Na realidade encontras clima Csa na "terra quente transmontana" e na região centro, a sul do sistema montanhoso Montejunto-Estrela, não necessariamente sotavento algarvio. Semi-árido está presente em parte do sul da PI, e até mesmo no território continental, no concelho de Mértola.
Que comunidade é?
O que eu acho interessante neste mapa do IPMA é
a classe do clima da Ponta de Sagres ser igual à das altitudes do Alto Minho!!!!! Pelas normais e séries longas (eg. SNIRH), certos locais acima dos 400m de cota recebem mais de 40-50mm
no mês mais seco, e mais de 2500mm/ano em média, só podendo ser classificado como Cfb na classificação de Koppen. Em Sagres temos quase um semestre seco e 400 ou 500mm de média anual...
MAs não é isso que me traz aqui. É precisamente a vozearia louca sobre a fortíssima seca que atualmente atravessamos... e a sua grande "novidade" e ligação às inevitáveis alterações climáticas - como se o clima, pela sua própria natureza, não fosse mutável ao longo dos séculos e milénios.
Pois recentemente foi publicado um artigo deveras interessante sobre as secas na península Ibérica, cuja leitura atenta eu recomendo vivamente. Coloco aqui alguns excertos.
"Drought Trends in the Iberian Peninsula over the Last 112 Years
P. Páscoa,1 C. M. Gouveia,1,2 A. Russo,1 and R. M. Trigo1
1Instituto Dom Luís, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, Edifício C8, Piso 3, 1749-016 Lisboa, Portugal
2Instituto Português do Mar e da Atmosfera, Lisboa, Portugal
The Iberian Peninsula (IP) is a drought-prone area located in the Mediterranean which presents a significant tendency towards
dryness during the last decades, reinforcing the need for a continuous monitoring of drought. The long-term evolution of drought
in the IP is analyzed, using the Standardized Precipitation Evaporation Index (SPEI) and the Standardized Precipitation Index
(SPI), for the period of 1901–2012 and for three subperiods: 1901–1937, 1938–1974, and 1975–2012. SPI and SPEI were calculated with
a 12-month time scale, using data from the Climatic Research Unit (CRU) database. Trends in the drought indices, precipitation,
and reference evapotranspiration (ET0) were analysed and series of drought duration, drought magnitude, time between drought
events, and mean intensity of the events were computed. SPI and SPEI significant trends show areas with opposite signals in the
period 1901–2012, mainly associated with precipitation trends, which are significant and positive in the northwestern region and
significant and negative in the southern areas. Additionally, SPEI identified dryer conditions and an increase in the area affected by
droughts, which agrees with the increase in ET0.The same spatial differences were identified in the drought duration, magnitude,
mean intensity, and time between drought events.
[...]
4. Discussion and Conclusions
[...]
The analysis of the three subperiods pointed to different behaviors in terms of drought trends, highlighting the need to perform a separate analysis at regional scale for the IP [35] aiming to reduce the vulnerability of the different regions and minimize losses induced by drought [36]. The results for the three smaller subperiods (1901–1937, 1938–1974, and 1975–2012) point to a generalized trend towards higher evaporative demand in the first and last period and of a lower ET0 in the intermediate period. While in the case of the first period a small area with positive trends of ET0 was found in the southeastern region, in the last period a corresponding area was found in the eastern part of Portugal. The spatial patterns of precipitation trends in the first 3 decades of the 20th century are similar to the spatial patterns found for the long-term period, with negative trends in the South and Southwest and positive trends in the North and Northwest of the IP. Moreover, a clear trend for wet conditions was observed in the intermediate period. Finally, less significant trends were observed in the last period and mainly concentrated in the North, where they are mostly negative, thus showing a shift in the trend.
[...]"
Isto é, após análise aprofundada da extensão, frequência, intensidade, etc. das secas verificaram-se padrões distintos nas várias regiões da península Ibérica e nos períodos analisados.
Vale a pena ser lido pelo pessoal do MeteoPT, até porque tem gráficos e mapas muito interessantes.