Mesoclimate of the LBA-ECO Santarem Study Area David Fitzjarrald Ricardo Sakai Osvaldo Moraes Matt Czikowsky Otavio Acevedo Raimundo Cosme de Oliveira Junior CD-03 University at Albany, SUNY Universidade Federal de Santa Maria EMBRAPA Amazonia Oriental
LBA-ECO weather station network • Resurrected at the behest of the • LBA Science Team (Miami meeting). • Motivation: • Determine regional biases/seasonal differences • (develop a methodology to determine context in • which flux observations are made.) • * Study the physical basis for the river breeze • identify mesoclimatic variabilities: • Cloudiness (incident solar radiation) • *Temperature/Humidity • * Precipitation • *gasp) support model studies… • *Accommodate the few remaining literalists who • use real (vs. reanalysis) data
LBA-ECO STM site special features… • Large seasonal variation • High correlation precipitation/ENSO signal • World class amplitude semidiurnal atm P tide • Strong influence river breeze/easterly interaction
Recent years in the LBA-ECO STM region: CIRSAN Pbel Pbel - Pstm Tstm Ustm S O index Precipitacao
Intraannual variability small but important… Cp T RH smaller qsat L q
This presentation from now on: Focus on diurnal variability ( & seasonal) Other (continuing) work Identify inland penetration of River breeze; frequency of occurrence; Gauge seasonal/interannual varibility; Minimize biases in standard climate data. Identify local wind circulations (e.g., Acevedo et al. presentation yesterday.)
Cloudiness delineates the river…. Silva Dias et al., 2003
Estacoes automaticas: (Campbell Sci.) Medidas: T, RH, K incidente, PAR incidente, T solo, Umidade solo, Pressao superficie, U, direccao, Precipitacao, GPS (relogio). 2 USFS (Keller), upgraded [julho 1998, Belterra, km117] 3 LBA-ECO [julho 2000, Jamaraqua, Mojui, Guarana] 3 EMBRAPA,upgraded [set 2002, Franca, CG, C-U]
Available date km83 flux tower Wind rose
Hourly data, LBA-ECO weather stations… River River
Local sites always make a difference in wind observations. Fujita Transmission Factors, LBA-ECO WX stations.
Jamaraqua Tapajos site km117 pasture site
River sites Incident global short-wave radiation
Std deviation of wind direction—separating the convective portion of the day…. Jamaraqua Franca Cacoal Grande
2 C River stations
Maximum wind events…. k 2001 350 1300 7.28 j 2003 84 1330 7.74 m 2001 204 0220 7.11 g 2002 19 1200 6.81 c 2001 54 1700 6.44 s 2003 37 2000 3.94 f 2002 68 1000 4.22 e 2002 208 0430 9.91 River
Sodar, Santarem airport……. NCL NCLriver Observer report.. From Silva Dias et al., 2003
NO clouds at night, dry season…. …and also look at interannual differences in the Onset of the wet season.
River stations Standard deviation of global solar radiation….
(See CD-03: Czikowsky et al. poster for details on the ceilometer observations at km67)
River breeze mesoscale pressure gradient can extract from station data; looks like model simulation results—(Silva Dias et al., 2003)
River-inland differences: 2 C temperature bias 20% cloud reduction in Kdn Still searching for the precipitation signal River breeze expressed actively for slack easterly cases. Cloud base determined by thermodynamics in cleared areas. Nocturnal winds appreciable only along river (a counter-current nocturnal river of air) River convective day and night.