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: P bel P bel - P stm T stm U stm S O index Precipitacao CIRSAN

q sat Intraannual variability small but important… C p T L q RH smaller

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.)

Silva Dias et al., 2003 Cloudiness delineates the river….

Moore et al. 2001

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 hourly data, flux tower km67

Wind rose Available date km83 flux tower

Hourly data, LBA-ECO weather stations… River

Km 77 flux tower…..

wind rose

km67

Local sites always make a difference in wind observations. Fujita Transmission Factors, LBA-ECO WX stations.

km117 pasture site Jamaraqua Tapajos site

River sites Incident global short-wave radiation

Vila Franca

Specific humidity, double peaks show CBL birth/death

Std deviation of wind directionseparating the convective portion of the day…. Jamaraqua Franca Cacoal Grande

2 C River stations

Maximum wind events…. k j m g c s f e River

From Silva Dias et al., 2003 Sodar, Santarem airport……. NCL NCL river Observer report..

…and also look at interannual differences in the Onset of the wet season. NO clouds at night, dry season….

From before……

Radiative consequences of cloud cover…

River stations Standard deviation of global solar radiation….

q sat

(See CD-03: Czikowsky et al. poster for details on the ceilometer observations at km67)

The natural clock of the tropics….

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.

Balao cativo –estudos no futuro……