisture that can bring heavy precipitation to the region. Even during a ‘normal’ year with no El Niño influence, it is a ‘noisy’ time with lots of moving parts and potential variability, with quite a few dry and wet extremes in the historical record.  Long story short, El Niño or not, we expect to see a lot of variability during this transition season, so the larger question is how much does El Niño typically impact this season?

The influence of El Nino during this Oct-Dec transition operates through the mechanisms of tropical storm activity and early winter storm tracks, both of which can impact precipitation patterns across the Southwest. Typically, tropical storm activity is enhanced in the east Pacific during strong El Niño events, raising the likelihood of above-average precipitation from these events.  And the southward shift in the winter storm track, which is a hallmark impact of El Niño events, can set up as early as November. Based on this, we did largely expect this period to be wetter than average for Arizona and New Mexico and it mostly was (Figure 2: Departure from Normal Precip Oct-Dec 2015). But when we look a bit more closely, how we got this precipitation was a bit unusual, and it really didn’t fit the typical El Niño driven patterns.

For example, in October a series of cut off low pressure systems wandered across the Southwest (at one point, the same cut off low visited Arizona twice) picking up abundant tropical moisture to the south and creating widespread precipitation events across Arizona and New Mexico. These cut-off lows formed off a very busy jet stream pattern across the Pacific Ocean that in part was energized by all of the tropical storm activity across the basin (see the NOAA discussion here). Instead of directly interacting with tropical storms in the east Pacific, El Niño appears to have brought us to above-average precipitation for October in a much more complicated way (Figure 3: Departure from Normal Precip Oct 2015).

A highly amplified jet stream pattern continued into November, again partially driven by tropical storm activity being absorbed into the jet stream in the west Pacific (see NOAA synoptic discussion), leaving the Southwest to contend with a busy weather pattern but very little to work with in the way of moisture. A parade of storms marched through the Southwest through the month, but originated in the Gulf of Alaska and brought very little moisture with them. Some higher elevation and more northern areas were able to squeak out some precipitation with these storm systems, but overall the month was cool and relatively dry for the Southwest (Figure 4: Departure from Normal Precipitation Nov 2015). This was in contrast to the expectation of a much stronger subtropical jet (which was present, but south of AZ and NM) pulling in abundant moisture from lower latitudes.

December was largely characterized the by same pattern with the Southwest seeing passing storms and cooler than average temperatures, but little in the way of precipitation (Figure 5: Departure from Normal Precipitation Dec 2015). New Mexico was able to buck this trend a bit late in the month as a historic blizzard (compared to a similar snowstorm that hit the region in January of 1983, also a strong El Niño winter) swept through the area. 

The final precipitation totals for Oct-Dec 2015 across the Southwest are more or less what you would expect (generally above-average precipitation across New Mexico and northern AZ) for an El Niño year and a bit of the unexpected (drier-than average conditions across parts of western Arizona). But again, maybe that is what we should expect. Two other strong El Niño events (1983, 1997) are depicted for the same time period and are very different from each other. Oct-Dec 2015 establishes itself as yet another flavor of potential precipitation impacts during the fall season across the Southwest U.S.