Arquivo da tag: Climatologia

WMO is concerned about impact of COVID-19 on observing system (WMO)

WMO concerned about impact of COVID19 on global observing system

1 April 2020 Press Release Number: 01042020

Geneva, 1 April 2020 – The World Meteorological Organization (WMO) is concerned about the impact of the COVID-19 pandemic on the quantity and quality of weather observations and forecasts, as well as atmospheric and climate monitoring.

WMO’s Global Observing System serves as a backbone for all weather and climate services and products provided by the 193 WMO Member states and territories to their citizens. It provides observations on the state of the atmosphere and ocean surface from land-, marine- and space-based instruments. This data is used for the preparation of weather analyses, forecasts, advisories and warnings.

“National Meteorological and Hydrological Services continue to perform their essential 24/7 functions despite the severe challenges posed by the Coronavirus pandemic,” said WMO Secretary-General Petteri Taalas. “We salute their dedication to protecting lives and property but we are mindful of the increasing constraints on capacity and resources,” he said.

“The impacts of climate change and growing amount of weather-related disasters continue. The COVID-19 pandemic poses an additional challenge, and may exacerbate multi-hazard risks at a single country level. Therefore it is essential that governments pay attention to their national early warning and weather observing capacities despite the COVID-19 crisis,” said Mr Taalas.

Large parts of the observing system, for instance its satellite components and many ground-based observing networks, are either partly or fully automated. They are therefore expected to continue functioning without significant degradation for several weeks, in some cases even longer. But if the pandemic lasts more than a few weeks, then missing repair, maintenance and supply work, and missing redeployments will become of increasing concern.

Some parts of the observing system are already affected. Most notably the significant decrease in air traffic has had a clear impact. In-flight measurements of ambient temperature and wind speed and direction are a very important source of information for both weather prediction and climate monitoring.

AMDAR observation - March 2020

Meteorological data from aircraft

Commercial airliners contribute to the Aircraft Meteorological Data Relay programme (AMDAR), which uses onboard sensors, computers and communications systems to collect, process, format and transmit meteorological observations to ground stations via satellite or radio links.

In some parts of the world, in particular over Europe, the decrease in the number of measurements over the last couple of weeks has been dramatic (see chart below provided by EUMETNET).  The countries affiliated with EUMETNET, a collaboration between the 31 national weather services in Europe, are currently discussing ways to boost the short-term capabilities of other parts of their observing networks in order to partly mitigate this loss of aircraft observations.

The AMDAR observing system has traditionally produced over 700 000 high-quality observations per day of air temperature and wind speed and direction, together with the required positional and temporal information, and with an increasing number of humidity and turbulence measurements being made.

Surface-based observations

In most developed countries, surface-based weather observations are now almost fully automated.

However, in many developing countries, the transition to automated observations is still in progress, and the meteorological community still relies on observations taken manually by weather observers and transmitted into the international networks for use in global weather and climate models.

WMO has seen a significant decrease in the availability of this type of manual observations over the last two weeks. Some of this may well be attributable to the current coronavirus situation, but it is not yet clear whether other factors may play a role as well. WMO is currently investigating this.

“At the present time, the adverse impact of the loss of observations on the quality of weather forecast products is still expected to be relatively modest. However, as the decrease in availability of aircraft weather observations continues and expands, we may expect a gradual decrease in reliability of the forecasts,” said Lars Peter Riishojgaard, Director, Earth System Branch in WMO’s Infrastructure Department.

“The same is true if the decrease in surface-based weather observations continues, in particular if the COVID-19 outbreak starts to more widely impact the ability of observers to do their job in large parts of the developing world. WMO will continue to monitor the situation, and the organization is working with its Members to mitigate the impact as much as possible,” he said.

Variability of surface observations - January 2020
(Map provided by WMO; countries shown in darker colors provided fewer observations over the last week than averaged for the month of January 2020 (pre-COVID-19); countries shown in black are currently not sending any data at all).

Currently, there are 16 meteorological and 50 research satellites, over 10 000 manned and automatic surface weather stations, 1 000 upper-air stations, 7 000 ships, 100 moored and 1 000 drifting buoys, hundreds of weather radars and 3 000 specially equipped commercial aircraft measure key parameters of the atmosphere, land and ocean surface every day. 

For further information contact: Clare Nullis, media officer. Email cnullis@wmo.int, Cell +41 79 709 13 97

See original article here.

Meteorologia pode sofrer impacto com covid-19, diz WMO (Climatempo)

02/04/2020 – por redação

Organização Meteorológica Mundial (WMO) teme que coronavírus influencie na qualidade das previsões e no monitoramento da atmosfera

A Organização Meteorológica Mundial (Word Meteorological Organization, WMO, na sigla em inglês) está preocupada com o impacto da pandemia do covid-19 na quantidade e qualidade das observações e previsões meteorológicas, bem como no monitoramento da atmosfera e do clima.

O Sistema de Observação Global da WMO serve como espinha dorsal de todos os serviços e produtos climáticos fornecidos a seus cidadãos pelos 193 estados e territórios membros da organização. Ele fornece observações sobre o estado da atmosfera e da superfície do oceano a partir de instrumentos terrestres, marinhos e espaciais. Estes dados são utilizados para a preparação de análises meteorológicas, previsão do tempo e monitoramento do clima.

“Os Serviços Meteorológicos e Hidrológicos Nacionais continuam desempenhando suas funções essenciais 24 horas por dia e sete dias por semana, apesar dos graves desafios impostos pela pandemia de coronavírus”, disse o secretário-geral da WMO, Petteri Taalas. “Saudamos sua dedicação em proteger vidas e propriedades, mas estamos atentos às crescentes restrições de capacidade e recursos”.

Taalas afirmou ainda que os impactos das mudanças climáticas e a crescente quantidade de desastres relacionados ao clima continuam. “A pandemia do Covid-19 representa um desafio que  grava os riscos de vários perigos em um único país. Portanto, é essencial que os governos prestem  atenção em seu alerta nacional e às capacidades de observação do clima, apesar da crise do Covid-19”.

Grande parte do sistema de observação, como os componentes de satélite e redes de observação terrestres, por exemplo, são parcialmente ou totalmente automatizados. Por isso, espera-se que continuem funcionando sem problemas significativos por várias semanas, em alguns casos até mais. Porém, se a pandemia durar mais de algumas semanas, a falta de reparos, manutenção e suprimentos, e as redistribuições se tornarão uma preocupação crescente.

Algumas partes do sistema de observação já estão sendo afetadas, com destaque para a diminuição significativa do tráfego aéreo. As medições de temperatura ambiente e da velocidade e direção do vento em voo são uma fonte muito importante de informações para a previsão do tempo e monitoramento do clima.

Dados meteorológicos de aeronaves 

Aviões comerciais contribuem para o programa “Airbus Meteorological Data Relay” (AMDAR), que usa sensores, computadores e sistemas de comunicação a bordo para coletar, processar, formatar e transmitir observações meteorológicas para estações terrestres via satélite ou rádio.

Em algumas partes do mundo, em particular na Europa, a diminuição do número de medições nas últimas duas semanas tem sido dramática.  Veja o gráfico fornecido pela  EUMETNET.

Total de observações do sistema AMDAR em março de 2020 (Fonte: WMO)

Os países afiliados à EUMETNET, que reúne 31 serviços meteorológicos nacionais na Europa, estão atualmente discutindo maneiras de aumentar as capacidades de curto prazo de outras partes de suas redes de observação, a fim de diminuir parcialmente a perda de observações de aeronaves.

O sistema de observação AMDAR normalmente produzia por dia mais de 700 mil observações de alta qualidade de temperatura do ar, velocidade e direção do vento. Além disso, fornecia informações posicionais e temporais necessárias, com número crescente de medições de umidade e turbulência.

Observações baseadas em superfície

Na maioria dos países desenvolvidos, as observações meteorológicas de superfície são quase totalmente automatizadas. No entanto, em muitos países em desenvolvimento, como é o caso do Brasil, a transição para observações automatizadas ainda está em andamento, e a comunidade meteorológica ainda depende de observações feitas manualmente por observadores, que as transmitem às redes internacionais para uso em modelos globais de tempo e clima.

A WMO registrou diminuição significativa na disponibilidade de observação manual nas últimas duas semanas. Parte disso pode estar relacionada à situação atual de coronavírus, mas ainda não está claro se outros fatores também podem ter contribuído. A WMO está investigando outras possíveis causas.

Atualmente, o impacto adverso da perda de observações na qualidade dos produtos para previsão do tempo ainda é relativamente pequeno. No entanto, à medida que a diminuição na disponibilidade de observações meteorológicas das aeronaves continua e se expande, podemos esperar uma queda gradual na confiabilidade das previsões”, disse Lars Peter Riishojgaard, diretor da filial do sistema terrestre no departamento de infraestrutura da WMO.

Segundo Riishojgaard, o mesmo vale se a diminuição das observações meteorológicas na superfície continuar e, em particular, se o surto de covid-19 começar a impactar de forma mais significativa a capacidade de trabalho de observadores em países subdesenvolvidos. “A WMO continuará monitorando a situação, e a organização está trabalhando com seus membros para mitigar o impacto o máximo possível”, afirmou.

Mapa fornecido pela WMO: os países mostrados em cores mais escuras forneceram menos observações na última semana do que a média do mês de janeiro de 2020 (pré-covid-19); os países mostrados em preto atualmente não estão enviando nenhum dado.

Atualmente, existem 16 satélites meteorológicos e 50 de pesquisa no mundo, além de mais de 10 mil estações meteorológicas de superfície automáticas e tripuladas, mil estações aéreas, 7 mil navios, 100 bóias ancoradas e mil flutuantes, centenas de radares meteorológicos e 3 mil estações comerciais especialmente equipadas em aeronaves, que medem parâmetros-chave da atmosfera, da terra e da superfície do oceano todos os dias.

Tradução e adaptação de Paula Soares e Amanda Sampaio, do conteúdo publicado no site da WMO – World Meteorological Organization.

Link da matéria original no site da WMO: https://public.wmo.int/en/media/press-release/wmo-concerned-about-impact-of-covid-19-observing-system

Link da matéria no site da Climatempo: https://www.climatempo.com.br/noticia/2020/04/02/meteorologia-pode-sofrer-impacto-com-covid-19-diz-wmo-2635

Climate change caused by ocean, not just atmosphere (Science Daily)

Date: October 25, 2014

Source: Rutgers University

Summary: Most of the concerns about climate change have focused on the amount of greenhouse gases that have been released into the atmosphere. A new study reveals another equally important factor in regulating Earth’s climate. Researchers say the major cooling of Earth and continental ice build-up in the Northern Hemisphere 2.7 million years ago coincided with a shift in the circulation of the ocean.

The ocean conveyor moves heat and water between the hemispheres, along the ocean bottom. It also moves carbon dioxide. Credit: NASA

Most of the concerns about climate change have focused on the amount of greenhouse gases that have been released into the atmosphere.

But in a new study published in Science, a group of Rutgers researchers have found that circulation of the ocean plays an equally important role in regulating Earth’s climate.

In their study, the researchers say the major cooling of Earth and continental ice build-up in the Northern Hemisphere 2.7 million years ago coincided with a shift in the circulation of the ocean — which pulls in heat and carbon dioxide in the Atlantic and moves them through the deep ocean from north to south until it’s released in the Pacific.

The ocean conveyor system, Rutgers scientists believe, changed at the same time as a major expansion in the volume of the glaciers in the northern hemisphere as well as a substantial fall in sea levels. It was the Antarctic ice, they argue, that cut off heat exchange at the ocean’s surface and forced it into deep water. They believe this caused global climate change at that time, not carbon dioxide in the atmosphere.

“We argue that it was the establishment of the modern deep ocean circulation — the ocean conveyor — about 2.7 million years ago, and not a major change in carbon dioxide concentration in the atmosphere that triggered an expansion of the ice sheets in the northern hemisphere,” says Stella Woodard, lead author and a post-doctoral researcher in the Department of Marine and Coastal Sciences. Their findings, based on ocean sediment core samples between 2.5 million to 3.3 million years old, provide scientists with a deeper understanding of the mechanisms of climate change today.

The study shows that changes in heat distribution between the ocean basins is important for understanding future climate change. However, scientists can’t predict precisely what effect the carbon dioxide currently being pulled into the ocean from the atmosphere will have on climate. Still, they argue that since more carbon dioxide has been released in the past 200 years than any recent period in geological history, interactions between carbon dioxide, temperature changes and precipitation, and ocean circulation will result in profound changes.

Scientists believe that the different pattern of deep ocean circulation was responsible for the elevated temperatures 3 million years ago when the carbon dioxide level in the atmosphere was arguably what it is now and the temperature was 4 degree Fahrenheit higher. They say the formation of the ocean conveyor cooled Earth and created the climate we live in now.

“Our study suggests that changes in the storage of heat in the deep ocean could be as important to climate change as other hypotheses — tectonic activity or a drop in the carbon dioxide level — and likely led to one of the major climate transitions of the past 30 million years,” says Yair Rosenthal, co-author and professor of marine and coastal sciences at Rutgers

The paper’s co-authors are Woodard, Rosenthal, Kenneth Miller and James Wright, both professors of earth and planetary sciences at Rutgers; Beverly Chiu, a Rutgers undergraduate majoring in earth and planetary sciences; and Kira Lawrence, associate professor of geology at Lafayette College in Easton, Pennsylvania.


Journal Reference:

  1. S. C. Woodard, Y. Rosenthal, K. G. Miller, J. D. Wright, B. K. Chiu, K. T. Lawrence.Antarctic role in Northern Hemisphere glaciation. Science, 2014; DOI:10.1126/science.1255586