forcing of and acts at all the scales, and unlike the classical turbulence theory, there is not a well-defined inertial subrange here. As also suggested by Waite and Snyder (2009), it is possible that the mesoscale kinetic energy spectrum does not arise from a cascade process.
All scales convect, no inertial subrange or scale-local cascade is indicated. So where does -5/3 come from?
spectrum budget terms
Panel e) shows that all scales convect. It's such an initialized problem that it is hard to say more, the net budget is so positive.
The buoyancy production generated by moist convection, while mainly injecting energy in the upper troposphere at small scales, could also contribute at larger scales, possibly as a result of the organization of convective cells into mesoscale convective systems.
A weak statement of the result as I see it, which is that all scales convect.
instead of an error cascade from smaller to larger scales (upscale growth), errors in more complex flows tend to grow uniformly at all scales (up-magnitude growth
all scales convect perhaps
Fig. 13. (a),(b) Spectral error growth in the predictability experiment compared with (c),(d) spectral error growth in idealized and turbulence
Classic
a) up-amplitude and b) up-scale error growth.
Notice also a similar figure 13 of Judt (2018)
Figure 1 illustrates some of the factors controlling the NGMS
A useful schematic (is the vertical axis p or z?)
As in Fig. 3b, but
Is it so hard to label or repeat a cue word or two?
reflectivity and PV include all vertical levels
an average? an integral? units? ok it is qualitatively clear enough.
the maintenance of the stratiform component largely depends on the well-organized parent convective component
"particle fountain" view, Fig 15 here123%3C1964:TDKAME%3E2.0.CO;2)
θe anomaly
worrisome how much T at 14km is involved
the linear transition zones between radii of 40–50 and 70–80 km were set when modifying the diabatic heating/cooling
stitches around the surgery
SHC0 and SHC200
"heating rate" of both signs
Role
Impacts, not sensitivities (or interactions).
heating
positive values only, or the whole heating rate field (of both signs)?
stratiform cooling
is this just the negative values within columns tagged as "stratiform"?
in
by?
initialized at 62 h of CTL
surgery details
distinct vertical heating profiles as displayed in Fig. A1b
the pre surgery diagnosis
The partitioning algorithm depends on the horizontal distribution of simulated reflectivity and vertical velocity, using three criteria (Steiner et al. 1995): intensity of reflectivity, peakedness (excess of reflectivity over a background value), and area within an intensity-dependent radius around a convective grid. At each time step of integration, the modified WRF code can automatically identify whether each grid point is categorized into convective, stratiform, or other
Texture of simulated reflectivity, based on algorithms for observed reflectivity.
artificially modifying the convective and stratiform heating/cooling between 40- and 80-km radii
intrusive internal surgery experiments
We describe a method for specifying the mass flux based on the convective inhibition at the top of the subcloud layer and the amount of turbulence within it.
Gratifying to see a statistical mechanics treatment of Ooyama's "dispatcher function" rather than the smotheringly acausal roundabout reasonings of QE overthinking.
the pressure level at which the radiative cooling decays linearly to zero is decreased from 200 to 125 mb, resulting in a ∼2.5 km increase in the depth of the cooling
Yes here is the cooling profile experiment Figs. 13-15
shallower depth of imposed radiative cooling
do they actually show that the profile of cooling affects wave speed? Yes, Figs. 13-15.
Equilibrium vs. activation controls
How chemists draw a conditional instability
two ways, discussed above, of breaking the problem into mutually exclusiveparts: scale separation, and moist-dry separation
A conceptual error in prior thought-framings, even though we all know the equations for Q1 and Q2.
The convective transports are a response to this forcing,and in the main produce the opposite effect - a warming and drying. Themean atmospheric state which we observe represents some balancebetween these opposing processes. However, as one might expect, this“balanced state” shifts in the direction of the forcing. The concept of a bal-anced state while convection is in progress is closely related to the quasi-equilibrium hypothesi
Here is some refreshingly causal reasoning, unlike the laundering of causality through equilibrium in papers like ENB
Composite temperature perturbation (solid) in the vicinity of MCS-like heating(profile shown dashed) in the imposed-heating model
Compare to observational Q'T' temporal covariances here
Large-scale upward motion in a convecting atmosphere increases convection and thus reduces the boundary-layer entropy, primarily through convective downdraughrs. Main- taining moht neutrality, the pee-atmosphere temperature is reduced. Thus the large-scale ascent ‘feels’ an effective, positive static stability
Is this just a contortion of large-scale upward motion cools the environment, which invigorates convection that soon cools the average condition (although not necessarily the warmest moistest air that is entering updrafts) in subcloud layer, through its downdraft outflows. Here's a less controted (in my view) framing.
must produce disturbances in the large-scale flow, rather than producing steady vertical transports
Horrors, einstein! Disturbances, in our tidy world??
no discontinuity in the heating
HUH?
superimposed on
interesting framing
latent heat energy released is two orders of magnitude greater than the amount needed to maintain the kinetic energy against frictional dissipation
this is even more problematic: it compares microscale energy to macroscale energy
it may become difficult to distinguish between the ‘large-scale’ and ‘convective’ motions
there's some daylight
conditionally unstable if it contains a nontrivial convective inhibition
with respect to ENTRAINING real convective clouds, not undilute cheat-clouds
statistical equilibrium was first applied systematically to the case of mist convection by Arakawa and Schubert (1974
Come on... this is just a generalization of the older idea of "convective adjustment", as Arakawa (2004) admits i think
description
is it a "description", or a direction-of-causality presumption?
time-scale of some chaotic, small-scale process is appreciably smaller than that of the large-scale
is this about space or time? woolly.
energy
mechanical
small
the key word here
always showed development at the smallest scales
called a "uv catastrophe" in physics... only now are there starting to be information-theory and causality theory responses to this more general problem with causal reductionism... agents above, atoms below.
the theory of CISK, as well as the representation of convection (Kuo 1965) that was implicitly based on it, has been an influential and lengthy dead-end road in atmospheric science
Boom
Given F(A) for all A
Ha ha... this is somehow better than the "given the heating..." trope that this whole essay is railing against?
account for
the causality presumptions so thick and deep here
upward motion associated with a large-scale disturbance
do you mean adiabatic upward motion in the intercloud environment?
compromised
like every balance statement does violence to causality
E is a bulk precipitation efficiency
only within a certain favored back story... literally, here, it is a bulk shortcoming of latent heating to quite cancel adiabatic cooling
virtually all extant simulations of convective clouds have proceeded in the ‘spin- down’ mode, in which convection is triggered by an aberration of the initial condition and thereafter uses the APE of the initial state, which is not resupplied
early "warm bubble" simulations
phase speed associated with hear normal modes
N/m, yes go on
for a = 0.9
what was a again? buried in math someplace -- is there a word? oh -relative humidity, just above
The inescapable conclusion from all these analyses is that lurge-scale ascent in convecting atmospheres is associated with a reduction of temperature; i.e. with a positive effective static stability
why not look at observations? is it really inescapable? does it apply only to unconditional vertical motions (forcings)?
an equatorial Kelvin wave
of single signed vertical structure, coming from somewhere (from where, if not forced by prior convection of that depth?)
The subcloud- layer entropy is reduced under the enhanced convective downdraughts associated with the ascent phase of the wave; this is, in equilibrium, associated with a reduction of the free-atmosphere temperature
causality presumption contortions again
very small
compared to what? why not look at observations?
time-scale for clear air to subside through the troposphere, about 30 days
students, you get this?
the conceptual simplifications inherent in statistical-equilibrium thinking will prove to be a boon to a new generation of tropical dynamicists
convective adjustment hasn't already been clear for a generation before 1974?
due to large-scale processes only
Problematic causality over interpretation of a data result, see Fig.16 of Mapes 1997 JMSJ
the elementary requirement that heating and temperature fluctuations must be positively correlated in order that disturbance energy be produced seems to have been overlooked here
But as the Stevens et al. comment paper shows, the present authors are overlooking observations
The dominant thinking
Do they characterize the "dominant thinking" fairly, or is it a bit of a straw man? Please reply (so I can what relpy alerts look like).
large-scale processes onl
This is not evidence that convection is responsive to "forcing" on these scales, as I showed here (figure 16 of Mapes 1997 JMSJ) https://www.jstage.jst.go.jp/article/jmsj1965/76/1/76_1_29/_pdf/-char/en
co-variance between temperature and vertical motion
implicitly gesturing at d[KE]/dt = [w'b']
what they characterize as a prevalent view of tropical convection
yeah characterizing "dominant" views is always debatable
of last year
Please use calendar year in blog posts that will be searched far into the future.
Fig. 16. Quasi-equilibrium test
"Quasi-equilibrium test" -- not causality evidence! This shows that QE can be acheived on these scales by the response of dynamics to heating, with no basis for inferring convection's responsiveness to a putative "forced" ascent.
Quasi-equilibrium test
It shows that QE can be acheived on these scales by the response of dynamics to heating, with no basis for inferring convection's responsiveness to a putative "forced" ascent.
intensity is assumed to be modulated by convective available potential energy (CAPE), while occurrence frequency is modulated by the ratio of convective inhibition (CIN)
Which is more important, available energy or triggering?
the sum of the Archimedean buoyancy and the buoyancy-induced pressure gradient acceleration, because this is the actual buoyancy acceleration
buoyancy acceleration, but how was the BPGF computed? It depends on geometry. Oh I see, they actually did an offline computation (Laplacian inversion) to compute the buoyancy-induced p', and then sampled it around the parcels.
convective heating in the upper and lower troposphere is the same in the control run and, thus, cannot explain the differing convective sensitivities.
This is too simplistic. Because of the great depth of the radiative cooling (extending well above where latent heating can balance it), the mean state is cold aloft so that eddy temperature flux convergence can do the job of balancing it. That means the parcels have abundant buoyancy aloft, and are less sensitive to small changes in it. See The first half of the third point in the abstract of my Water's Two Height Scales,… https://rmets.onlinelibrary.wiley.com/doi/epdf/10.1002/qj.49712757708
By many estimates, convective entrainment is the leading source of error in global climate models
Everybody talks about (this aspect of) the weather but few do anything about it! Here is the ony new conceptual model for convection since the episodic mixing models of Raymond and Blyth, summarized in Raymond's "wiring diagrams"
The preferred stratification established by the model convection depends on the treat-ment of precipitation and ice processes, and especially on the poorly-understood pro-cesses that determine mass flux in downdrafts associated with the evaporation ofprecipitation.
This test shows that responses to others' annotations do not appear in https://hypothes.is/users/brianmapes, only original annotations.
Gravity Waves, Compensating Subsidence and Detrainment around Cumulus Clouds
great paper
A second annotation typed in
Can one annotate an old pdf?
At CSU, in the project's first phase, she is working with Nicholas Kedzuf, a master's student, to look at data and to establish a comprehensive inventory of ice particle properties. ("It's an absolute joy to work with such an excellent student," says Chiu.)
Go Nick!
detailed solutions have been presented for the case of a stably stratified fluidwith a linear density gradient
stratified environment
Noteb y Sir Geoffrey Taylor
Note the "sir"
TheheightinmetrestowhichsmokewillrisefromvariousSOURCES IN A WIND-FREE I.C.A.N. STANDARD ATMOSPHERE
predictions and application
predictions made by comparing previous experimental data on unstratified fluidswith the present theory.
it works
laboratory experiments
try it in the lab
u (= F2/ W) vanishesvery close toxl — 2-8. This corresponds to the greatest height reached by the plumefluid. As this fluid from the plume spreads out sideways, most of it will fall back somedistance, but certainly not as far as the height corresponding with xx 2-125 atwhich the density difference first vanishes
overshoot and detrainment heights
a simpler transfer assumption was madeby Taylor (1945) in the hope that it would represent the broad outlines of themechanics of a rising plume of buoyant air without the necessity for understandingin detail how the turbulent eddies mix the heated and the ambient air
Taylor the great giant of the field see footnote at end
The present treatment is based on this assumption, which relates the inflow intothe edge of a convective plume to some characteristic velocity in the plume
Key entrainment assumption
Two governing parameters are provided by the physical conditions of theproblem, F0 and G, and these must determine the scale of the motion
Only 2 things can matter, then wrangle units
Three boundary conditions are required to determine a solution
strong inference from general considerations
the vertical flux of buoyancy remains constant at all heights.
Here is the key constraint
The conservation relations may then be written
area-perimeter ratio
the swapping experiment
parcelwise
percentage of cloudy parcels that cross the layer, which will be referred to as the crossing percentage
mass flux is 0 or 1 by crossing the layer
We binned the parcels based on their buoyancy acceleration and vertical velocity at the bottom level right before they ascend to the next level.
before and after encountering the perturbed T' layer
wind
Yes, and hit return -- no response
playing
No sound, on a Mac in either Chrome or Safari Dec 2018
the atmosphere radiatively cools less, and this drives the 3%–4% slowdown of the tropical circulation
decompose the circulation change into a sum of relative changes in subsidence area, static stability, and heating rate.
method (decomp)
taking advantage of the dynamical stability of these regions
They are easily observable with spaceborne instruments and offer a less uncertain view on the radiative fluxes than the cloudy regions (Pincus et al. 2015). Our SMF metric may therefore prove efficient in tracking the circulation changes in the present climate by analyzing satellite data records.
Pages jumped from <7000 in 2011 and before to >10000 in 2013 and since.
Two issues per month since 2000. when pages crossed 4000.
Both types of annotations appear when I log out. But my friend's annotations (on another page) are not visible to me. I don't understand groups, layers, and the lock icon that sometimes appears next to the word Public.
Highlights
Created as highlight, then this text added as an edit
Annotation
test: created from annotate icon
boreal summer stationary-wave amplitude (SWA) had a significantly positive trend during 1979–2013
http://iopscience.iop.org/article/10.1088/1748-9326/10/10/104009/meta#erl520543f1 observation
we define the SWA for each model as the variance of 925-hPa streamfunction at the latitude of the maximum stationary waves in that model. SWA is measured in stationary wave units (SWU), defined as 1013 m4 s−2. In this study, we use a 50-yr time length to compute the linear trend of SWA because this length is longer than most time periods of internal variability of atmospheric circulation.
c. Hydrological extremes To measure summer hydrological extremes, we count the number of days in a dry spell and the number of heavy-rainfall days in each summer. A dry spell is defined as an event of at least 3 consecutive days when daily precipitation is less than 1 mm, while a heavy-rainfall day is defined as a day when the precipitation exceeds the 99th percentile of daily precipitation in JJA during the period 1955–2005. We then count the number of dry-spell days and heavy-rainfall days at each grid point during JJA of each year.
SWA to increasing climate forcing using 31 CMIP5 GCMs
31 CMIP5 GCMs
increased heavy-rainfall-day frequency over South Asia, the Indochinese Peninsula, and southern China (SA-EA), and to increased dry-spell-day frequency over the northwestern and central United States
models reasonably capture the temporal statistics
benchmark for model evaluation
most energetic during austral summer, facilitating interaction with the concurrent NPMM conditions
(CMIP5) are used in this study to investigate further the SPMM and its role in ENSO predictability
Pacific meridional mode, a thermodynamically coupled mode of variability, links extratropical Pacific oceanic and atmospheric anomalies to the tropical Pacific
uggestive of ocean–atmosphere coupling.
Random internal variability causes apparent decadal modulations of ENSO correlations over the Indo-western Pacific, which are high during epochs of high ENSO variance.
POGA shows skills in simulating the ENSO-forced warming of the tropical Indian Ocean and an anomalous anticyclonic circulation pattern over the northwestern tropical Pacific in the post–El Niño
El Niño–Southern Oscillation (ENSO) peaks in boreal winter but its impact on Indo-western Pacific climate persists for another two seasons
High leakage periods are also related to reduced inland convective rainfall over southeastern Africa in austral summer
we find Agulhas leakage variability to be related to a meridional shift and/or strengthening of the westerlies
SAM-like pattern in wind stress
recreate a number of total velocity fields by modifying the eddying component to assess the dependence of leakage variability on the eddies.
Future changes to annual frequency, LMI, and the latitude of LMI are evaluated using the downscaled tracks where large sample sizes
large-scale environmental fields
commonly applied cluster analysis: 1) explicitly simulated tracks
hypotheses
Three hypotheses for the CRE balance are considered:
The CRE balance results from a fortuitous coincidence.
Feedbacks among cloud albedo, large-scale circulation, and SST cause the net CRE to be similar in neighboring regions of active and suppressed convection.
Radiative heating of clouds causes medium and thin anvil cloud to persist longer than thick anvil, which causes the cloud population to have a neutral net CRE.
Our results are consistent with the cloud–circulation–SST feedback hypothesis 2 and show that earlier criticism of this hypothesis is not supported by observations. Future work should focus on testing these hypotheses further.
More on the latter: Since radiative heating extends the lifetime of anvils, but the effect is stronger for thin and medium clouds than for thick ones, Hartmann and Berry (2017) hypothesized that radiative heating could cause the cloud population to have a neutral net CRE.
Shading from anvils causes cool anomalies in the underlying sea surface temperature (SST) of up to −0.6°C.
Daytime data (nighttime has zero effect) https://journals.ametsoc.org/na101/home/literatum/publisher/ams/journals/content/clim/2018/15200442-31.24/jcli-d-18-0154.1/20181127/images/large/jcli-d-18-0154.1-f11.jpeg
life cycle of mesoscale convective systems (MCS), their associated anvil clouds, and their effects on the radiation balance
from a geostationary satellite
consistent with the hypothesis that the cancellation in CRE is caused by feedbacks among cloud albedo, large-scale circulation, and SST.
" if the SW and LW CRE are balanced as a result of some robust physical process, then it opens the possibility that such a process could maintain the balance in the future."
investigate the accuracy of the GCM-based NCAR CAM3.0 water vapor kernel
"In the upper troposphere, the observation-based C3M + AIRS longwave kernel is less (more) sensitive in the tropics (extratropics). Note that it is possible for differences to be caused by discrepancies in the radiative transfer models themselves (Soden et al. 2008), something that is not explored in this work."
isolate the individual cloud, atmospheric, and surface property contributions to the variability of the radiation budget
nearly zero global average of broadband RH feedback is a result of spatial compensation and spectral compensation
spectrally resolved relative humidity (RH) feedbacks for 16 GCMs that participated in CMIP5
improved winds and surface heat fluxes must go hand in hand with improved subseasonal and parameterized ocean processes. Implications
agenda - whole programme and getting it right for right reasons, not compensations
Correcting FLOR’s climatological SST and wind stress biases via flux adjustment (FA) leads to weaker deep advective cooling of the ECT, which then erodes the upper-ocean thermal stratification, enhances vertical mixing, and excessively deepens the thermocline.
about half of the model uncertainty in the midlatitude cloud–circulation coupling stems from this impact of the circulation on the large-scale temperature structure of the atmosphere, and thus could be removed by improving the climatological circulation in models.
monthly-scale advection
upper-ocean heat budget
decline in cloudiness is steeper at 1200 UTC (0800 LT), when a trend of up to −6% decade−1 is observed over the central and eastern Amazon
atmospheric rivers (ARs), narrow bands of moisture originating in the tropics.
The circulation of northward-flowing Atlantic Water at the surface and returning overflow water at depth is particularly manifested—and observed—at the Greenland–Scotland Ridge where the water masses are guided through narrow straits.
Jianping Duana,bxJianping DuanSearch for articles by this author, Lun LicxLun LiSearch for articles by this author, Zhuguo MaaxZhuguo MaSearch for articles by this author, Jan EsperdxJan EsperSearch for articles by this author, Ulf BüntgenexUlf BüntgenSearch for articles by this author, Elena XoplakifxElena XoplakiSearch for articles by this author, Dujuan ZhanggxDujuan ZhangSearch for articles by this author, Lily WanghxLily WangSearch for articles by this author, Hong YinixHong YinSearch for articles by this author, and Jürg Luterbacherf,j
How was author order set? Not alphabetical at all.
Superposed epoch analysis (SEA)
"composite"
empirical orthogonal function (EOF) analysis
New to v4, uncertainties are calculated for each station series
global land series https://journals.ametsoc.org/na101/home/literatum/publisher/ams/journals/content/clim/2018/15200442-31.24/jcli-d-18-0094.1/20181119/images/large/jcli-d-18-0094.1-f13.jpeg
circulation patterns in the Arctic: the Arctic Oscillation (AO) and Arctic dipole (AD)
Statistical "modes" I bet
Changes in the AO and AD are relatively minor contributing factors to the projected temperature and precipitation changes in the Arctic
Good honest confession of limits of mode studies
21 papers if I count right.
Dataset: 1 AGW oriented climate modeling work: 7 Model development/ evaluation: 3 Mode or branded phenomenon: 3 Ocean driven phenomena: 2; Volcano 1 Process oriented (clouds/rad) 3
Forcing 3, response 4,
Relevant
hastening to justify
The soil moisture effect, however, does not fully fit into the surface θe argument and provides additional control on monsoon rainfall by inducing regional circulation and rainfall patterns
hmmm link to fig