Operatividad del monitoreo y pronóstico meteorológico de condiciones atmosféricas favorables a incendios forestales en el Perú

Universidad Nacional Agraria La Molina. Facultad de Ciencias. Departamento Académico de Ingeniería Ambiental, Física y MeteorologíaEl presente trabajo describe el proceso, así como los resultados de la Vigilancia Atmosférica de Incendios Forestales en el Perú que se realiza en la Subdirección de Predicción Meteorológica (SPM) de la Dirección de Meteorología y Evaluación Ambiental Atmosférica (DMA) del Servicio Nacional de Meteorología e Hidrología (SENAMHI). Los incendios forestales en Perú han ido en aumento en los últimos años y principalmente desde el 2016, vienen presentando problemas tanto ecológicos, como socioeconómicos; por ello surgió la necesidad de establecer un sistema de vigilancia de variables atmosféricas que propicien la ocurrencia y propagación de estos, con el objetivo de reducir los riesgos en las regiones vulnerables al peligro generado por la ocurrencia de incendios forestales, mediante la anticipación de ellos. Para implementar el sistema de Vigilancia Atmosférica se siguieron pasos tales como: reuniones de coordinación con las instituciones vinculadas al control y manejo de incendios forestales y así identificar las necesidades de estas; identificación de las variables meteorológicas responsables de las condiciones óptimas para la ocurrencia de incendios forestales; identificación de patrones sinópticos que favorezcan la ausencia de humedad, y por ende, los incendios forestales; cálculo y análisis del Índice Meteorológico de Incendios Forestales (FWI, por sus siglas en inglés) y su aplicación en el Perú; generación de productos y servicios especializados para incendios forestales; publicación de estos en la plataforma web; y las presentaciones institucionales para la mejora continua de los productos y servicios especializados brindados. Mediante la aplicación de los pasos mencionados en el párrafo anterior, actualmente se cuenta con una plataforma web denominada “Vigilancia Atmosférica de Incendios Forestales”, en la cual se realiza el monitoreo y pronóstico de condiciones favorables para la ocurrencia de incendios forestales. Esta plataforma tiene actualización en tiempo real y cuenta con productos generados de forma automática, como aquellos que son realizados con análisis de profesionales meteorólogos, ingenieros forestales, entre otros. Está disponible para el público en general, pero es utilizada, principalmente, por las instituciones tomadoras de decisiones

Behavior of the ITCZ second band near the Peruvian coast during the 2017 coastal El Niño

The behavior of the second band of the Intertropical Convergence Zone (ITCZ) near the Peruvian coast during early 2017 is studied, using precipitation, surface winds, sea surface temperature (SST) and atmospheric variables in different isobaric levels. The proposal of a daily index (Ia) to identify opportunely the formation of this band and the Lorenz energy terms in the region is also considered. This band was present from late January to early April 2017, associated with an anomalous dipole of sea level pressure between the east and west eastern Equatorial Pacific that configured anomalously northerly surface winds and the release of southeasterly trade winds near Peru. In medium levels, a zonally oriented positive mixing ratio anomaly was observed in early March over the ITCZ second band, associated with heavy rain systems over the northern Peruvian coastal region. In the same period, positive anomalies of divergence in high tropospheric levels were observed. The daily Ia index allowed an effective detection of the ITCZ second band 11 days before the maximum coastal precipitation, and the Lorenz energy terms showed eddy kinetic energy (KE) peaks in January and February and a contribution of barotropic instability in equatorial regions.En este estudio se analiza el comportamiento de la segunda banda de la Zona de Convergencia Intertropical (ZCIT) cerca de la costa peruana a inicios de 2017 usando precipitación, vientos superficiales, temperatura superficial del mar y variables atmosféricas en diferentes niveles isobáricos. Además, se propone un índice diario (Ia) para identificar de manera oportuna la formación de esta segunda banda y se considera el análisis de los términos de energía de Lorenz en la región. Esta banda estuvo presente desde los últimos días de enero hasta los primeros días de abril de 2017, asociada con un dipolo anómalo de presión reducida a nivel del mar hacia el este y el oeste del Pacífico Ecuatorial oriental, lo cual configuró vientos superficiales anómalos del norte y relajación de los vientos alisios del sur cerca de la costa peruana. En niveles medios de la troposfera, a inicios de marzo, se observó una anomalía positiva de relación de mezcla proveniente del este sobre la región de la segunda banda de la ZCIT, asociada con sistemas de precipitación intensos sobre la costa norte de Perú. En el mismo periodo se observaron anomalías positivas de divergencia en niveles altos. El índice diario Ia permitió la detección oportuna de la segunda banda de la ZCIT 11 días antes del máximo de precipitación en el norte de la costa peruana, y los términos de energía de Lorenz mostraron picos de energía cinética de las perturbaciones (KE) en enero y febrero, así como contribución de la inestabilidad barotrópica en regiones ecuatoriales

Comparison between the Operational and Statistical Daily Maximum and Minimum Temperature Forecasts in The Central Coast of Peru

Multiple linear regression models were developed for 1-3-day lead forecasts of maximum and minimum temperature for two locations in the city of Lima, in the central coast of Peru (12°S), and contrasted with the operational forecasts issued by the National Meteorological and Hydrological Service - SENAMHI and the output of a regional numerical atmospheric model. We developed empirical models, fitted to data from the 2000-2013 period, and verified their skill for the 2014-2019 period. Since El Niño produces a strong low-frequency signal, the models focus on the high-frequency weather and subseasonal variability (60-day cutoff). The empirical models outperformed the operational forecasts and the numerical model. For instance, the high-frequency annual correlation coefficient and root mean square error (RMSE) for the 1-day lead forecasts were 0.37-0.53 and 0.74-1.76°C for the empirical model, respectively, but around −0.05-0.24 and 0.88-4.21°C in the operational case. Only three predictors were considered for the models, including persistence and large-scale atmospheric indices. Contrary to our belief, the model skill was lowest for the austral winter (June-August), when the extratropical influence is largest, suggesting an enhanced role of local effects. Including local specific humidity as a predictor for minimum temperature at the inland location substantially increased the skill and reduced its seasonality. There were cases in which both the operational and empirical forecast had similar strong errors and we suggest mesoscale circulations, such as the Low-Level Cyclonic Vortex over the ocean, as the culprit. Incorporating such information could be valuable for improving the forecasts

Estudio de condiciones atmosféricas favorables a los incendios forestales en el Perú

El objetivo de este estudio se centró en evaluar las condiciones meteorológicas y circulación atmosférica favorable a la ocurrencia y/o propagación de un IF, usando datos in situ de las estaciones meteorológicas cercanas a las localidades con reporte de IF, reanálisis y modelos meteorológicos. En este contexto, se analizó el comportamiento del índice meteorológico de incendios forestales (FWI, por sus siglas en inglés) en el Perú, un índice utilizado en países tanto de latitudes medias como tropicales, con el fin de aplicarlo para el monitoreo y aviso de condiciones meteorológicas favorables a la propagación de incendios forestales

Reliability of cross-regional applications of global fire danger models: a Peruvian case study

Background: Fire danger indexes (FDIs) are used as proxies for fire potential and are often developed for specific locations. For practical purposes, the extrapolation of the underlying calculations into novel locations is common, but it is generally uncertain if the relationships between FDIs and fire potential observed in the environment in which the index was developed are equally relevant in others. For example, although a topographically, ecologically, and climatologically complex country, f ire danger forecasts in Peru use a standard set of nationwide thresholds applied to the Fire Weather Index. In this study, we validate the underlying assumption that weather-fire relationships are spatially uniform within Peru by (1) making cross-regional comparisons of the statistical distributions of four FDIs—Burning Index, Energy Release Component, Fire Weather Index, and Keetch-Byram Drought Index, and (2) making cross-regional comparisons of the expected daily MODIS hotspot count percentiles conditioned on FDI values. Results: Significant regional differences in the distributions of daily FDI values were observed in every pair of regions within Peru, and with the exception of a pair of regions within the Amazon, little data (< 90 days) were necessary to detect these differences. After controlling for FDI values and seasonal and annual effects with regressions, differences in predicted hotspot percentiles were common, differing by as much as 47 percentage points. Across the pairs of regions, the magnitude of these differences tended to decrease as climatic similarity increased, but some counterexamples were also apparent. Conclusions: The noticeable differences in the distributions of daily FDI values suggest that a standard set of breakpoints may produce unreliable inferences regarding fire potential. We also find that even if the climatic conditions were similar across Peru, the same FDI values in two locations can produce substantially differing predictions of wildfire activity. This suggests that other factors besides FDI values can strongly mediate wildfire activity and that better fire potential predictions could be produced if these factors are accounted for

Participatory rainfall monitoring: strengthening hydrometeorological risk management and community resilience in Peru

Heavy rainfall, floods and debris flow on the Rimac river watershed are recurring events that impact Peruvian people in vulnerable situations.There are few historical records, in terms of hydrometeorological variables, with sufficient temporal and spatial accuracy. As a result, Early Warning Systems (EWS) efficiency, dealing with these hazards, is critically limited. In order to tackle this challenge, among other objectives, the Participatory Monitoring Network (Red de Monitoreo Participativo or Red MoP, in spanish) was formed: an alternative monitoring system supported by voluntary community collaboration of local population under a citizen science approach. This network collects and communicates data captured with standardized manual rain gauges (< 3USD). So far, it covers districts in the east metropolitan area of the capital city of Lima, on dense peri-urban areas, districts on the upper Rimac watershed on rural towns, and expanding to other upper watersheds as well. Initially led by Practical Action as part of the Zurich Flood Resilience Alliance, it is now also supported by SENAMHI (National Meteorological and Hydrological Service) and INICTEL-UNI (National Telecommunications Research and Training Institute), as an activity of the National EWS Network (RNAT)

State of the climate in 2018

In 2018, the dominant greenhouse gases released into Earth’s atmosphere—carbon dioxide, methane, and nitrous oxide—continued their increase. The annual global average carbon dioxide concentration at Earth’s surface was 407.4 ± 0.1 ppm, the highest in the modern instrumental record and in ice core records dating back 800 000 years. Combined, greenhouse gases and several halogenated gases contribute just over 3 W m−2 to radiative forcing and represent a nearly 43% increase since 1990. Carbon dioxide is responsible for about 65% of this radiative forcing. With a weak La Niña in early 2018 transitioning to a weak El Niño by the year’s end, the global surface (land and ocean) temperature was the fourth highest on record, with only 2015 through 2017 being warmer. Several European countries reported record high annual temperatures. There were also more high, and fewer low, temperature extremes than in nearly all of the 68-year extremes record. Madagascar recorded a record daily temperature of 40.5°C in Morondava in March, while South Korea set its record high of 41.0°C in August in Hongcheon. Nawabshah, Pakistan, recorded its highest temperature of 50.2°C, which may be a new daily world record for April. Globally, the annual lower troposphere temperature was third to seventh highest, depending on the dataset analyzed. The lower stratospheric temperature was approximately fifth lowest. The 2018 Arctic land surface temperature was 1.2°C above the 1981–2010 average, tying for third highest in the 118-year record, following 2016 and 2017. June’s Arctic snow cover extent was almost half of what it was 35 years ago. Across Greenland, however, regional summer temperatures were generally below or near average. Additionally, a satellite survey of 47 glaciers in Greenland indicated a net increase in area for the first time since records began in 1999. Increasing permafrost temperatures were reported at most observation sites in the Arctic, with the overall increase of 0.1°–0.2°C between 2017 and 2018 being comparable to the highest rate of warming ever observed in the region. On 17 March, Arctic sea ice extent marked the second smallest annual maximum in the 38-year record, larger than only 2017. The minimum extent in 2018 was reached on 19 September and again on 23 September, tying 2008 and 2010 for the sixth lowest extent on record. The 23 September date tied 1997 as the latest sea ice minimum date on record. First-year ice now dominates the ice cover, comprising 77% of the March 2018 ice pack compared to 55% during the 1980s. Because thinner, younger ice is more vulnerable to melting out in summer, this shift in sea ice age has contributed to the decreasing trend in minimum ice extent. Regionally, Bering Sea ice extent was at record lows for almost the entire 2017/18 ice season. For the Antarctic continent as a whole, 2018 was warmer than average. On the highest points of the Antarctic Plateau, the automatic weather station Relay (74°S) broke or tied six monthly temperature records throughout the year, with August breaking its record by nearly 8°C. However, cool conditions in the western Bellingshausen Sea and Amundsen Sea sector contributed to a low melt season overall for 2017/18. High SSTs contributed to low summer sea ice extent in the Ross and Weddell Seas in 2018, underpinning the second lowest Antarctic summer minimum sea ice extent on record. Despite conducive conditions for its formation, the ozone hole at its maximum extent in September was near the 2000–18 mean, likely due to an ongoing slow decline in stratospheric chlorine monoxide concentration. Across the oceans, globally averaged SST decreased slightly since the record El Niño year of 2016 but was still far above the climatological mean. On average, SST is increasing at a rate of 0.10° ± 0.01°C decade−1 since 1950. The warming appeared largest in the tropical Indian Ocean and smallest in the North Pacific. The deeper ocean continues to warm year after year. For the seventh consecutive year, global annual mean sea level became the highest in the 26-year record, rising to 81 mm above the 1993 average. As anticipated in a warming climate, the hydrological cycle over the ocean is accelerating: dry regions are becoming drier and wet regions rainier. Closer to the equator, 95 named tropical storms were observed during 2018, well above the 1981–2010 average of 82. Eleven tropical cyclones reached Saffir–Simpson scale Category 5 intensity. North Atlantic Major Hurricane Michael’s landfall intensity of 140 kt was the fourth strongest for any continental U.S. hurricane landfall in the 168-year record. Michael caused more than 30 fatalities and $25 billion (U.S. dollars) in damages. In the western North Pacific, Super Typhoon Mangkhut led to 160 fatalities and$6 billion (U.S. dollars) in damages across the Philippines, Hong Kong, Macau, mainland China, Guam, and the Northern Mariana Islands. Tropical Storm Son-Tinh was responsible for 170 fatalities in Vietnam and Laos. Nearly all the islands of Micronesia experienced at least moderate impacts from various tropical cyclones. Across land, many areas around the globe received copious precipitation, notable at different time scales. Rodrigues and Réunion Island near southern Africa each reported their third wettest year on record. In Hawaii, 1262 mm precipitation at Waipā Gardens (Kauai) on 14–15 April set a new U.S. record for 24-h precipitation. In Brazil, the city of Belo Horizonte received nearly 75 mm of rain in just 20 minutes, nearly half its monthly average. Globally, fire activity during 2018 was the lowest since the start of the record in 1997, with a combined burned area of about 500 million hectares. This reinforced the long-term downward trend in fire emissions driven by changes in land use in frequently burning savannas. However, wildfires burned 3.5 million hectares across the United States, well above the 2000–10 average of 2.7 million hectares. Combined, U.S. wildfire damages for the 2017 and 2018 wildfire seasons exceeded $40 billion (U.S. dollars)

Heavy Snowfalls in the peruvian Andes: the wettest winter of the last 19 years

Most meteorological stations in the central and southern Peruvian Andes also received heavy rainfall in June and July. On 2 June, Ananea, which is located in Puno at 4660 m a.s.l., recorded 32.5 mm (monthly climatology is 8.4 mm), and Sicuani, located in Cusco at 3574 m a.s.l., accumulated 13 mm on 21 July (monthly climatology is 3.7 mm). The many precipitation events were associated with the entrance of troughs and cut-off lows from midlatitudes and by the increased moisture flux in the low and middle levels of the atmosphere (Quispe 2017; Quispe 2014; Quispe and Avalos 2006; Vuille and Ammann 1997). In the composite upper-tropospheric (250 hPa) analysis of seven snowfall events (Fig. SB7.5), an anomalous trough over the Pacific Ocean with the divergent side of the jet stream over southern Peru and an incursion of cold air created an optimal environment for the development of convective storms in the southern Andes of Peru, all of which are most likely to occur in the afternoon and night. Meanwhile, in the mid-troposphere, composites of daily mixing ratio analysis at the 500-hPa level (Fig. SB7.5) during all 2018 snowfall events show anomalous moisture over the central and southern Peruvian Andes, associated with an anomalous localization of a trough over the eastern Pacific Ocean near Peru. These conditions appeared farther north than their normal position, generating advection of cold air. In most of the snowfall events, these troughs evolved into a cut-off low over the Pacific Ocean. Of the seven strong and moderate snowfall events considered here, four were associated with the development of a cut-off low over the Pacific Ocean near Peru. This was the main factor that generated snow over the Peruvian Andes in the winter. One of these cut-off low events caused hail and electric storms in the central coast of Peru on 20 July. Overall, the snowfalls of 2018 affected over 300 000 people, and roads and highways were inaccessible in several regions due to the accumulated snow. Cattle raising was affected because snow covered and damaged the pastures, causing many of the animals to starve; official numbers indicated more than 25 700 sheep and 45 200 camels were lost

Análisis del Vórtice Ciclónico de Niveles Bajos (VCNB) en la costa central peruana. Informe Técnico

En el presente informe se identifica y clasifica los eventos de Vórtice Ciclónico de Niveles Bajos (VCNB) y luego se realiza el análisis estadístico básico de los mismos. Para su identificación se utilizaron imágenes cada 30 minutos en el canal visible del satélite geoestacionario GOES 13, desde el 2011 hasta el 2018

Actualización del estudio de frecuencia de nevadas en el Perú

El presente trabajo tiene como objetivo principal determinar la distribución espacial y la frecuencia mensual de nevadas en el Perú. Asimismo, establece las circulaciones atmosféricas que favorecen a la ocurrencia de eventos de nevada generalizada, con la finalidad de prevención. Se utilizó información registrada en las estaciones meteorológicas convencionales durante el periodo 1995-2018, así como reanálisis del ERA5